(n,2n) and (n,3n) cross sections of neutron-induced reactions on 150Sm for En from threshold to 35 MeV [electronic resource].
- Published:
- Washington, D.C. : United States. Dept. of Energy, 2009.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description:
- PDF-file: 30 pages; size: 0.8 Mbytes
- Additional Creators:
- Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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- Restrictions on Access:
- Free-to-read Unrestricted online access
- Summary:
- Cross-section measurements were made of prompt discrete γ-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on a ¹⁵°Sm sample fo 1550 mg/cm² of Sm₂O₃ enriched to 95.6% in ¹⁵°Sm. Results are compared with enhanced Hauser-Feshbach model calculations including the pre-equilibrium reactions. Energetic neutrons were delivered by the Los Alamos Neutron Science Center facility. The prompt-reaction γ rays were detected with the Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Incident neutron energies were determined by the time-of-flight technique. Excitation functions for thirteen individual γ-rays up to Eₓ = 0.8 MeV in ¹⁴⁹Sm and one γ-ray transition between the first excited and ground state in ¹⁴⁸Sm were measured. Partial γ-ray cross sections were calculated using GNASH, an enhanced Hauser-Feshbach statistical nuclear reaction model code, and compared with the experimental results. The particle transmission coefficients were calculated with new systematic 'global' optical model potential parameters. The coupled-channel optical model based on the soft rotor model was employed to calculate the particle transmission coefficients. The pre-equilibrium part of the spin distribution in ¹⁵°Sm was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK) and incorporated into the GNASH reaction model code. the partial cross sections for discrete γ-ray cascade paths leading to the ground state in ¹⁴⁹Sm and ¹⁴⁸Sm have been summed (without double counting) to estimate lower limits for reaction cross sections. These lower limits are combined with Hauser-Feshbach model calculations to deduce the reaction channel cross sections. These reaction channel cross sections agree with previously measured experimental and ENDF/B-VII evaluations.
- Report Numbers:
- E 1.99:llnl-jrnl-411366
llnl-jrnl-411366 - Subject(s):
- Other Subject(s):
- Note:
- Published through SciTech Connect.
03/16/2009.
"llnl-jrnl-411366"
Nuclear Inst. and Methods in Physics Research B, vol. 268, no. 2010, January 13, 2010, pp. 114-119 268 FT
Nelson, R; Mitchell, G; Wu, C; Becker, J; Kawano, T; Fotiades, N; Devlin, M; Dashdorj, D; Kunieda, S. - Funding Information:
- W-7405-ENG-48
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