Finite- stabilization of flute-like microinstabilities

Abstract

The stability of a finite- beta plasma with density and temperature gradients located in a cylindrically symmetric azimuthal magnetic field is investigated using the Vlasov-Maxwell set of equations. The frequency is assumed to be low but finite gyroradius and wave-guiding centre resonance effects are retained. It is found that beta can both stabilize and destabilize the fast flute mode depending on the gradients, but has no effect on the temperature gradient mode. The interchange mode is essentially unaffected by beta . This latter result is in agreement with results from fluid models, as one might expect.