Vacuum arc explosive cells

Summary form only given. The vacuum discharge implies a formation of plasma from the electrode material for a large current transfer. It consists of three stages - vacuum breakdown, vacuum spark, and vacuum arc ^1-3. The basic feature of all these stages is the formation of the explosive electron emission (EEE) pulses - ectons that arise from microscopic Explosive Centers at the cathode and are responsible for an electron emission current of a large density and large magnitude. One can propose that the EEE being similar to the boiling, whereas the electron emission on a common type being similar to the slow evaporation. As the intensity of bubbles formation at boiling depends on how low is the particle number (the pressure) above the surface, similarly the intensity of EEE pulses - ectons formation being larger the larger the electrical current is desirable to be transferred. Ignition of the EEE pulses, their decay, and the consequent self-sustaining is of strong interest. A two-step model of initiation of the explosive pulse under the external action has been proposed that implies (i) the dense primary erosion plasma production and (ii) the intense electron emission buildup that results in the electrical explosion 4. It has been found that the threshold energy flux to the surface, being of about 100 MW/cm2 for a `clean´ surface, reduces substantially for the surface covered by `easily eroding layers´, such as nanowires and metal films 5-7. The model of the initiation and decay of the EEE pulses has been improved with taking into account the external action, the micro-relief formation, and the magnetic field application.