Electrostatics of Dusty Plasmas

Abstract

The physical properties of a plasma are greatly dependent on the state of the macroscopic particles it may contain, e.g. dust grains. Placed in the plasma environment, the grains are subject to collisions with electrons and ions, thus acquiring a nonzero electric charge. The charge may also result from other physical effects, such as photoelectron emission, secondary electron or field emission, etc. The resultant charge carried by a dust grain may vary both in magnitude and sign, depending on parameters of the ambient plasma and spectral density of the ultraviolet and other short wave radiation. Generally, the charge of an isolated grain and that of a grain in a dusty cloud should be different. Moreover, the electric potential of a grain may prove a multivalued function of the ambient plasma parameters, suggesting more than one stationary value of the potential under the same external conditions. Which of the potentials and hence charge values is actually realized depends on the particle and plasma prehistory.