The study of a heated cathode discharge in pure metal vapours

A new type of electrical discharges is reported: a discharge can be produced by heating the cathode in pure metal vapor without any gas impurities. One of the most interesting basic problems is the possible cathode activation due to the dynamical coverage with the anode material atoms, like in the case of S-shaped Langmuir curves for Cs-refractory metals. Some examples are presented with different anode materials. The trends of future research in this field are discussed. (D.Gy.)