LHC accelerator physics and technology challenges

The Large Hadron Collider (LHC) incorporates many technological innovations in order to achieve its design objectives at the lowest cost. The two-in-one magnet design, with the two magnetic channels integrated into a common yoke, has proved to be an economical alternative to two separate rings and allows enough free space in the existing (LEP) tunnel for a possible future reinstallation of a lepton ring for e-p physics. In order to achieve the design energy of 7 TeV per beam, with a dipole field of 8.3 T, the superconducting magnet system must operate in superfluid helium at 1.9 K. This requires further development of cold compressors similar to those first used at CEBAF. The LHC will be the first hadron machine to produce appreciable synchrotron radiation which, together with the heat load due to image currents, has to be absorbed at cryogenic temperatures. Finally, the LHC is the first major CERN accelerator project built in collaboration with other laboratories. A brief review of the machine design is given and some of the main technological and accelerator physics issues are discussed