Covariances of Evaluated Nuclear Cross Section Data for (232)Th, (180,182,183,184,186)W and (55)Mn

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Nuclear Data Sheets

DOI:https://doi.org/10.1016/j.nds.2011.11.007· OSTI ID:1036216

Trkov, A ^[1]; Capote, R ^[2]; Soukhovitskii, E ^[3]; Leal, Luiz C ^[4]; Sin, M ^[5]; Kodeli, I ^[2]; Muir, D W ^[6]

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1. Jozef Stefan Institute, Slovenia
2. International Atomic Energy Agency (IAEA)
3. Joint Inst Power & Nucl Res Sosny
4. ORNL
5. University of Bucharest
6. Argonne National Laboratory (ANL)

The EMPIRE code system is a versatile package for nuclear model calculations that is often used for nuclear data evaluation. Its capabilities include random sampling of model parameters, which can be utilized to generate a full covariance matrix of all scattering cross sections, including cross-reaction correlations. The EMPIRE system was used to prepare the prior covariance matrices of reaction cross sections of (232)Th, (180,182,183,184,186)W and (55)Mn nuclei for incident neutron energies up to 60 MeV. The obtained modeling prior was fed to the GANDR system, which is a package for a global assessment of nuclear data, based on the Generalized Least-Squares method. By introducing experimental data from the EXFOR database into GANDR, the constrained covariance matrices and cross section adjustment functions were obtained. Applying the correction functions on the cross sections and formatting the covariance matrices, the final evaluations in ENDF-6 format including covariances were derived. In the resonance energy range, separate analyses were performed to determine the resonance parameters with their respective covariances. The data files thus obtained were then subjected to detailed testing and validation. Described evaluations with covariances of (232)Th, (180,182,183,184,186)W and (55)Mn nuclei are included into the ENDF/B-VII.1 library release.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1036216
• Journal Information: Nuclear Data Sheets, Vol. 112, Issue 12; ISSN 0090-3752
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CROSS SECTIONS
ENERGY RANGE
EVALUATION
MATRICES
NEUTRONS
NUCLEAR MODELS
NUCLEI
RESONANCE
SAMPLING
SCATTERING
SIMULATION
TESTING
VALIDATION