Micro-particles as electrostatic probes for plasma sheath diagnostics

Abstract

In basic plasma physics and plasma technology, micro-particles (dust grains) play an important role for the investigation and understanding of the behavior of different plasma species. It is well known that micrometer-sized particles can find an equilibrium position if all acting forces to the particles are balanced. This stable point is a few millimeters above the powered electrode in the plasma sheath. In our experimental set-up, we observed the position and the motion of microscopic test particles with a typical radius between 4.78 and 13.3 μm. In addition to the experiments, we also investigate the particle behavior by a numerical model. By comparison between the numerical model and the experimental observation, internal plasma parameters can be obtained. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.