Duration of Anode-Spot Mode Type 2 and Plume Mode in High-current Vacuum Arc

Abstract

A high-current vacuum arc generated between long-gap CuCr electrodes often transits from an anode-spot mode type 2 to a plume mode. In this study, we show that there is a positive correlation between the duration time of these two modes and that there is a threshold duration time for a vacuum arc in type 2 mode to transit to the plume mode. These results suggest that the transition to the plume mode and its duration time depend on the amount of neutral vapor injected into the gap during the type 2 mode.