Model of a vacuum arc spot on a mercury cathode

A model is proposed for a vacuum arc discharge. In this model a layer of space charge is formed in the plasma at some distance from the cathode, similarly to the formation of double layers in the case of a high-voltage discharge. This approach, in contrast to the traditional model of a surface layer, made it possible to understand the mechanism of electron emission in the cathode region and to explain the nature of two experimentally observed forms of an arc discharge on mercury.