Overview and status of the Next European Dipole (NED) joint research activity

The Next European Dipole (NED) Joint Research Activity was launched on 1st January 2004 to promote the development of high performance Nb$_{3}$Sn conductors in collaboration with European industry (aiming at a non-copper critical current density of 1500 A/mm2 at 4.2 K and 15 T) and to assess the suitability of Nb$_{3}$Sn technology to the next generation of accelerator magnets (aiming at an aperture of 88 mm and a conductor peak field of ~ 15 T). It is part of the Coordinated Accelerator Research in Europe (CARE) project, involves eight collaborators and is half-funded by the European Union. After briefly recalling the Activity organization, we report the main progress achieved over the last year, which includes: the manufacturing of a double-bath He II cryostat for heat transfer measurements through Nb$_{3}$Sn conductor insulation, detailed quench computations for various NED-like magnet configurations, the award of two industrial subcontracts for Nb$_{3}$Sn conductor development, the first results of a cross-calibration program of test facilities for Nb$_{3}$Sn wire characterization, detailed investigations of the mechanical properties of heavily cold-drawn Cu/Nb/Sn composite wires and the preliminary assessment of a new insulation system based on polyimide-sized fiber glass tapes. Last, we briefly review the efforts of an ongoing Working Group on magnet design and optimization.