Direct high-precision mass spectrometry of superheavy elements with SHIPTRAP
O. Kaleja, Brankica Anđelić, O. Bezrodnova, K. Blaum, M. Block, S. Chenmarev, Premaditya Chhetri, C. Droese, Ch. E. Düllmann, M. Eibach, S. Eliseev, J. Even, P. Filianin, F. Giacoppo, Stefan Götz, Yu. I. Gusev, M. J. Gutiérrez, F. P. Heßberger, N. Kalantar‐Nayestanaki, J. J. W. van de Laar, M. Laatiaoui, S. Lohse, N. Martynova, E. Minaya Ramirez, A. Mistry, T. Murböck, Yu. N. Novikov, S. Raeder, D. Rodrı́guez, F. Schneider, L. Schweikhard, P. G. Thirolf, A. Yakushev
Abstract
Direct mass measurements in the region of the heaviest elements were performed with the Penning-trap mass spectrometer SHIPTRAP at GSI Darmstadt. Utilizing the phase-imaging ion-cyclotron-resonance mass-spectrometry technique, the atomic masses of $^{251}\mathrm{No}$ ($Z=102$), $^{254}\mathrm{Lr}$ ($Z=103$), and $^{257}\mathrm{Rf}$ ($Z=104$) available at rates down to one detected ion per day were determined directly for the first time. The ground-state masses of $^{254}\mathrm{No}$ and $^{255,256}\mathrm{Lr}$ were improved by more than one order of magnitude. Relative statistical uncertainties as low as $\ensuremath{\delta}m/m\ensuremath{\approx}{10}^{\ensuremath{-}9}$ were achieved. Mass resolving powers of 11 000 000 allowed resolving long-lived low-lying isomeric states from their respective ground states in $^{251,254}\mathrm{No}$ and $^{254,255}\mathrm{Lr}$. This provided an unambiguous determination of the binding energies for odd-$A$ and odd-odd nuclides previously determined only indirectly from decay spectroscopy.