Effects of Hall currents and magnetic resistivity on the Rayleigh-Taylor instability of a stratified two-component plasma of finite depth

Instability in a composite plasma has been studied, taking into account simultaneously the effects of Hall currents, magnetic resistivity and viscosity when a uniform magnetic field, normal or antiparallel to gravity, pervades the whole medium. From the linearized perturbation equations, a variational principle is obtained. Making use of it, the dispersion relations are derived for a semi-infinite plasma in which the density is stratified exponentially along the vertical. It is found that the growth rate increases with both Hall currents and magnetic resistivity, and decreases with viscosity and neutral gas friction. The influence of the Hall currents and the finite resistivity is, therefore, destabilizing while that of viscosity and neutral gas friction is stabilizing. (author)