Onset of Resistive Interchange Mode in the Large Helical Device

摘要

The relationship between magnetohydrodynamic (MHD) modes and the linear stability boundary has been investigated by controlling the pressure gradient in the Large Helical Device. Edge plasma pressure was varied by inserting a pump limiter into the plasma, and the onsets of MHD modes were determined. A quantitative comparison between mode onsets and a linear stability index of the resistive interchange mode was performed under the condition of a specific magnetic Reynolds number. The experimental results are consistent within a factor of 2 with a rough estimation of the stability boundary of a resistive low-n mode.