Studies of two-body-decays at the FRS-ESR facility

A combination of the in-flight projectile fragment separator and the heavy-ion storage-cooler ring has been used to produced store and investigate cooled highly charged ions. The results of recently Performed experiments, at GSI Darmstadt studying two-body beta-decays of H-like and He-like ions are presented. The technique of Schottky lifetime spectroscopy has been applied to explore the electron capture and bound-state beta(-) decay processes of ions circulating in the heavy-ion storage ring.