Three-Dimensional Numerical Analysis of Ion Diamagnetic Effects on Interchange Mode in Heliotron Plasmas

The influence of the ion diamagnetic flow on the resistive interchange mode including dissipation in the Large Helical Device (LHD) plasmas is investigated with three-dimensional (3D) magnetohydrodynamic (MHD) codes. The contribution on the interchange mode stability depends on the difference between the ideal growth rate γI and the single fluid growth rate including resistivity and dissipation γD. When γD is close to γI, the ion diamagnetic effects are stabilizing. In this case the stabilization can be approximated by an analytic formula by analogy with the case without dissipation. When γD is far from γI the ion diamagnetic effects are destabilizing.