Exploring nuclear astrophysics with heavy-ion storage rings

Heavy-ion storage rings coupled to radioactive ion beam facilities offer unique capabilities for nuclear structure and astrophysics experiments. There are presently three operational facilities, namely the Experimental Storage Ring (ESR) at GSI in Darmstadt, Germany, the experimental Cooler-Storage Ring (CSRe) at IMP in Lanzhou, P. R. China, and the Rare-RI Ring (R3) Facility at RIKEN at which several research programs are being pursued. Well-established are mass measurements of short-lived nuclei as well as decay studies of highly-charged radionuclides. These nuclear properties are the important input for the astrophysical nucleosynthesis calculations. While the former determine the pathways of nucleosynthesis processes on the chart of nuclides, the latter affect the final elemental abundances. In addition, storage rings are being considered for nuclear reaction studies. Compared to external target experiments, here a thin windowless internal gas target combined with high revolution frequencies of stored ions offer advantageous conditions for a range of experiments. For instance it has been shown that proton capture reactions can successfully be measured in the ESR. The goal is to conduct proton and alpha-capture reactions directly in the Gamow window of the astrophysical p-process. Research programs at storage rings have proven their high discovery potential, which is clearly indicated by a number of new storage ring projects started around the world. ASTRUm stands for \Astrophysics with SToRed highly charged radionUclides" and is a project receiving funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 682841 \ASTRUm") This is a small research group within the Atomic Physics Division of GSI in Darmstadt which conducts research in domain of experimental astrophysics at storage rings. There are four key objectives of the grant which will be discussed in details in this presentation.