Two-Streaming Cyclotron Instability

Abstract

A new electrostatic instability of counterstreaming ions occurring at cyclotron frequency is exhibited and discussed. It is conjectured that this instability may provide the mechanism for the enhanced trapping of the injected ion beam in DCX-II. Stability criteria are developed and in the limit of high anisotropy of the ions and not-too-cold electrons, the criterion becomes approximately 12M ivs2<κTe/4 (unstable), where Mi is the ion mass, ±vs are the counterstreaming velocities, and Te is the electron temperature.