Integrated Modeling for Burning Plasmas

1. Integrated Modeling for Burning Plasmas Introduction to the 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. Integrated Modeling for Burning Plasmas - Session topics - Review progress towards a comprehensive theory/model for burning plasmas in ITER/DEMO -including- • -particle distributions in velocity and space and -heating • Burning plasmas in optimized shear/hybrid scenarios, dynamic evolution and positional stability of ITBs, current profile alignment including bootstrap current evolution • Transient and bifurcative phenomena in burning plasmas (dynamics of L-H transitions and edge-core coupling, ITB formation and evolution, thermal stability in optimized shear/hybrid scenarios, including the approach to burning conditions with additional heating) • Impurity and helium ash accumulation (including impurity penetration through SOL, ETB and ITB) • More speculative issues, such as -channelling

3. 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

4. What do we mean by a comprehensive theory/model for burning plasmas in ITER/DEMO? 5D Gyrokinetics Code 1½D Whole Device Modeling Code 3D Extended MHD Code Transport Module Full Wave RF Code MHD Module … -particle Module 5D Gyrokinetics Code + Edge Module 3D Extended MHD Code RF Modules 3D Extended MHD Code Equilibrium Module + Full Wave RF Code

5. New initiatives now planned or underway • Japan: BPSI: ( TASK, TOPICS ) • EU: JET initiative (ASTRA, CRONOS, JETTO), Integrated Modeling Task Force • 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 • Extended MHD and energetic particle effects • Scrape-off-layer, ELMs, and pedestal • Whole Device Modeling Codes • Integrated Modeling: • Detailed TSC/TRANSP transport and H&CD modeling and comparison with existing experimental details Kessel • Integrated TSC/TRANSP used to predict rotation, q-control, TAE activity, transport levels, NI-NBI sensitivity to aiming angle, ash accumulation, sensitivity to pedestal temperature: postprocess TAE prediction, Turbulence modeling with GYRO Budny

6. 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. • 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 • Integrated Modeling: • MHD-based ELM model (MARG2D) coupled into TOPICs system Ozeki

7. 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 • 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 • Turbulence Simulations • Integrated Modeling: • Gyrokinetic Turbulence  MHD , Wave Heating, Plasma Edge Lee

8. 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, … • kinetic edge turbulence: PARASOL, … • collisional edge turbulence: BOUT, … • Many issues remain: • L-H transition and pedestal physics • nonlinear ELM crash, transport, and pedestal recovery • density limit • material erosion including redeposition and dust formation • impurity transport • Edge-Plasma Integrated Modeling • Integrated Modeling: • Compatibility between impurity injection for a high edge radiation fraction and core fusion physics (confinement and fusion power) Takenaga • Integration of core, edge, PSI codes: neutrals, atomic physics, wall interaction, turbulence, transport, drifts, neoclassical effects Coster • Static and dynamic (with ELMs) semi-emperical pedestal models coupled to core transport: DIII-D, JET, and simulations for burning plasmas Kritz

9. 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 • RF, NBI, -particle, and fueling Sources • Integrated Modeling: • ICRH wave field  distribution function , MHD Hellsten • Interaction of -particles with LH by coupling SPOT and DELPHINE in CRONOS framework Schneider • RF-particles ion distribution function Fisch

10. Schedule