ASIPP
Magnet system of Experimental
Advanced Superconducting
Tokomak (EAST)
Weng Peide
Institute of Plasma Physics, Chinese Academy of Sciences,
April 6, 2009 CEA Cadarache
ASIPP
HT-7 Superconducting Tokamak
ASIPP
Introduction
• EAST is a Chinese national project started
(approved and funded) in the end of 1998, and
completed its construction in 2006. The main mission
of EAST is to develop an advanced superconducting
tokamak and explore scientific and technological
bases for fusion. The budget is extremely limited about 300 million RMB (~ 30 Million Euro) in total.
• It is the first tokomak with superconducting toroidal,
poloidal as well as central solenoid magnets, and will
operate long pulse elongated plasma.
ASIPP
Cryostat
Major Radius Ro 1.7 m
Minor Radius a
0.4 m
R/a
4.25
Vacuum Vessel Toroidal Field Bo 3.5 T
Plasma Current IP 1 MA
Elongation Kx
1.2 - 2
Triangularity δx 0.2-0.5
Pulse length
1000 s
Heating and Driving: ( first phase)
3 MW CW
ICRF
LHCD
3.5 MW CW
ECRH
0.5 MW
Thermal
Shield
SC coils
Configuration:
Single null divertor
Double-null divertor
ASIPP
16 D shape TF coil
Total weight 176 tons
Storage energy 300 MJ
PF1/ 6 coil
PF2/5 coil
PF3/4 coil
6 CS coil
Magnet
system
CS & PF magnets
Total weight 38.7 tons,
Total flux swing 10 VS
CIC conductor with segregated copper wires ; multi-pancake winding; epoxy
VPI; Low rigidity support; Supercritical helium forced flow cooling
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65
55
Critical current Ic (kA)
50
45
40
TF
PF1
PF2
PF3
calculated
35
30
25
20
15
B=4.5 T
dm/dt=2.8 g/s
PF3
PF3
PF2
PF2
TF
TF
PF1
PF1
14
12
10
ac losses, mJ/cc
IC
60
AC loses
8
6
4
2
10
5
0
0
5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8
0
2
4
6
f, HZ
Temperature T (K)
Short Sample test
Four TF & PF conductors
Assembled to 2 short
samples ( TF + PF1; PF2
+ PF3) were tested in
SULTAN facility CRPP.
The Ic, Tcs, AC losses
and stability have been
measured. TF and PF1
strand coated by Tin alloy,
PF 2, 3 strand coated by
Ni. 3rd stage sub-cable SS
tape rapping for PF1, 2
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Conductor design and R&D
(SC/Cu 1:1.38)
(SC/Cu 1:1.38)
TF
CS and PF 1/6
PF 2-5
Size
20.4 × 20.4
20.4 × 20.4
18.5 × 18.5
Number of SC strands
120
120
60
Coating
Sn alloy
Ni
Sn alloy
Cu / non-Cu
4.91
4.91
8.23
Void fraction
0.34
0.34
0.36
NbTi strand
copper ratio 1.38; total weight of strands : 20 tons
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CICC jacketing line 58 conductors (32 km) have been fabricated
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Coil fabrication
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TF coil case machining
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TF coil
16 D shape TF coil
Turns/coil 130
Size
3.52 × 2.51 m
Pancakes 2×
×6
I nom
14.3 kA
B max
5.8T
Tin
4.5 /3.8 K
ASIPP
CS coil after
VPI
CS Assembly
consists of 6 coils
Storage energy 30MJ
Turns
140
Size
1.42×
× 0.48 m
Pancakes
20
I nom
14.5 kA
B max
dB/dt
4.3T
6.8T/s
Tin
4.5 /3.8 K
CS1- 6
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PF 9- 10
米
米
PF1 / PF6 assembly
Turns
248
Pancakes 20
I max
dB/dt
14.5 kA
3.5 T/s
Storage energy 19 MJ
Size
2.67×
× 0.39 m
Weight
5.8 ton
B max
5T
Tin
4.5 /3.8 K
ASIPP
PF 2/5
PF 3/4
Pancake
Turns
Size (m)
PF 2/5
60
6.05 × 0.22 10
14.5
1.5
0.7
4.5 /3.8
PF3/4
32
6.65 × 0.18
14.5
1.5
0.7
4.5 /3.8
8
Imax (kA) Bmax (T) dB/dt(T/s) Tin (K)
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Coil Test
16 TF coils, one CS coil, CS
assembly, PF 1, PF 6 and CSMC
have been tested.
Test program :
•Insulation
•Cryogenic & thermal-hydraulic
behavior
•Resistance of coil internal joints
•Excitation to nominal current
•Quench current measurement.
•Simulate Plasma initiation
•AC losses test
Test facility
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TF coil in test facility
CS coil test
PF 1/6 coil test
CS assembly in test facility
ASIPP
Assembly
16 TF
coils
CS coils
PF 1/6
PF 2/5
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Cooling loops
TF case
16 in parallel
TF winding
96 in parallel
PF 1,2,5,6
48 in parallel
CS & PF 3,4
46 in parallel
PF 3/4
Power supply
1 for TF
6 for CS
6 for PF
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466 electrical breakers
70 superconducting
joints are made at
side
15 kA HTS current leads test
HTS current leads units
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EAST
Commissioning
2006 Feb.7- Mar.18
(45 days)
First cooldown
2006 July 26- Oct.14
(80 days)
First plasma
2006 Dec. 20
-2007 Feb.11
(53 days)
Elongated plasma
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Summary
• Some special technology applicable for fusion
magnet is well developed during the construction of
EAST, including the cable in conduit conductor
with segregated copper wires; multi-pancake
continuous winding; superconducting joint; epoxy
vacuum pressure impregnation for insulation; axial
and radial electrical breakers for cooling channel
and vacuum break; quench detection compensation
and HTS current leads for SC magnet.
• The results of first commissioning shows that EAST
tokomak has been constructed successfully.