https://doi.org/10.1140/epja/s10050-022-00779-7
Regular Article - Experimental Physics
High accuracy, high resolution 235U(n,f) cross section from n_TOF (CERN) from 18 meV to 10 keV
1
Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Italy
2
Dipartimento Interateneo di Fisica, Università degli Studi di Bari, Bari, Italy
3
INFN Laboratori Nazionali del Sud, Catania, Italy
4
Agenzia Nazionale per le Nuove Tecnologie (ENEA), Bologna, Italy
5
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Bologna, Italy
6
Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy
7
European Organization for Nuclear Research (CERN), Meyrin, Switzerland
8
University of Lodz, Genève, Poland
9
Institut de Physique Nucléaire, CNRS-IN2P3, University Paris-Sud, Université Paris-Saclay, 91406, Orsay Cedex, France
10
Technische Universität Wien, Vienna, Austria
11
CEA Irfu, Université Paris-Saclay, 91191, Gif-sur-Yvette, France
12
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
13
Charles University, Prague, Czech Republic
14
University of Manchester, Manchester, UK
15
Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
16
University of York, Heslington, UK
17
University of Santiago de Compostela, Santiago, Spain
18
Universitat Politècnica de Catalunya, Barcelona, Spain
19
Universidad de Sevilla, Seville, Spain
20
Dipartimento di Fisica, Università degli Studi di Bari, Bari, Italy
21
Instituto de Física Corpuscular, CSIC-Universidad de Valencia, Valencia, Spain
22
Paul Scherrer Institut (PSI), Villingen, Switzerland
23
Instituto Superior Técnico, Lisbon, Portugal
24
Joint Institute for Nuclear Research (JINR), Dubna, Russia
25
Goethe University, Frankfurt, Germany
26
Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
27
Japan Atomic Energy Agency (JAEA), Tokai-mura, Japan
28
European Commission, Joint Research Centre (JRC), Geel, Belgium
29
Karlsruhe Institute of Technology, Campus North, IKP, 76021, Karlsruhe, Germany
30
National Technical University of Athens, Athens, Greece
31
School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
32
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Brunswick, Germany
33
Istituto Nazionale di Fisica Nucleare, Sezione di Legnaro, Legnaro, Italy
34
Consiglio Nazionale Delle Ricerche, Bari, Italy
35
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste, Italy
36
Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy
37
University of Ioannina, Ioannina, Greece
38
Faculty of Physics, University of Vienna, Vienna, Austria
39
University of Granada, Granada, Spain
40
Department of Physics, University of Basel, Basel, Switzerland
41
Centre for Astrophysics Research, University of Hertfordshire, Hertfordshire, UK
42
Bhabha Atomic Research Centre (BARC), Trombay, India
43
Australian National University, Mumbai, Australia
Received:
1
March
2022
Accepted:
30
June
2022
Published online:
13
August
2022
The 235U(n,f) cross section was measured in a wide energy range (18 meV–170 keV) at the n_TOF facility at CERN, relative to 6Li(n,t) and 10B(n,α) standard reactions, with high resolution and accuracy, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. In this paper we report on the results in the region between 18 meV and 10 keV neutron energy. A resonance analysis has been performed up to 200 eV, with the code SAMMY. The resulting fission kernels are compared with the ones extracted on the basis of the resonance parameters of the most recent major evaluated data libraries. A comparison of the n_TOF data with the evaluated cross sections is also performed from thermal to 10 keV neutron energy for the energy-averaged cross section in energy groups of suitably chosen width. A good agreement, within 0.5%, is found on average between the new results and the latest evaluated data files ENDF/B-VIII.0 and JEFF-3.3, as well as with respect to the broad group average fission cross section established in the framework of the standard working group of IAEA (the so-called reference file). However, some discrepancies, of up to 4%, are still present in some specific energy regions. The new dataset here presented, characterized by a unique combination of high resolution and accuracy, low background and wide energy range, can help to improve the evaluations from the Resolved Resonance Region up to 10 keV, also reducing the uncertainties that affect this region.
© The Author(s) 2022
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