Modelling Neutron-induced Reactions on ^232-237U from 10 keV up to 30 MeV

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• 作者：M. Sin^a ; R. Capote^b ; ^{r.capotenoy@iaea.org} ; M.W. Herman^c ; A. Trkov^b
• 刊名：Nuclear Data Sheets
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：139
• 期：Complete
• 页码：138-170
• 全文大小：4040 K
• 卷排序：139

文摘

Comprehensive calculations of cross sections for neutron-induced reactions on 232–237U targets are performed in the 10 keV–30 MeV incident energy range with the code EMPIRE–3.2 Malta. The advanced modelling and consistent calculation scheme are aimed at improving our knowledge of the neutron scattering and emission cross sections, and to assess the consistency of available evaluated libraries for light uranium isotopes. The reaction model considers a dispersive optical potential (RIPL 2408) that couples from five (even targets) to nine (odd targets) levels of the ground-state rotational band, and a triple-humped fission barrier with absorption in the wells described within the optical model for fission. A modified Lorentzian model (MLO) of the radiative strength function and Enhanced Generalized Superfluid Model nuclear level densities are used in Hauser-Feschbach calculations of the compound-nuclear decay that include width fluctuation corrections. The starting values for the model parameters are retrieved from RIPL. Excellent agreement with available experimental data for neutron emission and fission is achieved, giving confidence that the quantities for which there is no experimental information are also accurately predicted. Deficiencies in existing evaluated libraries are highlighted.