Issue |
EPJ Web of Conferences
Volume 62, 2013
Fission 2013 – Fifth International Workshop on Nuclear Fission and Fission Product Spectroscopy
|
|
---|---|---|
Article Number | 08003 | |
Number of page(s) | 7 | |
Section | Fission Cross Sections | |
DOI | https://doi.org/10.1051/epjconf/20136208003 | |
Published online | 13 December 2013 |
https://doi.org/10.1051/epjconf/20136208003
Angular distribution in the neutron-induced fission of actinides
1 Institut de Physique Nucléaire, CNRS, Unviersité Paris-Sud, 91406 Orsay, France
2 Facultad de Fisica, Universidade de Santiago de Compostela, 15782, Spain
3 Johann-Wolfgang-Goethe Universität, Frankfurt, Germany
4 Uniwersytet Lódzki, Lodz, Poland
5 Istituto Nazionale di Fisica Nucleare, Bari, Italy
6 Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid, Spain
7 Charles University, Prague, Czech Republic
8 Commissariat à l'Energie Atomique (CEA) Saclay- Irfu, Gif-sur-Yvette, France
9 European Organization for Nuclear Research (CERN), Geneva, Switzerland
10 University of Manchester, Oxford Road, Manchester, UK
11 Department of Physics, Faculty of Science, University of Zagreb, Croatia
12 Universitat Politecnica de Catalunya, Barcelona, Spain
13 Instituto Tecnologico e Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa, Portugal
14 Universidad de Sevilla, Spain
15 National Technical University of Athens (NTUA), Greece
16 IFIC, Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, Spain
17 Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Italy
18 Aristotle University of Thessaloniki, Thessaloniki, Greece
19 Bhabha Atomic Research Centre (BARC), Mumbai, India
20 Atominstitut, Technische Universitat Wien, Austria
21 University of York, Heslington, York, UK
22 Karlsruhe Institute of Technology, Campus Nord, Institut für Kernphysik, Karlsruhe, Germany
23 Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA
24 University of Vienna, Faculty of Physics, Vienna, Austria
25 Dipartimento di Fisica, Universita di Bologna, and Sezione INFN di Bologna, Italy
26 Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile (ENEA), Bologna, Italy
27 Istituto Nazionale di Fisica Nucleare, Trieste, Italy
28 Horia Hulubei National Institute of Physics and Nuclear Engineering – IFIN HH, Bucharest – Magurele, Romania
29 European Commission JRC, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium
30 Department of Physics and Astronomy, University of Basel, Basel, Switzerland
31 Laboratori Nazionali del Gran Sasso dell'INFN, Assergi (AQ), Italy
32 Paul Scherrer Institut, Villigen PSI, Switzerland
33 Technical University of Munich, Munich, Germany
34 Department of Physics and Astronomy, University of Basel, Basel, Switzerland
Published online: 13 December 2013
Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC), for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n_TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered.
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.