1

Detector magnet and Structure for the GLD Detector

KEK Hiroshi Yamaoka

Mar. 03, ‘05

2

Introduction

Yoke design・ Design against magnetic field　 Optimize plate thickness/length to be satisfied field uniformity. Check leakage field

・ Design against forces　　 Self-weight, Earthquake, Magnetic force

・ Assembly with keeping good accuracy

・ Minimize support structure

・ Cable space, support structure for sub-detectors

・ Easy access to sub-detectors

・ Cost reduction

Cable

Earthquake

Self-weight

Mag. force

Solenoid Iron Yoke

BUniformity

H-Cal

EM Cal

Main Tracker

Muon Tracker

VTX

3

Boundary conditions for yoke designMagnetic Field Bc= 3 Tesla

Material: S10C(JIS) Carbon= 0.1wt%t=310MPae=205MPaallow=120MPa

Field Uniformity <2mm, <20mm

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0100

101

102

103

104

105

106

H(A

/m)

B(T)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.00

500

1000

1500

2000

2500

3000

Per

mea

bili

ty

B(T)

Permeability

These dimensions are fixed,Coil length, yoke dimensions are changed.

Belle

Air gap for muon is 10cm.

4

Magnetic Field Calculation

Perform ANSYS calculation to optimize

Iron Yoke configuration.

・ Plenty of amount of iron

・ Minimize Z1,R1

・ Optimize Z2,R2

Solenoid magnetZ2

R2

R1

Z1

max

02

Zmmdz

Bz

Br

3T

ANSYS: Two-dimensional Static Magnetic Analysis

Air

Infinite elements

Iron

CoilMain Tracker

Input; Permeability Current density(Coil)*Material properties

Axisymmetric

5

Calculations

dz Coil-L Bmin Bmax Bc Unif(%)60 4.31 2.965 3.078 3.05 3.67170 4.32 2.966 3.077 3.049 3.60780 4.33 2.968 3.076 3.049 3.51190 4.34 2.968 3.074 3.048 3.448

100 4.35 2.97 3.073 3.047 3.352120 4.37 2.972 3.071 3.046 3.224200 4.45 2.979 3.061 3.042 2.679500 4.75 3.003 3.027 3.023 0.793550 4.8 3.005 3.025 3.017 0.661600 4.85 3.008 3.026 3.017 0.595640 4.89 3.01 3.027 3.014 0.562650 4.9 3.01 3.026 3.013 0.529660 4.91 3.009 3.027 3.013 0.595700 4.95 3.004 3.027 3.01 0.76750 5 2.999 3.028 3.006 0.958 0 100 200 300 400 500 600 700 800

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Un

ifo

rmit

y(%

)

dz(mm)

1001(%)max

min

B

BUnif

dz

Coil-L

4.25m

6

R2.05m

R1.8m

R0.4m

R1.0m

0

2mm

1

Unif.=18mm

8 layers

Iron

7 layers

max

02

Zmmdz

Bz

Br

mmdzBz

BrZ20

max

0

*Air gap=10cm

7

0 10 20 30 40 501E-4

1E-3

0.01

0.1

1

Mag

neti

c F

ield

(T)

Distance from solenoid center(m)

Fringe/Leakage fieldMagnetic field/ Flux line

0 10 20 30 40 501E-4

1E-3

0.01

0.1

1

Ma

gn

eti

c F

ield

(T)

Distance from solenoid center(m)

max

02

Zmmdz

Bz

Br

mmdzBz

BrZ20

max

0

8

Air gap=5cm, Uniformity=20mm

Air gap=1cm, Uniformity=20mm

Magnetic field/ Flux line

Magnetic field/ Flux line

Unit: Tesla

Unit: Tesla

7.4m

7.16m

Coil=L4.58m

Coil=L4.50m

9

Max. 1.8mm

Max. 90MPa<120MPa

18000tons

Fixed

Stress/deformation of End Yoke

27

2

0

2

841042

3

2

S

BFZ

= 18400tons

ANSYS: 18342tons

Symmetry is NOT defined!

