Numerical simulation of CuCr vacuum arc considering stepwise ionization and radiation energy loss

The charge state distribution and energy radiation within the multi-species vacuum arc have always been a major research focus. In this paper, a magnetohydrodynamic method is employed to consider the comprehensive ionization–recombination processes of the plasma within the copper–chromium (CuCr) vacuum arc, including both direct and stepwise ionization. Radiation energy loss is also introduced to investigate the internal species distribution more accurately. Simulation results show that for the high-current subsonic vacuum arc, stepwise ionization is significantly stronger than direct ionization, resulting in the dominance of double-charged ions, and the introduction of the radiation model leads to a reduction in electron temperature. Conversely, for the low-current supersonic arc, the effect of stepwise ionization is practically negligible. As the current increases, the average charge state rises, and the ionization length of the high charge state ions shortens accordingly. Comparisons reveal that the simulation results are in good agreement with the experimental and theoretical analyses conducted by other researchers.