Mass Measurements of Stored Exotic Nuclei at Relativistic Energies

Relativistic exotic nuclei produced via projectile fragmentation were separated in flight by the fragment separator FRS and injected into the storage ring ESR for precise mass measurements using Schottky spectrometry. Nuclei with half-lives shorter than the time required for electron cooling have been investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique gives access to all nuclei with half-lives down to the μs-range.