Design of wide aperture/thin Design of wide aperture/thin septa of extraction system for septa of extraction system for

J-PARC-50GeV ring J-PARC-50GeV ring 1. The outline of septa system for

50GeVring

2. Designing of thin septa and medium

thin septa for fast/slow extraction

The extraction septa for 50GeVring

Septa for fast extraction

Number of septa 14Current 4.0kAmps~6.5kAmpsPattern operation

Septa for slow extraction

Number of septa 10

Current 4.5kAmps~5.0kAmps

CD operationLayout of 50GeVring

Configuration of magnetic septa for slow extraction

Thickness thin septa 1.5mm and 3.5mm Medium thick septa 7.5mm Thick septa 30mm~62mm

Field0.114T0.528T1.4T~1.66T

Configuration of septa for fast extraction

ThicknessMedium thick septa 9mmThick septa 30mm~62mm

Patten operation 0.17s(FB)+1.9s(Rise)+0.1(Top)+0.87s(Fall)=3.04s

Field0.459T1.38T~1.66T

The structure of SM10

The septum conductor is touched to the core in order todecrease the leakage flux. The core is laminated core.

Field 0.114TCurrent 5kAmpsMagnet length 1.5m

Clearance of Beam and septum

Since injection beam is close to core, inner support of septumconductor is adopted.

The structure of SM11

The conductor is a centipede structure for fixing the coil,The core is laminated core.

Current 5000ACurrent density 91A/mm2

Generation of heat 18.2kW

WaterWater speed 7m/sTin =25 ℃ Tout=70℃ConductorTw=73℃Tmax =247℃

The heat calculation of SM10

Thickness 1.0mm

The field calculation of SM10

0

50

100

150

200

250

300

0 10 20 30 40 50 60

Current distribution of edge cooling

I(A)

I(A)

y(mm)

Thickness 1.5mmFlatnessΔB/Bo=0.25% at y=0ΔB/Bo=0.5% at y=13mmLeak fieldLess than 10G

0

500

1000

1500

2000

-10 -5 0 5 10

Field distribution

By_y=0mmBy_y=13mm

B(G)

x(mm)

I_sus=17.4AI_cu=4982.6A

0

50

100

150

200

250

300

0 10 20 30 40 50

Temperature distribution of edge cooling

T()

℃

y(mm)

T_peak=122.2℃

T_ave=89.8℃

Current density 60.6A/mm2Generation of heat 9.9kWWater speed 5.7m/sTin 25 Tout 55℃ ℃

Medium thin septa SM2

Fast extraction Thickness of septum 9mm Bo=0.459TMagnet length 0.875m4 turn

Slow extractionThickness of septum7.5mmBo=0.528TMagnet length 0.875m6turn

Heat calculation of SM2 4turn (I=7458A) 6turn(I=4972A)

Water speed is too high and it’s dangerous considering cavitation of hollow conductor

50

60

70

80

90

100

110

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0

Temperature of water&conductor

T_water( )℃T_conductor( )℃

Tem

pera

ture(

)℃

water speed (m/s)

50

60

70

80

90

100

110

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0

Temperature of water&conductor

T_water( )℃T_conductor( )℃

Tem

pera

ture(

)℃

water speed (m/s)

Size 4.5mmx16.6mmHole φ3mm

Size 4.5mmx11mmHole φ3mm

Optimization of cooling pipe (thickness 7.5mm)

55

60

65

70

75

80

85

90

95

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0

Temperature of water&conductor

T_water( )℃T_conductor( )℃

T()

℃

ν (m/s)

The calculated temperature in case of containing stainless steal pipe are shown, When the diameter of pipe is 3.7mm, temperature is minimized. Thickness of pipe are chosen to be 0.3mm.

65.0

70.0

75.0

80.0

85.0

90.0

95.0

2.0 2.5 3.0 3.5 4.0 4.5

Temperature of outlet Water

T_water

T()

℃

φ (mm)

Test piece of conductor

Conductor size5mmx11mmDiameter of holesφ3mmSilver brazing

In order to reduce the risk of erosion and corrosion,Steel pipes are put into cupper conductor.

Test piece made by HIP(Hot Isostatic Pressing)

Size 4.5mmx17mmThickness ofStainless pipe is 0.5mm

The two stainless pipes are put into the cupper plate, then added pressing and heat. Finally machining to required shape and dimension.

Summary

Field calculation of thin septa for slow extraction has performed and obtained a flatness of field within 0.5%.

For the medium thin septa, A test piece of optimized conductor was made for the 6turn coil septum.

Hereafter, R&D test will be done to ensure the fabrication.