Open Access
Issue
ND 2007
2007
Article Number 159
Number of page(s) 4
Section Neutron cross section measurements
DOI https://doi.org/10.1051/ndata:07519
Published online 17 June 2008
International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07519

Capture cross section measurements of 186,187,188Os at n_TOF: the resolved resonance region

K. Fujii1, M. Mosconi2, P.M. Milazzo1, C. Domingo-Pardo2, 3, F. Käppeler2, A. Mengoni4, 5, U. Abbondanno1, G. Aerts6, H. Álvarez7, F. Álvarez-Velarde8, S. Andriamonje6, J. Andrzejewski9, P. Assimakopoulos10, L. Audouin11, G. Badurek12, P. Baumann13, F. Becvár14, E. Berthoumieux6, F. Calviño15, M. Calviani16, 17, D. Cano-Ott8, R. Capote4, 18, C. Carrapiço6, 19, P. Cennini5, V. Chepel20, E. Chiaveri5, N. Colonna21, G. Cortes22, A. Couture23, J. Cox23, M. Dahlfors5, S. David11, I. Dillmann2, W. Dridi6, I. Duran7, C. Eleftheriadis24, M. Embid-Segura8, L. Ferrant11, A. Ferrari5, R. Ferreira-Marques20, W. Furman25, I. Goncalves20, E. González-Romero8, F. Gramegna16, C. Guerrero8, F. Gunsing6, B. Haas26, R. Haight27, M. Heil2, A. Herrera-Martinez5, M. Igashira28, E. Jericha12, Y. Kadi5, D. Karadimos10, D. Karamanis10, M. Kerveno13, P. Koehler29, E. Kossionides30, M. Krticka14, C. Lampoudis6, 24, H. Leeb12, A. Lindote20, I. Lopes20, M. Lozano18, S. Lukic13, J. Marganiec9, S. Marrone21, T. Martínez8, C. Massimi31, P. Mastinu16, C. Moreau1, F. Neves20, H. Oberhummer12, S. O'Brien23, J. Pancin6, C. Papachristodoulou10, C. Papadopoulos32, C. Paradela7, N. Patronis10, A. Pavlik33, P. Pavlopoulos34, L. Perrot6, M.T. Pigni12, R. Plag2, A. Plompen35, A. Plukis6, A. Poch22, J. Praena16, C. Pretel22, J. Quesada18, T. Rauscher36, R. Reifarth27, C. Rubbia37, G. Rudolf13, P. Rullhusen35, J. Salgado19, C. Santos19, L. Sarchiapone5, I. Savvidis24, C. Stephan11, G. Tagliente21, J.L. Tain3, L. Tassan-Got11, L. Tavora19, R. Terlizzi21, G. Vannini31, P. Vaz19, A. Ventura38, D. Villamarin8, M.C. Vincente8, V. Vlachoudis5, R. Vlastou32, F. Voss2, S. Walter2, M. Wiescher23 and K. Wisshak2

1  Istituto Nazionale di Fisica Nucleare, Trieste, Italy
2  Forschungszentrum Karlsruhe GmbH (FZK), Institut für Kernphysik, Germany
3  Instituto de Física Corpuscular, CSIC-Universidad de Valencia, Spain
4  International Atomic Energy Agency (IAEA), Nuclear Data Section, Vienna, Austria
5  CERN, Geneva, Switzerland
6  CEA/Saclay-DSM/DAPNIA, Gif-sur-Yvette, France
7  Universidade de Santiago de Compostela, Spain
8  Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid, Spain
9  University of Lodz, Lodz, Poland
10  University of Ioannina, Greece
11  Centre National de la Recherche Scientifique/IN2P3-IPN, Orsay, France
12  Atominstitut der Österreichischen Universitäten,Technische Universität Wien, Austria
13  Centre National de la Recherche Scientifique/IN2P3-IReS, Strasbourg, France
14  Charles University, Prague, Czech Republic
15  Universidad Politecnica de Madrid, Spain
16  Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Italy
17  Dipartimento di Fisica, Università di Padova, Italy
18  Universidad de Sevilla, Spain
19  Instituto Tecnológico e Nuclear (ITN), Lisbon, Portugal
20  LIP-Coimbra & Departamento de Fisica da Universidade de Coimbra, Portugal
21  Istituto Nazionale di Fisica Nucleare, Bari, Italy
22  Universitat Politecnica de Catalunya, Barcelona, Spain
23  University of Notre Dame, Notre Dame, USA
24  Aristotle University of Thessaloniki, Greece
25  Joint Institute for Nuclear Research, Frank Laboratory of Neutron Physics, Dubna, Russia
26  Centre National de la Recherche Scientifique/IN2P3-CENBG, Bordeaux, France
27  Los Alamos National Laboratory, New Mexico, USA
28  Tokyo Institute of Technology, Tokyo, Japan
29  Oak Ridge National Laboratory, Physics Division, Oak Ridge, USA
30  NCSR, Athens, Greece
31  Dipartimento di Fisica, Università di Bologna, and Sezione INFN di Bologna, Italy
32  National Technical University of Athens, Greece
33  Institut für Isotopenforschung und Kernphysik, Universität Wien, Austria
34  Pôle Universitaire Léonard de Vinci, Paris-La Défense, France
35  CEC-JRC-IRMM, Geel, Belgium
36  Department of Physics-University of Basel, Switzerland
37  Università degli Studi Pavia, Pavia, Italy
38  ENEA, Bologna, Italy

kfujii@ts.infn.it

Published online: 21 May 2008

Abstract
The neutron capture cross sections of 186,187,188Os have been measured at the CERN neutron time-of-flight facility, n_TOF, in the neutron energy range from 1 eV up to 1 MeV. In this contribution, we report the results of the analysis of the resolved resonance region (RRR). Resonance parameters have been extracted from a full R-matrix fit of the capture yields with the SAMMY code. A statistical analysis has been performed and the related average resonance parameters are derived. This information is crucial for a complete understanding and modeling in terms of the Hauser-Feshbach statistical model of the capture and inelastic reaction channels, required for the evaluation of the stellar reaction rates of these isotopes. Maxwellian average cross sections for the range of temperatures relevant for s-process nucleosynthesis have been derived from the combined information of the experimental data in the resolved and unresolved resonance regions. A brief account of the implications of this analysis in the estimation of the s-process component of the 187Os abundance and the related impact on the estimates of the time-duration of the galactic nucleosynthesis through the Re/Os clock is given.



© CEA 2008