Particle flows in a dc discharge in laboratory and microgravity conditions

摘要

We describe a series of experiments on dust particles’ flows in a positive column of a horizontal dc dischargenoperating in laboratory and microgravity conditions. The main observation is that the particle flow velocitiesnin laboratory experiments are systematically higher than in microgravity experiments for otherwise identicalndischarge conditions. The paper provides an explanation for this interesting and unexpected observation. Thenexplanation is based on a physical model, which properly takes into account main plasma-particle interactionnmechanisms relevant to the described experimental study. A comparison of experimentally measured particlenvelocities and those calculated using the proposed model demonstrates reasonable agreement, both in laboratorynand microgravity conditions, in the entire range of discharge parameters investigated.