The Large European e+e- Collider Project LEP

A large European e+e- Collider Project (LEP) has been under study at CERN since 1976. The history of these studies up to the 1979 US Particle Accelerator Conference has been described in a review paper. Since that time the design study has been continued. A detailed description of LEP Version 8, the Pink Book, was issued in August 1979. A review of later developments was given at the 11th International Conference on High-Energy Accelerators in July 1980. This paper describes the most recent developments in the LEP Project which was submitted to the CERN Council in June 1980 for approval. It is hoped that Council will authorize the project in June 1981. LEP Version 11 described here has a circumference of about 27 km. With an RF system consisting of 128 cavities and 16 1-MW klystrons the luminosity reaches a peak of about 1031 cm-2s-1 at 51.5 GeV. Enough space is foreseen in the lattice for a considerable extension of the RF system, permitting 90 GeV to be reached with room-temperature RF cavities, and even more with superconducting ones. Progress of prototype work for the LEP magnet and RF systems is also briefly described.