Toroidal modeling of 3D perturbations generated by current filaments in scrape-off layer in tokamak with biased divertor targets

Nuclear Fushion

article

G.Z. Hao¹  G.Q. Dong¹  B.T. Cui²  Y.Q. Liu³  Y.H. Xu⁴  T.F. Sun¹  X.Q. Ji¹  S. Wang¹  Y.F. Zhao⁵  J.Q. Xu¹  X. Bai¹  N. Zhang¹  C.Y. Li¹  L. Wang¹  H.D. He¹  J.M. Gao¹  Yi Liu¹  W.L. Zhong¹  M. Xu¹  X.R. Duan¹ 

[1] Southwestern Institute of Physics;Department of Engineering Physics, Tsinghua University;General Atomics;Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University;Dalian University of Technology

关键词: divertor biasing current;    plasma response;    resonant magnetic perturbation;    magnetic footprint;   

DOI  :  10.1088/1741-4326/aca169

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

The divertor biasing technique offers a promising alternative to control the edge localized mode (ELM) as well as the divertor heat load in tokamaks, as compared to the resonant magnetic perturbation (RMP) generated by magnetic coils. The linear resistive MHD code MARS-F (Liuet al2000Phys. Plasmas73681) is employed to study the plasma response to then= 2 ( nis the toroidal mode number) field perturbation in HL-2A, produced by the divertor biasing current filaments flowing in the scrape-off layer region. The response field due to biasing currents is compared with the RMP field utilized for ELM control in HL-2A. The strength of the radial resonant field perturbation, produced by the biasing currents of 100 A level, is found to be comparable with RMP generated by several kA of ELM control coil currents for the reference plasma. The plasma normal displacement near the X-point and the associated neoclassical toroidal viscosity torque are also computed to be similar between these two techniques. The modeling results thus strongly suggest that the biasing technique can be applied to control ELMs. Moreover, the biasing currents produce field perturbations, including the plasma response, that are localized more near the plasma edge (compared to the RMP counterpart), thus reducing the chance of mode locking associated with core perturbations. Particle orbit tracing also reveals that the biasing current produced magnetic perturbation tends to widen the heat deposition region and induce the strike point splitting of the ion saturation flow on the outer divertor surface, consistent with experimental observations in HL-2A. These toroidal modeling results confirm the possibility of ELM control and plasma exhaust solution by the divertor biasing technique.

【 授权许可】

Unknown