First results on the study of the ^191,193Ir(n,tot) reactions at DICER

Nuclear data on Iridium are of great importance, since the natural isotopes of Iridium (^191,193Ir) can be used as passive radiochemical detectors in neutron-rich environments providing information about the neutron spectrum. Moreover, ¹⁹²Ir (produced from neutron capture on ¹⁹¹Ir) is used in high-dose rate brachytherapy. The ^191,193Ir(n,tot) reactions were studied at the Device for Indirect Capture Experiments on Radionuclides (DICER) at the Los Alamos Neutron Science CEnter (LANSCE). DICER was designed to perform neutron transmission measurements on radionuclides of very small mass, tightly constraining the capture cross sections. Isotopically enriched thin and thick ^191,193Ir samples were implemented for the transmission measurements with masses ranging from 6.7 mg to 41.0 mg. The preliminary cross-section results of the ^191,193Ir(n,tot) reactions will be presented, along with R-Matrix calculations performed via the SAMMY code in the energy range 0.1 – 300 eV, indicating the possibility for extending resonance parameters of current evaluations, and resolving existing discrepancies among them.