Characterization of (Re)BCO conductor for development of 32T superconducting magnet

D Abraimov H W Weijers W D Markiewicz M Santos J McCallister A Francis V Griffin J Jaroszynski J Jiang J Lu V Toplosky B

Jarvis S Carter Y L Viouchkov and D C Larbalestier all NHMFL

Quality Assurance procedure for 32T project

We are looking for compliance with our specification which includes

transport and geometrical properties of (Re)BCO tape using

minimum set of measurements

(Re)BCO coated conductor was purchased from SuperPower Inc

168 lengths 60 m or 110 m each

Comparison of 4K in- field Ic measured on short samples for conductors

from different manufacturers

This work was supported in part by the US National Science Foundation under Grant No DMR-0654118 DMR-0923070 and the State of Florida

Special thanks to AMSC Fujikura SuNAM SuperOx for providing samples for testing

BIIab High Jc

B at 18o to tape plane

bull One of the major limiting factors of coil performance is sharp Jc(Q) dependence in (Re)BCO

bull The minimum Ic for 32 T coil design occurs at 18o critical angle between tape plane and magnetic field of 17 T

Origins of specification for (Re)BCO conductor

Xu A et al Superconducting Science and Technology 23 014003 (2010)

BIIab

Restriction on Ic

bull Tape is being delivered in 110 or 60 m lengths making joints resistance critical

bull RRRgt50 for low resistance of stabilizer in case of quench

Dimensions bull Cu stabilizer layer should be uniform through

length and width of the tape to provide mechanical stability between pancake windings and get uniform heat propagation

bull Tape width should be uniform to avoid variations in Ic and mechanical properties difficulties in coil manufacturing

17 T

Other transport properties

Property of tape from the specification Value Units

Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle

gt256 A

n from V~I n fit gt25 -

Joints resistance measurements le230 mWmiddotcm2

Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -

Final conductor width 410 plusmn 005 mm

Final conductor Thickness le0170 mm

Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2

Substrate cross-sectional Area 020 plusmn 001 mm 2

Ag layer thickness 20 plusmn 05 mm

(Re)BCO conductor specification (short list)

Current biasing four Sorensen power supplies

bull up to 1400 A bull routinely up to 1050 A bull Analog connection

Current monitor Keithley 2000 Voltage measurement Keithley 2182A Magnet power supply Oxford IPS LabView based program for automatic B and Ibias sweeping and Ic calculation

Ic testing system for 32 T tape characterization

Oxford Instruments Superconducting 135 T (42K) magnet

sample holder

8 9 10 11 12 13 14 15 16 17

250

300

350

400

450

500

550

600

650

700 UP SP60 inner

Down SP60 inner

UP SP60 out

Down SP60 out

UP SP61 out

Down SP61 out

UP SP61 inner

Down SP61 inner

UP SP62 inner

Down SP62 inner

UP SP62 out

Down SP62 out

UP SP63 out

Down SP63 out

I c

A

B T

Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B

Orange horizontal line represents 256A minimum specified at 17T

B

Most of measured samples have Ic gt 256 A

No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a

I

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

BIIab High Jc

B at 18o to tape plane

bull One of the major limiting factors of coil performance is sharp Jc(Q) dependence in (Re)BCO

bull The minimum Ic for 32 T coil design occurs at 18o critical angle between tape plane and magnetic field of 17 T

Origins of specification for (Re)BCO conductor

Xu A et al Superconducting Science and Technology 23 014003 (2010)

BIIab

Restriction on Ic

bull Tape is being delivered in 110 or 60 m lengths making joints resistance critical

bull RRRgt50 for low resistance of stabilizer in case of quench

Dimensions bull Cu stabilizer layer should be uniform through

length and width of the tape to provide mechanical stability between pancake windings and get uniform heat propagation

bull Tape width should be uniform to avoid variations in Ic and mechanical properties difficulties in coil manufacturing

17 T

Other transport properties

Property of tape from the specification Value Units

Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle

gt256 A

n from V~I n fit gt25 -

Joints resistance measurements le230 mWmiddotcm2

Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -

Final conductor width 410 plusmn 005 mm

Final conductor Thickness le0170 mm

Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2

Substrate cross-sectional Area 020 plusmn 001 mm 2

Ag layer thickness 20 plusmn 05 mm

(Re)BCO conductor specification (short list)

Current biasing four Sorensen power supplies

bull up to 1400 A bull routinely up to 1050 A bull Analog connection

Current monitor Keithley 2000 Voltage measurement Keithley 2182A Magnet power supply Oxford IPS LabView based program for automatic B and Ibias sweeping and Ic calculation

