Transition from fishbone mode to $\beta$-induced Alfv\'en eigenmode on HL-2A tokamak
Abstract
In the presence of energetic particles (EPs) from auxiliary heating and burning plasmas, fishbone instability and Alfv\'en modes can be excited and their transition can take place in certain overlapping regimes. Using the hybrid kinetic-magnetohydrodynamic model in the NIMROD code, we have identified such a transition between the fishbone instability and the -induced Alfv\'en Eigenmode (BAE) for the NBI heated plasmas on HL-2A. When the safety factor at magnetic axis is well below one, typical kink-fishbone transition occurs as the EP fraction increases. When is raised to approaching one, the fishbone mode is replaced with BAE for sufficient amount of EPs. When is slightly above one, the toroidicity-induced Alfv\'en eigenmode (TAE) dominates at lower EP pressure, whereas BAE dominates at higher EP pressure.
Keywords
Cite
@article{arxiv.2103.10170,
title = {Transition from fishbone mode to $\beta$-induced Alfv\'en eigenmode on HL-2A tokamak},
author = {Zhihui Zou and Ping Zhu and Charlson C. Kim and Xianqu Wang and Yawei Hou},
journal= {arXiv preprint arXiv:2103.10170},
year = {2021}
}