Nature of the Mesyats effect-pulsed superheating of microscopic spikes on a cathode

A study is made of an effect observed experimentally by Mesyats which involves, prior to the electrical explosion, as such, the accumulation of an energy on the order of a few times the sublimation energy by a microscopic cathode spike during explosive emission from a cathode in a vacuum or gaseous discharge. The same effect is observed during electrical explosion of a wire. Simple estimates by various authors imply that the temperature of the wire should rise to 10⁵ K. In reality, when energy is applied very rapidly the wire cannot expand and it is superheated into a metastable state (essentially to the crystal-liquid spinodal). When the temperature rises above 10⁴ K, the specific heat of the metal increases as electronic degrees of freedom are unfrozen. Thus, the temperature attained prior to an electrical explosion does not exceed 17000 K. Zh. éksp. Teor. Fiz. 116, 2176–2181 (December 1999)