Transport Critical Current Properties of Silver-Sheathed Bi-Based Superconducting Tapes and Coils at 4.2 K

Transport critical current properties of silver-sheathed bismuth-based superconducting tapes and coils were investigated at 4.2 K and up to 25 T. Critical currents showed isotropic properties when the direction of the applied magnetic field changed from parallel to the tape surface to perpendicular, i.e., J c of 8.9×104 A/cm2 for H//tape and 6.6×104 A/cm2 for H⊥ tape at 23 T. Critical current properties of a three-double-pancake coil were consistent with those of short specimens, showing little change at from 5 to 23 T.