Simulation and experimental studies of anode activities in high-current vacuum arcs

The anode activities are critical for high-current vacuum arc characteristics, especially the interruption performance of vacuum interrupters. In order to understand the anode thermal process, a 2-D transient model was established. The simulation could provide temporal and spatial variation of anode temperature, the melting width and depth which have been validated by comparison with experiments. The basic features of anode erosion have been experimental investigated and the relation with the arc modes has been analyzed. A clockwise swirl flow of the liquid metal was found on anode surface under high current. Subsequent experiments indicated that the axial magnetic field (AMF) has great influence on the anode swirl flow. Both the theoretical analysis and experimental results shown that it is not the electromagnetic force but the interaction between ions from the inclined cathode plasma jets and the anode melting pool that leads to the observed swirl flow.