The effect of axial magnetic filed on the process of anode spot formation in a vacuum-arc discharge with $\text{CuCr}50$ electrodes

An experimental study is made of the effect of an external axial magnetic field on the process of anode spot formation in a pulsed vacuum-arc discharge in the range of currents from $5$ to $12$ kA in a discharge gap with $\text{CuCr}50$ electrodes. The times and currents, at which an anode spot is formed, are determined for each amplitude value of current depending on the magnitude of magnetic field. The minimal value of magnetic field preventing the anode spot formation is determined for each current. The measured values of diameters of the current channel are used to calculate the anode temperature. It is demonstrated that, under experimental conditions, the heating of anode is insufficient for marked evaporation, and the anode spot formation is associated with the critical flow of fast cathode ions.