Production possibility of [formula omitted] radioisotopes by alpha induced reactions on cobalt for PET studies

Abstract

Excitation functions were measured by the stacked-foil technique for 59 Co( α, n) 62 Cu , 59 Co( α,2 n) 61 Cu and 59 Co( α,3 n) 60 Cu nuclear reactions up to 60 MeV. The excitation functions were compared with the published data. The optimum energy range for the production of 61 Cu and 62 Cu was found to be 39 → 18 and 18.5 → 6 MeV, respectively. The calculated thick target yield of 61 Cu in this energy range was 21.0 mCi/ μA (supposing one half-life activation time); and 16.2 mCi/ μA (supposing three half-life activation time) for 62 Cu . The level of 60 Cu and 62 Cu impurities at 61 Cu production decreases to around 1% after a 1 h cooling time. The practical yield in this case is 17.2 mCi/ μA . For production of 62 Cu the contamination level of 61 Cu increases continuously after EOB, but remains below 1% if the cooling time is less than 0.5 h ( 1.9 mCi/ μA at 0.5 h after EOB). Unfortunately, in the case of 60 Cu production, the contamination level of 61 Cu and 62 Cu at EOB was found to be 18.4% and 47.9%, respectively, of the produced 60 Cu activity ( 6.4 mCi/ μA , after 60 min irradiation time, in the energy interval 60 → 44 MeV ).