超伝導極細多芯線の交流帯磁率とグレイン・ビーンモデル(電気情報工学科)

Abstract

Proximity-currents between filaments in a multifilamentary wire show a close resemblance with the inter-grain current in a high-T_c superconductor. The critical current densities of the proximity-induced superconducting matrix J_<cm> can be estimated from measured twist-pitch dependence of magnetization and have been shown to follow the well-known scaling law of the pinning strength. In the grained Bean model, the filaments are immersed in the proximity-induced superconducting matrix. Difference of the superconducting characteristics of the filament, the matrix and the filament content factor give a variety of deformation on the AC susceptibility curves. The computed AC susceptibility curves of multifilamentary wires using the grained Bean model are favorably compared with the experimental results.