Nimrod was a 7 GeV proton synchrotron operating in the Rutherford Appleton Laboratory in the United Kingdom between 1964 and 1978. It was used for studies of nuclear and sub-nuclear phenomena. Nimrod was dismantled and the space it occupied reused for the synchrotron of the ISIS neutron source.
http://www.isis.stfc.ac.uk/about-isis/target-station-2/publications/issue-1-september-20038209.pdf