Analysis Method for the Low-Order Resistive Interchange Instability in LHD with Stochastic Magnetic Field Line Structure

Abstract

In Large Helical Device experiments, independent low-order magnetic fluctuations due to the resistive interchange mode are commonly observed; investigating the characteristics of this instability is our ultimate goal. Two new methods for analyzing the single low-order instability in the stochastic region are developed. One method investigates it by constructing the initial single-mode perturbation. The other method investigates it by constructing a reference surface outside the last closed flux surface. The reference surface is necessary for constructing the coordinates that are used to extract the Fourier mode in the stochastic field line structure.

Plasma Physics Researches in Asia Pacific Region

“…For the KH mode the two-fluid contributions showed a stabilizing effect, while FLR terms were destabilizing. The resistive interchange instability [13] was studied in the presence of stochastic magnetic fields to understand experimental observations of the LHD edge plasma characteristics. An extended MHD simulation including anisotropy and a model Landau closure was used to study the problem of collisionless magnetic reconnection [14].…”

Introduction of the vector potential to a linear MHD simulation code based on a real coordinate system

“…In order to resolve this problem, a method for investigating the specified single-mode instability has been developed. 4 However, a large r Á B error is expected to yield instabilities with an undesirable mode and disturb the analysis of the specified single-mode instability.…”