Fragment Angular Distribution for Neutron Fission of 232Th and 238U

ORAL

Abstract

The fragment angular distribution data are crucial to the interpretation of the sub-barrier resonances. Recently structure is reported in neutron induced fission fragment angular distributions of even-even actinide nuclei near threshold. The fission fragment angular distributions of $^{232}$Th and $^{238}$U exhibit considerable structure in the vicinity of fission threshold. The energy dependence of fission fragment angular anisotropies for $^{232}$Th (n, f) and $^{238}$U (n, f) reactions have been calculated in the frame work of statistical model. The results have been compared with existing experimental data taken from the library of experimental nuclear reaction data (EXFOR). We have found that the periodic structure of anisotropy related to the set of (n, xn) reaction is not extended beyond the threshold of (n,4n) reaction at incident neutron energy En$\sim $25MeV. Above this a smooth decrease of fragment anisotropies is observed at higher neutron energies, results will be presented and discussed.

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Authors

  • A.N. Behkami

  • Andreas Bill

    Photonics CoE, Sciprint.org, LLNL, OSU, Imperial College London, General Atomis, UCSD, University of Milan, Instituto Superior Technico, University of Alberta, US Dept. of Agriculture, Agriculture Research Service, Parlier, CA, Dept. of Chemistry, California State University, Fresno, Dept. of Physics, California State University, Fresno, Weizmann Institute of Science, Stanford University, University of Connecticut, Storrs, UC Irvine, University of Missouri-Kansas City, California Institute of Technology, Ulm University, TU Darmstadt, UC Berkeley, GSFC, University of Regenberg, Germany, Lawrence Livermore National Laboratory, Clarendon Laboratory, Oxford, University of California, Los Angeles, Gesellschaft fuer Schwerionenforschung (GSI), Laboratoire pour l'Utilisation des Lasers Intenses, PSFC, MIT, University of California, Santa Barbara, Process Measurements Division, National Institute of Standards and Technology, Gaithersburg, MD, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, Division of Chemistry, California Institute of Technology, Pasadena, CA, Department of Physics, Fars Science and Research Center, Islamic Azad University, Texas A\&M University-Commerce, California State University, Long Beach, Materials Department, University of California Santa Barbara