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Indexed by:期刊论文

Date of Publication:2016-11-01

Journal:PLASMA PHYSICS AND CONTROLLED FUSION

Included Journals:SCIE、EI、Scopus

Volume:58

Issue:11

ISSN No.:0741-3335

Key Words:magneto-hydrodynamic; ideal kink mode; negative triangularity; kinetic effect; resistive wall mode

Abstract:The effects of an ideal/resistive conducting wall, the drift kinetic resonances, as well as the toroidal plasma flow, on the stability of the ideal external kink mode are numerically investigated for a reactor-relevant tokamak plasma with strongly negative triangularity (NTR) shaping. Comparison is made for a similar plasma equilibrium, but with positive triangularity (PTR). It is found that the ideal wall stabilization is less efficient for the kink stabilization in the NTR plasma due to a less 'external' eigenmode structure compared to the PTR plasma. The associated plasma displacement in the NTR plasma does not 'balloon' near the outboard mid-plane, as is normally the case for the pressure-driven kink-ballooning instability in PTR plasmas, but being more pronounced near the X-points. The toroidal flow plays a similar role for the kink stability for both NTR and PTR plasmas. The drift kinetic damping is less efficient for the ideal external kink mode in the NTR plasma, despite a somewhat larger fraction of the particle trapping near the plasma edge compared to the PTR equilibrium. However, the drift kinetic damping of the resistive wall mode (RWM) in the NTR plasma is generally as efficient as that of the PTR plasma, although the RWM window, in terms of the normalized pressure, is narrower for the NTR plasma.