The STAR-C nuclear power system with high-efficiency transparent thermionic converters

STAR-C is a nuclear space power concept for the power range of a few to 50 kWe per single unit for long duration applications. Here, an improvement to the STAR-C concept is described in which the 'conventional' thermionic converters are replaced by thermionic converters with 'transparent' collectors. The latter concept involves a collector consisting of a thin semitransparent surface layer of metal which absorbs little thermal radiation from the emitter. The reduction in radiative loss from the emitter increases conversion efficiency. Two variants of this concept are described: one in which the converters are located on the outside of the STAR-C core, and another in which the heat from the core is transported by heat pipes to the converters on the opposite side of the shield from the reactor.