0000000000065117
AUTHOR
A. Kohl
High-accuracy mass determination of unstable cesium and barium isotopes
Direct mass measurements of short-lived Cs and Ba isotopes have been performed with the tandem Penning trap mass spectrometer ISOLTRAP installed at the on-line isotope separator ISOLDE at CERN. Typically, a mass resolving power of 600 000 and an accuracy of $\delta \mbox{m} \approx 13$ keV have been obtained. The masses of $^{123,124,126}$Ba and $^{122m}$Cs were measured for the first time. A least-squares adjustment has been performed and the experimental masses are compared with theoretical ones, particularly in the frame of a macroscopic-microscopic model.
Accurate masses of neutron-deficient nuclides close to
Abstract Mass measurements with the Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN are extended to nonsurface ionizable species using newly developed ion-beam bunching devices. Masses of 179–197Hg, 196,198Pb, 197Bi, 198Po and 203At were determined with an accuracy of 1×10 −7 corresponding to δm≈20 keV. Applying a resolving power of up to 3.7×10 6 ground and isomeric states of 185,187,191,193,197Hg were separated. First experimental values for the isomeric excitation energy of 187,191Hg are obtained. A least-squares adjustment has been performed and theoretical approaches are discussed to model the observed fine structure in the binding energy.
Direct mass measurements of unstable rare earth isotopes with the ISOLTRAP mass spectrometer
Abstract Direct mass measurements of neutron deficient rare earth isotopes in the vicinity of 146 Gd were performed for the first time with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. Since ISOL-facilities deliver these isotopes with a large amount of isobaric contamination, these measurements became possible only after the installation of a new cooler trap which acts as an isobar separator. To date more than 40 isotopes of the elements Pr, Nd, Pm, Sm, Eu, Dy, and Ho have been measured with a typical accuracy of δm ≈ 14 keV. Some of these isotopes provide an important anchor for many other isotopes linked by known Q-values.
Towards higher accuracy with the ISOLTRAP mass spectrometer
To now the masses of more than hundred unstable isotopes have been determined with the ISOLTRAP mass spectrometer installed at ISOLDE/CERN. Typically a resolving power of mΔm ≈ 1 × 106 was used and the mass determinations were assigned an accuracy of δmm ≈ 1 × 10−7. We show that with improvements to ISOLTRAP and refinements of the experimental technique an accuracy of δmm ≈ 3 × 10−8 can be obtained.