Measurement of radiative α-capture cross sections on 98 Ru and 144 Sm for γ-process nucleosynthesis

• Published in: Journal of physics. Conference series 2020-10, Vol.1668 (1), p.12036
• Main Authors: Scholz, P., Wilsenach, H., Blazhev, A., Becker, H.-W., Heim, F., Fotinou, V., Giesen, U., Körschgen, M., Müller, M., Zell, K.O., Zilges, A., Zuber, K.
• Format: Article
• Language: English
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1668/1/012036

Since p isotopes cannot be produced in neutron-capture reaction networks, a production mechanism via photodisintegration reactions was proposed - the γ process. The specifc path of this reaction network, however, depends strongly on the statistically averaged ratios for proton-, neutron-, and α -decay widths. It was shown in the past, that the uncertainties in the α -decay widths have an impact on the isotopic abundance of the γ -process ashes. Besides systematic studies of the α +nucleus optical-model potential, direct measurements of (α, γ) reaction are needed to reduce the unpredictability of ( γ, α ) reaction rates. We present preliminary results from direct measurements of the 98 Ru( α,γ ) and 144 Sm( α,γ ) cross sections via in-beam measurements at the University of Cologne and the Ruhr-Universität Bochum and activation experiments at the Physikalisch-Technische Bundesanstalt in Braunschweig and the Technische Universität Dresden. The in-beam experiment might help to improve our understanding of the γ -process contribution to the p nuclei in the A ∼ 100 mass region, while the activation experiment is important for the determination of the initial isotopic abundance ratio of the 146 Sm/ 144 Sm chronometer.