Current and voltage distribution in composite superconductors withresistive barriers - asymmetric case

Abstract

An equivalent asymmetric scheme with distributed parameters isproposed and is aimed at simulating the current and voltage distributions incomposite high-Tc superconductors with thin resistive barriers around thefilaments. There are three longitudinal parallel branches in the scheme,representing the superconducting core, the metallic inner matrix around thiscore and the outer metallic matrix. The transversal current flow is controlledby two interlayer elements: one represents the barrier inserted between theouter and inner Ag matrices, while the second simulates the interfaceresistance between the inner Ag matrix and the superconducting Bi-2223 core.The superconducting core may be completely without resistance, but it can befound eventually in the resistive state.In this paper, referring to our previous paper, we deal with the case when thetransport current is supplied to the composite conductor through the outer Agmatrix and leaves via the superconducting Bi-2223 core with removed outer Agmatrix and resistive barrier. The current is forced to pass transversallythrough the barrier. The current and voltage distributions along the conductorsection followed are mainly governed by the properties of the resistivebarrier. In this way, the properties of the barrier can be reliably determined.The governing relation in the scheme is the product of thematrix-superconductor interface conductance and of the inner matrixresistance per unit length. The solution of the scheme leads to results thatdepend on the following dimensionless relations: the ratio of the barrier tothe matrix-superconductor interface conductances per unit length, the ratioof the outer to the inner matrices resistances per unit length and the ratioof the core resistance to the inner matrix resistance per unit length.