Wakes of plasma flowing around dust grains

Abstract

Summary form only given, as follows. The fundamental question important for the understanding of processes involving formation and evolution of various structures such as colloidal crystals and other self-organized formations like dust clouds, dust voids, etc in a complex plasma is the interaction of dust grains with themselves and the surrounding plasma. In a typical laboratory discharge, dust particles are negatively charged and usually levitate in the sheath or pre-sheath region under the balance of gravitational, electrostatic (due to the sheath electric field) and plasma (such as the ion drag) forces, these interactions involve collective processes associated with the flowing plasma. The characteristics of plasma particle kinetics in the presence of flowing ions around one and two stationary dust grains aligned in the direction of the flow as well as perpendicular to the direction of the flow are studied using analytical and a three-dimensional molecular dynamics simulation method. The dynamics of plasma electrons and ions as well as the charging process of the dust grain are simulated selfconsistently. The distributions of electron and ion number densities, and the electrostatic plasma potential are obtained for various distances, including those much less, of the order of, and more than the plasma electron Debye length.