MHD Hall current wave pattern generated by conducting obstacles in a flowing plasma

Abstract

Abstract The formation of standing MHD waves in a flowing plasma is a well understood and observed phenomena. However objects, such as asteroids and other small space bodies, may be small enough that the MHD approximation is not applicable. Inclusion of the Hall current effect is the most important modification in a cold plasma. Hall current effects included in an otherwise MHD formulation of the wave system generated by a point source current immersed in a warm compressible magnetoplasma couple the three MHD Alfven and magnetoacoustic modes in a dispersive as well as anisotropic system. In this paper we consider the associated system of stationary waves generated in a flowing plasma, such as would arise from the inductive interaction of between a conducting body and a magnetized plasma, as in the case of asteroid Gaspra or the Io-Jupiter system for example. In particular, in the special limit of a cold compressible flow we investigate the topology of the stationary wavecrest surfaces and the behaviour of the flow, magnetic and electric potential fields in the far field limit.