Dissipative mode coupling in ion-cyclotron resonance minority heating

Publisher Website
Google Scholar
Abstract
Coupled wave equations and the corresponding wave-energy-flow conservation law describing the fast magnetosonic and ion-Bernstein waves are derived for minority heating in the ion-cyclotron range of frequencies. This fourth-order full-wave system is subsequently reduced in order through representation by means of two, completely decoupled, second-order systems. One is a second-order equation for the fast wave in which the Bernstein mode is treated as a driven response. The second is coupled-mode equations for amplitudes varying slowly under the influence of coupling, inhomogeneity, and dissipation. The coupled-mode equations are approximately solved for both high-field and low-field incidence to give the transmission and mode-conversion coefficients in closed form for arbitrary wavenumbers parallel to the magnetic field. Good agreement with fourth-order calculations is obtained.