Influence of toroidal rotation on resistive tearing modes in tokamaks

Influence of toroidal equilibrium plasma rotation on m/n = 2/1 resistive tearing modes is studied numerically using a 3D toroidal MHD code (CLT). It is found that the toroidal rotation with or without shear can suppress the tearing instability and the Coriolis effect in the toroidal geometry plays a dominant role on the rotation induced stabilization. For a high viscosity plasma (tau(R)/tau(V) >> 1, where tau(R) and tau(V) represent resistive and viscous diffusion time, respectively), the effect of the rotation shear combined with the viscosity appears to be stabilizing. For a low viscosity plasmas (tau(R)/tau(V) << 1), the rotation shear shows a destabilizing effect when the rotation is large. (C) 2015 AIP Publishing LLC.