The York Research Database

The proton-rich isotope ⁶⁸Br was discovered in secondary fragmentation reactions of fast radioactive beams. Proton-rich secondary beams of ^70,71,72Kr and ⁷⁰Br, produced at the RIKEN Nishina Center and identified by the BigRIPS fragment separator, impinged on a secondary ⁹Be target. Unambiguous particle identification behind the secondary target was achieved with the ZeroDegree spectrometer. Based on the expected direct production cross sections from neighboring isotopes, the lifetime of the ground or long-lived isomeric state of ⁶⁸Br was estimated. The results suggest that secondary fragmentation reactions, where relatively few nucleons are removed from the projectile, offer an alternative way to search for new isotopes, as these reactions populate preferentially low-lying states.