Cathode-initiated vacuum breakdown in a pulse regime

Based on an analysis of the Joule heating of emitters by thermionic current, new methods and criteria are proposed for evaluating vacuum breakdown cathode-initiated in a pulse regime for an arbitrary cathode shape. The applicability of the proposed methods and validity of the new criteria are confirmed by the results of experiments using nanosecond pulses applied to coaxial copper electrodes with a gap width of d=0.2 mm and an area of S=2500 mm².