A NOVEL SCALING OF MAGNETIC-FIELD DEPENDENCIES OF CRITICAL CURRENTS FOR AG-SHEATHED BI-2223 SUPERCONDUCTING TAPE

Certain characteristics in magnetic field dependences of critical curr ent densities (J(c)) for the Ag-sheathed Bi-2223 superconducting tape have been found. One property regards the direction of the magnetic fi eld applied to the tape. Both J(c) values in the field, applied parall el and perpendicular to the tape surface, are on an identical curve wh en the magnitude of field (B), applied parallel to the tape surface, i s multiplied by a characteristic coefficient, which relates to the gra in alignment of each tape. Another concerns the relationship between J (c) and the magnitude of the field. The J(c) is expressed by a simple logarithmic function of B (log(B)) from a very low field to a high fie ld. This relation is applicable within a wide temperature range.