Measurements of high-energy neutron-induced fission of^natPb and ²⁰⁹Bi

D. Tarrío^1a, L. Tassan-Got², L. Audouin², B. Berthier², I. Duran¹, L. Ferrant², S. Isaev², C. Le Naour², C. Paradela¹, C. Stephan², D. Trubert², U. Abbondanno³, G. Aerts⁴, H. Álvarez¹, F. Álvarez-Velarde⁵, S. Andriamonje⁶, J. Andrzejewski⁷, P. Assimakopoulos⁸, G. Badurek⁹, P. Baumann¹⁰, F. Becvár¹¹, E. Berthoumieux⁶, F. Calviño¹², M. Calviani^13,14, D. Cano-Ott⁵, R. Capote^15,16, C. Carrapiço^17,6, P. Cennini¹⁸, V. Chepel¹⁹, E. Chiaveri¹⁸, N. Colonna²⁰, G. Cortes¹², A. Couture²¹, J. Cox²¹, M. Dahlfors¹⁸, S. David¹, I. Dillmann²², C. Domingo-Pardo^23,24, W. Dridi⁶, C. Eleftheriadis²⁵, M. Embid-Segura⁵, A. Ferrari¹⁸, R. Ferreira-Marques¹⁹, K. Fujii³, W. Furman²⁶, I. Gonçalves¹⁷, E. González-Romero⁵, F. Gramegna¹³, C. Guerrero⁵, F. Gunsig⁶, B. Haas²⁷, R. Haight²⁸, M. Heil²², A. Herrera-Martinez¹⁸, M. Igashira²⁹, E. Jericha⁹, Y. Kadi¹⁸, F. Käppeler²², D. Karadimos⁸, D. Karamanis⁸, M. Kerveno¹⁰, P. Koehler³⁰, E. Kossionides³¹, M. Krticka¹¹, C. Lampoudis^25,6, H. Leeb⁹, A. Lindote¹⁹, I. Lopes¹⁹, M. Lozano¹⁶, S. Lukic¹⁰, J. Marganiec⁷, S. Marrone²⁰, T. Martínez⁵, C. Massimi³², P. Mastinu¹³, A. Mengoni^15,18, P.M. Milazzo³, C. Moreau³, M. Mosconi²², F. Neves¹⁹, H. Oberhummer⁹, S. O’Brien²¹, M. Oshima³³, J. Pancin⁶, C. Papachristodoulou⁸, C. Papadopoulos³⁴, N. Patronis⁸, A. Pavlik³⁵, P. Pavlopoulos³⁶, L. Perrot⁶, M.T. Pigni⁹, R. Plag²², A. Plompen³⁷, A. Plukis⁶, A. Poch¹², J. Praena¹³, C. Pretel¹², J. Quesada¹⁶, T. Rauscher³⁸, R. Reifarth²⁸, C. Rubbia³⁹, G. Rudolf¹⁰, P. Rullhusen³⁷, J. Salgado¹⁷, C. Santos¹⁷, L. Sarchiapone¹⁸, I. Savvidis²⁵, G. Tagliente²⁰, J.L. Tain²³, L. Tavora¹⁷, R. Terlizzi²⁰, G. Vannini³², P. Vaz¹⁷, A. Ventura⁴⁰, D. Villamarin⁵, M.C. Vicente⁵, V. Vlachoudis¹⁸, R. Vlastou³⁴, F. Voss²², S. Walter²², M. Wiescher²¹ and K. Wisshak²²

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

^a e-mail: diego.tarrio@usc.es

Published online: 28 October 2010

Abstract

The CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of ^natPb and ²⁰⁹Bi relative to ²³⁵U and ²³⁸U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.