[History]
On August 29, 1992, Element 109 was made and identified by physicists at the Heavy Ion Research Laboratory (G.S.I.), Darmstadt, Germany, by bombarding a target of 209Bi with accelerated nuclei of 58Fe. The production of Element 109 has been extremely small. It took a week of target bombardment (1011 nuclear encounters) to produce a single atom of 109. Oganessian and his team at Dubna in 1994 repeated the Darmstadt experiment using a tenfold irradiation dose. One fission event from seven alpha decays of 109 was observed, thus indirectly confirming the existence of isotope 266109. In August 1997, the IUPAC adopted the name meitnerium for this element, honoring L. Meitner. Four isotopes of meitnerium are now recognized. |