Alpha-particle induced reactions on natsb and 121sb with particular reference to the production of the medically interesting radionuclide 124i

Excitation functions of the reactions natSb(α,xn)123,124,125,126I and 121Sb(α,xn)123,124I were measured from their respective thresholds up to 26 MeV, with particular emphasis on data for the production of the medically important radionuclide 124I. The conventional stacked-foil technique was used, and the samples for irradiation were prepared by a sedimentation process. The measured excitation curves were compared with the data available in the literature. From the experimental data the theoretical yields of the investigated radionuclides were calculated as a function of the α-particle energy. The calculated yield of 124I from the natSb(α,xn)124I process over the energy range Eα=22→13MeV amounts to 1.02 MBq/μA· h and from the 121Sb(α,n)124I reaction over the same energy range to 2.11 MBq/μA·h. The radionuclidic impurity levels are discussed. Use of natSb as target material would not lead to high-purity 124I. Using highly enriched 121Sb as target, production of 124I of high radionuclidic purity is possible; the batch yield, however, is low.