Studies on the breakdown and sustainment of hollow cathode discharges

Abstract

Summary form only given. The buildup of a thin (about 1 mm diameter) plasma column on the axis of a hollow cathode leads to a distortion of the electric field distribution in such a way that there is a substantial increase in the radial component of the electric field at the orifice. For sufficiently high fields in this region, a second breakdown can be expected from the walls of the cathode to the center of the axial plasma column. This will rapidly lead to the establishment of a high current hollow cathode discharge. The mechanism of this initially radial discharge is assumed to be determined by pendel electrons. These are electrons which are excited from the walls of the cylindrical cathode, are accelerated in the radial electric field, traverse the negative glow region on the axis, and are reflected back from the cathode fall in front of the opposite cathode surface. In order to study the effect of these pendel electrons on the sustainment of a hollow cathode discharge, one-dimensional steady-state Monte Carlo calculations, in a hollow linear cathode region have performed