Measurement of neutron capture and fission cross sections of ²³³U in the resonance region

¹ Centre d'Etudes Nucléaires Bordeaux Gradignan, CNRS/IN2P3, Univ. Bordeaux 1, Chemin du Solarium, 33175 GRADIGNAN, France
² Laboratoire de Physique Subatomique et de Cosmologie, CNRS/IN2P3, Univ. Joseph Fourier, INPG, 53 avenue des Martyrs, FR – 38026 Grenoble Cedex, France
³ EC-JRC, Institute for Reference Materials and Measurements, Reteiseweg 111, B-2440 Geel, Belgium
⁴ Horia-Hulubei National Institute for Physics and Nuclear Engineering, P. O. Box MG-6, 077125 Bucharest-Magurele, Romania

^a e-mail: companis@cenbg.in2p3.fr

Abstract

In the framework of studies concerning new fuel cycles and nuclear wastes incineration experimental data of the α ratio between capture and fission cross sections of ²³³U reactions play an important role in the Th/U cycle. The safety evaluation and the detailed performance assessment for the generation IV nuclear-energy system based on ²³²Th cycle strongly depend on this ratio. Since the current data are scarce and sometimes contradictory, new experimental studies are required. The measurement will take place at the neutron time-of-flight facility GELINA at Geel, designed to perform neutron cross section measurements with high incident neutron-energy resolution. A dedicated high efficiency fission ionization chamber (IC) as fission fragment detector and six C₆D₆ liquid scintilators sensitive to γ-rays and neutrons will be used. The method, based on the IC energy response study, allowing to distinguish between gammas originating from fission and capture, in the resonance region, will be presented.