SUPERCONDUCTING WIRE WITH A BUILT-IN NIOBIUM SURFACE COATING TO LIMIT INTERSTAND EDDY CURRENTS IN CABLES

THE STABILITY AND EFFICIENCY OF LARGE SCALE SUPERCONDUCTING MAGNET SYSTEMS OFTEN SUFFER FROM INTERSTAND EDDY CURRENT LOSSES. THERE ARE DRAWBACKS IN THE EXISTING HARD CHROME PLATING TECHNIQUE WHEN IT IS APPLIED TO NIOBIUM-TIN (NG3SN) STRANDS. A NEW TECHNIQUE OF DEVELOPING A CONTINUOUS, BUILT-IN NIOBIUM (NB) COATING ON THE SURFACE OF A SUPERCONDUCTING WIRE WILL BE INCORPORATED INTO THE MANUFACTURE OF NB3SN MULTIFILAMENTARY SUPERCONDUCTING STRANDS FOR THE INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR (ITER) PROJECT IN ORDER TO SIMULTANEOUSLY LIMIT THE INTERSTRAND EDDY CURRENT LOSSES IN A SUPERCONDUCTING CABLE AND PROTECT THE COPPER STABILIZER FROM RESIDUAL RESISTIVITY RATIO (RRR) DEGRADATION AFTER REACTION HEAT TREATMENT. THIS PROJECT DETAILS THE NECESSARY STEPS TO PROVIDE SUCH A SOLUTION. IN PHASE I THE FEASIBILITY OF THIS TECHNIQUE WILL BE EVALUATED GY FABRICATING A PROTOTYPE GRONZE-ROUTE NB-COATED NB3SN WIRE AND COMPARING JC AND RRR PERFORMANCE OF THIS WIRE WITH ITS COUNTERPART WIRE WITHOUT NB COATING. MOREOVER, THIS TECHNIQUE CAN ALSO BE APPLIED TO THE MANUFACTURE OF INTERNAL-TIN ROUTE NB3SN, NIOBIUM-TITANIUM (NBTI) AND OTHER SUPERCONDUCTING WIRES.