LEP beam spectrometer 1999 This view of the inside of the Large Electron-Positron (LEP) collider tunnel shows a special dipole magnet that was used to measure the energy of the accelerated particles. PHOTOLAB

Diagram of a LEP dipole magnet 1991 LEP used a revolutionary design of dipole magnet, having magnetic plates embedded in an iron-concrete yoke. Such magnets bend the beam around its circular path. A vacuum is maintained throughout the accelerator so that the beam remains stable by avoiding unwanted interactions. PHOTOLAB

LEP collider tunnel 1989 This is an image of the tunnel housing the LEP collider 100 m below the Swiss-France border. Due to the huge circumference of the tunnel it appears to be almost straight. PHOTOLAB

Diagram of a LEP superconducting cavity 1991 This diagram gives a schematic representation of the superconducting radio-frequency cavities at LEP. Liquid helium is used to cool the cavity to 4.5 degrees above absolute zero so that very high electric fields can be produced, increasing the operating energy of the accelerator. Superconducting cavities were used only in the LEP-2 phase of the accelerator, from 1996 to 2000. PHOTOLAB

The four main LHC experiments 1999 This diagram shows the locations of the four main experiments (ALICE, ATLAS, CMS and LHCb) that will take place at the LHC. Located between 50 m and 150 m underground, huge caverns have been excavated to house the giant detectors. The SPS, the final link in the pre-acceleration chain, and its connection tunnels to the LHC are also shown. PHOTOLAB

The scale of the LHC 2001 The area under which the tunnel for CERN's LHC can be found is shown near to Geneva and lac Leman. The French Alps with Mont Blanc can be seen in the background. PHOTOLAB

Accelerators chain of CERN : operating and approved projects 2001 PHOTOLAB

DELPHI's Ring Imaging Cherenkov Chamber 1989 The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification. PHOTOLAB

Overall view of LEP experiments 1989 PHOTOLAB