Heidelberg 2015 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 58: Nuclear Astrophysics 4
HK 58.6: Vortrag
Donnerstag, 26. März 2015, 18:15–18:30, K/HS2
Activation measurements of α-induced reactions at sub-Coulomb energies — •Philipp Scholz1, Anne Endres2, Alfred Dewald1, Stefan Heinze1, Jan Mayer1, Claus Müller-Gatermann1, Lars Netterdon1, and Andreas Zilges1 — 1Institute for Nuclear Physics, University of Cologne — 2Institute for Applied Physics, Goethe University Frankfurt am Main
Network calculations of the γ process rely almost completely on theoretically predicted reaction rates within the scope of the Hauser-Feshbach Statistical Model. Especially the prediction of cross sections for (γ,α)-reactions at energies within or close to the astrophysically relevant energy window remains a problem due to the uncertainties in the underlying α-optical-model potentials. Although experimental values far above the Coulomb-barrier are well reproduced, commonly used α-optical potentials often fail to describe the trend at energies comparable to those at astrophysical sites of the γ process. Improvements of the adopted optical-model potentials are hampered by the lack of experimental cross sections at sub-Coulomb energies. In order to enlarge the experimental data base, cross sections of the 187Re(α,n) and 108Cd(α,n) reactions were investigated using the activation technique with the Cologne Clover Counting Setup. Besides recent experimental results, future plans for more sensitive cross-section studies applying Accelerator Mass Spectrometry using CologneAMS will be presented.
Partly supported by the DFG (ZI 510/5-1 and INST 216/544-1) and the ULDETIS project within the UoC Excellence Initiative institutional strategy.