Elsevier

Nuclear Physics A

Volume 430, Issue 1, 19 November 1984, Pages 21-60
Nuclear Physics A

Fission yields at different fission-product kinetic energies for thermal-neutron-induced fission of 239Pu

https://doi.org/10.1016/0375-9474(84)90191-XGet rights and content

Abstract

At the recoil spectrometer “Lohengrin” of the Institut Laue-Langevin in Grenoble, the yields of the light fission products from the thermal-neutron-induced fission of 239Pu were measured as a function of A, Z, the kinetic energy E and the ionic charge states q. The nuclear charge and mass distributions summed over all ionic charge states were determined for different light fissionproduct kinetic energies between 93 and 112 MeV. The proton odd-even effect which was measured to be (11.6 ± 0.6)% causes considerable fine structure in the yields. The average kinetic energy of even-Z elements in the light fission-product group is 0.3 ± 0.1 MeV larger than for odd-Z elements. The neutron odd-even effect is (6.5 ± 0.7)%. The comparison with previously published data 1) for thermal-neutron-induced fission of 235U reveals a correlation between the proton odd-even effect in the yield and in the kinetic energy of the elements. The dependence of the proton odd-even effect on the fragmentation is very similar for 235U and 239Pu when it is considered as a function of the nuclear charge of the heavy fission products. The isobaric variances σz2. for thermal-neutron fission of 235U and 239Pu coincide at all kinetic energies if the influence of the proton odd-even effect is averaged out. This supports the hypothesis that the magnitude of σz2 is determined only by quantum-mechanical zero-point fluctuations. The influence of the spherical shells Z = 50 and N = 82 on the fragmentation is discussed.

References (33)

  • W. Lang et al.

    Nucl. Phys.

    (1980)
  • G. Mariolopoulos et al.

    Nucl. Phys.

    (1981)
  • E.A.C. Crouch

    At. Nucl. Data Tables

    (1977)
  • R. Brissot et al.

    Nucl. Phys.

    (1977)
  • E. Moll et al.

    Nucl. Instr. Meth.

    (1975)
  • H. Wohlfarth et al.

    Phys. Lett.

    (1976)
  • U. Quade et al.

    Nucl. Instr. Meth.

    (1979)
  • H.-G. Clerc et al.

    Nucl. Instr. Meth.

    (1975)
  • M. Asghar et al.

    Nucl. Phys.

    (1978)
  • V.S. Nikolaev et al.

    Phys. Lett.

    (1968)
  • A.C. Wahl et al.
  • H. Nifenecker et al.
  • H.-G. Clerc et al.
  • E. Moll et al.

    Kerntechnik

    (1977)
  • S. Amiel et al.

    Phys. Rev.

    (1977)
  • H. Wohlfarth et al.

    Z. Phys.

    (1978)
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