Program - Brookhaven National Laboratory

F. Farget, J. Pancin
GANIL, Caen, France
F.-R. Lecolley, G. Lehaut
LPC, Caen, France
FALSTAFF
Collaboration
The Neutrons for Science (NFS) facility will be one of the SPIRAL2 installations. The NFS time-offlight
hall will allow studying neutron-induced reactions for energies going from some hundreds of kev
up to 40 MeV. Taking advantage of this new installation, the development of an experimental setup for
a full characterization of actinide fission fragments in this energy domain has been undertaken. In the
literature, fission fragment isotopic yields are scarce and neutron multiplicities are poorly known. All
these data are of particular interest for the nuclear community in view of the development of the fast
reactor technology and of reactors dedicated to the incineration of minor actinides. These arguments have
motivated the development of a new detection system called FALSTAFF (Four Arm cLover for the STudy
of Actinide Fission Fragments). Based on time-of-flight and residual energy technique, the setup will allow
the simultaneous measurement of the complementary fragments velocity and energy. The necessary timing
resolution will be obtained by using secondary electron detectors for the TOF measurement. Segmented
Ionisation chambers will be placed behind the stop detector to measure the fragment residual energies. The
nuclear charge and the kinetic energy of the two fragments in coincidence will be measured. The combined
measurements of velocity and energy provide information on the mass of the fragments before and after
the neutron evaporation. Neutron multiplicity as a function of the mass distribution may then be deduced
directly from the difference between pre- and post-neutron masses. In this paper, the motivations for the
FALSTAFF experiment will be presented. The experimental setup will be described and the performances
of main detectors of FALSTAFF will be discussed. Expected resolutions based on realistic Geant4 will be
shown. Preliminary results of a prototype experiment with a Cf source will be presented.
PD 7 5:30 PM
Measurements of the Mass and Isotopic Yields of the 233U(nth,f) Reaction at the
Lohengrin Spectrometer
F. Martin, C. Sage, G. Kessedjian, A. Bidaud, A. Billebaud, N. Capellan, S. Chabod, O. Méplan, LPSC
Grenoble, CNRS/IN2P3, 53 rue des Martyrs, F-38026 Grenoble, France. O. Sérot, CEA, DEN, DER,
SPRC, Cadarache Center, F-13108 Saint-Paul-lès-Durance, France. C. Amouroux, A. Letourneau, T.
Materna, CEA, IRFU, SPhN, Saclay Center, F-91191 Gif-sur-Yvette, France. C.O. Bacri, X. Doligez,
Institut de Physique Nucléaire (IPN) ,15 rue Georges CLEMENCEAU, F- 91406 Orsay, France. H.
Faust, U. Köster, Institut Laue Langevin, 6 rue Jules Horowitz, B.P. 156, F-38042 Grenoble, France. L.
Mathieu, CENBG, Chemin du Solarium, Le Haut Vigneau, BP 120, F-33175 Gradignan, France. R.
Cywinski, Dept. Chemical and Biological Sciences, Univ. of Huddersfield, Queensgate, Huddersfield West
Yorkshire. HD1 3DH, United Kingdom.
Growing world energy consumption has renewed the interest in nuclear power. The rise of nuclear reactors
implies the study of innovative systems that could rely not only on the currently used fuel cycle of Uranium-
Plutonium (U-Pu), but also on the Thorium-Uranium (Th-U) one. The studies of different innovative fuel
cycle aspects such as calculation of residual heat or poison concentration in the fuel, requires the knowledge
of detailed isotopic and mass fission yields. An experimental campaign has been initiated within the frame
of a collaboration between the Institut Laue-Langevin and French laboratories from CEA and CNRS
to complete the existing data on fission products yields. This paper will present the analysis and the
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