Cross-Field Current-Driven Ion Acoustic Instability

The cross-field current-driven ion acoustic instability occurs when electrons and ions have a relative streaming velocity (along $x$) across a weak magnetic field. For certain ranges of conditions, the spatial growth rate is enhanced over the value with no field. Measurements of the growth rate in two different plasma configurations as a function of both field and frequency give results consistent with the linear dispersion relation for this instability.