Saturation Current Densities at the Critical Point of a Spherical Probe in a Moving Collisional Plasma with Negative Ions or Dust Grains

Abstract

The problem is considered of the probe diagnostics of a moving, weakly ionized, collision-dominated plasma containing singly charged negative ions or dust grains (heavy multicharged ions). Based on an asymptotic analysis, expressions are obtained that describe the saturation current densities of the electrons and of the charged particles of other species at the point where the plasma flowing around a spherical probe in the laminar boundary layer regime stagnates.