HOMOGENEITY STUDY OF BI-2223 AG MONOFILAMENTARY TAPES USING HALL SENSOR MAGNETOMETRY/

In this paper we report a homogeneity study of Bi-2223/Ag monofilament ary tapes prepared by two different mechanical deformation processes, rolling and semi-continuous pressing. We demonstrate how effects of me chanical deformation and heat treatments on the sample homogeneity and local critical current density can be revealed using Hall sensor magn etometry, Typical features of measured magnetic flux density profiles are interpreted by comparing the profiles to data obtained from resist ive critical current measurements, SEM micrographs and numerical calcu lations based on simplified models of screening current distributions. Our experimental results are in agreement with the concepts that pres sing leads to a rather homogeneous transport current path in a Bi-2223 /Ag tape and rolling is likely to induce transversal cracks and neckin g in the superconducting ceramic.