NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON D C
The potential performance of thermionic diodes converting reactor heat to electricity for propulsion of space vehicles is explored in a parametric study. Electron heating, thermal radiation, joulean heating, and heat conduction losses are included losses in the plasma are not. The diode system is compared with the Rankine cycle system using radiator area per unit of output power as the criterion. The diode system can surpass the turbogenerator if the diodes can be incorporated into the reactor fuel elements, electrodes with optimum work functions can be developed, and the anodes can be cooled by conduction without electrical short circuiting.