1. Overview of Magnetic Fusion Simulation in China J. Q. Dong Southwestern Institute of Physics China The Workshop on ITER Simulation May 15-19, 2006, Beijing, China

2. Outline 1, Introduction 2, Confinement 3, Stability 4, Divertor and Edge Physics 5, Wave Heating, Current Drive and Fuelling 6, Others 7, Summary

3. 1, Introduction A, Institutions and universities Southwestern Institute of Physics (SWIP), Chengdu Institute of Plasma Physics (IPP), Hefei University of Science and Technology of China (USTC), Hefei Tsinghua University (THU), Beijing Dalian University of Technology (DUT), Dalian Huazhong University of Science and Technology (HUST), Wuhan Institute of Physics (IP), Beijing PKU, ZJU, NKU & NHU

4. B, Devices HT-7 (IPP) SUNIST (THU) HL-2A (SWIP) EAST (IPP) J-TEXT (HUST)

5. HT-7

6. SUNIST device SUNIST SUNIST main parameters: major radiusR0.3m minor radiusa0.23m Aspect ratio A ~1.3 elongationκ~1.6 toroidal field （ R 0 ） B T 0.15T plasma currentI P 0.05MA central rod current of B T I ROD 0.225MA flux (double swing)ΔΦ0.06Vs

7. HL-2A R=1.65 m, a=40 cm, I p =350 kA, B t =2.5 T, t d =2s

8. EAST

9. J-TEXT From TEXT-upgrade, FRC, U-Texas R=1 m, a=26 cm, I p =300 kA, B t =2.5 T

10. C, Present Status of magnetic fusion simulation With a small scale, mainly at IPP and SWIP At a starting stage, 1) more universities are eager to participate 2) the big experiment program has to be supported by theory and simulation

11. 2, Confinement Works on MHD Equilibrium Theory of tokamak equilibria with central current density reversal (Wang, PRL, 2004) Analytic description of high poloidal beta equilibrium with a natural inboard poloidal field null (Shi, PoP, 2005) Tokamak MHD equilibria with toroidal flow or sustained by high fraction bootstrap current (Ren, PST, 2006 and Shi, CPL, 2003)

12. 2.1. MHD equilibrium (1) MHD equilibrium configurations of EAST were simulated with the EFIT code.

13. 10135020 重点基金结题 t=0 t=0.584 st=1.29 s t=1.99 s t=4.11 s

14. 2.1. MHD equilibrium (2) the HL-2A equilibrium configurations calculation with the SWEQU code

15. the HL-2A equilibrium configurations reconstruction with the EFIT code

16. 2.2. Micro-instabilities and turbulence (1) Electrostatic and electromagnetic micro- instabilities (ITG, ETG, TEM, AITG, SWITG, SWETG) are studied with fluid and kinetic theories Formation of large-scale structures in (ETG) turbulence: zonal flows or streamers, and the role of magnetic shear in the formation dynamics are numerically demonstrated.

17. 2.2. Micro-instability and turbulence (2) T e critical vs. T e /T i & R/L n

18. 2.2. Micro-instability and turbulence (3) JET experiment results

19. Micro-instability and turbulence (4) Formation of large-scale structures Streamer-like bump Zonal flow Zonal flow-like bump Streamers Modulation instability analysis show: Structure selection depends on spectral anisotropy of ETG fluctuations Magnetic shear governs spectral anisotropy of ETG; Structure selection of zonal flows or streamers Zonal flow dominatedHomogeneous ETG streamer dominated

20. 2.3. Predictive transport modeling (1) Reversed shear configuration formation on EAST

21. 2.3. Predictive transport modeling(2) Quasi-stationary RS operation establishment with current profile control on HL-2A Development of double transport barrier in shaped plasmas of HL-2A

22. Fig.1.1 Waveforms of the plasma current I p, loop voltage V p, the NBI power P NB, and the LH wave power P LH Fig.1.2 Magnetic geometry of the discharge

23. Fig.1.3 (a) The temporal evolution of LH wave driven current profile, and (b) q profiles at different times for the sustained RS discharge

24. The double transport barrier is indicated by two abrupt decreases of the ion heat diffusivity, of which the two minima are located near the shear reversal point,  min  0.55, and near the plasma edge,   0.95, respectively. The elevated heat diffusivity between the two minima separates the two barriers. Fig.2.3 Profiles of q and ion heat diffusivity,  i (at t=1.0s) for the elongated D-shape plasma.

