LLNL and Russians team up to discover new elements

摘要

The Two Newest super-heavy elements, elements 113 and 115, have been discovered by scientists from Lawrence Livermore National Laboratory, working in collaboration with researchers from the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, LLNL announced on February 2. In experiments conducted at the JINR U400 cyclotron with the Dubna gas-filled separator between July 14 and August 10, 2003, the team of scientists observed atomic decay patterns, or chains, that confirm the existence of element 115 and ele-ment 113. In these decay chains, element 113 is produced via the alpha decay of element 115. The experiments produced four atoms each of element 115 and ele-ment 113 through the fusion reaction of calcium-48 nuclei impinging on an amer-cium-243 target. The new elements will not be formally named until after they have been confirmed by an independent laboratory, but they hold temporary names: element 115 is ununpentium (abbreviated Uup), and element 113 is unun-trium (abbreviated Uut).