Collector Theory for Ions with Maxwellian and Drift Velocities

Abstract

For a gaseous discharge in which the ions have a drift velocity superimposed on a Maxwellian distribution, the Mott-Smith and Langmuir collector theory deals only with collectors having a high ratio of sheath to collector diameters. The present paper removes this restriction, but points out that except when there is negligible sheath distortion due to low drift velocity or to low collector potential the theory gives only approximate results. It is also shown that for ratios of drift to random current density as low as seven, the space potential is not indicated by a break on the semi-logarithmic plot of the collector characteristic.