First isochronous time-of-flight mass measurements of short-lived projectile fragments in the ESR.

We present a new method for precise mass measurements of short-lived hot nuclei. These nuclei were produced via projectile fragmentation, separated with the FRS and injected into the storage ring ESR being operated in the isochronous mode. The revolution time of the ions is measured with a time-of-flight detector sensitive to single particles. This new method allows access to exotic nuclei with half-lives in the microsecond region. We report on first results from this novel method obtained with measurements on neutron-deficient fragments of a chromium primary beam with half-lives down to 50 ms. A precision of δm/m≤5·10[sup -6] has been achieved. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]