Distribution Functions of the Spot Diameter for Single- and Multi-Cathode Discharges in Vacuum

摘要

The relation between current density in cathode spot and surface conditions was investigated. The results show that the behavior of the discharge varies according to surface conditions. Making use of this effect the crater size of a metal vapor discharge was determined accurately. At a given current value there appeared to be a fairly large variation in diameter according to a distributa metal vapor discharge was determined accurately. At a given current value there appeared to be a fairly large variation in diameter according to a distribut9abs 9The peak value of these distributthe most probable value of the diameter) was a linear function of the current. Investigations of a multicathode discharge show the behavior of the partial discharges to be governed by the same laws. It is stated that the results may contribute to an explanation of the large variation in current density. Finally, a theoretical model based on Joule heating explains some of the phenomena observed. (Author)