r-Process nucleosynthesis: Present status and future experiments at the FRS and ESR

No astrophysical process other than the rapid neutron capture process ( r process) is used more often to motivate the necessity of the new-generation radioactive beam facilities with higher beam intensities. In the dawn of these facilities (RIBF at RIKEN, FRIB at Michigan State University, and FAIR in Darmstadt) experiments carried out at the presently existing facilities mark a transition between the past and the future. Two such facilities are the Fragment Separator (FRS) and Experimental Storage Ring (ESR) at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt. Up to now one could only “scratch” the regions where the r process takes place–with the exception of the N = 126 region, which remains an experimental “terra incognita”. Owing to the upgrade of the GSI accelerator and to the development of new highly sensitive and efficient detection techniques in view of the future FAIR facility, planned experiments at the FRS and ESR aim at filling this gap, approaching the r -process path also at N = 126 .