Mechanics and field quality of the LHC main dipole

by Paolo Ferracin (LHC Division)

Thursday 14 Mar 2002, 14:15 → 15:15 Europe/Zurich

LHC Auditorium (CERN)

In the LHC superconducting dipole, the magnetic field strongly depends on the position of the coil conductors. The coils are clamped by a mechanical structure which compresses the cables to avoid conductor movements when the magnet is energised. During the assembly and the cool-down, stress changes affect the coil geometry, thus modifying field quality. We present measurements of the thermo-mechanical properties of the coil and their implementation in a finite element model of the dipole mechanical behaviour. The magneto-mechanical model has allowed a deep analysis of the field quality in the pre-series dipoles and of the available corrective strategies. We finally show how the model has provided a precise reconstruction of an assembly error observed in the dipole production.