Ic testing system for 32 T tape characterization

Oxford Instruments Superconducting 135 T (42K) magnet

sample holder

8 9 10 11 12 13 14 15 16 17

250

300

350

400

450

500

550

600

650

700 UP SP60 inner

Down SP60 inner

UP SP60 out

Down SP60 out

UP SP61 out

Down SP61 out

UP SP61 inner

Down SP61 inner

UP SP62 inner

Down SP62 inner

UP SP62 out

Down SP62 out

UP SP63 out

Down SP63 out

I c

A

B T

Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B

Orange horizontal line represents 256A minimum specified at 17T

B

Most of measured samples have Ic gt 256 A

No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a

I

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Property of tape from the specification Value Units

Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle

gt256 A

n from V~I n fit gt25 -

Joints resistance measurements le230 mWmiddotcm2

Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -

Final conductor width 410 plusmn 005 mm

Final conductor Thickness le0170 mm

Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2

Substrate cross-sectional Area 020 plusmn 001 mm 2

Ag layer thickness 20 plusmn 05 mm

(Re)BCO conductor specification (short list)

Current biasing four Sorensen power supplies

bull up to 1400 A bull routinely up to 1050 A bull Analog connection

Current monitor Keithley 2000 Voltage measurement Keithley 2182A Magnet power supply Oxford IPS LabView based program for automatic B and Ibias sweeping and Ic calculation

Ic testing system for 32 T tape characterization

Oxford Instruments Superconducting 135 T (42K) magnet

sample holder

8 9 10 11 12 13 14 15 16 17

250

300

350

400

450

500

550

600

650

700 UP SP60 inner

Down SP60 inner

UP SP60 out

Down SP60 out

UP SP61 out

Down SP61 out

UP SP61 inner

Down SP61 inner

UP SP62 inner

Down SP62 inner

UP SP62 out

Down SP62 out

UP SP63 out

Down SP63 out

I c

A

B T

Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B

Orange horizontal line represents 256A minimum specified at 17T

B

Most of measured samples have Ic gt 256 A

No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a

I

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Current biasing four Sorensen power supplies

bull up to 1400 A bull routinely up to 1050 A bull Analog connection

Current monitor Keithley 2000 Voltage measurement Keithley 2182A Magnet power supply Oxford IPS LabView based program for automatic B and Ibias sweeping and Ic calculation

Ic testing system for 32 T tape characterization

Oxford Instruments Superconducting 135 T (42K) magnet

sample holder

8 9 10 11 12 13 14 15 16 17

250

300

350

400

450

500

550

600

650

700 UP SP60 inner

Down SP60 inner

UP SP60 out

Down SP60 out

UP SP61 out

Down SP61 out

UP SP61 inner

Down SP61 inner

UP SP62 inner

Down SP62 inner

UP SP62 out

Down SP62 out

UP SP63 out

Down SP63 out

I c

A

B T

Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B

Orange horizontal line represents 256A minimum specified at 17T

B

Most of measured samples have Ic gt 256 A

No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a

I

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

8 9 10 11 12 13 14 15 16 17

250

300

350

400

450

500

550

600

650

700 UP SP60 inner

Down SP60 inner

UP SP60 out

Down SP60 out

UP SP61 out

Down SP61 out

UP SP61 inner

Down SP61 inner

UP SP62 inner

Down SP62 inner

UP SP62 out

Down SP62 out

UP SP63 out

Down SP63 out

I c

A

B T

Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B

Orange horizontal line represents 256A minimum specified at 17T

B

Most of measured samples have Ic gt 256 A

No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a

I

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

60 80 100 120 140 160 180 200 2200

50

100

150

200

250

300

350

400

450

500

550

600

650

700

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700 outer Ic(77KSF)

inner Ic(77KSF)

outer Ic(4K17T18

o)

inner Ic(4K17T18

o)

SP Min Ic(77KSF)

32T spec

Ic a

t 7

7K

SF

A

I c a

t 1

8o 4

2K

extr

ap

ola

ted

to

17

T A

Tape

Progress in Ic measurements SP60 ndash SP231 Data arranged by NHMFL numbers ndash delivery time line Observation very wide range of in-field Ic values at 4K

Tapes SP65 66 79 80 were sent for developing winding technique

168 lengths 60 m or 110 m each

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)

Observation tapes within one process have similar Ic M4 process yields tapes with higher Ic

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Uniform distribution with two steps at 270A and 480A

