Processes involved in vacuum arc triggering by E/spl times/B discharge

A vacuum arc triggering system based on the formation of cathode spots in E/spl times/B discharge plasmas have been used in the Mevva-V and Titan-2 ion sources. When a strong magnetic field is employed, significant improvements in triggering lifetime together with a decrease in the required background gas pressure can be obtained. The authors describe here the results of some further investigations of the triggering discharge and main vacuum arc plasma in a strong magnetic field and outline some of the physical processes responsible for the cathode spot ignition in this kind of configuration.