The HADES detector magnet-a large superconducting torus

HADES, the High Acceptance Di-Electron Spectrometer, is an experiment at the Gesellschaft fur Schwerionenforschung mbB (GSI) at Darmstadt in Germany. Its purpose is to investigate hot and dense nuclear matter formed in heavy ion collisions at incident beam energies of a few GeV per nucleon. At the heart of the system is a large, six-coil detector magnet producing a toroidal field of up to 3.8 T over a total volume of approximately 8 m/sup 3/. The contract to design, manufacture, install and commission the magnet system was awarded to Oxford Instruments in November 1995, and the system was delivered to GSI-three months ahead of schedule-in April 1998. This paper describes the design, manufacture and commissioning of the magnet.