Understanding origins of such Ic variability is important for making new tapes more uniform Estimating variations of Ic angular dependence may be useful for predicting quench behavior

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

150 200 250 300 350 400 450 500 550 600 650 700 7500

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(4K18

o17T) A

Histogram for Ic measured at 42 K 17 T 18deg

Before we were dealing mostly with this conductor produced with M3 machine

Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet

M4 ~16 Ic variability

M3 ~16 of Ic variability

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

90 100 110 120 130 140 150 160 170 180 1900

5

10

15

20

25

30

Num

be

r of sam

ple

s

Ic(SF77K) A

Histogram of Ic measured at 77K SF

ltIcgt=1304 A SD=109

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

0 20 40 60 80 100 120 140 160 180

0

50

100

150

200

250

300

350

400

450

500

550

600

650

M3 inner

M3 outer

M4 inner

M4 outer

I c a

t 4

2K

1

8o e

xtr

ap

ola

ted

to

17

T A

Ic SF 77K A

We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)

119868119888(11987244119870 1711987918119900)

119868119888(11987234119870 1711987918119900)=159

119868119888(119872477119870119878119865)

119868119888(119872377119870119878119865)=105

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

200 300 400 500 600 700

00

01

02

03

04

05

06

07

08

09

10

M3 inner

M3 outer

M4 inner

M4 outer

a

Ic at 42K 18

o extrapolated to 17T A

M3 ltIcgt =283 A ltagt= 083 +- 004

M4 ltIcgt =450 A ltagt= 084 +- 005

No dramatic changes in a values Interpretation pinning mechanism at 4K is probably similar for low Ic and high Ic tapes

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Standard deviation 57

At 77K SF just few tapes have relative spread above 10

End to end relative variation of Ic(77K SF) 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

At 42K in-field more tapes have relative spread above 10 1

00∙

119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905

119868 119888 119894119899119899119890119903+119868 119888 119900119906119905

2

End to end relative variation of Ic(4K 17T 18o)

Standard deviation 96

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Ag

ReBCO

SEM cross-section of M4 SP129

SEM cross-section of M3 SP159

Ag

ReBCO

Different thickness for M3 and M4 machines

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

77K self-field critical current vs ReBCO thickness dependence

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

M3

M4

4K in-field critical current density vs ReBCO thickness dependence

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 n1

SP60 n2

SP60 n3

SP64 n4

SP61

SP62

SP63

SP64

R

R(3

00

K)

Temperature (K)

For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo

For SP 60 from M3 have wider R vs T transition than SP61-64 tapes

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs

Maximum average 160 nW cm2

Peak maximum 230 nW cm2

Measurements done on standard lap joints with 80 mm overlap 80 mm

32T spec

M3-1033 M3-1062 have low Ic (4K) and high joint resistance

T=77K SF

0 20 40 60 80 1000

100

200

300

4001022-1

1024-3

1028-1

1029

1029-1

1030-1

1030-1

1030-1

1031-2

1031-2

1033-2

1033-2

1033-2

1033-2

1038

1038

1038

1038

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1038-2

1043-2

1045-3

1045-3

1045-3

1045-3

1047-4

1048-2

1048-21048-2

1048-2

1048-2

1048-2

1050-4

1052-3

1052-3

1052-3

1052-3

1060-2

1060-3

1061-2 1061-2

1061-2

1061-2

1061-2 1061-2

1061-2

1061-2

1061-2

1062-2

1062-4

1062-4

1063-2

1063-2

1063-2

1067-2

1071-2

1072-3

1078-2

1078-2

1078-2

1078-2

1084-2

1088-2

1088-2

1089-2

1094-2

1094-2

1111-2 1111-2

180-3

180-4

182-2

182-2

182-4

195-2

195-2

217-2

217-2

217-2

217-2

217-4

218-2 2

18-2

218-2

218-2

218-2

218-2

219-2 219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

219-2

236-2

239-3

239-3

239-3

M3

Co

nta

ct

resis

tan

ce

nW

cm

2

Tape

M4

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

RRR of stabilizer ndash parallel connection of Ag and Cu layers

RRR meets the specification

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Testing conductor for terminals in field at 4K Choose current and field to get the Lorentz force about 28 times larger than in the coil

Conditions in the terminals

bull Imax =180 A (45 A for one tape) bull Max radial field component B = 2T bull Number of 4mm wide tapes connected in parallel ndash 4 bull Length of free standing conductor ndash L = 2cm bull Max Lorentz force for one conductor F expected L =ILB= 45 0022=18 N bull Expected number of current cycles 10 000 ()

