Calculations of electrode erosion by vaporisation of the cathode spot

A closed system of equations was devised, enabling a model showing the behaviour of the cathode spot to be set up. The results obtained provide, for a given arc current I, the mean values of the following characteristic magnitudes: current total density, cathode spot area, density of the emitted current of electrons, electron fraction, electric field on surface temperature and erosion speed through vaporisation of the given material. The contacts along which the cathode spot moves were made of copper and silver. A comparison was made with results of other authors from a theoretical as well as experimental point of view.