Sextupole Spool Piece Correctors MCS

Each MCS magnet consists of six coils, a laminated iron yoke, an aluminium shrinking cylinder, an end plate that houses the electrical connections and an iron magnetic shield. The coils are made by counter-winding a single, rectangular cross-section, NbTi wire around a G11 central post. The superconductor has a rectangular cross-section and is enamel insulated. The coils are wet wound. After winding G11 end spacers are fitted to the ends of the coils which are then cured. The cured coils are assembled on a precise mandrel together with the connection plate, wrapped with a glass-fibre/epoxy pre-preg bandage and cured to make an MCS coil assembly. The MCS magnet module is built by stacking the eccentric yoke laminations [1] around the MCS coil assembly in 6 different azimuthal orientations and shrink fitting the aluminium shrinking cylinder. The radial interference between the inner diameter of the shrinking cylinder and the outer diameter of the yoke lamination stack is chosen such that the correct pre-stress is produced at operating temperature. This interference is obtained by precise machining of the cured coil assembly outer diameter. Precise dowel holes in the end plate allow accurate placement of the magnet module within the magnetic shield. The magnets are mounted on their support plate in the dipole cold mass by means of a bolted flange, this flange contains a pair of accurately drilled 6H7 holes for doweling to the support plate. Coil inter-connections are made by ultrasonic welding. Quench protection resistors are connected in parallel with each magnet and mounted in the gap between the shrinking cylinder and magnetic shield. [1] A. Ijspeert, J. Salminen, “Superconducting coil compression by scissor laminations”, EPAC-96, Sitges, Spain, June 1996.