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 (149)Tb by irradiation of (151)Eu with 70 MeV (3)He nuclei is proposed. For the first time, the cross sections for the formation of isotopes (149,150,151,152)Tb were measured experimentally using a stack foil technique in the (3)He particles energy range 70 → 12 MeV. The thick target yield of (149)Tb is 39 MBq/μAh, or 230 MBq/μA (149)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 (149)Tb can be produced in 8 hours irradiation, which is sufficient for therapeutic applications. The main impurities are (150)Tb (~100% in activity) and (151)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 (149)Tb from the bulk target material.