Program - Brookhaven National Laboratory

OA 2 2:00 PM
Event-by-Event Fission Modeling of Prompt Neutrons and Photons from Neutron-Induced
and Spontaneous Fission with FREYA
R. Vogt
Lawrence Livermore National Laboratory, Livermore, CA 94551, USA, Physics Department, University
of California at Davis, Davis, CA 95616, USA
J. Randrup
Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
The event-by-event fission Monte Carlo code FREYA (Fission Reaction Event Yield Algorithm) generates
large samples of complete fission events [1-3]. Using FREYA, it is possible to obtain the fission products as
well as the prompt neutrons and photons emitted during the fission process, all with complete kinematic
information. We can therefore extract any desired correlation observables. Concentrating on 239 Pu(n,f),
240 Pu(sf) and 252 Cf(sf), we compare our FREYA results with available data on prompt neutron and photon
emission and present predictions for novel fission observables that could be measured with modern detectors.
We also describe how FREYA is being made available to the user community. The work of R.V. was
performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory
under Contract DE-AC52-07NA27344. The work of J.R. was performed under the auspices of the U.S.
Department of Energy by Lawrence Berkeley National Laboratory under Contract DE-AC02-05CH11231.
[1] J. Randrup and R. Vogt, Phys. Rev. C 80, 024601 (2009). [2] R. Vogt and J. Randrup, Phys. Rev. C
84, 044621 (2011). [3] R. Vogt and J. Randrup, in preparation.
OA 3 2:20 PM
Investigation of n+ 238 U Fission Observables
O. Litaize, D. Regnier, O. Serot, C. Manailescu
CEA, DEN, DER, Physics Studies Laboratory, F-13108 Saint Paul Lez Durance. FRANCE.
The Monte Carlo simulation of the fission fragment deexcitation using FIFRELIN code [1] is used to
study fission observables from fast fission of 238 U using multi-modal parameters from Birgersson et al. [2]
but also mass yields and kinetic energy data as a function of pre-neutron fragment mass. This release
of the code is able to simulate prompt neutrons and gammas from two different calculation schemes (i)
an uncoupled scheme (in the sense neutron/gamma) using Weisskopf statistical theory and (ii) a coupled
scheme based on Hauser-Feschbach statistical theory recently implemented [3]. A quick review of the
models and hypothesis used in the code FIFRELIN is presented, and fission observables such as prompt
spectra and multiplicities of the reaction 238 U(n,f) for several incident neutron energies are calculated using
different model parameters and discussed.
[1] O. Litaize, O. Serot, Physical Review C82, 054616 (2010). [2] E. Birgersson, A. Oberstedt, S. Oberstedt,
F.-J. Hambsch, Nuclear Physics A817, 1-34 (2009). [3] D. Regnier, O. Litaize, O. Serot, Physics Procedia
31, 59 (2012).
OA 4 2:40 PM
Study for Heavy-Ion Induced Fission for the Heavy Element Synthesis
K. Nishio, H. Ikezoe, H. Makii, S. Mitsuoka, Y. Nagame, I. Nishinaka, Advances Science Research Center,
Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan. S. Hofmann, F.P. Hessberger, D.
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