Modeling of the effect of an axial magnetic field on the high-current vacuum arc

A 2D model of the high-current vacuum arc in an axial magnetic field (AMF) is proposed. It provides a novel condition for the two regimes of arc voltage vs. AMF, i.e., the falling voltage branch (low AMF) and rising voltage branch (high AMF). The transition between these regimes is complete when the individual cathode-spot plasma jets mix at a distance from the cathode equal to the interelectrode gap length. The model also predicts the observed smooth transition between the two branches. Calculated results are found to be in good agreement with experimental data