Abstract
An analysis of the cesium vapor arc discharge is presented. It is assumed that the discharge operates in the ball-of-fire mode, that cumulative ionization via the two resonance excited states is the predominant ionization mechanism, and that trapping in the plasma of the resonance radiation results in a long effective lifetime of the excited states. A volt-ampere characteristic is derived for the cesium arc and the results are applied to the thermionic energy converter. Good qualitative agreement is obtained between theory and experiment.