Synopsis

Wishing isomers a long life

Physics 3, s146
Long-lived excited states of some neutron-rich nuclei can now be discovered, trapped, and stored.

More than thirty years ago, nuclides in a region around hafnium ( Z=72) that contained more neutrons than the heaviest stable isotope were predicted to be capable of existing in metastable excited states known as isomers. These nuclides can be created when a heavy ion beam is accelerated and smashed into a target, but it was not possible to identify long-lived correlations among the products created. Now, in Physical Review Letters, an experimental collaboration from the UK, Germany, US, Australia, China, and Japan, working at the GSI accelerator facility in Darmstadt, Germany, reports that it has succeeded in storing ions produced from the collision of a gold ion beam with a beryllium target in a 108-meter-diameter storage ring. A total of two previously known and five previously unknown metastable states of hafnium and tantalum were found. The identified isomers have excitation energies up to 3 MeV, half-lives between seconds and minutes, and decay either by beta or gamma emission. These observations are made possible by the capability to accurately measure masses of both isomeric and ground-state ions in the storage ring.

These experiments will contribute to the understanding of nuclear structure, of conditions in supernovas where these isomers are created, and for the possible development of novel energy storage devices. A bountiful isomeric terrain now awaits exploration. – Brad Rubin


Subject Areas

Nuclear Physics

Related Articles

Colossal Magnetic Field Detected in Nuclear Matter
Nuclear Physics

Colossal Magnetic Field Detected in Nuclear Matter

Collisions of heavy ions briefly produced a magnetic field 1018 times stronger than Earth’s, and it left observable effects. Read More »

Three’s Company for Bottom Quarks
Nuclear Physics

Three’s Company for Bottom Quarks

Bottom quarks are increasingly more likely to exist in three-quark states rather than two-quark ones as the density of their environment increases. Read More »

New Signs of Stability in Proton-Rich Nuclei
Nuclear Physics

New Signs of Stability in Proton-Rich Nuclei

Adding what seems like too many protons to a nucleus can increase one measure of its stability. Read More »

More Articles