Excitation functions of (p,xn) reactions on highly enriched 122Te: Relevance to the production of 120gI

Excitation functions were measured by the stacked-foil technique for 122Te(p,xn)119,120m.g,121,122I reactions from their respective thresholds up to 45 MeV. Thin samples were prepared by electrolytic deposition of highly enriched 122Te (97.12%) on Ti-backing. All the data considered together depict a very systematic trend in the excitation functions of (p,xn) reactions on 122Te. Thick target yields of 119,120m.g,121,122I were calculated from the smooth curves drawn through the experimental data. For the production of the β+ emitting radioisotope 120gI (T1/2 = 1.35 h) the full energy range of 30 to 40 Mev can be utilized. Considering the cost of the target material, however, the energy range Ep = 37→32 MeV appears to be preferable. Over this energy range the thick target yield of 120gI amounts to 3.6 GBq (98 mCi)/μAh and the 120mI and 119I impurity levels to 25 and 6%, respectively.