December 1994

Discovery of the element 111 (isotope 272111) in 64Ni + 209Bi reactions at SHIP. Three decay chains have been observed (see publication).

https://www.gsi.de/fileadmin/_migrated/pics/Chains111.gif
Figure 1: Decay chains of element 111 (Image source: GSI Helmholtzzentrum für Schwerionenforschung)
2003

The International Union of Pure and Applied Chemistry (IUPAC) assigns the discovery of element 111 to Sigurd Hofmann and his group (see IUPAC-report).

17. November 2006

The name Roentgenium is given to the element 111 in an official ceremony at GSI.