The winding line for the CMS reinforced conductor

The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the length is 12.5 m and the free bore is 6 m. The use of a reinforced conductor for the CMS coil required a sustained activity of development at industrial level, to understand how to handle, to pre-bend and to wind the conductor with an inner winding technique. The winding line was designed and constructed according to this experience. The working principles of the line are under test through the winding of a prototype of a CMS coil module. The prototype has the same radius of a CMS module (6900 mm outer diameter), but a shorter axial length (670 mm against 2500 for the module). The critical operations are related to the accurate pre-bending of the conductor, the positioning of the turns into the winding, the axial compaction, and the correct handling of 50-ton windings.