Levitation of charged macroparticles in the anode region of a glow discharge

Levitation of dust particles in the anode region of a de glow discharge was observed for the first time. A dust cloud of several tens of particles for med at a distance of several millimeters above the central part of the anod e. When the discharge parameters were varied, the shape of the cloud and it s position above the anode varied. An analysis of the experimental conditio ns revealed that these particles are positively charged in contrast to othe r experiments on the levitation of dust particles in a gas-discharge plasma . An estimate of the particle charge taking into account processes of elect ron emission from their surface is consistent with results of measurements of the electric field strength. (C) 2000 MAIK "Nauka/Interperiodica".