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Recent progress is presented from experiments on masses and lifetimes of bare and few-electron exotic nuclei at GSI. Relativistic rare isotopes produced via projectile fragmentation and fission were separated in flight by the fragment separator FRS and injected into the storage ring ESR. This worldwide unique experimental technique gives access to all fragments with half-lives down to the microsecond range. The great research potential is also demonstrated by the discovery of new isotopes along with simultaneous measurements of mass and lifetime. Representative results from time-resolved Schottky mass spectrometry are compared with modern theoretical predictions. The measured isospin dependence of pairing-gap energies is not reproduced by conventional mass models. The first direct observation of bound-state beta decay has been achieved. Single particle decay measurements and the continuous recording of both stored mother and daughter nuclei open up a new era for spectroscopy. The combination of stochastic and electron cooling has allowed us to measure with Schottky analysis for the first time short-lived isomers. The future international NUSTAR facility at FAIR consisting of a new large-acceptance in-flight separator (Super-FRS) will be an ideal tool to study the r- and rp-process nuclei. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Schottky Mass Spectrometry turned out to be an excellent tool for systematic nuclear mass measurements. The newly developed data acquisition system [1] which yields several advantages for the data analysis, was used for the first time in Nov. 1997. Instead of online Fourier transformation as in former measurements [2,3] the signal is now digitized with a sampling rate of 640 kHz (16 bits of resolution) and stored as time-captures. With a continuous data rate of 1.2MB/s nearly 1TB of raw data were stored. The Fast Fourier Transformation offline analysis allows the study of the dynamical behavior of the stored ions in the ESR including cooling forces and decay. The new spectra contain enough reference nuclei to determine the deviations from the constant momentum compaction factor α[sub p]. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

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]