STATUS OF THE LARGE HADRON COLLIDER MAGNET DEVELOPMENT

CERN is preparing the construction of a new particle accelerator-colli der, the Large Hadron Collider (LHC), which will be installed in the e xisting 27 km tunnel of the Large Electron-Positron Collider (LEP). Th e LHC will require in total about 10'000 superconducting magnetic unit s, including main magnets and correction elements. For the regular arc s of the machine 1300, 13.5 m long dipole magnets of 8.65T and 600, 3. 2 m long quadrupoles of 220 T/m gradient will be used. These main magn ets will all be of the twin-aperture configuration, i.e. with the magn etic channels for the two beams placed in a common yoke and cryostat. R & D for the LHC high field magnets is now approaching its goals. The last short dipole model reached the record field of 10.51 T and after thermal cycling had all quenches well above the LHC required field. A 10 m long prototype confirmed the validity of two major technical cho ices by behaving perfectly in superfluid helium and showing no adverse effects of the twin-aperture configuration. Fabrication in industry o f seven full size dipoles is well advanced and two prototype quadrupol es are completed and ready for testing.