Ordinary-mode electromagnetic instabifity for counter-streaming ions with anisotropic temperatures

Abstract

The instability of the ordinary electromagnetic mode propagating perpendicular to an external magnetic field is investigated for two ion beams with anisotropic temperatures, counter-streaming along the magnetic field. A necessary and sufficient condition for instability is derived. The growth rate is calculated, and found to be typically several times the ion cyclotron frequency Ωi, although in extreme cases γmax may be as large as (Mi/me)½Ωi.