Cross-field-current-driven electrostatic instabilities in plasmas with generalized distribution functions

Abstract

The generalized distribution function is used to investigate the effects of loss-cone and temperature anisotropy on the cross-field-current-driven electrostatic instabilities, i.e. the modified two-stream instability, the ion-acoustic instability and the electron cyclotron drift instability. These effects are important only when λ=k ² p² _e/2~1 (k is the wave number and ρ_e the electron gyroradius). It is seen that non-Maxwellian plasmas with distribution index J≥1, can sustain fast-growing waves even in the region of k-space which is stable for a Maxwellian plasma. Moreover, when λ ~ 1, the temperature anisotropy is found to have a destabilizing effect on.the modified-two-stream instability and on the ion acoustic instability.