Isotope Production in Muon-Catalyzed-Fusion Systems

Abstract

Producing valuable isotopes with high-flux high-energy neutrons generated by muon-catalyzed fusion ($\mu$CF) reactions could substantially improve the economic prospects for muon-catalyzed fusion. Because no external heating is required for $\mu$CF, heat flux constraints are significantly relaxed compared with fusion systems requiring external heating. This could allow $\mu$CF to attain much higher neutron flux without breaching material heat flux limits. If muon production rates can be increased, $\mu$CF systems employing transmutation could be viable well before energy breakeven is possible. For $\mu$CF systems transmuting valuable isotopes, the required number of catalyzed fusion events per muon and muon energy generation cost can be relaxed by several orders of magnitude relative to electricity-generating systems, making $\mu$CF an attractive high-flux neutron source. We show an example $\mu$CF system with a 10 gram ${}^{226}\mathrm{Ra}$ feedstock and a steady-state muon rate of $10^{12}$ muons / second - roughly half a kilowatt of fusion power - could produce 20 mg of ${}^{225}\mathrm{Ac}$ per year - comparable to 400 times global supply in 2024. As higher muon rate sources become available, many other radioisotope transmutation pathways become viable. These findings motivate the accelerated development of $\mu$CF systems for neutron-driven isotope production far before net energy generation is possible.