State of the theory of vacuum arcs

Abstract
A review of vacuum arc phenomena including the cathode and anode processes with cold and hot electrodes as well as the processes in the interelectrode plasma is presented. In the case of cold electrodes, the current continuity mechanism, the nature of mass loss, spot motion, plasma jet generation in the spots, and the cathode potential drop are reviewed. The explosive and gas-dynamical models of cathode spot operation are described. In the case of hot electrodes, the diffuse current continuity mechanism is analyzed and a model for electron-current fraction calculation in discharge with cathode-anomalous electron emission is proposed. The present state of electrical and plasma characteristics of high-current arcs in magnetic fields are discussed.