Berlin 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MS: Fachverband Massenspektrometrie
MS 6: Poster
MS 6.7: Poster
Mittwoch, 19. März 2014, 14:00–14:00, DO24 Foyer
Probing the shell closure at N=32 by mass measurements of neutron-rich potassium isotopes — •M. Rosenbusch1, D. Beck2, K. Blaum3, Ch. Borgmann3, M. Breitenfeldt4, R. B. Cakirli3,5, S. George1, F. Herfurth2, M. Kowalska6, S. Kreim3,6, D. Lunney7, V. Manea7, D. Neidherr2,3, L. Schweikhard1, J. Stanja8, F. Wienholtz1, R. Wolf1, and K. Zuber8 — 1Ernst-Moritz-Arndt-Universität, Institut für Physik, 17487 Greifswald — 2GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt — 3Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg — 4Katholieke Universiteit, 3000 Leuven, Belgium — 5University of Istanbul, 334452 Istanbul, Turkey — 6CERN, CH-1211 Geneva, Switzerland — 7CSNSM-IN2P3-CNRS, Université Paris-Sud, 91406 Orsay, France — 8Technische Universität Dresden, 01069 Dresden
The Penning-trap mass spectrometer ISOLTRAP at the on-line isotope separator ISOLDE/CERN has been set up for precision mass measurements of short-lived nuclides and has been continuously improved for accessing more exotic nuclides. A crucial step forward has been made with the installation of a multi-reflection time-of-flight mass separator (MR-ToF MS), which enables high-resolution mass separation of contaminated ions, resulting, e.g., in the measurement of the nuclide 82Zn [1]. More recently, nuclear mass measurements have been performed directly in the MR-ToF MS instead of using a Penning trap. This paved the way for the determination of the masses of 53,54Ca [2], which would not have succeeded in ISOLTRAP’s Penning traps. The obtained two-neutron separation energies (S2n) unambiguously confirm a shell closure at N=32, which has been indicated earlier by measurements of the excitation energies of the first 2+ state in 52Ca [3]. In addition, with the MR-ToF MS at ISOLTRAP the masses of 52K and 53K have been determined for the first time. With a half-life of only 30 ms, 53K is the shortest-lived nuclide ever investigated at ISOLTRAP. The data are currently under evaluation. In this contribution, the new S2n values will be presented and the crossing of the neutron shell closure at N=32 for potassium will be discussed.
[1] R. N. Wolf et al., Phys. Rev. Lett. 110, 041101 (2013)
[2] F. Wienholtz et al., Nature 498, 346-349 (2013)
[3] A. Huck et al., Phys. Rev. C 31, 2226 (1985)