This paper revisits and extends previous simulation studies of pressure-driven magnetohydrodynamic (MHD) stability in high-beta plasmas in the Large Helical Device (LHD). In the conventional MHD model, resistive ballooning modes become unstable at low magnetic Reynolds numbers, while ideal interchange modes become unstable at high magnetic Reynolds numbers. Although these instabilities are initially destabilized in the peripheral region, their nonlinear development causes their impact to extend into the core region, ultimately resulting in core collapse. In contrast, kinetic-MHD hybrid simulations that include kinetic thermal and energetic ions demonstrate that the instabilities remain confined to the peripheral region, allowing high-beta plasmas to be sustained in agreement with experimental observations. These findings highlight the critical role of kinetic ions in accurately modeling the stability and confinement of high-beta plasmas in three-dimensional magnetic configurations.
Sato et al. (Sat,) studied this question.