Conceptual design of high power advanced low mass (HPALM) solar thermionic power system

The conceptual design of an innovative solar space power system based on thermionic conversion of heat to electricity is in progress. The system is particularly attractive for large power requirements (>20 kW). Solar energy is collected with an inflatable structure, which can be a parabolic reflector or a Fresnel lens or reflector. The solar flux is further concentrated with a secondary concentrator before entering the thermal receiver. The heat is converted to electricity directly by cylindrical inverted multicell (CIM) thermionic converters. Initial estimates of volume and mass yield a preliminary specific mass of /spl sim/80 W/kg and a preliminary specific stowed volume of /spl sim/40 kW/m/sup 3/.