Review of Quench Performance of LHC Main Superconducting Magnets

The regular lattice of the Large Hadron Collider (LHC) will make use of more than 1600 main magnets and about 7600 corrector magnets, all superconducting and working in pressurized superfluid helium bath. This complex magnet system will fill more than 20 km of the LHC underground tunnel. In this paper an overview of the cold test program and quality assurance plan to qualify all LHC superconducting magnets will be presented. The quench training performance of more than 1100 LHC main dipoles and about 300 main quadrupoles, cold tested to date, will be reviewed. From these results an estimate of the number of quenches that will be required to start operation of the whole machine at nominal energy will be discussed. The energy level at which the machine could be operated at the early phase of the commissioning without being disturbed by training quenches will be addressed. The LHC magnet program required the development of many new tools and techniques for the testing of superconducting magnet coils, magnet protection systems, cryogenics, and instrumentation. This paper will also present a summary of this development work and the results achieved.