Modeling these conditions using one 4mm wide sample

bull Max operating current 50A bull Max radial field (symbolically BIIc) component B = 5 T bull One 4mm wide tape bull Length of free conductor ndash L=2 cm (the rest of 45mm long sample is supported from one side with Cu plate)

bull Max Lorentz force FL =ILB= 50 5002=5 N (F=510 g force) bull The Lorentz force is x277(7) times larger then expected bull Maximum number of current cycles 50 000

B

Ib

FL

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

1 10 100 1000 10000

100

105

110

115

120

125

130

135

140

145

150

Sample N1

Sample N2

I c A

Number of sweeps

For two tested samples no degradation of Ic (77KSF) after 50 000 current sweeps up to 50A at 4K 5T

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

1 10

100

200

300

400

500

600

700

SuNAM N1

SuNAM N2

SuperOx N2

SuperOx N3

SuperOx N4

AMSC

Fujikura N1

Fujikura N2

SP77

SP129 N1

SP129 N2

SP132 N1

SP132 N2

SP127

I c

A

B T

Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane

B

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

bull Comprehensive analysis of various tape properties is necessary for building reliable magnet

bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K

bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes

bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet

bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)

bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy

Conclusions

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Additional slides

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

59 60 61 62 63 64 65

906

908

910

912

914

916

918 max dRdT

middle dRdT

small dRdT

Tp K

Tape number

bulk critical temperature Tc defined as maximum of dRdT

Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K

Peaks of dRdT

Interpretation SP60 has non-uniform

composition with multiple (Re)BCO phases

SP 61-64 have variable through length oxygen doping

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

0 1 2 3 4

120

130

140

150

160

170

180

SP60 inner

SP60 outer

SP61 inner

SP61 outer

SP62 inner

SP62 outer

SP63 inner

SP63 outer

SP64 inner

SP64 outer

Thic

kne

ss mm

Width mm

Thickness profiles measured with Nikon microscope

All profiles are nearly the same

Optical image of typical cross section (SP 60 inner)

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Width distributions for SP60 ndash SP64 tapes are within specification

0 100 200 300 400 500 600404

406

408

410

412

414

416

SP60 inner

SP61 inner

SP62 inner

SP63 inner

SP64 inner

SP60 outer

SP61 Outer

SP62 Outer

SP63 Outer

SP64 Outer

Max

Min

W

m

m

L mm

We noticed considerable improvement of tape width uniformity which eliminates substantial part

of variations in Ic and mechanical properties

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

120 125 130 135 140 145 150 155 160 165 170 175

406

408

410

412

414

416

418

420

422

424

426

428

430

max

min

mean

32T spec Min

32T spec Max

Wid

th

mm

SP number

Conductor width variation

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

120 125 130 135 140 145 150 155 160 165 170 175140

145

150

155

160

165

170

175

180

To

tal th

ickn

ess

um

SP number

Total thickness measured with micrometer

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

120 125 130 135 140 145 150 155 160 165 170 175037

038

039

040

041

042

043

044

045

Cu

are

a

mm

2

SP number

Cu area for SP125- 166 tapes

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)

No hysteresis and no damage during field sweep

SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

SP64 inner SP60 inner

SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64

After etching Cu and Ag

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Additional techniques used for study properties of ReBCO tapes

bull 16 T Quantum design PPMS for measuring in- field

variable temperature angular dependence of Ic and R(T)

bull Rotator with split coil electromagnet 1T 77K for

measuring angular dependence of Ic in full width tapes

bull YateStar system for measuring distribution of transport

critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

T=77K

B=1 T

SP125 inner

SuNAM

I c A

Qdegree

-30 0 30 60 90 120 150 180 210

10

1T

2T

4T

8T

12T

16T

Jc

MA

cm

2

Q degree904 906 908 910 912 914 916 918 920

000

005

010

015

020

025

030

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

1 10100

1000

SP67 inner

B at 18deg

SP83 inner

B at 18deg

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

1400A

700 A

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu) BII c

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c A

B T

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

1050 A

Fujikura

B at 18deg

GdBCO

SP89outer

B at 18deg

Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T

T=4K Ic(B) measured in OX II Max field is 135T

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

GdBCO Fujikura

BIIc

SP108 out

Bi_130222_pmm120822_143_A70

OP round wire diameter 1386mm1400A

700 A

Bi_130222_pmm120822_143_A71

OP round wire diameter 1399mm

Bi-2212 round wire

SP64 innerSP63 inner

ReBCO

SP 2013 (2x50um thick Cu) BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

I c

A

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108in

Bi-2212 round wire

130222pmm12082210A66

10mm

OP130508-27x7-7-100bar-B48

diameter 06883 mm ff=10

1050 A

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Fujikura

B at 18degGdBCO

Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Manufacturer Material a at BIIc a at 18deg

