1. Gamma-ray strength functions and their relation to astrophysics.
- Author
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Larsen, A. C., Goriely, S., Algin, E., Agvaanluvsan, U., Bürger, A., Görgen, A., Guttormsen, M., Hagen, T. W., Lönnroth, T., Mitchell, G. E., Nyhus, H. T., Rekstad, J. B., Renstro\m, T., Rose, S. J., Ruud, I. E., Schiller, A., Siem, S., Syed, N. U. H., Toft, H. K., and Tveten, G. M.
- Subjects
NUCLEAR astrophysics ,GAMMA rays ,NUCLEAR reactions ,NEUTRON capture ,NEUTRON cross sections ,PARTICLES (Nuclear physics) ,TIN isotopes ,RESONANCE - Abstract
The nuclear γ-ray strength function is one of the indispensable inputs needed for reaction-rate calculations, and is particularly important for the neutron-capture cross section. The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract simultaneously nuclear level density and γ-ray strength function from particle-γ coincidence measurements. Data on the strength functions of Sn nuclei as well as for lighter elements are presented. The Sn isotopes all display a resonance-like structure close to the neutron threshold, that could possibly be due to the neutron-skin oscillation mode. This so-called pygmy dipole resonance greatly influences the neutron-capture rates. In the lighter nuclei, an enhancement of the strength function at low γ energies is observed. The possible impact of this increase on Maxwellian-averaged reaction rates has been investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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