225-Ac and 223-Ra Production via 800 MeV Proton Irradiation of Natural   Thorium Target
  Cross sections for the formation of 225,227-Ac, 223,225-Ra, and 227-Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of 223,225-Ra, 227-Ac and 227-Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of 225-Ac and 223-Ra is a viable production method. 
J. W. Weidner, S. G. Mashnik, K. D. John, B. Ballard, E. R. Birnbaum,   L. J. Bitteker, A. Couture, M. E. Fassbender, G. S. ...
nucl-ex