Modeling And Simulation Of The Interaction Between High-Current Vacuum Arc And Anode Vapor

Vacuum arc widely appears in the ion source, coating, pulsed power and vacuum interrupter fields. When the arc current is very high, the heat flux density injected into anode will be larger and lead to the higher anode temperature. The strong anode evaporation drives the evaporated atoms from the anode surface to the arc column. Simultaneously, the anode evaporated atoms impact with the cathodic plasma, and then the micro processes as ionization and recombination between atoms and plasma will be happened. In this paper, the influence of the anode vapor and the micro processes on the arc column is obtained by solving the two fluid MHD equations, which controls anode neutral atoms and cathodic plasma respectively. The ionization of the neutral atoms and recombination of the ions are both considered in the simulation. Additionally, the momentum and energy exchange happened in the micro processes are also considered. In the simulation results, the ionization rate and recombination rate are both obtained. When the anode temperature is high enough, the anode neutral vapor will enter into arc column, and the strong ionization happened at the interface between anode vapor and cathodic plasma. The anode neutral vapor has the same temperature with anode surface, which is much lower than the temperature of arc column, so the anode neutral vapor has obviously cooling effect on the arc column. Whether the anode neutral vapor will enter into the arc column or not, is related to the balance between the anode neutral vapor and the cathodic plasma.