International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07493

Improved lead and bismuth (n,γ) cross sections and their astrophysical impact

C. Domingo-Pardo^{1, 2}, U. Abbondanno³, G. Aerts⁴, H. Álvarez⁵, F. Álvarez-Velarde⁶, S. Andriamonje⁴, J. Andrzejewski⁷, P. Assimakopoulos⁸, L. Audouin⁹, G. Badurek¹⁰, P. Baumann¹¹, F. Becvár¹², E. Berthoumieux⁴, F. Calviño¹³, M. Calviani^{14, 15}, D. Cano-Ott⁶, R. Capote^{16, 17}, C. Carrapiço^{4, 18}, P. Cennini¹⁹, V. Chepel²⁰, E. Chiaveri¹⁹, N. Colonna²¹, G. Cortes²², A. Couture²³, J. Cox²³, M. Dahlfors¹⁹, S. David⁹, I. Dillmann¹, W. Dridi⁴, I. Duran⁵, C. Eleftheriadis²⁴, M. Embid-Segura⁶, L. Ferrant⁹, A. Ferrari¹⁹, R. Ferreira-Marques²⁰, K. Fujii³, W. Furman²⁵, I. Goncalves²⁰, E. González-Romero⁶, F. Gramegna¹⁴, C. Guerrero⁶, F. Gunsing⁴, B. Haas²⁶, R. Haight²⁷, M. Heil¹, A. Herrera-Martinez¹⁹, M. Igashira²⁸, E. Jericha¹⁰, F. Käppeler¹, Y. Kadi¹⁹, D. Karadimos⁸, D. Karamanis⁸, M. Kerveno¹¹, P. Koehler²⁹, E. Kossionides³⁰, M. Krticka¹², C. Lampoudis^{4, 24}, H. Leeb¹⁰, A. Lindote²⁰, I. Lopes²⁰, M. Lozano¹⁷, S. Lukic¹¹, J. Marganiec⁷, S. Marrone²¹, T. Martínez⁶, C. Massimi³¹, P. Mastinu¹⁴, A. Mengoni^{16, 19}, P.M. Milazzo³, C. Moreau³, M. Mosconi¹, F. Neves²⁰, H. Oberhummer¹⁰, S. O'Brien²³, J. Pancin⁴, C. Papachristodoulou⁸, C. Papadopoulos³², C. Paradela⁵, N. Patronis⁸, A. Pavlik³³, P. Pavlopoulos³⁴, L. Perrot⁴, M.T. Pigni¹⁰, R. Plag¹, A. Plompen³⁵, A. Plukis⁴, A. Poch²², J. Praena¹⁴, C. Pretel²², J. Quesada¹⁷, T. Rauscher³⁶, R. Reifarth²⁷, C. Rubbia³⁷, G. Rudolf¹¹, P. Rullhusen³⁵, J. Salgado¹⁸, C. Santos¹⁸, L. Sarchiapone¹⁹, I. Savvidis²⁴, C. Stephan⁹, G. Tagliente²¹, J.L. Tain⁰, L. Tassan-Got⁹, L. Tavora¹⁸, R. Terlizzi²¹, G. Vannini³¹, P. Vaz¹⁸, A. Ventura³⁸, D. Villamarin⁶, M.C. Vincente⁶, V. Vlachoudis¹⁹, R. Vlastou³², F. Voss¹, S. Walter¹, M. Wiescher²³ and K. Wisshak<sup>1

1</sup>  Forschungszentrum Karlsruhe GmbH (FZK), Institut für Kernphysik, Germany
²  Instituto de Física Corpuscular, CSIC-Universidad de Valencia, Spain
³  Istituto Nazionale di Fisica Nucleare, Trieste, Italy
⁴  CEA/Saclay-DSM/DAPNIA, Gif-sur-Yvette, France
⁵  Universidade de Santiago de Compostela, Spain
⁶  Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid, Spain
⁷  University of Lodz, Lodz, Poland
⁸  University of Ioannina, Greece
⁹  Centre National de la Recherche Scientifique/IN2P3-IPN, Orsay, France
¹⁰  Atominstitut der Österreichischen Universitäten, Technische Universität Wien, Austria
¹¹  Centre National de la Recherche Scientifique/IN2P3-IReS, Strasbourg, France
¹²  Charles University, Prague, Czech Republic
¹³  Universidad Politecnica de Madrid, Spain
¹⁴  Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Italy
¹⁵  Dipartimento di Fisica, Università di Padova, Italy
¹⁶  International Atomic Energy Agency (IAEA), Nuclear Data Section, Vienna, Austria
¹⁷  Universidad de Sevilla, Spain
¹⁸  Instituto Tecnológico e Nuclear (ITN), Lisbon, Portugal
¹⁹  CERN, Geneva, Switzerland
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

cesar.domingo.pardo@cern.ch

Published online: 21 May 2008

Abstract
A series of (n,γ) neutron capture measurements on the lead isotopes and bismuth have been carried out at the CERN n_TOF installation in the neutron energy range from 1 eV up to 1 MeV. At n_TOF, contaminations due to scattered neutrons were reduced down to a negligible level by using improved γ-ray detectors with very low neutron sensitivity. The background level has been determined precisely from a complementary measurement. Other experimental effects related to the electronic threshold in the detectors and the angular distribution of the prompt γ-rays were investigated via Monte Carlo simulations and could be taken in account in the analysis of the capture data. With this set of measurements the energy differential (n,γ) cross sections of ^204,206,207Pb and ²⁰⁹Bi have been determined with good accuracy. The information obtained in this work becomes of interest for constraining r-process calculations and in particular for the Th/U cosmochronometer.

© CEA 2008