Theoretical optimization and validation of Iodine-123 and Iodine-124 production via tellurium and antimony targets

Using various theoretical models within TALYS-2.0, we computed excitation functions, thick-target yields at EOB and 12-h post-EOB impurity analysis. Models were selected for each reaction route using statistical analysis to define practical energy windows that balance production yield and radionuclidic purity. For ¹²³I, Te(p,xn) dominates: ¹²³Te(p,n), ¹²⁴Te(p,2n), and ¹²⁵Te(p,3n) gave calculated yields of 162, 570, and 990 MBq/μA·h within the selected 13 → 10, 26 → 21, and 38 → 30 MeV windows, respectively. Among these routes, ¹²³Te(p,n) is favored when lower proton-energy operation and impurity control are prioritized, with ¹²⁴I limited to only 0.05% when enriched ¹²³Te is used. For ¹²⁴I, ¹²⁵Te(p,2n) gave the largest calculated yield, 43.5 MBq/μA·h within 19 → 16 MeV, whereas ¹²⁴Te(p,n) gave 21.3 MBq/μA·h within 12 → 8 MeV with better impurity control, showing limited ¹²⁵I and ¹²³I impurities of 0.03% and 0.81%, respectively. Deuteron- and alpha-induced routes were generally less favorable because of lower yields, larger impurity contributions, or more demanding irradiation conditions. The evaluation of model performance revealed that global nucleon level density and optical models (e.g., GSM, SHFB, BFM, G-OMP) reliably reproduced cross sections for proton-induced processes, attaining R² values exceeding 0.93. Local deuteron potentials (DP Han, DP Haixia) are essential for the accurate examination of specific deuteron reactions, while α-optical potentials (Avrigeanu, Demetriou, Nolte) are vital for reactions that involve multi-neutron emissions on Sb. Overall, enriched Te(p,xn) remains the preferred clinical route.