Publikationen

Measurement of the <sup>235</sup>U(n, f) cross section relative to the <sup>6</sup>Li(n, t) and <sup>10</sup>B(n, α) standards from thermal to 170 keV neutron energy range at n_TOF

Autor(en)
S. Amaducci, L. Cosentino, M. Barbagallo, N. Colonna, A. Mengoni, C. Massimi, S. Lo Meo, P. Finocchiaro, O. Aberle, J. Andrzejewski, L. Audouin, M. Bacak, J. Balibrea, F. Bečvář, E. Berthoumieux, J. Billowes, D. Bosnar, A. Brown, M. Caamaño, F. Calviño, M. Calviani, D. Cano-Ott, R. Cardella, A. Casanovas, F. Cerutti, Y. H. Chen, E. Chiaveri, G. Cortés, M. A. Cortés-Giraldo, L. A. Damone, M. Diakaki, C. Domingo-Pardo, R. Dressler, E. Dupont, I. Durán, B. Fernández-Domínguez, A. Ferrari, P. Ferreira, V. Furman, K. Göbel, A. R. García, A. Gawlik, S. Gilardoni, T. Glodariu, I. F. Gonçalves, E. González-Romero, E. Griesmayer, C. Guerrero, F. Gunsing, H. Harada, S. Heinitz, J. Heyse, D. G. Jenkins, E. Jericha, F. Käppeler, Y. Kadi, A. Kalamara, P. Kavrigin, A. Kimura, N. Kivel, I. Knapova, M. Kokkoris, M. Krtička, D. Kurtulgil, E. Leal-Cidoncha, C. Lederer, H. Leeb, J. Lerendegui-Marco, S. J. Lonsdale, D. Macina, A. Manna, J. Marganiec, T. Martínez, A. Masi, P. Mastinu, M. Mastromarco, E. A. Maugeri, A. Mazzone, E. Mendoza, P. M. Milazzo, F. Mingrone, A. Musumarra, A. Negret, R. Nolte, A. Oprea, N. Patronis, A. Pavlik, J. Perkowski, I. Porras, J. Praena, J. M. Quesada, D. Radeck, T. Rauscher, R. Reifarth, C. Rubbia, J. A. Ryan, M. Sabaté-Gilarte, A. Saxena, P. Schillebeeckx, D. Schumann, P. Sedyshev, A. G. Smith, N. V. Sosnin, A. Stamatopoulos, G. Tagliente, J. L. Tain, A. Tarifeño-Saldivia, L. Tassan-Got, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, V. Vlachoudis, R. Vlastou, A. Wallner, S. Warren, C. Weiss, P. J. Woods, T. Wright, P. Žugec
Abstrakt

The 235U(n, f) cross section was measured at n_TOF relative to 6Li(n, t) and 10B(n,α) , with high resolution (L= 183. 49 (2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the 235U(n, f) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. Finally, from the present data, a value of 249. 7 ± 1. 4 (stat) ± 0. 94 (syst) b·eV has been extracted for the cross section integral between 7.8 and 11eV, confirming the value of 247. 5 ± 3 b·eV recently established as a standard.

Organisation(en)
Isotopenphysik
Externe Organisation(en)
Istituto Nazionale di Fisica Nucleare, Roma, Università degli Studi di Catania, ENEA Centro Ricerche Bologna, Università degli Studi di Bologna, European Organization for Nuclear Research (CERN), University of Lodz, Centre National De La Recherche Scientifique (CNRS), Technische Universität Wien, Université Paris-Saclay, Centro de Investigaciones Energeticas Medioambientales y Tecnológica, Charles University Prague, University of Zagreb, York University, Universidade de Santiago de Compostela (USC), Universitat Politècnica de Catalunya, Universidad de Sevilla, Università degli Studi di Bari, Universitat de València, Paul Scherrer Institute, Associação EURATOM/IST, Johann Wolfgang Goethe-Universität Frankfurt am Main, Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN HH), Japan Atomic Energy Agency, European Commission, Karlsruher Institut für Technologie, National Technical University of Athens (NTUA), University of Edinburgh, Physikalisch-Technische Bundesanstalt (PTB), Sezione di Legnaro, Consiglio Nazionale delle Ricerche (CNR), Padua, Università degli Studi di Trieste, University of Ioannina, Universidad de Granada, Universität Basel, University of Hertfordshire, Bhabha Atomic Research Centre, Australian National University, University of Manchester, Joint Institute for Nuclear Research
Journal
European Physical Journal A
Band
55
Anzahl der Seiten
19
ISSN
1434-6001
DOI
https://doi.org/10.1140/epja/i2019-12802-7
Publikationsdatum
07-2019
Peer-reviewed
Ja
ÖFOS 2012
103014 Kernphysik
Schlagwörter
ASJC Scopus Sachgebiete
Nuclear and High Energy Physics
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/measurement-of-the-235un-f-cross-section-relative-to-the-6lin-t-and-10bn--standards-from-thermal-to-170-kev-neutron-energy-range-at-ntof(ea89ea65-14b2-4eef-806f-cec81dafee2f).html