25. 2.4. Analysis of plasma relaxed states for inductively driven tokamaks of arbitrary aspect ratio A variety of current profiles observed in tokamak experiments are reproduced theoretically form principle of minimum dissipation rate subject to helicity and energy balance. (Zhang) 2.5. New Coulomb logarithm and its effects New Coulomb logarithm and its effects on the Fokker-Plank equation, relaxation time and cross field transport (Li)

26. 3, Macro-instabilities 3.1. Vertical displacement instability analysis of EAST

27. 3.2. Resistive TM and flow layer formation ( ) Evolution of magnetic island width and amplitude of velocity shear

28. Contour of

29. Profiles of velocity shear Assuming we estimated This is comparable with the turbulence suppression shearing rate

30. 3.3. Fast particle MHD Destabilization of internal kink modes at high frequency by energetic circulating ions (Wang, PRL 2001) Sawtooth stabilization by barely trapped energetic electrons (Wang, PRL 2002) Fish bone instability driven by energetic electrons (Wang, Z.T., PST, 2005 )

31. 4, Divertor and Edge Physics EAST SOL/Divertor physics analysis ( Zhu ) HL-2A SOL/Divertor physics analysis ( Pan ) Atomic and molecular physics: The neutral transport modeling was performed for the HT-7 hydrogen removal experiment with DEGAS2 code.

32. 5, Heating, Current Drive and Fuelling 5.1. ECRH and LHCD, Fokker-Planck study of tokamak ECRH & LHCD were performed for the HL-2A tokamak discharges (Shi & Jiao) 5.2. Ion cyclotron resonance heating (ICRH) (Ding) 5.3. Synergetic simulation of LHW and IBW/ICRF (Ding) 5.4. Penetration and deposition of a supersonic molecular beam in the HL-1M tokamak: The supersonic molecular beam (SMB) ablation and penetration processes in HL-1M tokamak experiments were studied (Jiao, PPCF, 2003) 5.5. Neutral beam relaxation analysis

33. 6,Others Simulation of collisionless shock wave with ideal MHD equations (Yang)

34. 7, Summary 7.1. Code development and import 1) MHD equilibrium codes SWEQU & TOQ 2) MHD equilibrium reconstruction code EFIT 3) Gyro-fluid code for ETG turbulence studies in a slab 4) Linear PIC code TPIC for ETG & ITG in a torus 5) Integral eigenvalue code HD7 for ETG, TEM & ITG in a torus 6) Integral eigenvalue code HD7slab for ETG & ITG in high β plasmas of slab

35. 7) FOKKER-PLANK codes RFP & FPPCRAY with & without relativistic effects 8) Code LSC for LHCD 9) Resistive (viscosity) MHD code DMHD 10) Ideal MHD instability codes GATO & BALLO 11) Edge physics simulation code SOLPS (B2.5+ EIRENE) 12) Plasma surface interaction codes PSIC & DEGAS2 13) Transport code TRANSP 14) MHD shock wave simulation code

36. 7.2. Important topics not touched 1) Resistive wall mode (RWM) & edge localized mode (ELM) 2) Toroidicity induced Alfven eigen-mode (TAE) 3) Ideal and resistive ballooning mode; 4) Nonlinear wave-plasma interactions 5) Kinetic simulation of turbulence and transport 7.3. Fields have to be emphasized in the future 1)Integrated modeling of tokamak discharges 2)Simulation of nonlinear processes in tokamak plasmas

37. 7.4. Suggestions Enhancing the existing programs Establishing new institutes for fusion theory and simulation & encouraging participation of universities Establishing a national program Dividing efforts to two fields: advanced plasma physics (turbulence & transport, MHD, coherent structure formation, wave plasma interaction, energetic particle physics and edge physics …) and tokamak modeling (modules & integrated simulations for experiments: HL-2A, EAST and ITER)

38. Thank Professors S.Z. Zhu, G.Y. Yu and D. Li for providing materials!