Magnetic field effect on the pulsed breakdown strength of vacuum gaps

The paper studies the effect of magnetic field on the pulsed (100 ns, 200 kV) breakdown strength of vacuum gaps. It is found that the breakdown strength E
_br
with no magnetic field is 1.5 ± 0.2 MV/cm and decreases to 0.7 ± 0.2 MV/cm as a magnetic field of about fractions of Tesla is applied. In the latter case, breakdowns are initiated at those sites of the cathode surface at which the normal component of the magnetic field is maximal. The research results raise new questions on the processes responsible for the initiation of a vacuum breakdown.