Elsevier

Nuclear Physics A

Volume 122, Issue 3, 30 December 1968, Pages 481-511
Nuclear Physics A

The evaporation of α-particles from heavy nuclei

https://doi.org/10.1016/0375-9474(68)90573-3Get rights and content

Abstract

Angular and energy distributions of emitted α-particles were measured in α-particle bombardments of Ta, Au and natural Pb at bombarding energies from 50 to 90 MeV. On the basis of the angular distributions and spectral shapes, it is possible to identify an evaporation component in the observed spectra. At backward angles, this component is generally an order of magnitude more intense than the other (direct-reaction) portion of the spectrum for outgoing α-particle energies between 15 and 25 MeV. For each bombardng energy and target, it was possible to determine values for the width of the evaporation spectrum and for the α-particle energy and the differential cross section at the peak of the spectrum. The observed values of these quantities were compared with those implied by the conventional statistical theory for particle evaporation from nuclei. It was found that the over-all quantitative agreement between theory and experiment over the entire range of observation was remarkably good. For best agreement, the value of the level density parameter a appears to lie between 17A and 110A. Some possible modifications to the usual formulation of evaporation theory are briefly discussed in connection with the small discrepancies which appear between the observations and the theory. Finally some predictions of cross sections are given for the evaporation from heavy nuclei of protons, deuterons, tritons and photons.

References (45)

  • M. Lefort et al.

    Nucl. Phys.

    (1966)
  • R.A. Esterlund et al.

    Nucl. Phys.

    (1965)
  • S. Fukushima et al.

    Nucl. Phys.

    (1965)
  • A. Rubbino et al.

    Nucl. Phys.

    (1966)
  • J. Muto et al.

    Nucl. Phys.

    (1963)
  • C. Hurwitz et al.

    Nucl. Phys.

    (1964)
  • J.R. Huizenga et al.

    Nucl. Phys.

    (1962)
  • D. Bodansky

    Ann. Rev. Nucl. Sci.

    (1962)
  • A.V. Malyshev

    Nuclear structure study with neutrons

  • V.F. Weisskopf

    Phys. Rev.

    (1937)
  • J.M. Blatt et al.

    Theoretical nuclear physics

  • J.D. Jackson

    Can. J. Phys.

    (1956)
  • D. Vinciguerra et al.

    Nucl. Phys.

    (1965)
  • R.M. Eisberg et al.

    Phys. Rev.

    (1954)
  • R.M. Eisberg et al.

    Phys. Rev.

    (1955)
  • R. Fox et al.

    Phys. Rev.

    (1961)
  • H. Dubost et al.

    Phys. Rev.

    (1964)
  • R.W. West

    Phys. Rev.

    (1966)
  • L.W. Swenson et al.

    Phys. Rev.

    (1966)
  • J.R. Huizenga et al.

    Phys. Rev.

    (1962)
  • I. Halpern

    Ann. Rev. Nucl. Sci.

    (1959)
  • W.J. Nicholson
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    Work supported in part by the US Atomic Energy Commission.

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