development of long duration plasma ......development of long duration plasma scenarios for west |...
TRANSCRIPT
DEVELOPMENT OF LONG DURATION PLASMA
SCENARIOS FOR WEST
| PAGE 1R. Dumont | 8th IAEA TM on Steady State
Operation of Magnetic Fusion Devices | May 26-29, 2015
R. Dumont, C. Bourdelle, J.-F. Artaud, L. Colas, L. Delpech, J. Decker,
A. Ekedahl, M. Goniche, W. Helou, J. Hillairet, G. Lombard, P. Mollard,
E. Nardon, Y. Peysson, E. Tsitrone and the Tore Supra / WEST TeamCEA, IRFM, F-13108 Saint-Paul-lez-Durance, France.
OUTLINE
• WEST in support of ITER
• Long-pulse plasma operation :from Tore Supra to WEST
• Preparing steady-state scenariosfor WEST
• Summary
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 2
WEST IN SUPPORT OF ITER : MAIN OBJECTIVES
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 3
• Pave the way towards the ITER actively cooled tungsten divertorprocurement and operation • Power handling capability / lifetime of
ITER tungsten divertor components in a tokamak environment(10 MW/m2 in steady-state)
WEST divertor
ITER divertor
[D. Van Houtte, Thursday, I-2]
• Master integrated plasma scenario over relevant plasma wall equilibrium time scale in a metallic environment
• Demonstration of integrated long pulse H mode scenario (optimization of RF heating, tungsten control and plasma density…)
• Investigation of advanced scenario regimes (fully non inductive H mode operation, highly radiating scenario, …)
| PAGE 4
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015
WEST IN SUPPORT OF ITER
LONG-PULSE PLASMA OPERATION : FROM TORE SUPRA TO WEST
PREPARING STEADY-STATE SCENARIOSFOR WEST
SUMMARY
WEST IS BUILT ON THE TORE SUPRA FOUNDATIONS
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 5
• Long pulse operation pioneered for more than 20 years (first plasma 1988)
• World record of injected/extracted energy in a tokamak (1GJ)
• Several generations of carbon PFCs designed, manufactured and operated
Tore Supra designed for long pulse operation• Superconducting toroidal coils
• Cryogenic plant
• Pressurized water loops
• 15 MW of RF power for H&CD
• Fuelling systems
• Diagnostics
GIGAJOULE PLASMA OPERATION AT INCREASING RF POWER IN TORE SUPRA
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 6
Years
• Various operational / physics issues addressed :IR monitoring of PFC, CFC limiter state of surface / conditioning, RF wave coupling
with simultaneous heating systems, MHD stability, non-linear oscillations…
[Van Houtte NF 2004, Ekedahl NF 2010, Goniche PoP 2014, Dumont PPCF 2014]
COMPLEMENTARY RF SYSTEMS KEY TOLONG-PULSE OPERATION IN TORE SUPRA
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 7
• Lower Hybrid Current Drive(LHCD)• 7MW / 1000s
• 2 launchers (FAM and PAM)
• Main current drive source to operate at Vloop ~ 0
• Ion Cyclotron Resonance Heating (ICRH)• 9MW / 30s, 3MW / 1000s
• 3 double-strap antennas
• Central plasma heating
• MHD stability (fast ion stabilization + changes of equilibrium)
[Dumont PPCF 2014]
TORE SUPRA WEST : NEW PLASMA CONFIGURATION & W ENVIRONMENT
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 8
• Full tungsten environment (bulk & coated) [D. Van Houtte, Thursday, I-2]
• Various system upgrades, e.g. cryoplant [V. Lamaison, Wednesday, P-2]
Limiter configuration Divertor configuration
WEST
Divertor coil
Divertor coil
Stabilizing plate
Stabilizing plate
• X-point cross section:• Insertion of two poloidal field coils inside the existing vacuum vessel• Minor radius reduced (a ~ 0.5m); Plasma volume reduced (15m3)• Large aspect ratio: A ~ 5 (R ~ 2.5m; a ~ 0.5m)
HEATING & CURRENT DRIVE IN WEST IS EXCLUSIVELY PROVIDED BY RF SYSTEM
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 9
• LHCD system (6-7MW / 1000s) : non-inductive operation• Adaptation to WEST : modification of FAM launcher toroidal curvature
• Challenges : RF power coupling, efficient current drive at high density
• ICRF system (9MW / 30s, 3MW / 1000s) : central plasma heating• Adaptation to WEST : Three new ELM-resilient antennas under
fabrication in collaboration with ASIPP [J. Hillairet, Friday, O-10]
• Challenges : RF power coupling, operation in W environment
Expected L to H power threshold: ~1.5-5 MW depending on plasma parameters
| PAGE 10
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015
WEST IN SUPPORT OF ITER
LONG-PULSE PLASMA OPERATION : FROM TORE SUPRA TO WEST
PREPARING STEADY-STATE SCENARIOSFOR WEST
SUMMARY
METIS SIMULATIONS OF WEST SCENARIOS
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 11
• Dynamic modelling using METIS code, 0D version of CRONOS [Artaud NF 2010]• Constraints on heat flux, maximum target temperature, H factor• Existing models for nsep, density peaking, W cooling rate, Wped…[Bourdelle NF 2015]• METIS simulations tuned and tested on JET-ILW and ASDEX Upgrade pulses
• Ongoing sensitivity studies, consistency checks against advanced modules
VARIETY OF EQUILIBRIUM / PROFILESWITH H=1 ARE CONSIDERED
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 12
Te (keV) ne (m-3) q
Scenario for METIS simulations (BT = 3.6T) High power Standard High fluenceIp (MA) 0.8 0.6 0.6ne (1019m-3) 8 7 6.7 fGW 64% 75% 72%Padd (MW) 15 12 10
ne,ped ~ 5×1019 m-3
ne,ped , Ttarget compatible with divertor and LHCD operation
[Bourdelle NF 2015]
FREQUENCY CHOICE FOR OPTIMAL H-MINORITYICRH SCENARIO
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 13
55.5MHz
RF power on H ions [kW/m3]
Optimizedfast ion confinement
54.0MHz
Maximum central heating, narrowest deposition
Two pre-set frequency bands at generator (55.5 ± 2MHz and 53.0 ± 2MHz)
EVE/AQL simulations: [Dumont NF 2013]
IMPACT OF ION / ELECTRON HEATING RATIO ON CORE W TRANSPORT STILL UNCLEAR
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 14
nH/ne=6%, PICRH = 6MW
Additional flexibility is desirable within D(H) heating scenario
• Higher ICRH power increases electron heating fraction
• Higher H-minority concentration favors ion heating
PICRH=6MW
nH/ne=6%
LHCD MODELLING FOR WEST DIFFERS FROM PAST TORE SUPRA RESULTS
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 15
Te (keV)
ne (m-3)
LUKE/C3PO simulations: [Decker PoP 2014]
• 6MW coupled by two launchers: FAM & PAM, n//0 = 2.0.
