Electron-magnetohydrodynamic description of a steady-state current flow in a plasma with a three-dimensional localized density perturbation

Abstract

The problem of a steady-state current flow through a localized density perturbation is analyzed in the framework of electron magnetohydrodynamics. It is examined how the degree of localization of such a flow depends on the plasma magnetization parameter and the geometric characteristics of the density perturbation. Corrections to the unperturbed current field are found by the iteration method. It is shown that the first-order correction to the current can be determined for an arbitrary perturbation. In the case of perfectly conducting plasma, the second-order correction can be found only for dipole perturbations, for which the integral change in the density is zero. In this case, the first-order correction to the current is localized, which makes possible the existence of the second-order correction. The finite plasma conductivity also assists current localization; therefore, for sufficiently small values of the plasma magnetization parameter, both first- and second-order steady-state corrections to the current can be obtained for any moderate plasma density perturbation.