Mock-up of the Large Hadron Collider. The Large Hadron Collider (LHC) is the proposed new accelerator for the CERN European particle physics laboratory. The magnets for the LHC (seen here in blue) will sit on top of the existing Large Electron-Positron (LEP) accelerator at CERN's Geneva site. The LEP occupies a tunnel some 27km in circumference. Advances in magnet design mean that the LHC will be able to bend beams of protons and heavy ions around the same curvature as the far lighter electrons used in LEP. This will create far higher collision energies than the existing LEP ring, allowing scientists to delve even further into sub-atomic processes.