Resonance Surfaces in the Ion Cyclotron Frequency Range in Toroidal Systems

Abstract

Resonance surfaces are investigated in a toroidal geometry for waves in the ion cyclotron frequency regime. In this geometry stationary waves are described by partial differential equations. Three kinds of resonances appear in this regime of a multicomponent plasma, the fundamental ion cyclotron resonance, the perpendicular ion cyclotron resonance, and Buchsbaum's ion-ion hybrid resonance. In a two-dimensional axially symmetric plasma the last two resonances can be obtained by solving ordinary differential equations. The perpendicular ion cyclotron resonance coincides with a magnetic surface, while the ion-ion hybrid resonance in general makes a small angle of the order of meB/miBP with the magnetic surfaces, except close to the fundamental cyclotron resonances, where the angle becomes large.