May 3, 2014
Superheavy Element 117 Moves One Step Closer To Getting A Name
redOrbit Staff & Wire Reports - Your Universe Online
A superheavy element originally discovered in 2010 by scientists at the Lawrence Livermore National Laboratory (LLNL) and their colleagues has been successfully reproduced by an international team of chemists and physicists, bringing it one step closer to being named, officials from the federally funded research and development center announced on Thursday.
In an upcoming edition of the journal Physical Review Letters, Professor Christoph Düllmann of the GSI Helmholtz Centre for Heavy Ion Research and colleagues from 16 institutions in Australia, Finland, Germany, India, Japan, Norway, Poland, Sweden, Switzerland, the US and the UK describe in detail how they found evidence for the element’s artificial creation.
Professor Düllmann’s team bombarded berkelium with calcium ions until they collided, which resulted in the formation of element 117. Their findings, as well as the original research resulting in the element’s discovery, will now be reviewed by the International Union of Pure and Applied Chemistry (IUPAC).
According to the LLNL, the IUPAC will then decide whether or not there is enough evidence to acknowledge its discovery, or if additional experiments will be required. If element 117’s discovery is accepted, the organization would then determine which institution will be permitted to propose names for the new superheavy element.
All elements beyond atomic number 104 are dubbed superheavy elements, the most long-lived ones are expected to possess nuclei with extremely long half-lives, scientists from Johannes Gutenberg University Mainz (JGU) explained in a statement. While these elements have not been discovered in nature, they can be produced by accelerating beams of nuclei and then shooting them at the heaviest possible target nuclei, they added.
When the two nuclei fuse, the can produce a superheavy element – though the researchers note that this happens very rarely. Currently accessible fusions typically are short-lived. The new measurements of element 117 required a collaboration between GSI’s accelerator and detection capabilities and the unique actinide isotope production and separation facilities at Oak Ridge National Laboratory (ORNL) in America.
“The special berkelium target material, essential for the synthesis of element 117, was produced over an 18-month-long campaign,” the Mainz University researchers explained. The process required “intense neutron irradiation” and “chemical separation and purification” at two different ORNL facilities, and afterwards roughly 13mg of the “highly-purified isotope Bk-249” were shipped to JGU.
“There, the facilities and expertise are available to transform the exotic radioisotope into a target, able to withstand the high-power calcium-ion beams from the GSI accelerator,” the university added. “Atoms of element 117 were separated from huge numbers of other nuclear reaction products… and were identified through their radioactive decay. These measured chains of alpha-decays produced isotopes of lighter elements with atomic numbers 115 to 103, whose registration added to the proof for the observation of element 117.”