Low-pressure arc discharge motion between concentric cylindrical electrodes in a transverse magnetic field.

Abstract

A theoretical and experimental investigation of the Lorentz, stationary, and retrograde modes of motion of a low-pressure arc discharge is presented. It was found that an increase in the applied magnetic field strength will cause either an increase or a decrease in the arc's rotational speed, depending on the pressure. Experimental information obtained by highspeed photography reveals the nature of the low-pressure arc kinematics for the aforementioned three modes of motion. The films show the cyclic structure by which these modes progress under the action of an applied transverse magnetic field. The effects of temperature nonequiiibrium on the electrical conduction current density in the arc discharge are discussed. It is shown that in arc regions of high nonequiiibrium with large spatial gradients in the electron temperature, electrical currents can occur in a direction opposite to that produced by the electromagnetic field alone. The various characteristics of the arc discharge are discussed as the results of temperature nonequiiibrium.