Pulsed Surface Tracking in Air and Various Gases

Abstract

This short study of surface tracking was partly a return to some simple experiments performed several years ago and partly in the hope of providing a zero work function surface covering a large area. The potential application for this is in molecular gas lasers, where a uniform background of electrons is required before a large amplitude multiplying voltage pulse is applied. Such a background of electrons can be provided by u. v. pre-ionisation, but an alternative approach is to drift the electrons from an array of hopefully zero work function surface sparks through the gauze cathode of the laser discharge cell and across this. It is this objective (yet to be tested) which provided the necessary impetus to investigate surface tracking and the characteristics of the subsequently produced surface arcs. As these investigations were rather developmental in nature, the accuracy of the measurements is not very high and also, as usual, the range of parameters studied rather limited. However, even with the above limitations, the data obtained in three weeks or so may be worth recording.

J.C. Martin SSWA/JCM/745/735 May 1974