Waves and instabilities in collisional dusty plasmas

Abstract

Summary form only given. Dusty plasmas (plasmas containing charged dust grains of micron to sub-micron size) occur in a wide variety of space and laboratory environments. The presence of dust, with a much smaller charge-to-mass ratio than the ions, can both modify the properties of standard ion waves and instabilities and give rise to new low frequency dust waves and instabilities. Dusty plasmas in the laboratory may exhibit strong coupling (i.e., the electrostatic interaction energy between neighboring grains exceeds their kinetic energy) which also affects wave properties. Here, recent theoretical work on several instabilities in collisional dusty plasmas is summarized, with applications to dusty plasmas in the Earth's lower ionosphere and in laboratory experiments where neutral densities are relatively high. Instabilities driven by electron cross-field drifts are considered with application to dusty plasmas in the upper mesosphere or low E-region (e.g., dusty meteor trails or polar mesosphere summer echo regions). This includes studies of the effects of charged dust on electrojet instabilities and conditions for exciting low frequency dust acoustic instabilities, along with implications for radar scattering. Dust wave instabilities driven by ion drifts are discussed with application to various laboratory dusty plasma wave experiments. This includes studies of a very low frequency resistive instability, and the effects of strong coupling on ion-dust streaming instabilities. Aspects of the interaction of electromagnetic waves with strongly coupled dusty plasmas are also considered.