Accelerator production routes for therapeutic alpha emitters

Determine the optimal production route for Ac-225 and related $\alpha$ emitters by measuring excitation functions and co-produced impurities for proton spallation of thorium-232, photonuclear production from Ra-226, and deuteron or $\alpha$ routes, in the energy ranges used by available accelerators. Key figure of merit: yield per beam hour at required radionuclidic purity, in particular Ac-227 contamination. An answer is cross sections and yields fixing the preferred route.

Measured excitation functions and target tests reporting yield and impurity levels for each route.