“Universal” Drift Instability in a Collisional Plasma

Abstract

The effect of electron‐ion collisions on the “universal” drift instability in an inhomogeneous plasma, using a Fokker‐Planck collision operator is considered and compared with the results obtained using the Bhatnagar, Gross, and Krook model. It is found that for small collision frequency, the BGK model gives a destabilizing effect while the Fokker‐Planck model indicates a stabilizing effect. For larger values of collision frequency, growth rates for collisional drift waves increase in both models but the growth rate obtained from the Fokker‐Planck model is not nearly as high as would be expected from the results derived from the Krook model calculations. For very large collision frequency, growth rates tend to vanish in both models.