Theoretical modeling of 65Zn production via charged particle reactions on 66Zn

Abstract

This study presents a comprehensive theoretical investigation into the production of the medically and industrially relevant radionuclide 65Zn via the 66Zn (p, pn)65Zn, 66Zn (d, t)65Zn and 66Zn (alpha, alpha n)65Zn reactions. A combination of Monte Carlo transport simulations (Geant4 toolkit and SRIM module) and nuclear reaction modeling (TALYS-2.0) was employed to evaluate the reaction mechanisms, excitation functions, and production yields. Stopping powers and penetration ranges of incident projectiles (proton, deuteron, alpha particle) in 66Zn were calculated using Geant4 and SRIM, showing strong mutual agreement. Excitation functions were simulated using both Geant4's hadronic physics models and TALYS-2.0, incorporating various optical model potentials and nuclear level density (NLD) formulations. Theoretical yields of 65Zn were determined for each reaction pathway, highlighting a marked improvement in production efficiency with increasing 66Zn isotopic enrichment. Geant4 was also utilized to assess the impact of target thickness on cross-section behavior, while final activation values and end-of-bombardment (EOB) activities were estimated for each reaction under standardized irradiation conditions. Among the investigated channels, the 66Zn (p, pn)65Zn reaction demonstrated the highest production yield and activity, confirming it as the most effective route for 65Zn generation within the examined energy range.