Mechanical characterization and assessment of the CMS conductor

The Compact Muon Solenoid (CMS) is one of the experiments which are being d esigned in the framework of the Large Hadron Collider (LHC) project at CERN , The design field of the CMS magnet is 4 T, the magnetic length is 12.5 m and the free aperture is 6 m in diameter, This is achieved with a 4 layer a nd 5 module superconducting Al-stabilized coil, resulting into 20 lengths o f conductor of 2.5 km each, energized at a nominal current of 20 kA at 4.5 K, One of the unique features of this thin solenoid is an Al-stabilized con ductor reinforced by an Al-alloy, An extensive characterization of mechanic al properties at room temperature and 4.2 K has been carried out in order t o define the most appropriate alloy and temper for the reinforcement, The e ffect of the coil curing cycle on the alloy properties has been taken into account. This paper summarizes the main results of these tests.