Wave Excitation in Compressible Plasma and Equivalence Relations

Abstract

A general, unified solution of the wave excitation due to electric-current sources, magnetic-current sources, fluid-flux sources, and mechanical-body sources in a compressible plasma which may be anisotropic and inhomogeneous is presented. The Maxwell—Euler equations are reformulated through linear operator and generalized transform techniques into an equivalent matrix integral equation. The dispersion relation can be obtained from the kernel of the integral equation. When the medium is homogeneous, this integral equation has an ideal kernel and the explicit solution can be easily obtained. Equivalence relations between different types of sources are obtained from the forcing function of the integral equation, which can be employed to express the field excited by one type of source in terms of the field excited by another type of source. Generalized telegraphist's equations are also derived in due course. Some dispersion curves, and asymptotic solutions for the radiation field from a point current source oriented in the direction of a constant magnetic field, are presented in graphical form. A proper ionospheric plasma is assumed for this calculation, which combines some of the results obtained for anisotropic cold-plasma problems on the one hand and some of the results obtained for isotropic warm-plasma problems on the other hand.