ON THE EMISSION MECHANISM OF BARIUM CONTAINING THERMIONIC CATHODES
关于钡系统热阴极的电子发射机理

Through the analysis and synthesis of data obtained from barium containing thermionic cathodes, especially those by modern surface analysis technique, we have come to a unified theory-the dynamical surface emission center model. Barium adsorbed on the surface of alkaline earth metal oxides in case of oxide cathode or of aluminate, tungstate etc. in case of dispenser cathode may form the emission center. Its size should be large enough to screen off the attractive field produced by the substrate, but small enough to facilitate the transport of electrons from the substrate to the emitting center. The compositions and the dynamical characters of the surface emission center are also discussed.