Development of a Nb3Sn quadrupole magnet model

One possible application of Nb3Sn, whose superconducting properties far exc eed those of NbTi, is the fabrication of short and powerful quadrupole magn ets for the crowded interaction regions of large particle accelerators. To learn about Nb3Sn technology and to evaluate fabrication techniques, DAPNIA /STCM at CEA/Saclay has undertaken an R&D program aimed at designing and bu ilding a 1-m-long, 56-mm-single-aperture quadrupole magnet model. The model relies on the same coil geometry as the LHC: are quadrupole magnets, but h as no iron yoke. It is expected to produce a nominal field gradient of 211 T/m at 11,870 A. Tile coils are wound frail; Ruthorford-type cables insulat ed with quartz fiber tapes, before being heat-treated and vacuum-impregnate d with epoxy resin. Laminated, austenitic callers, locked around the coil a ssembly by means of kegs restrain the Lorentz forces. After reviewing the c onceptual design of the magnet model, we report on the cable and cable insu lation development programs and we present the results of NbTi-Nb3Sn cable splice tests.