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Title: Hybrid simulation of fishbone instabilities in the EAST tokamak

Hybrid simulations with the global kinetic-magnetohydrodynamic (MHD) code M3D-K have been carried out to investigate the linear stability and nonlinear dynamics of beam-driven fishbone in the experimental advanced superconducting tokamak (EAST) experiment. Linear simulations show that a low frequency fishbone instability is excited at experimental value of beam ion pressure. The mode is mainly driven by low energy beam ions via precessional resonance. Our results are consistent with the experimental measurement with respect to mode frequency and mode structure. When the beam ion pressure is increased to exceed a critical value, the low frequency mode transits to a beta-induced Alfven eigenmode (BAE) with much higher frequency. This BAE is driven by higher energy beam ions. Nonlinear simulations show that the frequency of the low frequency fishbone chirps up and down with corresponding hole-clump structures in phase space, consistent with the Berk-Breizman theory. In addition to the low frequency mode, the high frequency BAE is excited during the nonlinear evolution. Furthermore, for the transient case of beam pressure fraction where the low and high frequency modes are simultaneously excited in the linear phase, only one dominant mode appears in the nonlinear phase with frequency jumps up and down during nonlinear evolution.
 [1] ;  [2] ; ORCiD logo [3] ;  [1] ; ORCiD logo [1] ;  [1]
  1. Chinese Academy of Sciences (CAS), Hefei (China). Inst. of Plasma Physics
  2. Dalian Univ. of Technology (China). Key Lab. of Materials Modification by Laser, Ion and Electron Beams
  3. Zhejiang Univ., Hangzhou (China). Inst. for Fusion Theory and Simulation; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Publication Date:
Grant/Contract Number:
YZJJ201510; 11505022; 11605245; AC02-09CH11466
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 57; Journal Issue: 11; Journal ID: ISSN 0029-5515
IOP Science
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; fishbone instability; EAST; frequency chirping; hole-clump formation; wave-particle resonance; beam-driven instabilities; clump pair creation; internal kink mode; diii-d tokamak; plasma; ions; reconstruction
OSTI Identifier: