Emission life and surface analysis of barium-impregnated thermionic cathodes

The use of cathode covered with greatly emissive Os layer aids in examining the emission life of thermionic cathodes impregnated with barium, and in studying their life pattern. These cathodes can be used in TV tubes, and it is revealed that the emission current reduces slowly and then drops suddenly. The reciprocal of the cathode temperature and the logarithm of the lifetime have a linear association.