Cross-sections of the reaction 232Th(p,3n)230Pa for production of 230U for targeted alpha therapy

230U/226Th is a promising novel alpha-emitter system for application in targeted alpha therapy of cancer. The therapeutic nuclides can be produced by proton irradiation of natural 232Th according to the reaction 232Th(p,3n)230Pa, followed by subsequent beta decay of 230Pa to 230U. In this study, the experimental excitation function for the 232Th(p,3n)230Pa reaction up to 34 MeV proton energy has been measured using the stacked-foil technique. The proton energies in the various foils were calculated with the SRIM 2003 code and gamma-ray spectrometry was used to measure the activities of the various radioisotopes produced. The measured cross-sections are in good agreement with selected literature values and with model calculations using the EMPIRE II code. The reaction 232Th(p,3n)230Pa allows the production of carrier-free 230U in clinically relevant levels.