Effect of non-uniform core thickness on critical current density of silver-sheathed oxide superconducting tapes

The fabrication of long silver-sheathed oxide superconducting tapes by the powder-in-tube technique tends to lead to non-uniformity in the core thickness during mechanical deformation and densification. This non-uniformity restricts current flow and reduces the critical current density. Using a simple model, the detrimental effects of various types of core thickness non-uniformity on the critical current density are investigated. Also the degree to which such non-uniformity needs to be controlled, based on the temperature of application of these conductors, is qualitatively inferred.