Long-lived isomers in 190Ir

Evaluated Iridium, Yttrium, and Thulium Cross Sections and Integral Validation Against Critical Assembly and Bethe Sphere Measurements

“…Specifically, recent GEANIE data assessing 191 Ir(n, xnγ) excitation functions [42,43], along with Garrett et al data [44,45], enable a new and improved analysis of neutron-induced reactions on 191 Ir. The new evaluation and ENDF file, LANL2006, was based in part on new GNASH calculations and on the measured data (cross sections and nuclear structure spectroscopy):…”

“…[22]. We have now included all presently known discrete states [44] in the chain of iridium isotopes in our calculations. More recently -though not included in the evaluations discussed in this paper -Cowell et al have extended these calculations to include FKK preequilibrium modeling so as to more accurately represent the residual spin distribution after the emission of high-energy neutrons before the equilibrium stage, see Ref.…”

“…Thanks to the experimental data of Garrett [44,45] and Fotiades [42,43,49], we could compute the production cross section for a third isomeric state (state (4)+ at 36.1 keV, T 1/2 =1.4 ms). All states included in our final ENDF file are given in Table V. The calculated cross section of 191 Ir (n, 2n) 190 Ir is shown in Fig.…”