Two-Dimensional Kinetic Model of a Short High-Current Vacuum Arc Discharge

A two-dimensional kinetic model of a short high-current vacuum arc discharge has been developed in which magnetized electrons move in the hydrodynamic regime and fast cathode ions move in the free-flight regime in a two-dimensional electric field. The model includes the distribution of ions over the emission angles at the cathode boundary of the plasma. A method has been proposed for calculating the distribution of the plasma density in the gap. The two-dimensional distributions of the plasma density, electric field, discharge current density, and trajectories of ions in an external longitudinal magnetic field have been calculated. It has been shown that ion trajectories intersect each other and some ion trajectories return to the cathode. The number of ion trajectories reaching the anode decreases with a decrease in the external magnetic field. The ion “starvation” effect appears near the anode and can lead to the violation of steady-state current transfer and to the formation of an anode spot. It has been found that the kinetic description of the motion of ions does not indicate the appearance of a shock wave.