Program - Brookhaven National Laboratory

from the Iwamoto-Harada(-Bisplinghoff) model [2–4], generalized by us some years ago [5]. Having in
mind the importance of nuclear deformation on the α emission, demonstrated by Blann and Komoto [6],
we follow the way initiated recently [7] and combine — though in a simplified manner — all the ingredients
together. Finally, we illustrate our approach on some examples.
[1] P. Obloˇzinsk´y: Phys. Rev. C35 (1987), 407; P. Obloˇzinsk´y, M.B. Chadwick: ibid. C42 (1990), 1652
[2] A. Iwamoto, K. Harada: Phys. Rev. C26 (1982), 1821 [3] J. Dobeˇs, E. Betak: in Internat. Conf.
React. Models 77, Balatonfüred, ed. L.P. Csernai, p. 195 [4] J. Bisplinghoff: Phys. Rev. C50 (1994), 1611
[5] E. Betak in Int. Conf. Nuclear Data for Sci. and Technol., Santa Fe 2004, eds. R.C. Haight, M.B.
Chadwick, T. Kawano, P. Talou. AIP Conf. Proc. 769 (2005), 1168. [6] M. Blann, T.T. Komoto: Phys.
Rev. C24 (1981), 426 [7] E. Betak: Eur. Phys. J. Web of Conf. 21 (2012), 09004
PC 6 5:15 PM
Angular Momentum Distribution of Fission Fragments
I. Stetcu, P. Talou, T. Kawano
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
M. Jandel
C-NR, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
Accurate modeling of prompt neutron and gamma-ray emission depends strongly on the initial angular
momentum of the fragments. However, no direct measurements of this quantity are available and, typically,
it has to be extracted from other fission observables such as isomeric ratios [1], gamma-ray de-excitation
feeding patterns of the ground-state bands [2] and angular anisotropy of prompt-fission gamma-rays [3].
The interpretation of measured isomeric ratios using statistical models [4] has been extensively used for
the determination of initial angular momentum of primary fission fragments. In this work, we use the
recently developed code CGMF [5], based on the Monte-Carlo Hauser-Feshbach approach, to simulate the
de-excitation of fission fragments. The isomeric ratios of the selected fission products are calculated as a
function of the initial angular momentum of the primary fission fragments, and compared with the available
experimental data. Finally, our results are used in full scale simulations of the primary fission fragment
de-excitation. Simulated prompt fission gamma-ray properties will be compared to recent experimental
results on prompt fission gamma-ray energy and multiplicity distributions obtained at DANCE facility at
LANSCE.
[1] J. R. Huizenga and R. Vandenbosch , Phys. Rev. 120, 1305 (1960); ibidem 1313 (1960); H. Naik, S.
P. Dange, and R. J. Singh, Phys. Rev. C 71, 014304 (2005). [2] J. B. Wilhelmy, E. Cheifetz, R. C. Jared,
S. G. Thompson, H. R. Bowman, and J. O. Rasmussen, Phys. Rev. C 5, 2041 (1972). [3] S. S. Kapoor
and R. Ramanna, Phys. Rev. 133, B598 (1964); M. M. Hoffman, Phys. Rev. 133, B714 (1964); [4] N. D.
Dudey and T. T. Sugihara, Phys. Rev. 139, B896 (1965). [5] B. Becker, P. Talou, T. Kawano, Y. Danon,
and I. Stetcu, to be submitted (2012).
PC 7 5:30 PM
Average Description of Dipole Gamma-Transitions in Hot Atomic Nuclei
V.A. Plujko, O.M. Gorbachenko, E.P. Rovenskykh
Nuclear Physics Department, Taras Shevchenko National University, Kyiv, Ukraine
V.A. Zheltonozhskii
Institute for Nuclear Research, NAS of Ukraine, Kyiv, Ukraine
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