EXCITATION-FUNCTIONS OF (P,XN) REACTIONS ON HIGHLY ENRICHED TE-122 - RELEVANCE TO THE PRODUCTION OF I-120G

Excitation functions were measured by the stacked-foil technique for T e-122(p,xn)I-119,I-120m.g.121,I-122 reactions from their respective th resholds up to 45 MeV. Thin samples were prepared by electrolytic depo sition of highly enriched Te-122 (97.12%) on Ti-backing. All the data considered together depict a very systematic trend in the excitation f unctions of (p,xn) reactions on Te-122. Thick target yields of I-119,I -120m.g.121,I-122 were calculated from the smooth curves drawn through the experimental data. For the production of the beta(+) emitting rad ioisotope I-120g (T-1/2 = 1.35 h) the full energy range of 30 to 40 Me V can be utilized. Considering the cost of the target material, howeve r, the energy range E-p = 37 --> 32 MeV appears to be preferable. Over this energy range the thick target yield of I-120g amounts to 3.6 GBq (98 mCi)/mu Ah and the I-120m and I-119 impurity levels to 25 and 6%, respectively. (C) 1997 Elsevier Science Ltd. All rights reserved.