SuperPower ReBCO 067-076 07-09

SuNAM ReBCO 06 06 069 068

SuperOx ReBCO 054 054 0588 059

Fujikura ReBCO 0641 069 070

AMSC ReBCO 074

Sumitomo Bi-2223 018 0164

OP processed Bi-2212- round d=138mm 033

OP processed Bi-2212 d=1154 mm 027 026 0238

OP processed Bi-2212 d=0688 mm 027

Comparison ofavalues

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

1 10100

1000

ReBCO

SuperOx B at 18o

ReBCO

SuperOx BIIc

SP108in

Bi_2212

130222_pmm

120822_143_A70

OP round wire

diameter 1386mm

Bi 2212

130222_pmm 120822_12_A69

1154 mm round wire

Bi-2212 round wire

130222pmm12082210A66

SP64 inner

SP63 inner

ReBCO

SP 2013

(2x50um thick Cu)

BII c

Bi-2223

Sumitomo 2011 tape

BIIc

SP108out

ReBCO

2013 SuNAM tape

in brass stabilizer

B at 18deg to tape

J

e A

mm

2

B T

Bi-2223

Sumitomo 2012 tape

BIIc

ReBCO

SP 2013

(2x50um thick Cu)

B at 18 deg

ReBCO

2013 SuNAM tape

in brass stabilizer

BIIc

SP108 out

Bi2212

130222pmm

120822_143_A71

OP round wire

1399mm

17T

GdBCO

Fujikura

B at 18deg

Fujikura

BIIc

GdBCO

Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

0 100 200 300 400 500 600 700

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

I c(4

K B

at 1

8o)

A

Ic(4K BIIc) A

SuNAM

Fujikura

SuperOxSuperPower

X2

X15

X1

Difference in anisotropy

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field

Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124

Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes

Based on standard deviation of Ic relative difference 935

Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape

-50 -45 -40 -35 -300

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

Cou

nt

Min relative Ic change (below average per tape)

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt

Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic

Uniform distribution with two steps at 270A and 480A

0 20 40 60 80 100 120

150

200

250

300

350

400

450

500

550

600

650

700

ltIc(4 K 17 T 18 deg)gt

Ic(4 K 17 T 18 deg) inner

Ic(4 K 17 T 18 deg) outer

32T spec

I c(4

K 1

7T

1

8o)

A

Tape

M4

M3

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

60 62 64 66 68 70 72 74 76 780

20

40

60

80

100

120

140

160

180

200

220

0

20

40

60

80

100

120

140

160

180

200

220

Inner Ic(4K17TBIIc)

Outer Ic(4K17T BIIc)

Inner Ic(77K SF)

Outer Ic(77K SF)

Ic S

F 7

7 K

A

I c e

xtr

ap

ola

ted

to

17

T

42

K

A

Tape Number

B

I

Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes

All tapes from M3 machine

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Relation between a values and Ic (4K 17T BIIc)

For tapes with higher Ic we observe larger a values

Ic~B-a

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

58 60 62 64 66 68 70 72 74

00

02

04

06

08

10

12

14

16

18

20

22

Inner

Outer

I c(4

K1

7T

18

o)

Ic(4

K1

7T

B

IIc)

SP number

Mean 182

Standard deviation 012 (66)

Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation

BIIc and 18o orientations measured on different samples

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

Other techniques routine QA tests

Nikon iNexiv VMA-2520 microscope

Final conductor width Surface condition Thickness profiles

Vibromet 2

Preparation cross-sections

SEM visualization with Zeiss 1540 XB Cross beam

Olympus Microscope BX41M-LED

Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area

Simplimet 3000

Ag thickness ReBCO uniformity ab-plane orientation

Transport measurements of Rc Ic of lap joints in LN self field

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64

100 150 200 250 300

00

02

04

06

08

10

SP60 inner 1

SP60 inner 2

SP60 inner 3

SP60 inner 4

SP61 inner

SP62 inner

SP63 inner

SP64 inner

RR

(30

0K

)

Temperature (K)

Normalized R vs T for samples from ldquoinnerrdquo part of spools

Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K

Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64