Bonn 2020 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 58: Nuclear Astrophysics II

HK 58.6: Talk

Friday, April 3, 2020, 12:30–12:45, J-HS B

α-spectroscopy to determine ¹⁴⁴Sm(α,γ)¹⁴⁸Gd production — •Heinrich Wilsenach¹, Philipp Scholz², Andreas Zilges², and Kai Zuber¹ — ¹TU Dresden, Institut für Kern- und Teilchenphysik, Germany — ²University of Cologne, Institute for Nuclear Physics, 50937 Köln, Germany

Measurements of p-nuclei production rates help to shed some light on the observed abundances and help to constrain predictions made with extended reaction networks. One of the outstanding measurement is the ¹⁴⁴Sm(α,γ)¹⁴⁸Gd cross section [1]. The predicted cross section varies from the measurement by more than an order of magnitude [2], making this cross section the most uncertain p-process nuclide production. For this reason a re-measurement was performed using isotopically enriched ¹⁴⁴Sm, activated at various energies close to the Gamow window. The ¹⁴⁸Gd α-decay was used to determine the amount of the produced material. The decay rates were expected to be in the range of 4 per hour. To measure such a low count-rate an ultra-low background ionisation chamber at IKTP TU Dresden was used. The chamber achieved a background rate in the region of interest (1 MeV to 4 MeV) of around 0.27 counts per day per MeV. The subject of this talk is to describe the method used to determine the amount of ¹⁴⁸Gd produced in the (α,γ) activation of enriched ¹⁴⁴Sm samples. Advanced simulations are fitted to data to help constrain systematic uncertainties. [1] E. Somorjai et al. Astron. Astrophys. 333, (1998) 1112-1116 [2] T. Rauscher et al. Rep. Prog. Phys. 76, (2013) 066201 (38pp)