Publikationen

Upper limits for the existence of long-lived isotopes of roentgenium in natural gold

Autor(en)
Franz Dellinger, Walter Kutschera, Oliver Forstner, Robin Golser, Alfred Priller, Peter Steier, Anton Wallner, Gerhard Winkler
Abstrakt

A sensitive search for isotopes of a superheavy element (SHE) in natural gold materials has been performed with accelerator mass spectrometry at the Vienna Environmental Research Accelerator, which is based on a 3-MV tandem accelerator. Because the most likely SHE in gold is roentgenium (Rg, Z = 111), the search concentrated on Rg isotopes. Two different mass regions were explored: (i) For the neutron-deficient isotopes  Rg261 and Rg265, abundance limits in gold of 3×10−16 were reached (no events observed). This is in stark contrast to the findings of Marinov et al. [Int. J. Mod. Phys. E 18, 621 (2009)], who reported positive identification of these isotopes with inductively coupled plasma sector field mass spectrometry in the (1−10)×10−10 abundance range. (ii) Theoretical models of SHEs predict a region of increased stability around the proton and neutron shell closures of Z = 114 and N = 184. We therefore investigated eight heavy Rg isotopes, ARg, A = 289, 290, 291, 292, 293, 294, 295, and 296. For six isotopes no events were observed, setting limits also in the 10−16 abundance range. For Rg291 and Rg294 we observed two and nine events, respectively, which results in an abundance in the 10−15 range. However, pileup of a particularly strong background in these cases makes a positive identification as Rg isotopes—even after pileup correction—unlikely.

Organisation(en)
Isotopenphysik
Journal
Physical Review C
Band
83
Anzahl der Seiten
9
ISSN
0556-2813
DOI
https://doi.org/10.1103/PhysRevC.83.015801
Publikationsdatum
2011
Peer-reviewed
Ja
ÖFOS 2012
103014 Kernphysik
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/upper-limits-for-the-existence-of-longlived-isotopes-of-roentgenium-in-natural-gold(910bb8e9-efa3-4304-9074-362ff847e0c4).html