CALCULATED CROSS SECTIONS FOR 123I FORMATION IN PHOTON-, PROTON- AND HELIUM-ION INDUCED REACTIONS ON HIGHLY ENRICHED 124Xe TARGETS

E. Beták1, M. Kapusta2, E. Rurarz3, J. Tys4

1 Slovak Academy of Sciences, Institute of Physics, 84228 Bratislava, Slovakia,
2 Warsaw University, Lab. Medical Physics, 69, Hoza St., 00-681 Warsaw, Poland,
3 Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk, Poland,
4 Warsaw University, Heavy Ion Lab., 4, Banacha St., 02-097 Warsaw, Poland



A unified method for the production of pure 123I from highly enriched 124Xe targets bombarded by photons, protons and helium ion beams is described. A computer code ALICE 85/300, based on the pre-equilibrium hybrid model of nuclear reactions, was used fore the calculation of excitation functions for the 124,126Xe (p, xnyp) 123Cs->123Xe->123I and 124Xe (3,4He, xnyp) 123Ba->123Cs->123Xe->123I reactions from theresolds up to 120 MeV for proton and 100 MeV for 3,4He ions. A comparison of calculated cross section with experimental data for the 124Xe (p, 2n)123Cs and 124Xe (p, pn)123Xe reactions measured in the energy range 16-44 MeV shows good agreement. For the 126Xe (p, xnyp) 123Cs->123Xe->123I reaction we expect a similar accuracy. Excitation functions of the 124Xe (gamma, n) reactions have been calculated using another computer code (PEQAG), also based on the pre-equilibrium-equilibrium process. Due to the lack of experimental data for photoneutron reactions on Xe targets, we compared the results calculated in the present work with existing experimental data for neighbouring elements of Xe. It has been found that the data for these elements agree well with the present results. The calculated excitation functions for the 124Xe (3,4He, xnyp) 123Ba 123Cs->123Xe->123I reactions are suggested to be used an estimate in the planning of an experiment. This study has arisen from an interest in predicting optimal conditions for production of 123I (needed in nuclear medicine) using one target system connected with cryogenic technique.