Simulation of transport critical current of Bi2223/Ag tape with ferromagnetic shielding

Ferromagnetic shielding (FS) was coated onto the surface of the Bi2223/Ag multi-filamentary tape. Transport critical current of the Bi2223/Ag multi -filamentary tape with a FS was systematically studied by numerical simulation. In the help of a finite element analysis (FEA) tool, we are able to understand how the FS alters the flux inside the superconductor region and thus increases and decreases the critical current density locally. The results show the open FS function both positively and negatively to the performance of the tape. An optimization process was proposed, aiming to reach a tradeoff between I-c increasing and less usage of the ferromagnetic material. Three important shielding parameters, shielding width, shielding thickness, and shielding material were taken into account. (C) 2008 Elsevier B.V. All rights reserved.