Shielding and charging of dust particles in the plasma sheath.

Abstract

General physical features of the ion particle distribution function in the plasma sheath derived theoretically and observed experimentally are used for describing the dust shielding and charging in the sheath. It is shown that the shielding and charging of dust depend strongly on the degree of anisotropy of the ion distribution function and on the difference in the ion temperatures parallel and antiparallel with respect to the ion flow. Regions of "antishielding" appear both along the ion flow and perpendicular to it. The potential wells can be responsible for the attraction of other dust particles and for the creation of dust aggregates. This effect is related to the change of the sign of the dielectric function in the range of wave vectors corresponding to the strong Landau damping.