IMPROVEMENT IN THE LOSS AND CRITICAL CURRENT DENSITY PROPERTIES OF INTERNAL-TIN NIOBIUM-TIN

THE AIM OF THIS WORK IS TO FURTHER IMPROVE THE PROPERTIES OF INTERNAL-TIN NIOBIUM-TIN (NB3SN) STRANDS FOR FUSION APPLICATIONS. A CONDUCTOR HAS BEEN DEVELOPED WHICH MEETS ALL THE HP-1 INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR (ITER) SPECIFICATIONS. IN THIS PROJECT LOSSES WILL BE FURTHER LOWERED BY REDUCING THE "BRIDGING" THAT OCCURS BETWEEN NEIGHBORING FILAMENTS. IN PHASE I THE EFFECTS OF VARIOUS HEAT TREATMENTS AND TIN CONCENTRATIONS ON THE CRITICAL CURRENT CURRENT (JC) AND LOSS PROPERTIES WILL BE EXAMINED. THE LOSS PROPERTIES OF THE INDIVIDUAL SUBELEMENTS WILL BE COMPARED WITH THOSE OF THE 19 SUBELEMENT ASSEMBLIES AT DIFFERENT SIZES, IN ORDER TO DETERMINE THE ABSOLUTE SPACING BELOW WHICH COUPLING OCCURS BETWEEN THE FIRST AND SECOND ROW OF FILAMENTS AND ALSO THE EFFECTS OF FILAMENTS AND ALSO THE EFFECTS OF DISTORTION. IN PHASE II THE DATA OBTAINED IN PHASE I WILL BE USED TO DESIGN A SUBELEMENT STRAND AND AN IDEAL RESTACK ARRAY FOR LOW LOSS, HIGH JC OPERATION.