Magnetic Measurements of the LHC Quadrupole and Dipole Magnets at Room Temperature

Field measuring systems operating at room temperature have been installed on each magnet manufacturers' premises in order to validate the integrated field gradient and the field quality (harmonics). The aim of the systems is also to verify the quality of the collared coils in their earliest state in order to correct the assembly process in case of defect. The device consists of a sensitive measuring probe, a data acquisition system and an on-line analysis program. The magnets are powered with low current to avoid excessive heating and voltages across the normal conducting coils hence the magnetic probes must be very sensitive. The program gives results instantly to fit production requirements. This paper describes the measuring system, the method adopted and the performance observed based on the results of the magnetic measurements