Barium Vapor Activation of Oxide Cathodes

Publisher Website
Google Scholar
Abstract
Experimental results are presented for (BaSr)O cathodes exposed to a heated barium‐covered surface. These results indicate that there is a maximum in the steady‐state level of pulsed thermionic emission as a function of increasing barium source temperatures, when the oxide is at a much higher temperature. Analysis of these results in terms of nonequilibrium thermodynamics leads to the development of a model for the barium activation of oxide cathodes. This model considers the chemical reaction rate of barium with the surface of the oxide in terms of the entropy transferred when a barium atom reacts with the oxide. This leads to a time‐dependent differential equation which is solved for steady‐state conditions, for some of the transient behavior obtained in this study, and for the complete time response of a few alloy‐based chemical reduction systems.

This publication has 9 references indexed in Scilit: