The Superconducting Horizontal Bend Magnet for the Jefferson Lab's 11 GeV/c Super High Momentum Spectrometer

A collaboration between NSCL and Jlab has developed the reference design and coil winding for Jlab's Super High Momentum Spectrometer (SHMS) horizontal bend magnet. A warm iron ¿C¿ type superferric dipole magnet will bend the 12 GeV/c particles horizontally by 3° to allow the SHMS to reach angles as low as 5.5°. This requires an integral field strength of up to 2.1 T.m. The major challenges are the tight geometry, high and unbalanced forces and a required low fringe field in primary beam path. A coil design based on flattened SSC Rutherford cable that provides a large current margin and commercially available fiberglass prepreg epoxy tape has been developed. A complete test coil has been wound and will be cold tested. This paper present the modified magnet design includes coil forces, coil restraint system and fringe field. In addition, coil properties, quench calculations and the full mechanical details are also presented.