Model of the explosive-emission center ignition on a cathode surface

The processes of origin of centers of explosive emission are considered at operation of a cathode spot of a vacuum arc. It was supposed, that the origin of centers is stipulated by absorption by a cathode surface of a variable electromagnetic field energy. It was supposed also, that such field takes place in a layer separating discharge plasma from the cathode. Some versions are considered, when the material of the cathode has no dispersion properties, can exhibit properties of a dispersion, and also case of absorption of electromagnetic waves by microparticles, flying from the cathode.