10

Stress/deformation of Barrel Yoke

13300tons

FixedFixed

Max. 7mm

Max. 65MPa<120MPa

Thickness= 5cm

11

4.2mm

30

mm

4.3mm

NbTi:Cu:Al= 1:0.9:15.6

Strand diameter: 1.23mm

Filament diameter: 20m

Jc in NbTi at 5T, 4.2K: > 2750A/mm2

Ic at 5T, 4.2K: > 20300A

(For ATLAS)

Superconducting Solenoid

Cryostat Inner radius 3.72mOuter radius 4.4mHalf length 5.25m

Coil Mean radius 4.0mHalf length 4.93m

3T4576 turns

741A/mm2

5338A81.0H1.8GJStored Energy

Central magnetic field

Nominal currentInductance

# of turns(2 layers)

Current density

* Uniformity=2mm, Air gap=10cm

Ｓ uperconductor

12

0 1 2 3 4 5-40

-20

0

20

40

60

80

100

120

140

Str

ess(

MP

a)

Distance from center(m)

Circum. direction

Axial direction

Co

mp

ress

ion

Stress level in the coil

Development of High-strength Al

4.93m(Half)

R4.

0m

Support cylinder(t=50mm) Conductor

(h=30mm)

8mm

4mm

Deformation of the coil

Solenoid center

By Makida

13

- Outer vac. vessel

40mm rLtr

Ep

2

52

75.0

1

855.0

p: Buckling pressure 0.1MPa x 2(safety factor)

2000tons

Fixed Fixed

Thickness of ・ Inner vacuum vessel ・ End plateswere optimized.

Load conditions Weight of the calorimeter: 2000tons Weight of the solenoid : ～ 140tons Vacuum : 0.1MPa

Cryostat design

SUS304t =530MPa y =210MPaallow=140MPa

2000tonsFixed Fixed

Model-1

Model-2

14

118MPa<140MPa

9mm

t=40mm(Outer)

t=60mm(Inner)t=100mm(End plate)

2000tons

Fixed Fixed2000tons

Fixed Fixed

2000tons

x0.3G

Fixed Fixed

9mm

125MPa

274MPa>140MPa

15mm

t=40mmt=60mm

t=100mm

Stiffness: D

IED 12

3HeightWidthI

E: Young’s modulus

I: Moment of Inertia

Model-1 Model-2Material: SUS304

Weight of the calorimater should be supported at horizontal position. - Calorimeter is divided to several modules in the axial direction. - One module of calorimeter has to be stiff enough.

Important

15

2mm10cm 10cm 5cm 1cm

Barrel 5 layers 5 layers 5 layers 5 layersYoke End 8 layers 7 layers 7 layers 7 layers

Width(Half) 8.45m 7.7m 7.4m 7.16mWeight(Yoke) 13262tons ～12500tons ～12500tons ～12500tons

Cryostat Inner radius 3.72m 3.72m 3.72m 3.72mOuter radius 4.4m 4.4m 4.4m 4.4mHalf length 5.25m 5.0m 4.9m 4.82m

Coil Mean radius 4.0m 4.0m 4.0m 4.0mHalf length 4.93m 4.63m 4.58m 4.5m

3T 3T 3T 3T4586 turns 4306turns 4260turns 4186turns

741A/mm2 741A/mm2 741A/mm2 741A/mm2

5338A 5338A 5338A 5338A1.77GJ 1.67GJ 1.64GJ 1.62GJ

20mmUniformityAir Gap

Stored Energy

Central magnetic field

Nominal current

# of turns(2 layers)

Current density

・ Design against magnetic field　 Optimize iron thickness/length to be satisfied field uniformity. Leakage field

・ Design against forces Self-weight, Earthquake, Magnetic force

・ Support structure for sub-detectors

To be designed ・ Assembly with keeping good accuracy

・ Easy access to sub-detectors

・ Cost reduction

Conclusion

Almost fixed. Depends on the allowable uniformity and air gap for Muon

These are calculated roughly.Detail calculations are required.These are investigated roughly.Detail design should be done.

H-CalSolenoid

Main track

EM-CalIron Yoke Moun

R4

00

0

R4

40

0

t=50mm

2 layers

*Coil support system is not designed.

R4.

0m

Support cylinder(t=50mm) Conductor

(h=30mm)

Solenoid Magnet

16

17

力に対する支持

End Yoke

Barrel Yoke

800tons

650tonA

B

A と B をあわせた後、支持板をはめ込む

支持板

方針　・ボルトではなく、支持材　 ( 面 ) で支えるようにした　・測定器の領域を削らない

18

耐震設計

手順

入力加速度80 gal

応答加速度How much?

＊ 1 gal = 1 cm/sec2

1 G = 9.8 m/sec2

= 980 gal80 gal = 4.5(Intensity: 震度階 )

0.3G の静解析

260gal

Time(sec)

Acc

.(g

al)

詳細な構造検討により、健全性が確認された。