Choose timezone
Your profile timezone:
Description
The requirements for the dipole cold mass geometry stem from the LHC beam optics and from mechanical deformation limits in the interconnection zone. To provide the largest possible mechanical aperture, the dipole cold masses should match the circular trajectory of the beams. The method to accurately measure the geometry of the cold mass by measuring the cold bore tube axes using a high accuracy 3D system based on optical methods is presented, and results obtained for several cold masses are given. After the magnets arrive at CERN, metrological measurements are made for 10% of the cryo-dipoles in order to verify that the transport does not affect the geometry. The fiducialisation and the measurement of the tube position at the extremities
of the magnet will be explained. The problem of the cold mass stability with respect to its cryostat will be addressed. For the SSS, the positioning of cold bore tubes and beam position monitor (BPM) supports in industry, the alignment of the drift tube and BPM at CERN, and the measurement of the position of all other tubes at each extremity require additional metrological measurements.