NDE OF SUPERCONDUCTING MAGNET WIRE USING SCANNING ACOUSTIC PULSE SPECTROSCOPE (SAPS)

LONG CONTINUOUS CONDUCTORS, I.E. MINIMUM NUMBER OF SPLICE JOINTS ARE HIGHLY DESIRABLE IN SUPERCONDUCTING MAGNET APPLICATIONS. AT PRESENT THE PIECE LENGTH OF MULTIFILAMENTARY SUPERCONDUCTOR WIRE HAS BEEN A PROBLEM AND THIS HAS DRIVEN UP THE COSTS OF MAGNETS FOR THE SSC. LOW DUCTILITY IS A CAUSE OF SHORT PIECE LENGTH AND THIS MAY BE DUE TO THE PRESENCE OF IMPURITIES, INCLUSIONS, OR LACK OF BONDING BETWEEN MANY INTERFACES. THE PRECISE CAUSE OF SHORTPIECE LENGTHS REMAINS TO BE DETERMINED. CURRENT ULTRASONIC NDE TECHNIQUES FACE LIMITATIONS WHEN WIRE DIAMETERS ARE SO SMALL THAT ECHOES FROM THE FRONT SURFACE AND IMPURITIES OR VARIOUS INTERFACES BECOME INDISTINGUISHABLE. THIS SBIR PROJECT DESCRIBES A NEW METHOD BASED ON SCANNING ACOUSTIC PULSE SPECTROSCOPY (SAPS) FOR NONDESTRUCTIVE DETECTION OF DEFECTS IN SMALL-DIAMETER SUPERCONDUCTING MAGNET WIRES. THE EMPLOYMENT OF PULSE SPECTROSCOPY IS BASED ON THE FACT THAT THE CLOSER THE SEPARATION IS BETWEEN TWO PULSES IN THE TIME DOMAIN, THE FARTHER THE SEPARATION IS BETWEEN TWO NODESIN THE FREQUENCY DOMAIN. THE COMPLETION OF THE PHASE I PROJECT WILL IDENTIFY A "PRACTICAL" METHOD FOR NDT OF DEFECTS WITHIN A FINE WIRE AND LEAD TO THE DETERMINATION OF THE CAUSE OF SHORT PIECE LENGTH. SONOSCAN STAFF MEMBERS ARE RECOGNIZED LEADERS IN THE FIELD OF ACOUSTIC MICROSCOPY AND WILL BRING A LARGE KNOWLEDGE BASE TO THE DEVELOPMENT OF A TECHNIQUE FOR NDE OF SMALL DIAMETER MULTIFILAMENTARY SUPERCONDUCTING WIRE.