124,125Te(p,xn)123,124I ve 123,124Te(d,xn)123,124I İçin Reaksiyon Tesir Kesitleri

Abstract

The iodine isotopes of 123I and 124I with half lives of 13.2 hours and of 4.2 days respectively are commonly used in nuclear medicine and are becoming more widespread recently. The isotope of 123I is ideal for a gamma camera with the energy of 159 keV to the patient with a much less radiation dose whereas the radionuclide 124I is a positron emitter and is useful in some positron emission tomography (PET) for radiopharmaceuticals. The gamma ray will penetrate tissue very effectively without an excessive radiation dose. Iodine-123 decays by electron capture emitting gamma rays at 0.028 and 0.160 MeV that has high penetration power to tissue but no excessive radiation dose. The half-life of 4.2 d and the 23% positron decay allow localization with monoclonal antibodies, and the PET imaging which makes Iodine-124 radionuclide a good candidate for being a diagnostic and a therapeutic.This study aims on the calculation of the excitation functions for 123I and 124I various production mechanisms. TALYS 1.6 is used to calculate the reaction cross sections for 123,124,125Te bombarded with protons and deuteriums to produce 123,124I radioisotopes commonly used in medical applications. The calculated results were compared with available experimental results from EXFOR. The results are interpreted in terms of deciding which radoisotope is more appropriate to produce with which reaction and evaluating the effects in the reaction mechanisms. In addition, the relative reaction cross-sections of 123,124I radioisotopes obtained by bombarding 124Te target with protons were discussed, and the common reaction for the production of 123I was evaluated to be the 124Te(p, 2n)123I reaction on the highly enriched 124Te. Thus, it is considered that a very high level of enrichment on the target must be achieved in order to prevent contamination caused by competing reactions of (p, n) and (p,2n). It is concluded that 123I production is more suitable for small and mediumi-sized cyclotrons.