Trapped field magnets of high-T/sub c/ superconductors

To develop trapped field magnets with YBCO bulks at and below 77 K, a series of trapped field magnets have been developed and tested. With two /spl Phi/26 mm/spl times/10 mm YBCO bulks, a trapped field magnet of 7.09 T at 29.8 K with low creep has been achieved. Cracks occur when 10 T magnetic field is applied to charge this magnet. With two /spl Phi/16 mm/spl times/10 mm YBCO bulks, a trapped field magnet of 7.02 T at 12.8 K has been achieved. Creep behavior of trapped field magnets at low temperatures are also investigated. When the trapped field is much lower than critical field, almost no creep was observed in the authors´ experiments.