Exploring the uncertainties of (α, xn) reactions for the weak r-process

¹ Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstr. 2, Darmstadt 64289, Germany
² GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, Darmstadt 64291, Germany
³ Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
⁴ Institute of Nuclear & Particle Physics, Department of Physics & Astronomy, Ohio University, Athens, OH, 45701 USA
⁵ Institute for Nuclear Research (ATOMKI), H-4001 Debrecen, Bem tér 18/c, Hungary
⁶ National Superconducting Cyclotron Laboratory, East Lansing, MI, 48824, USA
⁷ Joint Institute for Nuclear Astrophysics – Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
⁸ Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore CA USA 94550

^* e-mail: psaltis@theorie.ikp.physik.tu-darmstadt.de

Published online: 24 February 2022

Abstract

“Light” heavy elements (Z = 38 − 47) can be synthesized in the neutrino–driven ejecta of core–collapse supernovae via the weak r–process. This nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from (α, n) reactions on neutron–rich nuclei, and are mostly based on statistical model calculations. We present preliminary results from a recent sensitivity study, using the Atomki–V2 α-nucleus potential to identify the most important (α, n) reactions that can affect the production of “light” heavy elements between strontium and silver under different astrophysical conditions. We also discuss the planning of studies to experimentally determine (α, xn) reaction rates using the MUSIC detector at Argonne National Laboratory and the SECAR recoil separator at FRIB.