Association Euratom-CEA
TORE SUPRA
Physics and operational integrated
controls for steady state scenario
E. Joffrin, J.F. Artaud, O. Barana, V. Basiuk, C. Bourdelle, S. Brémond, J. Bucalossi, F.
Clairet, L. Colas, Y. Corre, R. Dumont, A. Ekedahl, G. Giruzzi, M. Goniche, F. Imbeaux,
F. Kazarian, L. Laborde, D. Mazon, P. Monier-Garbet, P. Moreau, P. Maget, B. Pégourié,
Y. Peysson, F. Rimini, F. Saint-Laurent, E. Tsitrone, J.M. Travere, F. Turco
Outline:
- Stationary scenario for plasma control in TS.
- Profile control experiments
- Integration of controls for steady state scenarios
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
1
Association Euratom-CEA
TORE SUPRA
Advanced steady state tokamak regime
Advanced tokamak scenario demands the combination of challenging conditions:
1.
High pressure & bootstrap current:
bN . H >8 and Iboot/Ip>50%

2.
Steady state long duration discharges:
Duration >> tR & power handling
3.
High degree of control over q & P profiles: Control broad q & P profile


Using actively cooled plasma facing
components and non-inductive current drive,
Tore Supra can address 2 & 3
Objective: achieve integrated stationary scenario with
• Active profile control
• Active control of local heat flux on PFCs
• Duration:
>>tR & ~ thermal constant of all components
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
2
Association Euratom-CEA
TORE SUPRA
Tore Supra operational domain for stationary scenario
Tore Supra produces long discharges with high level of RF power
(LH & ECCD current drive and ICRH electron heating)
PLOSS
SSEP
0.12
TS-2004 TS-2005
ITER
1- Using actively cooled PFC
components, Tore Supra has developed
pulse length close to 400s (>1GJ).
0.1
0.08
0.06
JET
0.04
Long Pulse
(2003)
1GJ
2- Recent progress in total injected
power for times exceeding 60s has
extended the domain in
PLOSS=Pconv+ Pcond
comparable to ITER when normalised to
the surface of the separatrix.
0.02
0
10
100
1000
Pulse duration (for 80% of the energy content)
22nd Fusion Energy Conference, Chengdu, China.
Profile control experiments can be
appropriately developed in discharges
lasting more than 10tR ~60s
Emmanuel Joffrin 16-21 Oct. 2006
3
Association Euratom-CEA
TORE SUPRA
Integrated stationary scenario for plasma control schemes
Over 60s duration (tR~5s)
6MW / ~400MJ
36182 (BT=3.7T, qedge=8)
PFCI & PLH [MW]
1.5
3
1.0
2
Ip [MA]
1- Using 2 LH coupler and 3 ICRH antenna and
2 gyrotrons and actively cooled components
1
0.5
PFCE [MW]
6
2- WTH~ 1.3 WITER-L at bp~1 and 65% n/nG
4
3- e-ITB formation with ECCD q profile change
Teo [keV]
From CRONOS + HXR
<ne> [x1019 m-3]=0.65 nG
2
t=30s
8
ILH [MA]
0.4
0.3
0.2
Vloop [V]
Iboot [MA]
0.1
0
10
20
30
40 50 60
Time [s]
4- 85% non-inductive:
6
Iboot=20% ; ILH=65%
4
70
22nd Fusion Energy Conference, Chengdu, China.
2
1
0
JLH x10
[MA/m2]
q
Emmanuel Joffrin 16-21 Oct. 2006
1
4
Association Euratom-CEA
TORE SUPRA
Real time sensors for profile control and long pulses operation
1- Real time thermographic system
8 Cameras monitors all 3 ICRH antennas, all 2 launchers and the toroidal pumped limiter
2- Real time Hard X-ray diagnostic
Emissivity profiles computed in real
time every 16ms and representative
of the LH deposition profile
LH-Launcher
BT = 3.33 T
2500
60-80 keV
energy
band
3
. str . s)
Counts / (mm
3000
Suprathermal electrons
local emissivity profile
HXR diagnostic
38 viewing lines
2000
1500
1000
HXR width
500
0
22nd Fusion Energy Conference, Chengdu, China.
0
0.2
0.4
0.6
0.8
1
Plasma normalised radius
Emmanuel Joffrin 16-21 Oct. 2006
5
Association Euratom-CEA
TORE SUPRA
Plasma profile control: preliminary experiments
LH-power deposition control profile is best demonstrated at low density (n=30%nG)
n// of LH-wave
HXR width
LH power
35588 (BT=3.7T ; <ne>=1.3.1019 m-3)
35579 (BT=3.7T ; <ne>=1.3.1019 m-3)
Ip [MA]
0.6
0.2
0.3
0.0
0.0
3.0
2.0
1.0
n//
0.1
PLH [MW]
n//
2.0
1.5
HXR profile width
0.4
0.2
VLoop [V]
0.3
PLH [MW]
1.0
Ip [MA]
0.6
0.1
VLoop [V]
HXR width
HXR profile width
0.40
0.35
0
Request
5
10
15
20
25
30
0.35
35
Time [s]
0
Request
5
10
15
20
25
30
35
Time [s]
Both n// and LH-power can be used to broaden the current deposition profile
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
6
Association Euratom-CEA
TORE SUPRA
LH deposition profile control at constant Vloop
Previous experiment show that the remaining ohmic current plays a role in plasma core:
#36133
CRONOS
4
2.0 JW
2
PLH [MW]
0
0.8
1.5
1.0
Feedback window
0.6
Target
waveform
s
2
n//
0.4
width HXR
0.1
0.05
0
-0.05
0
VLoop [V]
10
20
30
Time [s]
40
50
t=12s
t=22s
t=33s
JLH [MA/m2]
0.5
IP [MA]
1.5
[MA/m2]
60
70
0.0
0
1.0
n//
HXR width
PLH
IP
primary
VLoop=60mV
The effect of the ohmic current profile can be
minimised by the control of the boundary flux
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
7
Association Euratom-CEA
TORE SUPRA
ECCD and n// as potentials actuator for ITB control
Stationary scenario can develop higher confinement mode with Te oscillation: O-regime
With LH-wave index n//
With ECCD
Current balance at 59s [MA/s]
6
r/a=0
Te [keV]
CRONOS
2.0
JTOT
5
4
r/a=0.3
300kW ECCD
1.0 JLH
8Hz
Johm
JFCE
qo
2.0
r*T (x100)
0
Jboot
0.5
r/a
n//
4.5Hz
1.0
1.5
qmin
1.0
57
58
59
60
Time [s]
Giruzzi et al. PRL 2005
• Confirm that local current is an adequate control
parameter for stabilising the O-regime.
