Cross section measurements with enriched 50Ti targets for the production of the theranostic 47Sc and its contaminants 46Sc, 48Sc, and 48V.

Abstract

One of the goals of the REMIX (Research on Emerging Medical Radionuclides from the X-sections) project, an ancillary project of the LARAMED (LAboratory of RAdionuclides for MEDicine) program at INFN-LNL (National Institute of Nuclear Physics-Legnaro National Laboratories), is the investigation of excitation functions induced by protons to produce the theranostic radionuclide ⁴⁷Sc which has properties suitable for nuclear medicine applications. In this work, the cross sections for the ⁵⁰Ti(p,x)⁴⁶Sc, ⁴⁷Sc, ⁴⁸Sc, and ⁴⁸V nuclear reactions were measured in collaboration with both the GIP ARRONAX facility and the LHEP (Laboratory for High Energy Physics) of the University of Bern. The measurements covered the entire energy range between 10 and 70 MeV. Enriched ⁵⁰Ti targets, manufactured at INFN-LNL, were used, and the results were corrected for the contributions of the impurities of ⁴⁸Ti and ⁴⁹Ti present in the target material. In addition to ⁴⁷Sc, its radioactive contaminants were also considered since they can administer an additional undesired radiation dose to a patient or staff. Particular attention is given to the isotopic contaminants, since they cannot be separated by means of chemical methodologies. From our results, a promising energy interval for the ⁴⁷Sc production has been identified. However, a comprehensive study of the production yield and radionuclidic purity needs the investigation of the ^44mSc and ^44gSc co-production. This requires the correction of their cross sections for the contributions of the target material impurities ⁴⁶Ti and ⁴⁷Ti, for which experimental data are not currently available in literature. For this reason, further studies are ongoing.