Coupled MEMS Nuclear Battery and FEEP Thruster System

Abstract

This paper describes research on combining a microelectromechanical system (MEMS) nuclear battery with a field‐emission electric propulsion (FEEP) thruster, thereby providing potentially attractive solutions to precise satellite stationkeeping and propulsion requirements. The MEMS nuclear battery, under development at the University of Wisconsin, consists of multiple layers of a radioisotope source alternating with pn junction semiconductor energy converters. Many radioisotopes were assessed for this purpose, typically with average beta‐particle energies of 50–250 eV, and the beta‐emitter Cs‐137 tentatively has been identified as most suitable. A slit‐style, cesium‐propellant FEEP thruster was chosen for the present study because it is a relatively mature technology. For use with a FEEP thruster, many modular MEMS nuclear batteries must be arrayed in series in order to achieve a sufficiently high voltage (∼10 kV). Critical issues include achieving an attractively high MEMS nuclear battery efficiency, maximizing the battery’s lifetime against radiation damage, producing the relatively high voltage (∼10 kV) required for a FEEP thruster, and providing an effective interface between the MEMS nuclear battery modules and the FEEP thruster.