Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 29, 1987 | public
Journal Article

The ^2H(d,γ) ^4He reaction at low energy and the D-state admixture in ^4He

Abstract

The cross section and angular distribution of the ^2H(d,γ) ^4He reaction have been measured from E^(CM) = 50 to 500 keV. For E⩽200 keV, the observed near-constant cross-section S-factor and isotropy show that the dominant radiative capture amplitude is ^5S_2→^5D_0, instead of the ^1D_2→^1S_0 amplitude that dominates at higher energies. Thus the ^4He D-state admixture can be determined from the low-energy cross section alone. Values obtained from different models range up to 14%. As the new astrophysical S-factor is 32 times larger than previously estimated, it will likely affect inhomogeneous big-bang nucleosynthesis models.

Additional Information

© 1987 Elsevier. Received 24 June 1987. Two of us (TRD and CR) wish to acknowledge the hospitality of the W.K. Kellogg Radiation Laboratory. Fruitful discussions with W.A. Fowler, R.W. Kavanagh, T.A. Tombrello, and R.V. Wagoner are acknowledged. We thank U. Schroder for the DC calculations, A. Rice for assistance, and H.J. Assenbaum, K. Langanke, J. Piekarewicz, and S.E. Koonin for communication of their analyses prior to publication. This work was performed in part under the Department of Energy contract W-7405-Eng-48 with the Lawrence Livermore National Laboratory, and was also supported in part by the National Science Foundation, Grants PHY85-05682 at Caltech and PHY85-04733 at Ohio State University.

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023