TRANSPORT-PROPERTIES OF BI-2212/AG SUPERCONDUCTING MAGNET WITH I-C OVER 500 A

A compact 3 T-class superconducting magnet has successfully been fabricated using 6 stacks of single pancake coils prepared from Bi-2212/Ag multifilamentary composite tapes. The dimensions of the magnet were 45 mm in height, 45 mm in outer diameter and 13 mm in clear bore. Maximum coil current reached 550 A (10(-13) Ohm . m), generating a magnetic field at the center B-0 = 3.1 T and maximum field of the magnet B-m = 3 T without backup magnetic field. The J(c) of the coil was estimated to he approximately 55% of the short-sample results. A single pancake coil generated B-m = 0.42 T in a backup field of 20 T, although degradation of J(c) due to large electromagnetic force was observed.