Zian Zhu

• Basic parameters• Coil design• Magnetic field analysis• Cryostat design• Coil support structure• Cryogenics• Yoke configuration• Cost and milestone

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Basic Parameters• Physics requirement• Central field B = 1.0 T

• Dimension of magnet(RT volume): L = 3.9 m, D = 2.65 m

• Uniformity B/B < 5% in the tracking volume

• Cool-down time t < 10 days

• Configuration• Single layer solenoid coil, steady field

• In-direct cooling by two phase flow liquid helium

• Pure aluminum based stabilizer

• NbTi/Cu superconductor

• Ramp rate: reached to operating current in 0.5hours

• Recovery time: <1 day

• Field stability: 5×10-4

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Basic Parameters

Concept Design of BESIII Superconducting Magnet

Cryostat

Inner radius 1.325m

Outer radius 1.7m

Length 3.9m

Coil

Effective radius 1.45m

Length 3.5m

Cable dimension 3.7mm*20mm

Electrical parameters

Central field 1.0T

Nominal current 3000A

Inductance 2.0H

Stored energy 9.2MJ

Cold mass 3.5ton

Total Weight 14.6tonRadiation thickness 1.86X0

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Design

Concept Design of BESIII Superconducting Magnet

4N Purity aluminum-stabi1izerRRR=~300

nIB 00

Cross section of the superconducting cable

mm05.007.3

921 turns for a 3.5m long coil

lDB

lSB

VBHE 42

1

2

1)

2

1(

2

0

2

0

2

= 9.2MJ

mm1.0020

nD

BnSB 4

2dt

dIL

dt

d

I

L

= 2H

70K

EVh EtlDh

Dlh

Et

20mm

32.470 /2.16/6000 mMJkgJhhh KK

,w=3.7mm

,I=3000A

Working 3000A@1T-----Critical 6000A@2TNbTi wire， JC=3800A/mm2@2T, NbTi/Cu ratio 1.09:1

Cross Section Area of NbTi/Cu: 3.2mm2

3.2mm2

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Design

Concept Design of BESIII Superconducting Magnet

Stress in the Coil

0

2

2Z

r

BP

t

rB

t

rP Zrh

0

2

2 Hoop stress

Radial Magnetic Pressure

t is thickness of coil plus support cylinder

When thickness of support cylinder is15mm, t=35mm

Maximum hoop stress is 19 Mpa

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Design

Concept Design of BESIII Superconducting Magnet

Other analysis Esti mati on of the vol tage by quench

0. 050. 0

100. 0150. 0200. 0250. 0300. 0350. 0

1 2 4 8 10 20 30Quench Length (m)

Coil

Voltage (

mV

)

Voltage versus length of quench area in the coil

Estimation of coil Ohmic heats by th joints: 2.54 mW

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Design

Concept Design of BESIII Superconducting Magnet

Coil Cross Section

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Magnetic field analysis

Concept Design of BESIII Superconducting Magnet

Contour plotFlux line

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Magnetic field analysis

Concept Design of BESIII Superconducting Magnet

B along beam axis field uniformity inside the Drift chamber

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Magnetic field analysis

Concept Design of BESIII Superconducting Magnet

End Yoke L1~L9 30,30,30,30,30,40, 80, 80, 300mmBarrel Yoke L1~L9 20,20,20,40,40,80,80,100, 400mm

End Yoke L1~L9 30,30,30,30,30,40,80,80,80mm

Barrel Yoke L1~L9 30,30,30,40,40,80,80,80,80mm

gaussmB

MDCB

B

435.3@

%9.1@

When anti-solenoid excited

gaussmB

MDCB

B

875.3@

%3.2@

End Yoke L1~L9 30,30,30,30,30,40,80, 80,300mm

Barrel Yoke L1~L9 30,30,30,40,40,80,80,80,400mmgaussmB

MDCB

B

535.3@

%9.1@

gaussmB

MDCB

B

885.3@

%14@

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Cryostat Design

Concept Design of BESIII Superconducting Magnet

Material: SUS316L

)()()1(

855.0

2

5

4

32

r

l

t

r

Epcr

Buckling check

Outer cylinder,Inner cylinder,End plates

1cr

c

crP

P

Buckl i ng Check of the Outer Vessel

02468

101214

10 11 12 15 16 18

Thi ckness (mm)

Pcr

kg

/mm

2

ANSYSNASA

Mechanical strength check

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Cryostat Design

Concept Design of BESIII Superconducting Magnet

Max. Stress: 43 MPa

Max. Deformation: 0.18mm

Thickness: Outer vessel =16 mm Inner vessel = 5 mm End vessel = 32 mm

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Support Structure

Concept Design of BESIII Superconducting Magnet

12 radial support rods6 at each end

12 axial support rodsat chimney side

Rods material: GFRP

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Coil Support Structure

Concept Design of BESIII Superconducting Magnet

Axial decentering force 416340 N/5cm

Radial decentering force 34695 N/5cm

Diameter of the rods for the nitrogen shield is 15mm,6mm for radial and axial support.

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Weight and Radiation thickness

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Cryogenics

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Cryogenics

Concept Design of BESIII Superconducting Magnet

Cooling Type Normal: Forced 2-Phase Helium Cooling Trouble: Thermo-syphon Cooling

Volume of Working Fluid Coil: 50 LService Port: 200 LShield: 16 L

Coil Pipe Outer Diameter: 31 mmInner Diameter: 25 mmTotal Length: 102 mNumber of Line: One

Shield Pipe Outer Diameter: 18 mmInner Diameter: 14 mmTotal Length: 70 mNumber of Line: Two (One for each side)

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Cryogenics

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Yoke Configuration

Concept Design of BESIII Superconducting Magnet

End Yoke L1~L9

30,30,30,30,30,40,80, 80,300mm

Barrel Yoke L1~L9

30,30,30,40,40,80,80,80,400mm

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Magnet support structure

Concept Design of BESIII Superconducting Magnet

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Concept Design of BESIII Superconducting Magnet

Cost Estimation

Item Cost(Million RMB,exclude Tax)

Superconducting Cable 9.8

Magnet Fabrication 31.0

Field Mapping 0.9

Vacuum Device 0.4

Control System 0.6

Power Supply/Quench Device

2.4

Sporadic Machining 0.2

Business trip 0.3

Total 45.6

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Milestone

Concept Design of BESIII Superconducting Magnet

Year 2002 2003 2004 2005 2006Month 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3Solenoid Magnet

Concept Design

Ordering of superconducting cable

Making&Get superconducting cable

Ordering of Magnet and Chimney

Fabrication of Magnet&Chimney

Magnet test in the factory

Magnet Transportation

Magnet Installation

Installation of field mapping device

Installation of QCS, Alignment

Commissioning magnet&cryogenics

Field mapping

Cryogenics

Concept design

Ordering of key components

Manufacture of main devices

Installation and Leakage test

Performance Test

Commissioning with magnet

Iron Yoke

Design

Ordering

Material and Instrumentation

Machining and Fabrication

Transportation

Installation

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu

Concept Design of BESIII Superconducting Magnet

Acknowledgement

KEK experts group:

Prof. H.Tsuchiya, Y.Makida, H.Yamaoka.

Design group members:

S. Han, L.Liu

Leaders:

S. Kurokawa, Weiguo Li

BESIII Collaboration Meeting, June 5~6, 2002, Zian Zhu