Initial Stage of an Arc Discharge in Vacuum and Ectonic Model

Currents and voltages are measured in a short vacuum gap at the initial stage of an arc discharge initiated by an auxiliary spark discharge on the dielectric surface. It is found that a cloud of a rarefied plasma in the vacuum gap is formed due to ionization of the residual gas by electrons emitted from the auxiliary discharge. The passage of a cathode electron beam and an ion beam in the vacuum gap is registered. It is shown that electrons in the corpuscular flux directed from the cathode to the anode carry a charge that is an order of magnitude larger than that carried by ions. An acceleration mechanism in a cathode plasma associated with plasma polarization and the formation of explosive electron emission centers is experimentally identified.