A New Accelerator Superconducting Dipole Suitable for High Precision Field

Work on superconducting dipoles for accelerators started about twelve years ago in several High Energy Physics laboratories. At present, many problems have been solved and three big superconducting synchrotrons or storage rings are under construction : the "Doubler" and "Isabelle" in the USA and "UNK" in the USSR. In Europe, the DESY Laboratory in Hamburg is studying the "HERA" project (not yet approved). All these projects use dipole fields in the range of 4 to 5 teslas in coil bores of 75 to 130 mm in diameter. However, these magnets still raise difficulties and their required field quality remains hard to achieve due to the high level of accuracy needed in conductor placement. In this paper a new design is proposed to improve this accuracy. Models along this design are being developped at Saclay, requiring a quite novel technology, whose advantages and possible difficulties are reviewed.