Acoustic modes in a collisional dusty plasma

Abstract

The acoustic modes in a collisional dusty plasma are studied, taking into account the influence of ion-neutral collisions, ion drag, and neutral friction. It is assumed that the frequency of ion-neutral collisions is greater than the frequency of ion-dust collisions. Two limiting cases of short-wavelength and long-wavelength modes are considered separately, depending on the ratio of the dust-ion acoustic frequency to the frequency of ion-neutral collisions. It is shown that for the long wavelengths coupling between the modes becomes strong, causing the appearance ol the hybrid long-wavelength mode. It is also found that in the long-wavelength case there are two types of instability caused by ionization. The theoretical results are compared with the data obtained in experiments with growing particles. © 1999 American Institute of Physics.