Gießen 2007 – wissenschaftliches Programm

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HK: Fachverband Physik der Hadronen und Kerne

HK 15: Kern- und Teilchen-Astrophysik

HK 15.6: Vortrag

Dienstag, 13. März 2007, 15:30–15:45, E

Neutron capture cross section of ⁷⁶Ge — •Justyna Marganiec¹, Iris Dillmann¹, Cesar Domingo Pardo¹, Peter Grabmayr², and Franz Käppeler¹ — ¹Institut für Kernphysik, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany — ²Physikalisches Institut der Universität Tübingen, Morgenstelle 14, D-72076 Tübingen, Germany

The (n,γ) cross section of ⁷⁶Ge is important for s-process nucleosynthesis in Red Giant Stars as well as for obtaining reliable background estimates in double beta decay experiments. So far, this reaction has been described only by theoretical data. The present measurement was based on the activation technique. Neutrons were produced at the Karlsruhe Van de Graaff accelerator via the ⁷Li(p,n)⁷Be reaction. For proton energies just above threshold, one obtains a neutron spectrum similar to a Maxwellian distribution for kT = 25 keV. A set of samples was irradiated in this quasi-stellar neutron spectrum together with gold foils for normalization of the neutron flux. The results obtained at kT = 25 keV are presented and an extrapolation to lower and higher thermal energies is suggested.