Speaker
Arnd R. Junghans
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany)
Description
The gamma ray strength function of heavy nuclei is an important quantity to determine
their reaction rates in in high temperature environments envisioned in explosive nucleosynthesis.
Especially p-process nuclides are formed through sequences of photodisintegrations from sand
r-process seeds. In these reactions the gamma ray strength function around the neutron
separation energy on the low energy side of the giant dipole resonance plays a decisive role.
Recently, photon scattering and photodisintegration experiments [1] have been made at the
ELBE accelerator at FZ Dresden Rossendorf in this energy range and the gamma ray strength
function has been investigated.
Based on these data a new parameterization [2] of the electric dipole strength is proposed
which can be of great importance for cosmic nucleosynthesis calculations. With only two new
parameters it allows us to describe the dipole strength in all heavy nuclei with A> 80. Although
it differs significantly from previous parameterizations it holds for spherical, transitional, triaxial
and well deformed nuclei. The GDR spreading width depends in a regular way on the
respective resonance energy, but it is independent of the gamma ray energy.
[1] M. Erhard et al., C. Nair et al. Proc. Int. Conf. Nuclear Physics in Astrophysics IV,
Frascati, 2009; C. Nair et al. Phys. Rev. C 78 (2008) 055802; R. Schwengner et al., Phys.
Rev. C 77 (2008) 064321.
[2] A.R. Junghans et al. Phys. Lett. B 670 200 (2008).
Author
Arnd R. Junghans
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany)
Co-authors
A. Wagner
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany)
E. Grosse
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany and Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden, 01062 Dresden, Germany)
G. Rusev
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany)
R. Schwengner
(Forschungszentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden, Germany)