EXCITATION-FUNCTIONS OF TE-124(P,XN)I-124,I-123 REACTIONS FROM 6MEV TO 31MEV WITH SPECIAL REFERENCE TO THE PRODUCTION OF I-124 AT A SMALL CYCLOTRON

Excitation functions were measured by the stacked-foil technique for (p, xn) reactions on highly enriched Te-124 in the proton energy range of 6-31 MeV. Thin uniform films of Te-124 on Ti-backing were prepared by an electrodeposition method. Above 17 MeV our data agree within experimental errors with the literature values, thus validating the I-123-yields and I-124-impurity levels associated with the Te-124(p, 2n)I-123 production process. Detailed measurements near the threshold of the Te-124(p, n)I-124 reaction, on the other hand, show that, contrary to the general assumption, the thick target yield of I-124 is fairly high, amounting to 20 MBq (0.54 mCi)/mu Ah over the optimum energy range E(p) = 13 --> 9 MeV. A comparison of the three suggested routes for the production of I-124, viz. Te-124(d, 2n)-, Te-126(p, 3n)-, and Te-124(p, n)-processes, is given. The yield and impurity-level data suggest that the Te-124(p, n)I-124 reaction has a great potential for production at a small cyclotron.