Excitation of Flute-Type Negative-Energy Ion-Cyclotron Waves due to Ion Gradient-B Drifts in High-β Mirror-Confined Plasmas

Abstract

An excitation of flute-type negative-energy ion-cyclotron waves by means of an ion gradient-β drift is analyzed on the basis of the linearized local dispersion relation. The excitation mechanism of these negative-energy waves is found to be a kind of an ion-cyclotron damping. This instability occurs even in axially homogeneous plasmas, and is still not stabilized even at a radial scale length large enough to stabilize the DCLC (drift-cyclotron loss-cone) instability. This instability is stabilized in the same way as the DCLC instability by an addition of a warm plasma.