Constraining astrophysical reaction rates: using the storage rings at FAIR/GSI

Ion optical calculations for a storage ring at the present GSI facility for direct proton-induced reactions relevant for different astrophysical processes are presented. As an example case, the Cu-59(p, gamma) and Cu-59(p, alpha) reactions are shown. The branching of these two reactions is important in X-ray burst scenarios, since it determines the breakout out of the major Ni-56 waiting point.