In:
Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 71, No. 19 ( 2022), p. 192501-
Abstract:
Natural iridium acts as a high-quality activated detector for probing the energy components of a neutron fluence. Measurements of 〈sup〉191〈/sup〉Ir(n,2n)〈sup〉190〈/sup〉Ir cross sections are carried out near 14 MeV by the activation method based on 〈sup〉93〈/sup〉Nb(n,2n)〈sup〉92m〈/sup〉Nb reaction cross section standard by PD-300 neutron generator DT neutron source. The (n,2n) products are measured by using a calibrated high pure Ge detector. The cross sections of 〈sup〉191〈/sup〉Ir(n,2n)〈sup〉190〈/sup〉Ir, 〈i〉σ〈/i〉〈sub〉m2〈/sub〉 and 〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉, are measured carefully. The 〈sup〉191〈/sup〉Ir(n,2n)〈sup〉190〈/sup〉Ir cross sections: 〈i〉σ〈/i〉〈sub〉m2〈/sub〉, 〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉, 〈i〉σ〈/i〉〈sub〉g+m1+m2〈/sub〉 and cross section ratio of 〈i〉σ〈/i〉〈sub〉m2〈/sub〉/〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉 are obtained in an energy range of 13.40–14.86 MeV. Experimental uncertainties are in a range of 3.4%–3.5%. The measured cross sections for the reaction of 〈sup〉191〈/sup〉Ir(n,2n)〈sup〉190〈/sup〉Ir at 14 MeV are 〈i〉σ〈/i〉〈sub〉m2〈/sub〉 = (136.05 ± 4.93) mb, 〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉 = (1972.35 ± 67.06) mb, 〈i〉σ〈/i〉〈sub〉g+m1+m2〈/sub〉 = (2108.40 ± 71.99) mb, and 〈i〉σ〈/i〉〈sub〉m2〈/sub〉/〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉 = 0.0690 ± 0.0024. The present data are compared with the previous experimental data and the ENDF/B-VIII.0 and JEFF3.0/A evaluated data, showing that the experimental data from the literature are in good agreement with the present data for 〈i〉σ〈/i〉〈sub〉g+m1〈/sub〉, the evaluated data from JEFF3.0/A are underestimated by 5%–20% in comparison with the present data for 〈i〉σ〈/i〉〈sub〉m2〈/sub〉, the evaluated data from ENDF/B-VIII.0 are underestimated by 10% in comparison with the present data for 〈i〉σ〈/i〉〈sub〉m2〈/sub〉, and the ENDF/B-VIII.0 data are consistent with the present data for 〈i〉σ〈/i〉〈sub〉g+m1+m2〈/sub〉. The discrepancies between the data from the literature and the present data are analyzed and clarified. The present data show significant improvement in accuracy in comparison with data from the literature, these results provide more reliable nuclear data for improving the future evaluation.
Type of Medium:
Online Resource
ISSN:
1000-3290
,
1000-3290
DOI:
10.7498/aps.71.20220776
Language:
Unknown
Publisher:
Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
Publication Date:
2022
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