On the formation of non-radioactive copper during the production of 64Cu via proton and deuteron-induced nuclear reactions on enriched 64Ni targets

Abstract

Routine production of 64Cu commonly exploits the 64Ni(p,n) or 64Ni(d,2n) reactions. Above specific threshold energies, however, non-radioactive 63Cu and/or 65Cu are also co-produced. The non-radioactive (cold) Cu can significantly decrease the specific activity (SA) of 64Cu-labelled radiopharmaceuticals. Based on nuclear model calculations for the formation of non-radioactive Cu isotopes, theoretical specific activities (TSA) for 64Cu were estimated. Reported current production methods, however, often yield SA values that are lower than the corresponding TSA predictions by more than an order of magnitude. Most of the non-radioactive Cu causing this has been found to originate from sources other than co-production, indicating that there is still significant potential for method improvement.