Fundamental properties of the vacuum switch

The main results of a study of the various phenomena which take place during the interruption of currents in high vacuum are given. The experimental results obtained lead to a theory of the basic mechanism affecting switching in high vacuum. With a proper design of the switch, a constant working pressure can be obtained which represents an equilibrium between gases and vapors evolving from the electrodes and a pumping action based on the sputtering of cathode material. A detailed study is made of the factors determining the loss of electrode material because of switching. The most essential design features of a vacuum switch are discussed briefly.