Nuclear isomers in superheavy elements as stepping stones towards the island of stability

A long-standing prediction of nuclear models is the emergence of a region of long-lived, or even stable, superheavy elements beyond the actinides. These nuclei owe their enhanced stability to closed shells in the structure of both protons and neutrons. However, theoretical approaches to date do not...

Full description

Saved in:
Bibliographic Details
Published in:Nature (London) 2006-08, Vol.442 (7105), p.896-899
Main Authors: Leppänen, A.-P, Moon, S, Theisen, Ch, Leino, M, Venhart, M, Rahkila, P, Eskola, K, Sun, Y, Uusitalo, J, Eeckhaudt, S, Gray-Jones, C, Ketelhut, S, Pakarinen, J, Grahn, T, Greenlees, P. T, Darby, I. G, Nyman, M, Jones, G. D, Hessberger, F. P, Steer, A, Herzberg, R.-D, Butler, P. A, Page, R. D, Jones, P, Korten, W, Pritchard, A, Scholey, C, Julin, R, Sarén, J, Juutinen, S
Format: Article
Language:English
Subjects:
Actinides
Exact sciences and technology
Fermium
Fusion
Humanities and Social Sciences
Ions
letter
multidisciplinary
Neutrons
Nobelium
Nuclear physics
Nuclear structure
Nuclear-structure models and methods
Physics
Protons
Science
Science (multidisciplinary)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A long-standing prediction of nuclear models is the emergence of a region of long-lived, or even stable, superheavy elements beyond the actinides. These nuclei owe their enhanced stability to closed shells in the structure of both protons and neutrons. However, theoretical approaches to date do not yield consistent predictions of the precise limits of the 'island of stability'; experimental studies are therefore crucial. The bulk of experimental effort so far has been focused on the direct creation of superheavy elements in heavy ion fusion reactions, leading to the production of elements up to proton number Z = 118 (refs 4, 5). Recently, it has become possible to make detailed spectroscopic studies of nuclei beyond fermium (Z = 100), with the aim of understanding the underlying single-particle structure of superheavy elements. Here we report such a study of the nobelium isotope 254No, with 102 protons and 152 neutrons-the heaviest nucleus studied in this manner to date. We find three excited structures, two of which are isomeric (metastable). One of these structures is firmly assigned to a two-proton excitation. These states are highly significant as their location is sensitive to single-particle levels above the gap in shell energies predicted at Z = 114, and thus provide a microscopic benchmark for nuclear models of the superheavy elements.
ISSN:0028-0836
1476-4687
DOI:10.1038/nature05069