The research team includes Oak Ridge National Laboratory, Joint Institute of Nuclear Research (Dubna) Russia, Research Institute for Advanced Reactors (Dimitrovgrad), Lawrence Livermore National Laboratory, Vanderbilt University and University of Nevada Las Vegas.
A
Oak Ridge produced berkelium-249 isotope, which was subjected to an extended, months-long run at a heavy ion accelerator at Dubna, Russia. ORNL Director of Strategic Capabilities, Jim Roberto, a principal author on the PRL paper, said berkelium was produced in a recent study to produce californium-252, a radioisotope widely used in industry and medicine. "Russia had proposed this experiment in 2004, but since we had no californium production at the time, we could not supply the berkelium. With the initiation of californium production in 2008, we were able to implement collaboration," Roberto said. Prof Joe Hamilton of Vanderbilt University introduced Roberto to Yuri Oganessian of Russia's JINR. Five months of the Dubna JINR U400 accelerator's calcium- 48 beam, one of the world's most powerful, was dedicated to the project.
Six atoms made
The massive effort produced six atoms of element 117 and reams of data in evidence. The project started with irradiation producing 22 milligrams of berkelium-249, which has a 320-day half-life., then processing at REDC to separate and purify berkelium. The Bk-249 target was prepared at Dimitrovgrad and bombarded.
Lawrence Livermore has been involved in the discovery of six elements; 113, 114, 115, 116, 117, and 118,
Oak Ridge once was involved in joining element 61, promethium, discovered at the Graphite Reactor during the Manhattan project and reported in 1946. The Periodic Table now extends further into the neutron-rich regime for heaviest elements. New isotopes observed in these experiments continue a trend toward higher lifetimes for increased neutron numbers, providing evidence for proposed 'island of stability' among super-heavy nuclei.
Since half-lives get longer up the weight scale, there is potential to study the chemistry of these nuclei, opening new frontiers of chemistry.
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PAGE 18 APRIL 2010 MINER’S CHOICE
M
DM Engineering Group is appointed metallurgical
engineering consultant for the Manyoni Heap Leach Pre- Feasibility Study in Tanzania. Manyoni project is near surface, in largely unconsolidated clay, sand, and weathered product host sediments, which suggest low mining costs and conventional processing. Test work at Manyoni has shown the potential amenability to heap leach processing. Uranex MD John Cottle welcomed MDM to the Manyoni team, on schedule for completion in the September quarter. George Bennett, MDM executive director, said their clients have for 22 years largely been junior and mid-tier mining corporations with operations in
new chemical element, named 117 after its near impossibly high atomic weight, has been added to the Periodic Table.
ANIMATION BY KWEI-YU CHU/LLNL.The discovery fills in a notable gap in the periodic table and bolsters the idea that neutron-rich superheavy nuclei could be extremely stable, perhaps having lifetimes of many millions of years.
Africa.
In May 2008, the company listed on the AIM market of the London Stock Exchange. The company has adopted an open-book engineering, procurement, and construction management (EPCM), or 'cost plus' approach.
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