Numerical simulation of CuCr alloys vacuum arc under conditions of arc contraction, deflection, and anode vapor

In practical arc ignition processes of high-current vacuum arcs, despite the calibration effect of the axial magnetic field, the strong magnetic constriction force still causes the arc to contract. Additionally, during the actual electrode opening process, due to the random nature of the arcing position, the center of the arc column is often not located at the center of the electrode. At this point, the behavior of the vacuum arc can be understood as an asymmetric three-dimensional (3D) process under the influence of the spatial magnetic field, affecting the generation of anode vapor and the characteristics of arc species. Therefore, it is useful to conduct simulation studies on multi-species vacuum arc behavior considering arc contraction and arc deflection. In this paper, the spatial magnetic field distribution under different electrode effective areas and different arc center deflection distances have been simulated, and the influence of actual magnetic field-induced by arc contraction and deflection on 3D spatial distribution characteristics of arc plasma has been studied based on a 3D multi-species (CuCr alloys) vacuum arc model with anode vapor. The simulation results show that with the contraction of the arc column, the area occupied by neutral atomic vapor decreases correspondingly, but the ionization and recombination process between the arc column regions becomes more intense. The axial current density and electron temperature distribution around the neutral atomic vapor area become more non-uniform. When the arc column deviates from electrode center, the neutral atomic vapor area shows an asymmetrical distribution on both sides of the arc column center axis, and the axial current density and electron temperature gather and enhance in the opposite direction of the arc deflection, thereby significantly affecting the distribution of arc species.