A MgB2 superferric racetrack magnet

A magnesium diboride, cryogen-free, H-dipole magnet with cold iron yoke was constructed and tested. The racetrack coil, 48?cm long, was wound with 350?m of nickel-clad, copper-MgB2 tape. The iron yoke forms a 2.6?cm gap. The magnet was connected to a cryocooler and tested at different temperatures ranging between 8.5 and 24?K. The maximum current, 263?A, was reached, without training, at 8.5?K. The corresponding field in the gap was 2.35?T.