Eur. Phys. J. A (2012) 48: 29
https://doi.org/10.1140/epja/i2012-12029-2

Tools for Experiment and Theory

Simultaneous measurement of neutron-induced capture and fission reactions at CERN

¹ European Organization for Nuclear Research (CERN), Geneva, Switzerland
² Centro de Investigaciones Energéticas Medioambientales y Technológicas (CIEMAT), Madrid, Spain
³ Centre National de la Recherche Scientifique/IN2P3 - IPN, Orsay, France
⁴ Uniwersytet Łódzki, Lodz, Poland
⁵ Charles University, Prague, Czech Republic
⁶ Istituto Nazionale di Fisica Nucleare, Trieste, Italy
⁷ Commissariat à l’Énergie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette, France
⁸ Universitat Politècnica de Catalunya, Barcelona, Spain
⁹ Instituto Tecnológico e Nuclear (ITN), Lisbon, Portugal
¹⁰ Istituto Nazionale di Fisica Nucleare, Bari, Italy
¹¹ Universidad de Sevilla, Sevilla, Spain
¹² Physik Department E12 and Excellence Cluster Universe, Technische Universität München, Munich, Germany
¹³ GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
¹⁴ Universidade de Santiago de Compostela, Santiago de Compostela, Spain
¹⁵ Bhabha Atomic Research Centre (BARC), Mumbai, India
¹⁶ Instituto de Física Corpuscular, CSIC-Universidad de Valencia, Valencia, Spain
¹⁷ Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, Italy
¹⁸ Atominstitut, Technische Universität Wien, Wien, Austria
¹⁹ Karlsruhe Institute of Technology, Campus Nord, Institut für Kernphysik, Karlsruhe, Germany
²⁰ University of Vienna, Faculty of Physics, Vienna, Austria
²¹ Dipartimento di Fisica, Università di Bologna, INFN, Sezione di Bologna, Bologna, Italy
²² Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Bologna, Italy
²³ Department of Physics and Astronomy, University of Basel, Basel, Switzerland
²⁴ Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN HH, Bucharest, Magurele, Romania
²⁵ National Technical University of Athens (NTUA), Athens, Greece
²⁶ University of Manchester, Manchester, UK
²⁷ University of York, York, UK
²⁸ Aristotle University of Thessaloniki, Thessaloniki, Greece

^* e-mail: carlos.guerrero@cern.ch

Received: 21 December 2011
Accepted: 14 February 2012
Published online: 12 March 2012

Abstract

The measurement of the capture cross-section of fissile elements, of utmost importance for the design of innovative nuclear reactors and the management of nuclear waste, faces particular difficulties related to the -ray background generated in the competing fission reactions. At the CERN neutron time-of-flight facility n_TOF we have combined the Total Absorption Calorimeter (TAC) capture detector with a set of three ²³⁵U loaded MicroMegas (MGAS) fission detectors for measuring simultaneously two reactions: capture and fission. The results presented here include the determination of the three detection efficiencies involved in the process: , and . In the test measurement we have succeeded in measuring simultaneously with a high total efficiency the ²³⁵U capture and fission cross-sections, disentangling accurately the two types of reactions. The work presented here proves that accurate capture cross-section measurements of fissile isotopes are feasible at n_TOF.