Wave Coupling Across a Shock Wave in a Fully Ionized Gas

Abstract

This paper presents a theory of the coupling between electron-acoustic, ion-acoustic, and electromagnetic plane waves at an idealized shock front in a two-fluid, fully ionized, inviscid plasma. The equations of hydrodynamics and Maxwell's equations are used to derive the dispersion equation relating the frequency and propagation constant of possible modes of propagation in a plasma. Boundary conditions which must hold at the shock front in the presence of an incoming perturbation are then derived, and the amplitudes of predicted wave modes generated at the boundary are calculated. A generalized Poynting vector is used to calculate energy coupling ratios for the waves. In agreement with previous work on sound-shock wave interaction in neutral gases, we find enhanced ion-acoustic transmission in the present work. In addition, we also find enhanced propagation in the electron-acoustic coupled mode.