Electrode erosion and gas evolution of vacuum arcs

The characteristics of the evolution of gas from metals in vacuum arcs are presented. New materials have been developed having ungettered gaseous impurity concentrations of the order of 1 part in 109. Loss of vacuum in a vacuum switch by desorption and by diffusion of helium and other gases is negligible when good techniques are employed. Data are presented for electrode erosion for gas-free metals in the vacuum arc.