Non-Ideal Effects on the Stability of a Cylindrical Current-Carrying Plasma

Abstract

The stability of a cylindrical plasma, limited by fixed boundaries and having a constant current distribution and constant density, is considered. For parallel wave numbers k _∥ ≃ 0, non-ideal effects are shown to play an important role. Solutions of the linearized equations including viscosity, thermal conductivity and resistivity are obtained. It is shown that viscosity is always stabilizing, as expected on physical grounds, but the range of unstable modes remains unchanged. Resistivity, on the other hand, reduces both the growth rates and the unstable domain of incompressible modes, provided that viscosity is not negligible. If it is, then resistivity plays an equivalent role to viscosity. When the pressure gradient attains a critical value, there exists a marginal mode with zero parallel wave number which characterizes the onset of large-scale steady convection in the plasma.