0000000000338760

AUTHOR

T. Winkler

Mass measurement of cooled neutron-deficient bismuth projectile fragments with time-resolved Schottky mass spectrometry at the FRS-ESR facility

Masses of 582 neutron-deficient nuclides ($30\leq{Z}\leq{85}$) were measured with time-resolved Schottky mass spectrometry at the FRS-ESR facility at GSI, 117 were used for calibration. The masses of 71 nuclides were obtained for the first time. A typical mass accuracy of 30 $\mu$u was achieved. These data have entered the latest atomic mass evaluation. The mass determination of about 140 additional nuclides was possible via known energies ($Q$-values) of $\alpha-$, $\beta-$, or proton decays. The obtained results are compared with the results of other measurements.

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First isochronous mass spectrometry at the experimental storage ring ESR

Short-lived exotic nuclei can be produced and separated with the high-energy secondary nuclear beam facility FRS at GSI. These nuclides can be injected and stored in the storage ring ESR. The lower lifetime limit of the presently existing methods for mass measurements on these nuclides at the ESR is about a few seconds. We have developed and investigated an isochronous operational mode of the ESR, that makes mass measurements of nuclides with lifetimes down to a few ls feasible. It has been commissioned in experiments using long-lived nuclides with known masses. A mass resolving power of about 150 000 has been achieved in a "rst pilot experiment. A suitable detector system has been implemen…

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Schottky mass measurements of stored and cooled neutron-deficient projectile fragments in the element range of 57≤Z≤84

Abstract A novel method for direct, high precision mass measurements of relativistic exotic nuclei has been successfully applied in the storage ring ESR at GSI. The nuclei of interest were produced by projectile fragmentation of 930 MeV / u bismuth ions, separated in-flight by the fragment separator FRS, stored and cooled in the ESR. The mass values have been deduced from the revolution frequencies of the coasting cooled ions. We have measured 104 new mass values with a precision of about 100 keV and a resolving power of 3.5×10 5 for the neutron-deficient isotopes of the elements 57≤Z≤84 . This paper presents the experimental method, the mass evaluation and a table of the experimental mass …

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