• Ray propagation limited by accessibility, then upshift due to X-point, large aspect ratio.
High power High fluence
THE TAIL LH MODEL PREDICTS CENTRAL LH POWER DAMPING WITH GOOD EFFICIENCY
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 16
• Tail LH model has successfully reproduced Tore
Supra and EAST discharges.
• 50% of LH power in main lobe to higher n//.[Decker PoP 2014, Peysson EPS 2015]
η = 1.23 1019 A/W/m2η = 1.46 1019 A/W/m2
• Central LH power damping; good CD efficiency
• Weak effect of radial transport (< 4m2/s).
High power High fluence
SEVERAL SCENARIOS COMPATIBLE WITH LONG PULSE OPERATION AT HIGH PEDESTAL DENSITY
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 17
Scenario (BT = 3.6T) METIS simulations, H98 = 1.0 High power Standard High fluence,
less LHCD
Ip (MA) 0.8 0.6 0.6ne (1019m-3) 8 7 6.7 fGW 64% 75% 72%LHCD (MW) 6 6 6.3ICRH (MW) 9 6 3Tped (keV) 0.6 0.4 0.3nped (1019m-3) 5.3 4.8 5.0Bootstrap fraction (%) 19 30 29LHCD fraction (%) 53 63 73LHCD eff. (1020A/W/m2) 0.14 0.11 0.12Loop voltage (mV) 78 23 6Pulse length (s): 14 Wb or ICRH generator limit 30s 60s 1000s
Long pulse operation achievable at ne,ped compatible with divertor operation
| PAGE 18
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015
WEST IN SUPPORT OF ITER
LONG-PULSE PLASMA OPERATION : FROM TORE SUPRA TO WEST
PREPARING STEADY-STATE SCENARIOSFOR WEST
SUMMARY
SUMMARY
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 19
• WEST aims at testing ITER PFC in steady-state conditions (10MW/m2)• Built on the Tore Supra experience
• Circular → X-point plasma cross section, H mode
• New set of PFC adapted to steady-state operation
• First assembly phase completed – First plasma : mid-2016
• Heating and current drive exclusively provided by RF systems• ICRF in D(H) scenario with frequency range suited for central/HFS
deposition, additional flexibility by varying nH/ne
• LHCD predicted to be central, with efficiency 0.10-0.15x1020A/W/m2
• Long-pulse scenarios being prepared with integrated modelling tools• High power (30s), standard (60s), high fluence (1000s)
• Sustainment of ELMy H-mode with 10-20MW/m2 achievable
• All collaborations welcome. Call for participation : 2nd semester 2015
DSMIRFMSCCP
Commissariat à l’énergie atomique et aux énergies alternativesCentre de Cadarache | 13108 Saint Paul Lez Durance CedexT. +33 (0)4 42 25 46 59 | F. +33 (0)4 42 25 64 21
Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 019
| PAGE 20
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015
WEST RF CAPABILITIES SHOULD BE SUFFICIENTTO ENSURE ACCESS TO H-MODE REGIMES
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 21
[Bourdelle NF 2015]
Some remaining uncertainty related to aspect ratio, magnetic ripple level
X-POINT HEIGHT FLEXIBILITY TO ENSUREOPERATION AT 10-20MW/M2
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 22
Accessible Ip and X–point height depend on regime of operation(CEDRES++ equilibria, Bt=3.7T)
[Bourdelle NF 2015]
FLEXIBLITY ON HEAT FLUX ON DIVERTOR TARGETSFROM X-POINT HEIGHT, ADDITIONAL POWER
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 23
[Bourdelle NF 2015]
PREDICTION OF TARGET TEMPERATURE VERSUS DENSITY AT SEPARATRIX
R. Dumont | 8th IAEA TM on Steady State Operation of Magnetic Fusion Devices | May 26-29, 2015 | PAGE 24
[Bourdelle NF 2015]