Quench protection study of a prototype for the LHC low-beta quadrupole magnets

LHC low-beta quadrupole magnets are being developed at KEK as part of the collaboration between CERN and KEK. Based on R&D progress of five 1-m long model magnets, a full-scale 6.7-m long prototype was developed and excitation tests were performed at KEK. A magnet protection scheme for the full-scale magnet is very important in case of the quench because a large stored energy has to be fully dissipated into the coils. The quench protection system which consists of heaters and power supplies was examined in a series of heater tests for the prototype. It was concluded that the quench protection system will protect the production magnet even in the worst quench situation.