Bending Magnets for the Metrology Light Source

P. Budz, M. Abo-Bakr, K. Bürkmann, V. Dürr, J. Kolbe, D. Krämer*, J. Rahn, G. WüstefeldBESSY GmbH, Berlin, Germany; * now at GSI, Darmstadt, Germany

R. Klein, G. Ulm Physikalisch-Technische Bundesanstalt, Berlin, Germany

I. Churkin, A. Batrakov, S. Belokrinitskiy, I. Ilyin, A. Philipchenko, E. Rouvinski, L. Schegolev, E. Semenov, S. Sinyatkin, A. Steshov, K. Zhilyaev Budker INP, Novosibirsk, Russia

OUTLOOKStatus of MLS

Bending Magnet: view, requirements

Manufacturing: lamination, yoke, coils, support

Measurements:

• mechanical (technique, results)

• magnetic (technique, results)

Conclusion

Metrology Light Source

Energy 200 - 600 MeV

Circumference 48 m

Current Lifetime

200 mA1 – 10 h

Bending magnetsQuadru/sextu/octu- poles

824 / 24 / 4

2008 - user operation

metrology and technology development in

UV and EUV

P.Budz … “Status of MLS”

MLS SR Bending Magnets

Front view

Back view

MLS SR Bending MagnetsNumber of magnets 8

Nominal Beam energy, MeV 600

Bending angle, deg 45

Bending radius, mm 1528

Gap, mm 50 ± 0.02

Identity of mean gap value from magnet to magnet, mm ± 0.02

Effective magnetic length, m 1.2

Field range, T up to 1.5

Good field area, mm2 60 x 36

Homogeneity dB/B 2.5x10-

4

Current, A 630

Power Consumption, kW 8

Weight, kg 6500

Bending Magnets

SAGA dipole• smaller• 22.5 of bending angle

BESSY • straight dipole

ANALOGS

Manufacturing

Lamination960 x 729.5

15 m for --- 50 m

Stamping by «Sibtekstilmash”

Novosibirsk

0.5 mm M940-50 (EBG, Bochum, Germany)

Stabolit 70 – end packs (100 mm)

Stabolit 20 – central part

ManufacturingCombined technology:• 100 mm glued end packs• Welded central part

Manufacturing

ManufacturingThermal stress testing - for every 4th coil

20 cycles: 30 °C 95°C 30 °C

23.5 min duration of cycle

21 x 12 / 5 mm2 OFHC (Outokumpu)

14 windings in 2 layers6 “pancakes” (2 with trim coils)

Epoxy impregnation

ManufacturingStand for Dipole

Shuttle distance - 370 mm

The tolerance of Dipole positioning is ± 0.2 mm

Pedestals for Dipoles

average gap of dipoles

0,999

0,99925

0,9995

0,99975

1

1,00025

1,0005

1,00075

1,001

1 2 3 4 5 6 7 8 9 10 11

along axis

ga

p,

u.e

.

Mechanical measurementsGap Reference (± 0.02) Average magnet

Shim in, mm 48.611 48.600 ± 0.015

Middle, mm 50.000 50.005 ± 0.010

Shim out, mm 48.611 48.610 ± 0.015

“1” = 50 mm

Mechanical measurements

Parameter Reference Measured average dipoleYoke length L, mm 11080.5 1108.265 ± 0.424 Distance between chamfers Lc, mm 10820.1 1081.925 ± 0.110 (10-4)

Sag, mm < 0.3 < 0.3Stacking factor, % 97 99.7 ± 0.2

Magnetic measurements

Carriage with Hall probes in the guide mounted in the magnet

aperture

Magnetic field mapping in Cartesian coordinates by 2 runs (with parallel shift)

Magnetic measurements

Carriage with the Hall probes 1 –temperature sensor, 2 –Hall probes,

3 – NMR probeDipole at the magnetic measurement stand (BINP)

Magnetic measurements

Parameter B/B I /I

Spatial alignment (Hall probes, direction and linearity of carriage movement)

1.5.10-5 1.7.10-5

Temporal stability of *: BM`s excitation current Hall probe current

2.10-5

10-5

1.8.10-6

0.9.10-6

Temperature stability 2.4.10-5

Accuracy of Hall probe calibration 4.5.10-5

Electronics noise contributions 4.4.10-5 4.0.10-6

Resulting accuracy 7.2.10-5 6.2.10-5

Capability of magnetic measurement system

Magnetic measurements

Magnetic field profiles in the central cross-section at B=1.3

T

-0,0006-0,0003

00,00030,00060,00090,00120,0015

-6 -4 -2 0 2 4 6Y, cm

dB

/B

calc

meas

Magnetic field profiles in the central cross-section at

B=0,21 T

Magnetic measurements

Integral magnetic field profiles (measured and calculated at B=1.3 T)

Magnetic measurements

Typical longitudinal profile (dipole #3) of the magnetic field (B0=1.3 T)

Integral = 1.5504 ± 0.0017 T.m (1.1.10-3)

B=1.3005 ± 0.0013 T (10-3)

E = 591.8 ± 0.7 MeV

Leff = 119.219 ± 0.068 cm (6.10-4)

Magnetic measurements

Dependence of the effective length from excited current (measurement results for dipole #1 and calculation)

117,5

118,0

118,5

119,0

119,5

120,0

120,5

0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6magnetic field, T

Leff

, cm

meas

calc 0.98

calc uni

Magnetic measurementsCalculation Measurement

 Laminated

magnetLaminated

magnetSolid

magnetAverage magnet

Stacking factor (yoke laminations)

0.98 0.98 1.0 0.997

Curren.turns, A.turns 4297 26502 26502 26124

Magnetic field, T 0.212 1.305 1.305 1.301

Calculated particle energy, GeV

0.0968 0.5882 0.5956 0.5918 ± 0.0007

Effective magnetic length, cm

119.70 118.04 119.57 119.22 ± 0.07

Dipole h (1/m): 0.656 0.665 0.657 0.655

Quadrupole k (1/m2): -0.0188 -0.0293 -0.0271 -0.0239 ± 0.0010

Sextupole s (1/m3): -0.531 -0.809 -0.762 -0.7238 ± 0.0188

Octupole o (1/m4): -7.15 -9.95 -16.48 - 10.51± 1.43

Conclusion

Produced Bending Magnets meet the requirements

Magnetic and mechanical measurements are correlated

Magnetic measurements confirm 3D modeling

Bending Magnets are being installed on the SR MLS

ConclusionInternational Team

and Bending Magnet

at BINP Workshop

Bending Magnets

at MLS