Abstract
A nuclear spectroscopy experiment was conducted to study -decay chains stemming from isotopes of flerovium (element ). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions and provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to and , respectively. A prompt coincidence between a 9.60(1)-MeV particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely . Spectroscopy of decay chains fixed . In one case, a -MeV decay from into was observed, with fissioning after only . The impact of these findings, aggregated with existing data on decay chains of , on the size of an anticipated shell gap at proton number is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.
- Received 16 November 2020
- Accepted 3 December 2020
DOI:https://doi.org/10.1103/PhysRevLett.126.032503
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
synopsis
An Octad for Darmstadtium and Excitement for Copernicium
Published 22 January 2021
The discovery that copernicium can decay into a new isotope of darmstadtium and the observation of a previously unseen excited state of copernicium provide clues to the location of the “island of stability.”
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