Exploring Alpha Particle Confinement and Aerogel Attenuation for Fission Fusion Fragment Rocket Applications

Advances in nuclear propulsion are being explored to revolutionize space travel, allowing for more efficient transportation beyond Earth's orbit. Our research focuses on developing new fission fragment rocket engines (FFRE) for deep space exploration, which offer significantly higher propellant efficiency than existing rocket technologies. The engine concept relies on embedding fissile fuel particles in ultra-low-density aerogel matrices to achieve high specific impulse and power density. A key aspect of the research involves determining whether such a fuel assembly can reach critical mass and allow the escape of fission fragments without significant attenuation. To study particle confinement, we utilized 3.19 µCi of Am-241 as a source of α-particles, which served as surrogates for fission fragments. The source was placed within a cylindrical vacuum chamber, which was further enclosed by 3 Tesla MRI superconducting magnets at the Texas Tech Neuroimaging Institute (TTNI). The experimental setup was optimized using COMSOL and MCNP simulations. Additionally, CR-39 detectors and aerogels of varying compositions and properties were employed to assess the aerogel’s attenuation of high-energy alpha particles. Initial results support the feasibility of the FFRE concept.