Concept Study of a Fission Fragment Propulsion System

Abstract Deep space exploration holds immense significance for the future of space exploration, and it requires propulsion systems with high specific impulse characteristics to accomplish long-duration space missions. The performance of prevalent nuclear thermal and nuclear electric propulsion systems is constrained by fuel element cladding temperatures and energy conversion systems efficiencies, precluding further enhancement of specific impulses. This paper focuses on a space nuclear propulsion system with a magnetic collimation structure based on the direct propulsion of fission fragments of Am-242m. The system employs eight control rods for reactive adjustments, the system’s critical and propulsion characteristics are analyzed by the combination of RMC and MATLAB. The calculation results demonstrate that the system exhibits superior comprehensive performance, with a specific impulse of approximately 4 × 104s while the keff of the system is optimized to reach about 1.06. The results also indicate that the system possesses excellent safety features and can play a crucial role in deep space exploration. The exploration of propulsion systems utilizing Pu-239 and U-235 as well as the investigation of enhancing the fission fragment escape rate and energy utilization rate will be continued in the future.