Instability of obliquely propagating dust waves in a collisional highly magnetized plasma

Abstract.We investigate the instability of obliquely propagating dust waves in a collisional, magnetized plasma containing negatively charged dust grains. It is assumed that the magnetic field strength is such that the ions and electrons are magnetized, while the dust is unmagnetized. We consider both modified two-stream and dust-acoustic instabilities that are driven by an ion cross-field drift and that occur for waves propagating obliquely to the magnetic field. We use parameters that may be representative of possible laboratory experimental conditions to illustrate the growth rates. We also compare our results with prior theoretical studies of a Hall current instability of perpendicularly propagating electrostatic waves. It is found that these obliquely propagating wave instabilities may also be important for representative laboratory parameters when the cross-field drift speed is a significant fraction of the ion thermal speed.