Anisotropy of energetic particles and thermal transport on internal kink stability in HL-3

Abstract

The kinetic effects of Neutral Beam Injection (NBI) induced energetic particles (EPs) on the stability of internal kink mode are numerically investigated in the presence of anisotropic thermal transport for the new medium-sized tokamak HL-3, utilizing the MHD-kinetic hybrid code MARS-K (Liu Y Q et al. 2008 Phys. Plasmas 15 112503). It is found that after including realistic level of thermal transport, the kinetic effect of EPs on the mode stability is stabilizing in the co-NBI case while destabilizing in the counter-NBI case, in contrast to the similar stabilizing effect with both NBI cases at vanishing thermal transport. Detailed investigation reveals that this opposite effect with the two NBI cases is due to the different non-adiabatic transit resonance contributions of passing EPs in the presence of thermal transport. Anisotropic thermal transport can indirectly affect the non-adiabatic contribution of passing EPs by modifying the mode eigenvalue, which also contributes to the resonance condition between the mode and passing EPs. The non-perturbative approach adopted in the study also enables comparison of different modifications to the mode eigen-structure between the two NBI cases.