Extraction of matrix resistivity from short samples of superconducting multifilamentary composite tapes: influence of strand twist and internal structure

摘要

An expression for loss in untwisted, aspected strands (aspect ratio a/b) has been used to extract the effective transverse matrix resistivity, rho(perpendicular to), of NbTi/Cu and Bi-based multifilamentary strands with low numbers of filaments in coarse arrays. The rho(perpendicular to) values were significantly higher than expected for both strand types by factors of 5-10. This was attributed to filament array coarseness and geometry, and was predicted to be much mom noticeable for untwisted than twisted tapes. Additionally, a loss equation is given for the special case of twisted tapes with resistive cores. Here, the loss is estimated to be about a/b times lower than the uncored case. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 10]