Anisotropic thermal transport in Bi2223/Ag superconducting tape with sandwiched structure

The thermal conductivity, kappa(T), of the Bi2223/Ag tape reinforced by metal tapes (stainless steel (SS) or copper-based alloy (CA)) from both side was evaluated along the length (l) and width (w) directions. kappa(T) along the l-direction was measured directly using a single tape and that along the w-direction was estimated from the kappa(T) measured for a stacked bundle which consists of several sandwiched Bi2223/Ag tapes. We analyzed the obtained kappa(T) curves using an equivalent heat current circuit, and found that the heat transports along both directions were nearly the same and that the route of heat-flow depended on the species of the reinforcing metal. The absolute values of kappa(T) at 77 K along the l-and w-directions for the Bi2223/Ag-SS tape were 174 and 140 Wm (1) K (1) and those for the Bi2223/Ag-CA tape were 206 and 206W m (1) K (1), respectively, the values of which were approximately 30-40% and 10-15% smaller than those of the standard Bi2223/Ag tape. (C) 2012 Elsevier B.V. All rights reserved.