Plasma voids (holes) in a dusty plasma

Abstract

A theory for plasma voids (large amplitude plasma holes) in a dusty plasma is presented. Specifically, it is proposed that the plasma voids are self-consistent solutions of Poisson's equation in which the electron density response is Boltzmannian and the ion density response is non-Maxwellian due to the ion trapping in large amplitude plasma potentials. Poisson's equation, with appropriate electron and ion number densities, is then reduced to an energy integral which provides criteria for the existence of the plasma voids. The latter are characterized as regions of significant ion and electron density depletions in association with negative plasma potentials. The voids shrink when the dust grains are added into the plasma, and they tend to disappear if the dust number density is sufficiently high.