• Local ECCD power deposition or n// can play this role
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
8
Association Euratom-CEA
TORE SUPRA
Analysis of RF heat flux sources onto LH launchers
At higher density  all RF systems can couple power to the plasma.
Heat flux sources are identified from IR and calorimetry analysis in dedicated experiments
Interaction
Mechanism
Heat load location
Controller action
Choc 35611-C3
LH  LH
Fast e(proportional to:
PLH, ne,grill)
Decrease the LH
private power the
launcher
Launcher side protection
See A. Ekedahl PSI 2006
Choc 36143 (67.4s) – C3
ICRH  LH
Fast ions orbit
drift in rippled field
(proportional to:
PFCI, 1 / ne2)
Decrease
ICRH total power
Lower part of LH-launcher
22nd Fusion Energy Conference, Chengdu, China.
Goniche et al. EX/P6-12
Emmanuel Joffrin 16-21 Oct. 2006
9
Association Euratom-CEA
TORE SUPRA
Analysis of RF heat flux sources onto ICRH antennas
From IR camera and calorimetry analysis
Interaction
Mechanism
Heat load location
Controller action
Choc 35568-Q5
LH  ICRH
Fast electrons
accelerated
at grill mouth
(a PLH, ne,grill)
Decrease the
total LH-power
Side protection of antenna
See A. Ekedahl PSI 2006
Choc 35961-Q1
ICRHICRH
Decrease the ICRH
private power
RF sheath effects
Antenna screen and septum
Goniche et al. EX/P6-12
Identified over-heat flux area inserted in the controller and linked for relevant action
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
10
Association Euratom-CEA
TORE SUPRA
Integration of profile control and IR-avoidance scheme (1)
5
4
Shot 36192 (BT=3.7T, n/nG=0.65)
PLH [MW]
Ip [MA]
3
2
1
0.6
0.4
0.2
PFCI [MW]
2.2
n//
0.5 Reference
0.45
HX-ray
width
1.0
LH-power [MW]
0.5
200
10
IR temperature
IR limit avoidance algorithm:
700°C
LH launcher side
protection
800°C
PLH
100%
1.8
TIR [°C]
600
0
PLH , PICRH
2.0
800
400
HXR width
20
30
40 50 60
Time [s]
Protection
0.6
0.55
n// of LH wave
70
25%
LH launcher IR view
TIR
n// increase leads to:
 PReflec increase
 TIR increase on LH launcher (fast e-)
 PLH modulated by controller
Profile control achieved despite PLH modulation
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
11
Association Euratom-CEA
TORE SUPRA
Integration of profile control and IR-avoidance scheme (2)
With « Search optimisation » algorithm
36194 (BT=3.7T ;
1.0
0.5
<ne>=2.5.1020
m-3)
PICRH [MW]
Ip [MA]
VLoop [V]
n// and PLH
HXR width
PLH , PICRH
IR temperature
2
1
Optimum
found
n//
3
2
2.5
PLH [MW]
1
n//
2
Start
0.5
1.6
HXR profile width
0.4
qo
1.4
PLH
Antenna
septum
1.2
0.3
1
1.0
0
TIR [Deg]
10
20
30
40
50
Time [s]
Integrated stationary
scenario achieved with:
• Constant Vloop
• qo increases by 0.4
1000
PQ1 [MW]
0.5
Target: broadest
HXR profile
• No MHD detected
900
ICRH antenna IR view
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
12
Association Euratom-CEA
TORE SUPRA
Conclusions
In actively cooled device with CFC components, optimising current drive deposition
and producing broader q profile appears feasible using integrated control in stationary
scenario for. It looks also compatible with local heat flux control of PFCs for durations
exceeding ten resistive times.
In Tore Supra, plasma operation with PLOSS/SSEP approaching ITER values for long
duration (>60s) and high power demonstrate the importance of the heat flux analysis
and control for stationary or steady state scenario.
This work is pioneering the integration work that will be required on the operation of
ITER stationary and steady state scenarios when combining several types of
challenging plasma controls (global performance control, profile control, radiation
control and plasma instability control) and limit avoidance schemes.
22nd Fusion Energy Conference, Chengdu, China.
Emmanuel Joffrin 16-21 Oct. 2006
13