Comparison of 192Os(p,n)192Ir and 192Os(d,2n)192Ir Nuclear Reactions for 192Ir Production

Abstract

Iridium-192 (¹⁹²Ir ) is a radionuclide currently suggested for brachyteraphy. One of the methods employed to produce high purity ¹⁹²Ir is by irradiation of Osmium-192  (¹⁹²Os) target using cyclotron. The success of ¹⁹²Ir radionuclide production in cyclotrons requires deep understanding of irradiation parameters, including particle energy, target preparation and thickness, particle beam curent and irradiation time. Therefore, theoretical calculations of the ¹⁹²Ir radioactivity yields should be carried out as a preliminary measure for more efficient ¹⁹²Ir production. In this study, ¹⁹²Ir production was simulated using the SRIM 2013 program to determine the optimum target thickness while the nuclearcross-section data were extracted from TENDL 2017. Two nuclear reactions for ¹⁹²Ir production yield calculations were compared, i.e., ¹⁹²Os(p,n)¹⁹²Ir  and ¹⁹²Os(d,2n)¹⁹²Ir. The radioactivity yields for ¹⁹²Os(p,n)¹⁹²Ir nuclear reaction was found to be lower than  ¹⁹²Os(d,2n)¹⁹²Ir reaction. For proton and deuteron energy of 30 MeV, the maximum radioactivity yield was 6.79 GBq for ¹⁹²Os(p,n)¹⁹²Ir and  26.14 GBq for ¹⁹²Os(d,2n)¹⁹²Ir. Several radionuclide impurities such as ^191mIr, ¹⁹⁰Ir, ¹⁹¹Os and ¹⁸⁹Re were predicted to be generated during ¹⁹²Os(p,n)¹⁹²Ir reaction for proton incident energy between 1 and 30 MeV; meanwhile, ¹⁹²Ir, ^191mIr, ¹⁹³Os, ^193mIr, ^192mOs and ¹⁹¹Os radionuclides were expected to contaminate during ¹⁹²Os(d,2n)¹⁹²Ir reaction for deuteron energy between 1 and 30 MeV. Results of this study can be used as a reference for future ¹⁹²Ir radionuclide production when proton or deuteron beams are considered to be employed.