General Dispersion Relation for Surface Waves on a Plasma?Vacuum Interface: Application to Magnetised Plasmas

Abstract

The general dispersion relation for electromagnetic surface waves on a plasma-vacuum interface, recently derived by Rowe (1991), is applied to the case of a cold magnetised plasma bounded by a vacuum. It is illustrated how the dispersion relation and the surface wave fields may be determined in practice, and some general results are given. It is remarked that a plasma of this type satisfies the consistency conditions which were derived for the general theory by Rowe. These general results are then used to reproduce the dispersion relation of Cramer and Donnelly (1983) for low frequency surface waves in an electron-ion plasma. This example illustrates the general principles of the theory. A major difference between the derivation in their paper and the calculation of this paper is that in the former the plasma was assumed to be infinitely conducting whereas here the plasma is strictly assumed to have finite conductivity.The transition to infinite conductivity, which involves a slight extension of the general theory to include surface currents, is thus also discussed.