Analysis of the dc and Pulsed Thermionic Emission from BaO

The effects of field penetration and donor mobility on the chemical potential of BaO have been computed by using a nondegenerate single donor level semiconductor model. Calculations which neglect the effects of surface states and porosity predict that the pulsed emission starts lower, but increases with field more rapidly than given by simple Schottky theory, actually being capable of exceeding the theoretical Schottky emission. The dc emission level is always lower than the pulsed emission, the difference being more pronounced at higher fields and for less active cathodes.