No abstract

In this study, the physical structure for the propagation of whistler waves in ducts of nonuniform cold plasma density is investigated by means of electrodynamics theory. Expressions for the solution of the field equations are determined analytically using perturbation technique, and power transmitted by modes is evaluated in terms of a parabolic model for the plasma density distribution. The set of eigenmodes and their spatial structure are analyzed and the dependencies of the eigenmode propagation properties on the duct characteristics are studied.

No abstract

No abstract

Most of the mode conversion theories considered so far assume only a plane-layered medium, i.e. a medium where the parameters depend on one spatial coordinate. We generalize the mode-conversion method of Cairns and Lashmore-Davies to plasmas with two-dimensional inhomogeneities. In the method presented here, the frequencies ω 1 and ω 2 of the uncoupled modes belonging to two different dispersion equations are considered as functions of the space variable r and the wave vector k and are coupled together via a small quantity η. We calculate the energy transmission and conversion coefficients analytically by solving two coupled wave amplitude equations in the electron cyclotron range of frequencies. The results are applicable to electron Bernstein wave heating of plasmas with two-dimensional inhomogeneity, e.g. spherical tokamaks.