Magnetic alignment measurements at room and cryogenic temperature of LHC cryodipoles and associated correctors at CERN

Considerable effort is spent at CERN on magnetic alignment measurements of main lattice LHC dipoles, including field direction, curved axis shape and position of in-built correctors, essential to verify the geometry of the assembly and to guarantee correct installation with respect to the reference beam orbit. The current baseline includes measurements of a statistically relevant percentage of cold masses and cryostated magnets before, during and after cryogenic tests. For this, we use a range of scanning probes based either on harmonic coils or fixed coils in AC mode, with laser and telescope trackers to measure position with respect to cryostat fiducials. The dipole is usually powered in "quadrupole mode" to create a convenient magnetic reference. In this paper, we first recall objectives, equipment and methods. Then, we report the status of the test activities, showing results obtained on the first pre-series dipoles, including cross-checks of various measurement systems and correlation between measurements at room and cryogenic temperatures.