In the authors’ experimental conditions it was found that the first splitting at instantaneous current value of the cathode spot decreases with increased axial magnetic field and the qroup of cathode spots under the influence of axial magnetic field were nearly uniformly distributed in dynamic form within a definite area on the cathode surface. It was also shown that the cathode spot covered area reached a maximum value which however slightly lagged behind the peak arc current and the group of the cathode spots expanded and contracated at the speed of the so-called "bihump" characteristics

i.e.

the spots twice expandep at high speed before the maximum value of spot-covered area was reached. These experimental results are briefly discussed in this Paper.