The GSI accelerator. Image via Helmholtz Gemeinschaft.
Move over Livermorium, because a new element is pulling up a chair at the Periodic Table. Scientists based out of the GSI Helmholtz Centre for Heavy Ion Research have announced that they created the superheavy element 117. Their results were published this week in Physical Review Letters.
Element 117 has been temporarily given the very literal name ununseptium (one-one-seven in Latin), and will only honored with a real name once the the International Union of Pure and Applied Physics and Chemistry (IUPAPC) confirms its synthesis at the GSI accelerator. Ununseptium is 40 percent heavier than lead, making it on par with the heaviest atoms ever observed.
Its properties seem to confirm that the existence of the so-called “island of stability”—a theory suggesting that the half-lives of superheavy isotopes will lengthen as their atomic numbers increase further away from uranium. Any element with an atomic number greater than 103 is considered superheavy (or in the “transactinide class,” if you prefer the scientific jargon). Transactinides can only be observed artificially in a laboratory, and synthesizing them is no easy task.
For example, it took a year and a half to create the exact right riff on berkelium required for the GSI experiment. 13 milligrams of top notch berkelium-249 were irradiated to a high level of purity at the Oak Ridge National Laboratory in Tennessee, before being shipped off to the GSI particle accelerator in Darmstadt, Germany.
A video introduction to making ununseptium, via YouTube.
The berkelium isotope was then bombarded with calcium ions, producing spectacular subatomic fireworks. The debris from these exotic explosions were examined by the highly sensitive TransActinide Separator and Chemistry Apparatus (TASCA), providing evidence that ununseptium had briefly graced us with its presence.
But perhaps the bigger story is that the experiment produced two intriguing isotopes of other elements, dubnium (105) and lawrencium (103). The half-lives of these byproducts measured one hour and 11 hours respectively, which makes them among the longest-lived superheavy isotopes ever discovered.
"This is of paramount importance as even longer-lived isotopes are predicted to exist in a region of enhanced nuclear stability," the GSI study's lead author Christoph Düllmann said in a statement. He is referring to the island of stability.
This is not the first time scientists have claimed to have synthesized the 117th element. In 2010, the Joint Institute for Nuclear Research, a collaborative institute between Russia and the United States, announced that they had successfully forged the element in their accelerator.
However, IUPAPC did not consider that experiment substantive enough to stand on its own merits, which is why researchers with all kinds of backgrounds have made such an effort to reproduce the results. And they really went all out on this one. The GSI experiment included 72 scientists and engineers from 16 institutions in 11 countries.
It remains to be seem whether the IUPAPC will finally allow ununseptium into the official element club. But if it does get the green light, I can take a pretty good stab at what its real name will be. Given that the majority of the other transactinides are named after the relevant research centers, let's assume this superheavy newcomer will be called helmholtzium. You heard it here first.