Radiative neutron capture on 242Pu in the resonance region at the CERN n_TOF-EAR1 facility

Scientific paper - Original scientific paper

• Author: J. Lerendegui-Marco
• Author: ...
• Author: Damir Bosnar; MBZ: 134936
• Author: ...
• Author: Petar Žugec; MBZ: 326085
• Collaboration: n_TOF Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of 242Pu there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, postirradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on 242Pu carried out at n_TOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The 242Pu(n, γ) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of n_TOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.

• Keywords (english): neutron capture; 242Pu; resonance analysis; n_TOF
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C
• Numbering: vol. 97, no. 2, 024605
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.97.024605
• URN:NBN: urn:nbn:hr:217:426942
• Publication: 2018
• Document URL: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.97.024605
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2018 American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Received 2 November 2017; published 6 February 2018.
• Created on: 2020-03-01 12:05:48