The LHC Superconducting Magnets

The Large Hadron Collider (LHC) is under construction at CERN. Most of its 27 km underground tunnel will be filled with superconducting magnets, mainly 15 m long dipoles and 3 m long quadrupoles. The 1232 main dipole and 392 main quadrupole magnets, are complemented by a number of insertion quadrupole magnets: including 86 MQM (matching), 26 MQY (wide aperture) and 32 low-beta quadrupoles (the latter built by KEK and Fermilab). The about 6000 superconducting corrector magnets, many of them individually powered, are also very critical for the functioning of the accelerator. Using copper stabilized NbTi Rutherford cables or single strands, these superconducting magnets will operate in superfluid helium at 1.9 K. The paper reviews the main characteristics of these magnets and addresses the critical points of the design with respect to their use in such a complicated accelerator like LHC. Then the status of the production of the superconducting cable and of the magnets is given, with particular emphasis given to the QA/QC procedures taken to ensure the industrial production according to the tight requirements, and the results on the first 30 main dipoles is presented. Finally, the plan put in place to meet the LHC schedule is discussed.