| Issue |
EPJ Web of Conf.
Volume 294, 2024
WONDER-2023 - 6th International Workshop On Nuclear Data Evaluation for Reactor applications
|
|
|---|---|---|
| Article Number | 04007 | |
| Number of page(s) | 7 | |
| Section | Evaluation of Nuclear Data | |
| DOI | https://doi.org/10.1051/epjconf/202429404007 | |
| Published online | 17 April 2024 | |
https://doi.org/10.1051/epjconf/202429404007
Effective R-Matrix Parameterizations for Nuclear Data*
1 Oak Ridge National Laboratory, Oak Ridge, TN, USA
2 OECD Nuclear Energy Agency, Paris, France
** e-mail: arbanasg@ornl.gov
Published online: 17 April 2024
We derive an effective Reich-Moore approximation (RMA) of the Wigner-Eisenbud R-matrix formalism parameterized by complex-valued resonance energies and widths; this RMA exactly reproduces the total eliminated cross section. We show that resonance parameters evaluated for a conventional *** boundary conditions (BCs), Bc = Sc(E),are approximately equal to the R-matrix parameters in Park’s formalism by employing a linear approximation of the shift function therein [T.-S. Park, Phys. Rev. C 106 (2021) 064612]. We outline a method for converting Park’s observed reduced width amplitudes (RWAs) and their covariance matrix into Brune’s alternative R-matrix RWAs and their covariance matrix [C. Brune, Phys. Rev. C 66 (2002) 044611]. We extend the Park’s R-matrix formalism into the complex plane by introducing a complex-valued basis set of eigenfunctions of a complex-symmetric (non-Hermitian) Hamiltonian in the R-matrix interior. We observe that its R-matrix resonance energies and widths are directly related to the poles and residues, respectively, of Hwang’s sum-over-poles representation of cross sections [R.N. Hwang, Nucl. Sci. Eng. 96 (1987) 192].
Notice: This manuscript has been authored by UT-Battelle LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
© The Authors, published by EDP Sciences, 2024
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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