Design and construction of a hybrid - Nb3Sn, NbTi - dipole magnet

A two layer superconducting dipole magnet - D19H, with a Nb3Sn inner layer and a NbTi outer layer was designed, constructed and tested, The 50mm bore inner layer of an existing NbTi dipole magnet (D19A), has been removed and replaced with a Nb3Sn coil, The outer NbTi coil, collars, iron yoke, ring, collets and outer skin from the disassembled D19A magnet have all been reused, Employing glass insulated cable with aluminum-bronze poles and end spacers the Nb3Sn coil was reacted at 660 degrees C for 240 hours and fully epoxy impregnated, The design and construction of the magnet are described and test results reported elsewhere in these proceedings[1].