Pulsed electric discharges in vacuum

The current status of research concerning high-speed processes on electrodes and in the gap during pulsed and static breakdown in vacuum, in the spark and arc stages of a discharge, is examined. The mechanism for the initiation and development of the discharge is discussed, and experimental results are presented concerning cathodic processes in the case of explosive electron emission. Particular consideration is given to: pulsed nanosecond breakdown of vacuum gaps; the plasma of a cathodic jet; spark current flow in vacuum; the formation of new emission centers on the cathode; nonstationary processes in the cathodic spot of a vacuum arc; and anodic phenomena caused by a high-power electron beam in the spark stage of the discharge.