Influence of spin on the fragment Anisotropies

ORAL

Abstract

Several selected fission fragment angular distributions when at least one of the spins of the projectile or target is appreciable have been investigated. The known experimental data for example$^{11}$B+$^{209}$Bi was analyzed by means of the Couple Channel spin formulism. This formulism suggests that the projectile spin has sizable effect on the angular anisotropies within the limits of energy near the fusion barrier. The analysis of the fission fragment angular distributions has also made using the statistical secession model (SSM). Variance K$^{2}_{o}$ of the K distribution are compared with their corresponding S$^{2}_{o}$ values. It turns out that the variances from these two models differ by about 20{\%} for most cases studied. However, in the case of $^{12}$C+ $^{237}$Np the value of K$^{2}_{o}$ is comparable with its corresponding S$^{2}_{o}$ value. This suggests that the effect of the projectile spin on angular anisotropies is more noticeable. The effect of the choice of the level density parameter of the compound nucleus on angular anisotropies has also been investigated. It is found that angular anisotropies are very sensitive to level density parameter. It turns out that the experimental anisotropies are well produced with the model calculation using higher values of the level density predicted by Fermi gas model. This effect will be presented and discussed.

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Authors

  • A.N. Behkami

    Fars Science and Research Center, Islamic Azad University, Iran

  • John Poate

    Brigham Young University, Los Alamos National Laboratory, Department of Physics and Astronomy, University of Utah, USA, MV Systems, Inc., USA, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Abteilung Silizium-Photovoltaik, Germany, Colorado School of Mines, Department of Physics, USA, Georgia Institute of Technology, Arizona State University, Physics Department of Babolsar University, Iran, Physics Department, New Mexico State University, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-1604, USA, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA, Department of Physics, Arizona State University, Tempe, AZ, 85287-1504, USA, Colorado State University, University of Wisconsin, NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, BYU-Provo, Michigan Technical University and Pierre Auger Collaboration, University of Colorado, Colorado School of Mines, Department of Physics, Colorado State University, Department of Physics, Cornell University, NASA, University of Massachusetts at Amherst, University of Massachusetss at Amherst, APS President, Harvard University, Society of Physics Students, Duke University, Computer Science, Brigham Young University, Chemistry \& Biochemistry, Brigham Young University, University of Arizona, University of Utah, Kansas State Univ., Bethel University, University of New Mexico, Stanford University, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, National Renewable Energy Laboratory, University of Denver, University of Colorado, Boulder, NREL, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287- 1604, USA, DU, ERI, Eleanor Roosevelt Institute (ERI), Cerro Tololo Interamerican Observatory, Utah State University, Center for Atmospheric and Space Sciences, Sciprint.org, University of Colorado at Boulder, JILA and University of Colorado, Kirchhoff Institute for Physics, University of Heidelberg, Utah Valley University, University of New South Wales, San Francisco State University, Weber State University, Cambridge University, Department of Physics and Astronomy, University of Utah, Kansas State University, Columbia University, NY, University of Colorado/JILA, Vice-President for Research and Technology Transfer, Colorado School of Mines