A heat-driven monochromatic light source

The efficiency with which heat may be converted into resonance radiation in a cesium thermionic diode is investigated theoretically. An analytical model of a thermionic converter is used which combines the coupled effects of line radiation transport, excited-state kinetics, and plasma diffusion. Operating regimes are established for various degrees of optical density in the plasma. The results indicate that monochromatic radiation can be produced with efficiencies on the order of 30% provided there is an adequate voltage drop across the plasma. A drop of one volt was used since it can be maintained without any electrical power input to the device. It is found that high efficiencies are due to the higher interelectrode distances which the solutions will accommodate, and that radiation can be generated efficiently, even with optically dense gases