Theoretical Estimation of the Activity of the Medical Isotope Gallium-68 Produced by the Reaction 68Zn(p, n)68Ga

A theoretical evaluation of the activity of the medical radioisotope 68Ga produced by cyclotron irradiation of zinc targets via the 68Zn(p, n)68Ga reaction has been performed. Using SRIM/TRIM, proton energy losses in the target material and the dependence of proton energy on target depth (thickness) were determined. Effective cross–sections σ(E) for the 68Zn(p, n)68Ga reaction were obtained using the TALYS 1.9 code. It was established that the optimal proton energy range (12.5–4.6 MeV) provides a high theoretical product yield while minimizing side reactions. For irradiation of natural and enriched zinc targets, the calculated theoretical yields were 0.82 and 4.36 GBq/(μA h), respectively, which agree with literature data. The results obtained can be used to optimize the technical parameters for the production of 68Ga for medical applications.