One possible application of Nb3Sn, whose superconducting properties far exceed those of NbTi, is the fabrication of short and powerful quadrupole magnets for the Interaction Regions (IR) of large particle accelerators. In some cases, as in the future linear collider TESLA, the quadrupole magnets are inside the detector solenoid and must operate in its background field. This situation gives singular Lorentz force distribution in the ends of the magnet. To learn about Nb3Sn technology, evaluate fabrication techniques and test the interaction with a solenoidal field, DAPNIA/SACM at CEA/Saclay has started the manufacturing of a 1-m-long, 56-mm-single-aperture quadrupole magnet model. The model relies on the same coil geometry as the LHC arc quadrupole magnets, but has no iron yoke. It will produce a nominal field gradient of 211 T/m at 11,870 A. The coils are wound from Rutherford-type cables insulated with glass fiber tape, before being heat-treated and vacuum-impregnated with epoxy resin. Laminated collars, locked around the coil assembly by means of keys, restrain the Lorentz forces. After a recall of the conceptual design, the paper reviews the progress in the manufacturing and test of the main components as well as in the design and delivery of the main tooling. The first coil is expected to be wound and heat treated during the last quarter of 2003. |
