Au-197(n, gamma) - towards a new standard for energies relevant to stellar nucleosynthesis

Author(s)

Claudia Lederer, N Colonna, I Dillmann, César Domingo-Pardo, Ulrich Giesen, Frank Gunsing, Michael Heil, Franz Käppeler, Cristian Massimi, Alberto Mengoni, Marita Mosconi, R Nolte, Rene Reifarth, S Schmidt, Anton Wallner

Abstract

Two experiments were performed to resolve a discrepancy of the Au-197(n, gamma) cross section between the IAEA standard evaluation and the reference cross section for astrophysical experiments in the lower keV energy region. We measured the Au-197(n, gamma) reaction by means of the time-of-flight technique with n_TOF at CERN and extracted the cross section in the unresolved resonance region between 5-400 keV with an overall uncertainty from 3.9-6.7% for a resolution of 20 bins per energy decade. Additionally, we remeasured the neutron spectrum of the Li-7(p, n)(7) Be reaction with E-p=1912 keV, which was used as a neutron source for determining the astrophysical reference cross section. The n TOF data are already fully analyzed and published. The results are in good agreement with the ENDF standard evaluation, but uncertainties don't allow to draw definite conclusions. The analysis of the neutron spectrum of Li-7(p, n)Be-7 is underway, preliminary results will be reported here.

Organisation(s)

Isotope Physics

External organisation(s)

Istituto Nazionale di Fisica Nucleare (INFN), Roma, Karlsruher Institut für Technologie, Universitat de València, Physikalisch-Technische Bundesanstalt, French Alternative Energies and Atomic Energy Commission (CEA), International Atomic Energy Agency (IAEA), GSI Helmholtzzentrum für Schwerionenforschung, Johann Wolfgang Goethe-Universität Frankfurt am Main

Journal

Journal of Physics: Conference Series

Volume

337

No. of pages

5

ISSN

1742-6588

DOI

https://doi.org/10.1088/1742-6596/337/1/012045

Publication date

2012

Peer reviewed

Yes

Austrian Fields of Science 2012

1030 Physics, Astronomy

Portal url

https://ucrisportal.univie.ac.at/en/publications/ab394c7c-f2b1-4652-87be-9bade2ab0cc8