Integrated Modeling for Burning Plasmas

1
Integrated Modeling for Burning Plasmas
Discussion Session S. C. Jardin Princeton Plasma
Physics Laboratory

• Workshop (W60) on Burning Plasma Physics and
  Simulation
• 4-5 July 2005, University Campus, Tarragona,
  Spain
• Under the Auspices of the IEA Large Tokamak
  Implementing Agreement

2
Progress towards a comprehensive theory/model for
burning plasmas in ITER/DEMO

• Whole Device Modeling Codes
• Extended MHD and Energetic Particles
• Turbulence Simulations
• Edge-Plasma Integrated Modeling
• RF, NBI, ?-particle, Impurities, and Fueling
  Sources

3

• Whole Device Modeling Codes

• New initiatives now planned or underway
• Japan BPSI ( TASK, TOPICS )
• EU JET initiative (ASTRA, CRONOS, JETTO),
  Integrated Modeling Task Force DINA/CRONOS
  coupling
• US NTCC (modules library), PTRANSP (TSC/TRANSP
  ), FSP (not yet begun) (also BALDUR, ONETWO,
  CORSICA)
• Need for more sophisticated modules in most
  areas
• Turbulent Transport models need to be improved/
  quantified
• Extended MHD and energetic particle effects
• Scrape-off-layer, ELMs, and pedestal
• Need better particle/impurity transport models
• General need for better benchmarking. Submit
  ITER plasmas to ITPA Profile Database

4

• Extended MHD and energetic Particles

• Need to further develop 3D Nonlinear Extended MHD
  codes and validate on existing experiments.
• Sawtooth Full 3D nonlinear sawtooth simulation
  now possible for small tokamaks, not yet for
  ITER. Good semi-analytical models available
  (Porcelli model)
• ELMs Some progress (BOUT-Snyder,
  JOREK-Huysmans, NIMROD-Brennan, M3D-Strauss) Not
  yet a full 3D ELM simulation for even small
  tokamaks. Good semi-analytical models being
  developed. (including ideal-MHD/Enhanced
  transport model with MARG2D in TOPICS)
• NTMs Not yet a full 3D NTM simulation.
  Modified Rutherford equation (semi-analytical)
  models widely used.
• Resistive Wall Modes Not yet a full 3D
  nonlinear model.
• Locked Mode Threshold Not yet a fundamental
  model
• TAE 3D Hybrid particle/fluid simulation model
  possible for short times and weakly nonlinear
  behaviorfull nonlinear integration with thermal
  particles not yet possible.
• Disruption Modeling Axisymmetric modeling in
  fairly good shape, 3D modeling just beginning

5

• Turbulence Simulations

• Focus is presently on core turbulence ITG,
  ETG, ITG/ETG coupling, finite beta effects,
  transition from Bohm to gyro-Bohm, turbulence
  spreading
• need to develop long-time (transport timescale)
  predictive simulation capability
• Calculation of particle diffusivities from
  transport simulations
• turbulence and neoclassical simulation
  integration
• mechanisms for transport barrier formation
• pedestal region and core-edge simulation
  integration
• how to couple with whole-device-modeling codes
• impurities and helium ash transport
• may be possible to extend Gyrokinetics codes to
  include MHD, Wave Heating, and Plasma Edge

6

• Edge-Plasma Integrated Modeling

• Full 3D predictive edge model is lacking
• Numerous edge codes exist to provide qualitative
  understanding and quantitative results for
  specific phenomena
• edge transport CSD, SONIC, UEDGE, SOLPS
  (B2-Eirene),EDGE2D-NIMBUS
• kinetic edge turbulence PARASOL, DALF
• collisional edge turbulence BOUT,
• local codes erosion/depositon ERO,
• Coupled Core-Edge COCONUTJETTO-SANCO-EDGE2D-NIM
  BUS, SOLPS beginning (disruptions, ELMs)
• semi-analytical/emperical NTCC PEDESTAL module
• increasing evidence that ELMs are triggered by
  current-driven MHD modes
• MARG2D ELM model incorporated into TOPICS
• Fusion Simulation Projects proposed to study
  integrated edge-plasma
• Many issues remain
• L-H transition and pedestal physics
• nonlinear ELM crash, transport, and pedestal
  recovery
• density limit and impurity transport
• material erosion including redeposition and dust
  formation- work in progress to integrate plasma
  and plate (SOLPS5-B2)need to characterize mixed
  materials
• Move physics from edge transport codes into edge
  turbulence codes
• Need to include drifts into edge transport
  codes, and to move to 1D neoclassical

7

• RF, NBI, ?-particle, and fueling Sources

• Comprehensive suites of RF and neutral beam
  codes exist
• Integrated computations between full-wave ICRF
  and FP solvers are underway, but not yet in
  routine use
• Integrated modeling that combines advanced ICRF
  antenna modules with full-wave solvers are
  underway
• RF and NB source modules have been combined with
  WDM codes, but generally not the most advanced RF
  packages.
• RF/FP Codes need to be coupled to MHD codes in
  order to simulate instability control
• Modeling of Mode Conversion physics in ITER
  scale plasma not yet possible
• Need to incorporate all RF and NB systems
  together with FP for ions and electrons
  self-consistently, and with energetic particle
  MHD
• Coupling of SPOT(?-particles) and DELPHINE(LH
  wave propag. and absorp., el. Distrib. Func.) in
  CRONOS framework

• RF? ?-particles ?ion distribution function
  Fisch