Program - Brookhaven National Laboratory

Ackermann, V.F. Comas, S. Heinz, J.A. Heredia, J. Khuyagbaatar, I. Kojouharov, B. Lommel, R. Mann,
GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany. Y. Aritomo, A.G.
Popeko, A.V. Yeremin, Flerov Laboratory of Nuclear Reactions, JINR, 141980 Dubna, Russia. Y.
Wakabayashi, Nishina-Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198, Japan.
S. Antalic, S. Saro, Department of Nuclear Physics and Biophysics, Comenius University, 84248
Bratislava, Slovakia. K. Hirose, T. Ohtsuki, Laboratory of Nuclear Science, Tohoku University, Sendai
982-0826, Japan. Y. Watanabe, High Energy Accelerator Organization (KEK), Tsukuba 305-0801, Japan.
K. Hagino, Department of Physics, Tohoku University, Sendai 980-8597, Japan.
Fission fragment mass and kinetic energy distributions were measured in the reactions of 30 Si, 31 P, 34,36 S,
40 Ar, 40,48 Ca + 238 U at energies around the Coulomb barrier [1-3]. The mass distributions changed
drastically with incident energy. The results are explained by a change of the ratio between fusion and
quasifission with nuclear orientation. A calculation based on a fluctuation dissipation model reproduced
the mass distributions and their energy dependence [4]. Fusion probability was defined as the ratio of
fusion-fission events to total fission events and was obtained in the calculation to determine the cross
sections to produce superheavy nuclei (SHN). The calculated cross sections agreed with the experimental
data for 263,264 Sg [2] and 267,268 Hs [3] produced in the reactions of 30 Si+ 238 U and 34 S+ 238 U, respectively. It
is shown that the reaction at sub-barrier energies can be used for heavy element synthesis. The calculation
for 48 Ca+ 238 U also demonstrated that the SHN can be produced at lower incident energies than those used
to produce the copernicium isotopes in [5,6], suggested that more neutron rich SHN can be produced with
smaller number of neutron evaporation.
[1] K. Nishio et al., Phys. Rev. C, 77, 064607 (2008). [2] K. Nishio et al., Phys. Rev. C,82, 044604 (2010).
[3] K. Nishio et al., Phys. Rev. C, 82, 024611 (2010). [4] Y. Aritomo et al., Phys. Rev. C, 82, 044614
(2012). [5] Yu.Ts. Oganessian et al., Phys. Rev. C, 70, 064609 (2004). [6] S. Hofmann et al., Eur. Phys.
J. A 32, 251 (2007).
Session OB assimilation
Thursday March 7, 2013
Room: Met West at 1:30 PM
OB 1 1:30 PM
Progress on Consistent Nuclear Data Assimilation
G. Palmiotti, M. Salvatores, H. Hiruta, M.W. Herman, S. Hoblit, A. Palumbo, G. Nobre
INL, CEA, BNL
The major drawback of the classical adjustment method is the potential limitation of the domain of
application of the adjusted data. The multigroup structure, the neutron spectrum used as weighting
function and the code used to process the basic data file are significant constraints to these adjustments
which are made on the multigroup data. A new approach has been developed in order to adjust physical
parameters and not multigroup nuclear data with the objective being to correlate the uncertainties of
some basic parameters that characterize the neutron cross section description to the discrepancy between
calculated and experimental values for a large number of clean, high accuracy integral experiments. In
an ND2010 paper, the first application of the methodology (applied to the nuclear data of 23Na and
using neutron propagation experiments) was presented. This paper is devoted to progress made on the
methodology when applied to fissile isotopes as well as to a fission product isotope. A series of integral
experiments were analyzed using the EMPIRE evaluated files for 235U, 239Pu, 242Pu and 105Pd. In
most cases, the results have deviated more with respect to those of the corresponding existing evaluations
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