Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV

Cross sections for 223,225Ra, 225Ac and 227Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for 223,225Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of 225Ac and 223Ra below 200 MeV is a viable production method.

► Natural thorium targets were irradiated with protons up to a nominal 200 MeV. ► 225Ac, 223,225Ra, and 227Th production cross sections were measured. ► Multi-curie quantities of 225Ac and 223Ra can likely be produced at Los Alamos and Brookhaven. ► Accelerator-based production of 225Ac and 223Ra is a viable production method