HIGH-SPEED, HIGH-RESOLUTION ULTRASONIC NDT/E OF SUPERCONDUCTING MAGNET MONO-AND MULTIFILAMENTARY WIRE

DEVELOPMENT OF AN ULTRASONIC, NONDESTRUCTIVE TEST DEVICE FOR INSPECTION OF MONOFILAMENT ROD AND POTENTIALLY MULTIFILAMENTARY WIRE FOR SUPERCONDUCTING MAGNETS IS THE LONG-TERM GOAL OF THIS PROJECT. THE ROD AND WIRE TO BE INSPECTED ARE THE HIGH CRITICAL-CURRENT CONDUCTORS USED IN HIGH FIELD MAGNETS PROPOSED FOR PARTICLE ACCELERATORS. THERE IS NO ESTABLISHED TECHNIQUE FOR DETECTING FLAWS IN SMALL DIAMETER (LESS THAN 0.5") ROD OR WIRE. THIS TECHNIQUEPROVIDES GREAT LEVERAGE BY FINDING PROBLEMS AT AN EARLY, LOW COST POINT IN THE MANUFACTURING PROCESS. TO PROVIDE INTERNAL INSPECTION, MONITOR INTERFACE CONTINUITY, INSPECT THE ROD SURFACE FOR DEFECTS, AND MONITOR LAYER THICKNESS, THE INSPECTION SYSTEM MUST COMBINE SCANNING LASER ACOUSTIC MICROSCOPY (SLAM) TECHNIQUES WITH HIGH FREQUENCY PULSE-ECHO TECHNIQUES. FOR PRACTICAL SCANNING TIMES FOR 30-FOOT-LONG ROD AND QUANTITIES OF ONE MILLION POUNDS OVER SEVERAL YEARS, HIGH-SPEED SIGNAL PROCESSING AND DATA ACQUISITION WILL BE REQUIRED. PHASE I WILL EXAMINE THE FEASIBILITY OF 10-100 MHZ FREQUENCIES FOR INTERNAL INSPECTION OF THE SUPERCONDUCTING CORE AND STABILIZER CLADDING IN MONOFILAMENTROD FOR INCLUSIONS AND VOIDS (SIZE GREATER THAN 3% OF CORE DIAMETER AND 5% OF CLADDING THICKNESS). SLAM OPTICAL AND ACOUSTIC IMAGING WILL BE EXAMINED FOR MONITORING ROD SURFACE DEFECTS. A FOCUSED, 50-100 MHZ PULSE-ECHO SYSTEM WILL BE DEVELOPED FOR MONITORING BARRIER AND STABILIZER LAYER THICKNESSES, UNIFORMITY, AND CONTINUITY. THE CLOSE COORDINATION OF THE TWO DETECTION TECHNIQUES, DATA ACQUISITION, AND SIGNAL PROCESSING FOR RAPID SCANNING TIME WILL BE DETAILED. THE DEVICE'S USEFULNESS FOR MULTIFILAMENTARY WIRE WILL BE CONSIDERED.