Special magnets forSuperKEKB
M. TawadaContents

2004.2.17

Design constraints
Design of special magnets (normal conducting)
Belle detector and QC1 magnets
Further study

Ninth KEKB Review

IR Magnet configuration

4 magnets for HER
QC1LE, QC1RE(Vert f.)
QC2LE, QC2RE(Horz f.)
2 magnets for LER
QC2LP, QC2RP(Horz f.)

2004.2.17

Ninth KEKB Review

Design constraints
KEKB

SuperKEKB

longitudinal position
of Special magnet

50cm closer to IP

Crossing angle

22mrad30mradβx / βy33cm / 1cm

20cm / 3mm

Damping ring

Unnecessary

Necessary for e+SR Power (HER/LER)

27kW (1.1A) /10 kW (2.6A)

194kW(4.1A) /78 kW(9.4A)

Aperture for SR
Pole Shape2004.2.17

w/ COD error
w/ dynamic effectfive septum Q,
one half Q

Ninth KEKB Review

six septum Q

Design constraints
 Beam aperture for β*x/β*y= 20cm/3mm Optics (by H. Koiso) Acceptances (w/ damping ring for e+ )
 (by Y. Funakoshi)
 8 GeV : 1.9×10-6(Horz) / 8.0×10-8(Vert)
 3.5 GeV : 2.6×10-6 (Horz) / 1.8×10-7 (Vert) Aperture for synchrotron radiation (by Y. Funakoshi) COD error + 3σx/y (w/ dynamic effect)

2004.2.17

Angle error at IP

Offset error at IP

Beam size (w/dynamic effect)

Horizontal±0.7mrad±0.4mm

3σx

Vertical±0.5mrad±0.2mm3σyNinth KEKB Review

IR Beta functions, Orbit&')$#

1200!"#$!%#$&')"#&'+"#!"#$!%#$

1500&'+$#!x (m)

βx

800

βy&')$+600&'($#&')"+ &'("#400
200

641000&'($#&'("#2&'(")&'*$

0&'*$&'*"

500&'*"

0!y (m)1000-2-40-66&'($)

42

Distance from IP (m)0-2-4-6

Distance from IP (m)642HER-2LER
0-2-4-664!"#$%

LER
20-2

Distance from IP (m)Ninth KEKB Review!"#$(!")$(!"'$!"'&!")&(0Distance from IP (m)2004.2.17

HER!"#&(2y (mm)!"'&4!"#&%200!"#&%

100!"#$(*+,,+-./,+0/12-341.

!"#&(!")&(SR from QCSL

0V-Orbit

SR from QCSR-100!"'$x (mm)-200!")$(H-Orbit!"#$%-300-4-6

Parameters of special magnets
Centerposition
from IP(m)G (T/m)L (m)Bore radius Space for(mm)coil (mm)

QC2LE

6.7

3.37

2.050293

QC2LP

4.3

6.69

0.680

189

QC1LE

2.8

15.54
42.9

0.64
0.232

2531108(super)

QCSL

0.969

34.24

0.418

90

QCSR

1.163

36.01

0.333

90

QC1RE

3.8

1234.0

0.75
0.266

4880

101(super)

QC2RP

5.5

3.05

1.0

40

148

QC2RE

7.2

8.8

0.890

206

2004.2.17

Ninth KEKB Review

QC1LE, QC1RE magnet
Aperture for SR

Aperture for beams

QC1LE

QC1RE

G=15.54T/m, L=0.64, R0=25mm
3turn-8x8-φ53920AT, I=1300A, i=30A/mm2
2004.2.17

G=12.0T/m, L=0.75, R0=48mm
3turn-9x9-φ
3turn-9x9-φ611050AT, I=3700A, i=70A/mm2
P=157kW, water flow: 4m/sec
dT=30℃
dT=30℃

Ninth KEKB ReviewNeeds further studyKEKB QC1LE
 Operation current: 2500A
Current density: 70A/mm2
 Power 80 kW
 3 turn coil per pole 3 water circuits per pole.
 Water flow speed: 5 m/sec
 Fast protection systemagainst coil burn out.
 Low oxygen water
2004.2.17Ninth KEKB Review

QC2LP, QC2RP magnet
Aperture for SR

Aperture for beam

QC2LP

QC2RP

G=6.69T/m, L=0.6, R0=80mm
15turn-7x7-φ4
17100AT,I=1150A, i=32A/mm2

G=3.05T/m, L=1.0, R0=40mm
3turn-8x8-φ5
1980AT, I=660A, i=15A/mm2

2004.2.17

Ninth KEKB Review

QC2LE, QC2RE magnet
Aperture for SR

Aperture for beam

QC2LE

QC2RE

G=3.37T/m, L=2.0, R0=50mm
8turn-12x12-φ83400AT,I=450A, i=10A/mm2

G=8.8T/m, L=0.8, R0=90mm
16turn-10x10-φ7
28400AT,I=1800A, i=25A/mm2

2004.2.17

Ninth KEKB Review

Leakage Fields[Gauss]

Belle and QC1 magnets
QC1(SuperKEKB)

1000

100

QC1(KEKB)

10

Measured Bz
3d calculation

1250300

350

400

450

500

550

600

distance from detector center [cm]

 Leakage fields for QC1

80 -> 250 Gauss

2004.2.17

Space between QC1 and Belle
detector are very tight.
We need to install He transfer
line, support table, vacuum
chamber, etc. in this space.

Ninth KEKB Review

Further study Detailed design of QC1 and QC2.
 Estimation of the leakage field effect on QC1magnets.
 Interference with the vacuum chambers, Belle
detector, QCS helium transfer line, supportingsystem, etc.

2004.2.17

Ninth KEKB Review