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
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
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
ATLAS Central Solenoid
Troid
Barrel
End-Cap Toroid
End-Cap Toroid
Central Solenoid
Central Solenoid
Bc = 2T (I = 7600A)
5.3m × f2.3m × 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
Feature of
ATLAS Central Solenoid
30 x 4.25 mm2
Pure Al-strip
quench propagator
High-Strength
Al-stabilized
superconductor
Y.S. = > 100 MPa
RRR > 500
Ic at 5T, 4.2K = 22 kA
Composite structure formed by
Micro-alloying and precipitation
Ni --> High
200
0.1%
0.5%
Yield Strength at 4.2 K [MPa]
Ni 20000-ppm
(20%)
150
(20%)
100
( +)
Cu
(20%)
50
Ni 1000-ppm
(0 %)
Zn 200-ppm
(0 %)
(0 %)
0
0
500
1000
Residual Resistivity Ratio
Al3Ni: Contributes as structural component
Pure-Al: Keep low resistivity
1500
2000
Progress in High-Strength
Al Stabilizer
200
83-O
A50
)
/Al
u
C
/
bTi
N
(
r
cto
u
d
Con
ppm
Al with Ni 1000
160
120
2/3
100
<
<67
４５
Stress [MPa]
140
６７
180
Reinforcement
>3 times
80
高強度線による設計
60
従来の設計
Pure Al ( 4N～5N )
40
20
0
0.0
0.1
Stress in the Coil
0.2
0.3 0.4
Strain [%]
0.5
0.6
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
Alignment
Coil Position＜1mm
Installation and On-surface Test
Extension Chimney
Proximity Cryogenics
Bulkhead
Main Chimney
Solenoid
Cooling combined with Lar Calorimeter
6/7
Start Cooling
Solenoid
6/23
Cooling complete
Cooling Characteristics of ATLAS CS
Technical problem
in Refrigerator
Temperature
（
ｋ
）
LHe filled/boosted
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
Imax = 8.14 kA
Iop = 7.6 kA
Quench Protection with
pure-Al strips
Bus line
0.08m
MCB
Diode
Bank
DC PS
10kA, 5V
dV~8V
Dump R
50m
Super.QD
Coil
Bridge VQD
1.27 H
DCB
Bus line
0.08m
w/o Energy extraction
Homogenized energy dump
into the whole coil
コイル全体
kz=270W/m・K,
Kz/kf=0.1
Test with pure-Al strips and quench protection heater
Concept of Quench Protection
by using Pure-Al Strips
Temperature Uniformity
VS Axial Coil Thermal Conductivity
Temperature (K)
250
Min. Temp
Pure Al Strip
without pure Al strips
Vf
200
Measurement
150
Expectation
100
Vz
Maximum Temperature
Minimum Temperature
50
0
10
-4
10
-3
10
-2
kz/kf
-1
10
=(Vz/Vf)2
Quench Propagation
Vf = J
γC
Loθs
θs θ0
VZ =
kf
Vf
kz
10
0
Larger
Quench Origin
Max. Temp.
k f : Homogenized
k z Energy Dump
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
(w/o QPHT)
(with QPHT)
T-peak = 118 K @ 8.1 kA at
chimney end with QPHT
V-tap
Thermometer
Heater
centre
edge
Radiation Thickness of
Various Solenoids
3
Thickness in Radiation Length [X]
Thickness [X]
2.5
Transparency [X]
CLEO-II
ALEPH
2
H1
DELPHI
1.5
SDC-PT
D0
1
ZEUS
VENUS
0.5
TOPAZ
CELLO
PEP4
CDF
ATLAS
WASA
BESS
0
0
1
2
3
2
4
B x R [Tesla
5
2
• m]
6
7
8
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.

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