Improved Modeling of Fast Neutron-Induced Reactions on Chlorine and Beyond

Neutron-induced reactions on Cl-35 have recently been measured and analyzed in a Hauser-Feshbach framework at Los Alamos National Laboratory. Particular focus has been applied to the "fast" energy range above 100 keV, where these reactions become important for applications like detector characterization (CLYC) and advanced molten chloride fast reactors (MCFRs). However, challenges in modeling the key reaction channels in this mass range persist as cross section fluctuations and deviations due to low-mass structure near the N=Z=20 shell closure. In this presentation these challenges and their current solutions will be highlighted for the isotopes Cl-35, Cl-37, and K-39, representing improved agreement with available data over the current databases. Ongoing efforts at LANL to extend the measurements down to thermal neutron energies will also be discussed, filling in remaining gaps important for stellar nucleosynthesis and criticality safety.