Jim Roberto

Jim Roberto, an associate laboratory director at Oak Ridge National Laboratory, will discuss the discovery of elements 115 and 117, super-heavy nuclei, and the “island of stability” during a Wednesday evening talk next week.

Roberto, ORNL associate laboratory director for science and technology partnerships, will give the featured talk to the ORION astronomy club at 7 p.m. Wednesday, March 16. The talk will be at the Grove Theater at 123 Randolph Road in Oak Ridge.

Roberto’s talk is titled “The Discovery of Elements 115 and 117: SuperHeavy Nuclei and the ‘Island of Stability.'” Roberto will review recent progress in super-heavy element research with particular focus on the significance of element 117 and its decay products as evidence for the existence of the presumed “island of stability” for super-heavy nuclei, a press release said.

The press release said ORION has supported educational and astronomy activities in Oak Ridge and the surrounding region since 1974. Among other various types of programming, ORION offers free public star gazes at the Tamke-Allan Observatory in Rockwood scheduled on the first and third Saturday of the month. See www.roanestate.edu/TAO or contact David E. Fields at [email protected].

Here is more information from a January press release on the discovery of new elements 115 and 117:

Berkelium-249, contained in the greenish fluid in the tip of the vial, was crucial to the experiment that discovered element 117. It was made in the research reactor at DOE’s Oak Ridge National Laboratory. (Photo by ORNL)

Twenty-two milligrams of a very pure synthetic material produced at Oak Ridge National Laboratory were used in the discovery of two new chemical elements that will help fill out the seventh row of the periodic table.

The synthetic element, berkelium-249, was produced in a project that started with a six-month irradiation of a target material at the High Flux Isotope Reactor at ORNL. The resulting product was separated and processed during a three-month period at the lab’s Radiochemical Engineering Development Center.

The berkelium-249 was then shipped to the Joint Institute for Nuclear Research, or JINR, in Dubna, Russia, where it was intensely bombarded, or irradiated, with calcium-48 ions, creating six atoms of element 117, said Jim Roberto, ORNL associate lab director for science and technology partnerships. Berkelium-249, which does not exist in nature, has a 300-day lifetime, so researchers had a short time to do their experiments.

Element 117 is one of four new elements that have been officially verified by the International Union for Pure and Applied Chemistry. The IUPAC announced the discoveries on December 30. The other three are elements 113, 115, and 118. Element 115 is produced when element 117 decays.

The IUPAC recognized ORNL and its collaborators, the JINR and Lawrence Livermore National Laboratory in California, for the discovery of elements 115 and 117. The RIKEN collaboration team in Japan discovered element 113, and the Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory discovered element 118.

Roberto said the researchers have extended the periodic table to new nuclei with more neutrons and more protons. They have been invited to submit names and symbols for the new elements.

Read the full story here.

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