Activation of natural Hf and Ta in relation to the production of 177Lu

The isotope 177Lu is used in nuclear medicine and biology for in vivo applications as a radioactive label of various targeting agents. To extend the availability of no-carrier added 177Lu, we investigated the feasibility of its production in a proton accelerator. Tantalum and Hf targets were irradiated and chemically processed to determine the radioisotope yield and cross-sections. The largest cross-sections (∼20 mb) were found for the Hf target at 195 MeV; however, the presence of co-produced Lu isotopes may limit the product applications. The results are in good agreement with theoretical data calculated using computer codes MCNPX and ORIGEN2S. Production of relevant medical isotopes such as 167Tm and 169Yb from the above targets is discussed as well.