Measurements on Particle Fluxes from dc Vacuum Arcs Subjected to Artificial Current Zeroes

Abstract

A mass and energy analyzer capable of time‐resolved analysis of the separate constituents of the flux from vacuum arcs near and through current zero has been constructed. The following results are obtained in looking at the radial flux from 50‐ and 100‐A copper arcs subjected to rapidly forced current zeros: (i) A burst of low‐energy ions is produced at the time of arc extinction (within the resolving power of the apparatus, <5 μsec), this burst being attributed to the collapse of a potential hump near the cathode. (ii) The presence of copper ions depresses the level of background gas signal, especially for hydrogen.