Development of global magnetohydrodynamic instabilities in Z-pinch plasmas in the presence of nonideal effects

Abstract

The development of global magnetohydrodynamic (MHD) instabilities in Z-pinch plasmas has been studied with a three-dimensional hybrid simulation model. Plasma equilibria without and with axial sheared flow, and with different values of the parameter εH, which appears as a coefficient before the Hall term in dimensionless nonideal MHD equations, have been considered. Increasing the parameter εH leads to larger simulation growth rates for both m=0 sausage and m=1 kink modes. The hybrid simulations do however show that axial sheared flow severely curtails the linear and nonlinear development of both sausage and kink instabilities. In these respects, the hybrid simulations are in qualitative agreement with linear Hall MHD results. Moreover, in the nonlinear stage, long wavelength modes dominate the excited wave spectrum when the parameter εH is small. For the larger value of the parameter εH, small-scale structures do however develop nonlinearly in the excited wave spectrum at late times.