Determination of effective resonance energy for the 193Ir(n,γ)194Ir reaction by the cadmium ratio method

Abstract In this work, the effective resonance energy, E ¯ r -value for the 193 Ir(n,γ) 194 Ir reaction was measured using cadmium ratio method. A dual monitor ( 197 Au– 98 Mo), which has convenient resonance properties, was employed for characterization of the irradiation sites. Then analytical grade iridium oxide samples diluted with CaCO 3 to lower neutron self-shielding effect stacked in small cylindrical Teflon boxes were irradiated once with a 1 mm thick Cd cylindrical box placed in a thermalized neutron field of an 241 Am–Be neutron source then without it. The activities produced in samples during 193 Ir(n,γ) 194 Ir reaction were measured using a p-type HPGe detector γ-ray spectrometer with a 44.8% relative efficiency. The correction factors for thermal, epithermal neutron self-shielding ( G th , G epi ), true coincidence summing ( F coi ) and gamma-ray self-absorption ( F s ) effects were determined with appropriate approaches and programs. Thus, the experimental E ¯ r -value was determined to be 2.65 ± 0.61 eV for 193 Ir target nuclide. The recent data for Q 0 and F Cd values for E ¯ r determination were based on k 0 -NAA online database. The present experimental E ¯ r value was calculated and compared with more recent values for Q 0 and F Cd for 193 Ir. Additionally, the E ¯ r -values was theoretically calculated from the up-to-date resonance data obtained from ENDF/B VII library using two different approaches. Since there is no experimentally determined E ¯ r -value for the 193 Ir isotope, the results are compared with the calculated ones given in the literature.