Influence of the collector emission properties on the efficiency of a thermionic energy converter in the arc regime

The effect of the emission properties of the collector surface (electronic work function and transmittance) on the potential jump near the collector in the arc operating regime of a thermionic converter is studied. Two models are examined: neglecting and taking into account the influence of cold emission electrons on the gradient of the electron temperature of the plasma near the collector. The proposed model, which takes account of the influence of cold emission electrons, with a decreasing electronic transmittance and the presence of emission from the collector results in the fact that the useful voltage also decreases substantially. This agrees with the experimental data for oxygen-containing converters with a high collector temperature. 4 figures, 5 references.[PUBLICATION ABSTRACT]