Signature of the agreement concerning the legal status of the Organization in France 16 June 1972

CERN's first large accelerator, the Proton Synchrotron (PS), had hardly come into operation at the beginning of the 1960s, when physicists started to dream of a machine ten times more powerful, operating at 300 Gigaelectronvolts. The construction of such an accelerator required a new laboratory to be built and several European sites were candidates. John Adams, the project leader, suggested using the PS as an injector for the new machine, to achieve the higher energy level at a lower cost. The new Laboratory was therefore to be built on a site adjacent to CERN. The project was approved in 1971, but the CERN Convention, which only provided for a single laboratory, had to be amended. An agreement was signed with France on 16 June 1972 (see photograph), establishing a new site at Prévessin, in the Pays de Gex. The two laboratories, which each had their own administrative structures and Directors-General, were merged in 1976.