Microwave Interaction with Bounded Gyroelectric Plasmas.

Abstract

In the following we investigate, theoretically, the interaction of microwaves with gyroelectric plasmas of finite extent, particularly those having cylindrical or spherical boundaries. Within the latter class of problems, only those involving the axially magnetized column with circular cross section are amenable to rigorous analysis. We find that one of the important effects of the anisotropy is to induce changes in the polarization of the scattered field resulting from interaction with an obliquely incident plane wave. As a means of solving problems which involve uniform but arbitrarily directed magnetization, we develop the perturbation theory of microwave interaction in which the static magnetic field is regarded as a small perturbation of the isotropic plasma. The field equations are derived for all orders but only those of first order, linear in the magnitude of the static magnetic field, are solved. This solution is carried out in general, the only restriction being that the fields for the isotropic problem are assumed to be known. The first order theory is then applied to cylindrical and spherical problems. When the approximate solution for the axially magnetized column is compared with the exact result, agreement is obtained provided that the static magnetic field is weak, as expected. Finally we consider the problem of a magnetic dipole radiating from within a weakly magnetized plasma sphere.