Elsevier

Nuclear Physics A

Volume 462, Issue 2, 26 January 1987, Pages 385-412
Nuclear Physics A

The 12C(α, γ)16O cross section at stellar energies

https://doi.org/10.1016/0375-9474(87)90555-0Get rights and content

Abstract

The capture reaction 12C(α, γ)16O has been investigated at E = 0.94 to 2.84 MeV with the use of an intense α beam and implanted 12C targets of high isotopic purity. The studies involved NaI(Tl) crystals and, for the first time, germanium detectors. The measurement of absolute cross sections, γ-ray angular distributions and excitation functions is reported. A cross section of 48 pb is found at E = 0.94 MeV. The data provide information on the E1 and E2 capture amplitudes involved in the transition to the ground state as well as to excited states. The S-factor at stellar energies has been determined by means of theoretical fits. The results verify the previous report of a substantial higher S-value compared to the value recommended in 1975. The present uncertainty in the S-value as well as possible improvements are discussed. This S-value is of crucial importance to nuclear astrophysics.

References (35)

  • K.U. Kettner et al.

    Z. Phys.

    (1982)
  • P. Descouvement et al.

    Nucl. Phys.

    (1984)
  • C. Funck et al.

    Phys. Lett.

    (1985)
  • F. Ajzenberg-Selove

    Nucl. Phys.

    (1982)
  • A. Redder et al.

    Phys. Rev. Lett.

    (1985)
  • J.W. Hammer et al.

    Nucl. Instr. Meth.

    (1975)
  • A. Redder
  • S. Seuthe

    Diplomarbeit

    (1985)
  • C. Rolfs
  • A.M. Lane et al.

    Rev. Mod. Phys.

    (1958)
  • D.C. Weisser et al.

    Nucl. Phys.

    (1974)
  • G.J. Clark et al.

    Nucl. Phys.

    (1968)
  • F.C. Barker, private communication to S.E. Koonin and T.A. Tombrello, and preprint...
  • R. Plaga

    Diplomarbeit

    (1986)
  • W.A. Fowler

    Rev. Mod. Phys.

    (1984)
  • F.K. Thielemann et al.
  • S.E. Woosley
  • Cited by (0)

    Supported in part by the Deutsche Forschungsgemeinschaft (R5429/15-1), the U.S. National Science Foundation (PHY-8203699) and NATO (078.82), and through U.S.-Germany International Science Grants (NSF: INT-8203057; DFG: Ro429/13-3).

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