https://doi.org/10.1140/epja/i2019-12692-7
Regular Article - Experimental Physics
Cross section measurements of 155,157Gd(n,
) induced by thermal and epithermal neutrons
1
Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari, Italy
2
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Bologna, Italy
3
Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy
4
European Organization for Nuclear Research (CERN), Geneva, Switzerland
5
University of Lodz, Lodz, Poland
6
Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, F-91406, Orsay Cedex, France
7
Technische Universität Wien, Wien, Austria
8
CEA Irfu, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
9
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
10
Charles University, Prague, Czech Republic
11
University of Manchester, Manchester, UK
12
Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
13
University of York, York, UK
14
University of Santiago de Compostela, Santiago de Compostela, Spain
15
Universitat Politècnica de Catalunya, Barcelona, Spain
16
Universidad de Sevilla, Sevilla, Spain
17
INFN Laboratori Nazionali del Sud, Catania, Italy
18
Dipartimento di Fisica, Università degli Studi di Bari, Bari, Italy
19
Instituto de Física Corpuscular, CSIC - Universidad de Valencia, Valencia, Spain
20
Paul Scherrer Institut (PSI), Villingen, Switzerland
21
Instituto Superior Técnico, Lisbon, Portugal
22
Joint Institute for Nuclear Research (JINR), Dubna, Russia
23
Goethe University Frankfurt, Frankfurt, Germany
24
Horia Hulubei National Institute of Physics and Nuclear Engineering, Măgurele, Romania
25
Japan Atomic Energy Agency (JAEA), Tokai-mura, Japan
26
European Commission, Joint Research Centre, Geel, Retieseweg 111, B-2440, Geel, Belgium
27
Karlsruhe Institute of Technology, Campus North, IKP, 76021, Karlsruhe, Germany
28
National Technical University of Athens, Athens, Greece
29
School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
30
Agenzia nazionale per le nuove tecnologie (ENEA), Bologna, Italy
31
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Braunschweig, Germany
32
Istituto Nazionale di Fisica Nucleare, Sezione di Legnaro, Legnaro, Italy
33
Consiglio Nazionale delle Ricerche, Bari, Italy
34
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste, Italy
35
Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy
36
University of Ioannina, Ioannina, Greece
37
University of Vienna, Faculty of Physics, Vienna, Austria
38
University of Granada, Granada, Spain
39
Department of Physics, University of Basel, Basel, Switzerland
40
Centre for Astrophysics Research, University of Hertfordshire, Hatfield, UK
41
Bhabha Atomic Research Centre (BARC), Mumbai, India
42
Australian National University, Canberra, Australia
* e-mail: massimi@bo.infn.it
Received:
20
September
2018
Accepted:
7
December
2018
Published online:
28
January
2019
Neutron capture cross section measurements on 155Gd and 157Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n_TOF experimental area EAR1, at 185 m from the neutron source, with an array of 4 C6D6 liquid scintillation detectors. At a neutron kinetic energy of 0.0253 eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for 155Gd and 157Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181 eV and 307 eV, respectively for 155Gd and 157Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1 keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of and
; average total radiative width of 106.8(14) meV and 101.1(20) meV and s-wave resonance spacing 1.6(2) eV and 4.8(5) eV for n + 155Gd and n + 157Gd systems, respectively.
© SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2019