Cross section measurements of 151 Eu( 3 He,5n) reaction: new opportunities for medical alpha emitter 149 Tb production

Method for production of alpha emitter Tb by irradiation of Eu with 70 MeV He nuclei is proposed. For the first time, the cross sections for the formation of isotopes Tb were measured experimentally using a stack foil technique in the He particles energy range 70 → 12 MeV. The thick target yield of Tb is 39 MBq/μAh, or 230 MBq/μA Tb at saturation. The optimal energy range from the point of view of radioisotopic purity is 70 → 40 MeV. At these conditions about 150 MBq/μA Tb can be produced in 8 hours irradiation, which is sufficient for therapeutic applications. The main impurities are Tb (~100% in activity) and Tb (~30% in activity). The proposed method surpasses its counterparts by the high content of the target isotope in the natural mixture and the simplicity of the radiochemical separation of Tb from the bulk target material.