Actinium isotope cross sections for 226Ra(p,xn) reactions measured at low energies.

Cross sections for production of the medical isotope 225Ac by the 226Ra(p,2n) reaction have not previously been measured in fine steps over the relevant energy region, and no measurements are presently available in the literature for the actinium contaminant isotopes created by the adjacent 226Ra(p,n)226Ac and 226Ra(p,3n)224Ac reactions. We report thin-target cross-section measurements for production of 224Ac and 225Ac by protons of 15.1–16.8 MeV incident on radium. An upper limit for the 226Ac cross section is also reported. • Optimal cyclotron-based production of the medical isotope 225Ac requires knowledge of the 226Ra(p,xn) reactions. • We report thin-target cross-sections for production of 224Ac and 225Ac by protons of 15.1–16.8 MeV on radium. • An upper limit for the 226Ac cross section is also reported. • Production of 225Ac is observed to peak for a higher proton energy than predicted by commonly used simulation codes. [ABSTRACT FROM AUTHOR]