Radioisotope Thermoradiative Cell Power Generator

Abstract

The thermoradiative cell (TRC) is theoretically investigated, coupled with a radioisotope heat source, to provide primary power for a cubesat mission where photovoltaic power is impractical. Using a representative heat source, such as a single pellet of 238Pu from a General Purpose Heat Source (GPHS), provides 62.5 W of thermal energy. Using the 3K universe as a heat sink and a nominal power conversion efficiency of over 19%, a mass specific power of 30 W/kg is predicted. This represents a order-of-magnitude improvement over conventional radioisotope thermal generators. Realization of practical TRC devices by Metalorganic Vapor Phase Epitaxy (MOVPE), and development of identified low-bandgap materials such as InAs0.91Sb0.09 (0.28 eV) or InP0.63Sb0.37 (0.47 eV), is discussed.