MAGNETIC-FIELD IN THE VICINITY OF BSCCO TAPES CARRYING TRANSPORT CURRENT

Measurements of magnetic field components B-x,B-y,B-z, produced by bot h shielding and transport currents in BSCCO/Ag tapes are presented. Th e measured sample BSCCO 2223 was prepared by the powder in tube techni que and the self field critical current densities were of the order of 10(4) A/cm(2) at 77 K. The shielding currents were induced by the ext ernal magnetic field perpendicular to the tape surface. The sample mag netic field was measured using 3 Hall probes with small active area (a bout 10(-2) and mm(2)) and sensitivity of the order of 10mV/T. They we re fixed to a special holder so that they sense x, y and z component o f the sample magnetic field at the distance greater than or equal to 0 .5mm from the sample surface. The measured profiles provide informatio n on the critical current density inhomogeneities along the sample as well as on the spatial and time distribution of both transport and mag netization currents.