Japanese Efforts on the Integrated Modeling - Part II : JAEA Contribution - T. Takizuka (JAEA) acknowledgments : T. Ozeki, N. Hayashi, N. Aiba, K. Shimizu, Y. Ishii, and members of analysis/theory groups in JAEA 10th Meeting of the ITPA Confinement Database & Modeling Topical Group, April 2006, Princeton

JAEA Ozeki Takizuka Hayashi Shimizu Aiba Hamamatsu Kawashima JAEA Kishimoto Azumi Idomura Ishii Kagei Matsumoto Miyato Tokuda Tuda JAEA

Strategy for Burning Plasma Research Burning Plasma Simulation Code Cluster Transport code TOPICS Heating and Current Drive Edge Pedestal Impurity Transport Divertor High Energy Particle MHD Validation of Modeling and Integration JT-60 Experiments and database - Heat and particle transport property - MHD phenomena and instability - Divertor property - High energy phenomena Simulation base on the first principle - Turbulence simulation - MHD simulation - Divertor simulation Fundamental Researches

Burning Plasma Simulation Code Cluster in JAEA Tokamak Preduction and Interpretation Code Time dependent/Steary state analyses 1D transport and 2D equilibrium Matrix Inversion Method for NeoClassical Trans. ECCD/ECH (Ray tracing, Relativistic F-P), NBCD (1 or 2D F-P) 1D transport for each impurities,Radiation: IMPACT Perp. and para. transport in SOL and Divertor, Neutral particles, Impurity transport on SOL/Div. : SOLDOR, NEUT2D, IMPMC Tearing/NTM, High-n ballooning, Low-n: ERATO-J, Low and Mid.-n MARG2D Transport by  -driven instability:OFMC Transport code TOPICS Heating & Current Drive Edge Pedestal Impurity Transport Divertor MHD High Energy Behaviour

First-Principle Simulation Code Cluster (NEXT project in JAEA) MHD Linear Stability MARG2D ERATO Ideal MHD3D toroidal AEOLUSResistive MHD3D toroidal Nonlinear simulation MHFVSPCompressible3D, 3D toroidal ALSTOR_NEOReduced set3D, 3D toroidal Core Transport Nonlinear turbulence simulation R5F GFS Landau fluid model 3D, 3D toroidal 3D local G3D, GT3D  i scale,  e scale Gyro kinetic model 3D, 3D toroidal DIVERTOR SOL-divertor simulation SONIC (SOLDOR + NEUT2D + IMPMC) Integrated divertor code 2D toroidal PARASOLParticle model2D (2D toroidal)

Transport Model for ITB Sharp reduction of anomalous transport in RS region (k ~ 0) can reproduce JT-60U experiment of strong RS current-hole plasmas Transport becomes neo-classical level in RS region, which results in the autonomous formation of ITB and strong RS through large bootstrap current. (N. Hayashi et al., Nucl. Fusion 45 (2005) 933)

radial poloidal J.Q. Li et al., Nucl. Fusion 45 (2005) 1293 ee First-principle simulation (GFS) of the ETG turbulence Control of fluctuation via magnetic shear

Simulation of ELM 2D Equilibrium data Linear stability of finite n modes (from low to high) by MARG2D 2D Newcomb equation is solved with parallel computer S.Tokuda, Phys. Plasmas 6 (8) D Transport code: TOPICS 1D transport equations : 1D current diffusion equation : 2D MHD equilibrium : Grad-Shafranov equation ELM model ： enhance the transport Eigenvalue and eigenfunction Impurity : C 6+, T imp =T i, assumed profile Z eff ρ = (Φ(ρ)/Φ(1)) 0.5

Diffusivities in the transport eqs. : Neoclassical transport : Diffusivity and bootstrap current : Matrix inversion method for Hirshman & Sigmar Formula ( M.Kikuchi, et al., Nucl. Fusion 30(1990)343. ) Neoclassical resistivity : Hirshman & Hawryluk model ( Nucl. Fusion 17(1977)611. ) Anomalous transport : Empirical transport model : constant (=0.18[m 2 /s]) :NBI power Density profile Model of transport: Neoclassical in peripheral region (   > 0.9) and anomalous in inside region (   < 0.9)  

ELM Model The stability is examined in each iteration step of TOPICS. –When the plasma is unstable, the thermal diffusivity increases according to the eigen-function. –When the mode becomes stable,  ELM =0. Eigen function of unstable mode of n=7  ii

Results: Simulation of ELM Parameters –R maj =3.4m, a=0.9m, Ip=1.5MA, Bt=3.5T,  ~1.5,  ~0.2 –Ti edge =300eV, ne edge =1x /m 3, Z eff = –  N ~ , P NB(perp) =8MW, –n=1-20 modes time(sec) Stored Energy(MJ)  i (  >0.9)reduced to N-C level (H-mode transition) n=7 mode unstable (ELM)  Pressure(N/m2) Safety factor t= Eigenfunction of n=7 unstable mode The edge pressure and the bootstrap current increase.

Collapse and Recovery of T i n=7 mode becomes unstable at 1.7. The other modes are stable (n=1-6, and 8-20). The heat conductivity increases according to the eigen function. The pedestal of the ion temperature is degraded. –The instability was checked when the shoulder of T i relaxed by 80%.  W/W ped ~ Stored Energy t(s)  t= t= T i (eV)  t= Collapse (3  s) Early phase of recovery (1ms) Recovery (30ms)

Repetition of collapse and recovery  t= = = t= = = After collapse Before collapse T i (eV) Destabilizations of the n=7 mode were repeated. The repetition time is ~47ms (39ms at the first period). The profiles of Ti before and after the collapses are very similar. Stored Energy (MJ) t(s)

Future work: Integrated model of Core-Pedestal-SOL/Divertor Dynamic 5-point SOL/Divertor model

Plasma 2D Fluid Code SOLDOR Neutral MC Code NEUT2D Impurity MC Code IMPMC Particle Simulation Code PARASOL SOL/Divertor Codes in JAEA Fundamental Physics Analysis / Prediction

SOLDOR/NEUT2D Simulation Simulation realizes X-point MARFE in JT-60U with high n e and low T e Pumping efficiency increases with small d gap and L s. Divertor control by pumping is possible. Divertor design for JT-60 modification SOLDOR/NEUT2D is now used for the ST divertor design by Kyushu university.

Collaboration (BPSI) among Universities, NIFS and JAEA Burning Plasma Simulation Code Cluster : TOPICS etc Validation of modeling with JT-60 experiments and first-principle simulations Transport Model for ITB ELM Simulation Integration of Core-Pedestal-SOL/Divertor Summary