Analysis of nonequilibrium plasmas in close-spaced thermionic converters

The effects of varying interelectrode spacings, current outputs, and cesium pressures on the spatial profiles of the electron temperature and density are determined for an ignited thermionic converter. A new method is introduced for the determination of the boundary conditions of the three transport equations which describe the electron and ion diffusion and the electron energy transport in the interelectrode plasma. Special emphasis is placed on the change of plasma properties as the interelectrode spacing varies from large values to very small values.