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. 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 • Whole Device Modeling Codes

4. 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 behavior…full nonlinear integration with thermal particles not yet possible. • Disruption Modeling: Axisymmetric modeling in fairly good shape, 3D modeling just beginning • Extended MHD and energetic Particles

5. 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 • Turbulence Simulations

6. 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-EdgeCOCONUT:JETTO-SANCO-EDGE2D-NIMBUS, 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 • Edge-Plasma Integrated Modeling

7. 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, NBI, -particle, and fueling Sources • RF-particles ion distribution function Fisch