Operating experience with the HEUB superconducting dipoles

Four large aperture superconducting dipole magnets were installed in the High Energy Unseparated Beam at the Brookhaven AGS. This beam services the Multiparticle Spectrometer (MPS) facility. The upstream two magnets are mounted on a sliding base so that they can also be used as part of beam A3. These two magnets have been in use since the fall of 1976 and all four magnets were in operation by the end of that year. The magnet power supplies are computer controlled by the same system that operates the conventional beam line magnets. The operating experience with these magnets, their refrigeration system, and the associated instrumentation are summarized