13 years ago
Element 111 was officially discovered by Peter Armbruster, Gottfried Münzenber, and their team working at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany on December 8, 1994. Only three atoms of it were observed (all 272Rg), by the cold fusion between 64Ni ions and a 209Bi target in a linear accelerator:
20983Bi + 6428Ni → 272111Rg + 10n
In 2001, the IUPAC/IUPAP Joint Working Party (JWP) from concluded that there was insufficient evidence for the discovery at that moment in time. The GSI team repeated their experiment in 2000 and detected a further 3 atoms. In their 2003 report, the JWP decided that the GSI team should be acknowledged as the discoverers.