Status of the Large Hadron Collider and magnet program

The Large Hadron Collider (LHC), approved by the CERN Council in December 1994, is a 7+7 TeV proton accelerator-collider, to be installed in the existing 27 km long LEP tunnel. It will represent a unique research facility for particle physics, allowing proton-proton collisions with a luminosity of 10^34 cm^-2s^-1 capable of providing also heavy ion (Pb-Pb) collisions with a luminosity of 10^27 cm^-2s^-1, using the existing CERN heavy ion source. The main technological challenges of the machine are the superconducting magnet system, in total over 8¹000 magnet units immersed in superfluid helium, with the lattice dipoles operating at 8.4 T, and the very large cryogenic system, which maintains the entire string of cryomagnets at its working temperature below 2 K. The paper discusses briefly the main issues which have led to the present layout of the LHC, gives an overview of the different machine components and characteristics and describes in more detail the recent development work and results of the LHC magnet program.