ATLAS 超伝導ソレノイドのCERN での組み込みと励磁試験の成功

KEK, 東芝 , CERN山本　明、槙田康博、河合正徳、近藤良也、土井義城、春山富義、近藤敬比古、水牧祥一、 R. Ruber, F. Haug

1. 磁場＋粒子透過性能の 追求2. 組み込みと地上試験結果3. まとめ

ATLAS Central Solenoid

Bc = 2T (I = 7600A)

5.3m × 2.3m × 45mm

wall thickness = 0.66 X0

E/M = 7.1 kJ/kg

To be as transparent as possible: • High strength Al stabilized S.C. • Pure-Al strip quench protection, • Common Cryostat with LAr-CAL

End-Cap Toroid

End-Cap Toroid

Central SolenoidCentral Solenoid

Feature of ATLAS Central Solenoid

High-Strength Al-stabilized superconductor

Y.S. = > 100 MPaRRR > 500Ic at 5T, 4.2K = 22 kA

Pure Al-stripquench propagator

30 x 4.25 mm2

Al3Ni: Contributes as structural componentPure-Al: Keep low resistivity

Ni --> High

0.1% 0.5%

Composite structure formed by Micro-alloying and precipitation

0

50

100

150

200

0 500 1000 1500 2000

Yie

ld S

tre

ng

th a

t 4

.2 K

[

MP

a]

Residual Resistivity Ratio

Ni 20000-ppm

Zn 200-ppm

Ni 1000-ppm

(20%)

(20%)

(20%)

(0 %)

(0 %) (0 %)

(+)

Cu

0.0 0.1 0.2 0.3 0.4 0.5 0.60

20

40

60

80

100

120

140

160

180

200

Al with Ni 1000ppm

Pure Al ( 4N 5N )～

Str

ess

[MP

a]

Strain [%]

Reinforcement >3 times

Stress in the Coil

20% cold work

Progress in High-Strength Al Stabilizer

< 67

従来の設計 高強度線による設計

< ６

７

2/3

４ ５

Material saved to be 2/3

Progress of ATLAS Central Solenoid 　

@ Toshiba（ 1999）Test @ Toshiba（ 2000-12）

Arrive at CERN （ 2001-9 ）Maiani 所長らと

Assembly into LAr Cryostat

Common Cryostat with LAr Calorimeter

Assembly into LAr Calorimeter

Coil Position＜1mm

Alignment

Installation and On-surface Test Proximity Cryogenics

Main Chimney

Solenoid

Extension Chimney

Bulkhead

6/7Start Cooling Solenoid

6/23Cooling complete

Cooling combined with Lar Calorimeter

Cooling Characteristics of ATLAS CS

Technical problem in Refrigerator

LHe filled/boosted

Tem

perature

（ｋ）

Performance Test• Maximum Excitation Test up to 8.14 kA

– training quenches at 7.9 and 8.1 kA (> Iop = 7.6 kA– heater initiated quench at 4, 6 and 7.6 kA– chimney heater initiated quench at 6 kA

• Additional testing after test @ Toshiba: – thermal cycling– transportation– assembly work at

CERN

Iop = 7.6 kA

Imax = 8.14 kA

コイル全体kz=270W/m ・ K,Kz/k

Quench Protection with pure-Al strips

Diode Bank

dV~8V

DCB

MCB

Coil

1.27 HSuper.QD

DC PS 10kA, 5V

Bus line 0.08m

Bus line 0.08m

Dump R 50m BridgeVQD

w/o Energy extraction

Homogenized energy dump into the whole coil

Test with pure-Al strips and quench protection heater

10- 4 10- 3 10- 2 10- 1 1000

50

100

150

200

250without pure Al strips

Measurement

Expectation

Tem

pera

ture

(K

)

kz/ k

Maximum Temperature Minimum Temperature

=(Vz/V)2

Pure Al Strip

Quench OriginMax. Temp.

Min. TempTemperature Uniformity VS Axial Coil Thermal Conductivity

Vz

V

Quench Propagation

V

kkV

zZ

0s

so

θθθL

γCJV

Larger : Homogenized Energy Dump

zkk

Concept of Quench Protection by using Pure-Al Strips

Effect of Pure AL Strips and Protection Heaters at 6kA

Adjusted value for well simulation.

Ideally （ no thermal resistance b/w winding and pure al strips) 0.1.

Peak Temperature after Quench

centreV-tapThermometerHeater

edge

T-peak = 118 K @ 8.1 kA at chimney end with QPHT

(with QPHT)

(w/o QPHT)

Radiation Thickness of Various Solenoids

0

0.5

1

1.5

2

2.5

3

0 1 2 3 4 5 6 7 8

Thickness [X]

Transparency [X]

Th

ickn

ess

in R

ad

iati

on

Le

ng

th [

X]

B2 x R [Tesla 2 • m]

ATLAS

SDC-PT

ZEUS

BESS

WASA

VENUS

ALEPH

H1

DELPHI

TOPAZCELLO

CDF

D0

PEP4

CLEO-II

Status at ATLAS site (Pit -1)

Conclusions• ATLAS Central Solenoid successfully assembled

into a common cryostat with Liquid Argon Calorimeter,

• Safe operation in cooling and excitations up to 107 % of Nominal Current:– maximum current 8.14 kA @nominal current 7.6 kA

• Quench safety verified– With quench test with T-peak = < 120 K

• Installation at pit to be completed by autumn 2005• Excitation test with iron flux-return yoke to be in

early 2006.