THE DEVELOPMENT OF A PROCESS FOR MAKING MULTIFILAMENTARY NBN

PRESENTLY, THE ONLY SUPERCONDUCTOR AVAILABLE COMMERCIALLY INSIGNIFICANT VOLUME FOR OPERATION AT FIELDS ABOVE 12 T, IS NB3SN, AND IT HAS BEEN SHOWN TO BE SENSITIVE TO IRRADIATION DAMAGE AND TO HAVE VERY SIGNIFICANT STRAIN SENSITIVITY, PARTICULARLY AT HIGH FIELDS. BOTH OF THESE FACTS MAKE LARGE HIGH-FIELD PLASMA CONFINEMENT MAGNETS COSTLY AND DIFFICULT TO DESIGN. NBN HAS BEEN MADE IN SMALL QUANTITIES BY SEVERAL INVESTIGATORS AND HAS BEEN SHOWN NOT TO BE SUBJECT TO THE ABOVE DRAWBACKS OF THE PRESENT SUPERCONDUCTING A 15 COMPOUNDS. THE PROBLEM IS TO SCALE UP AN NBN PROCESS TO ONE THAT WILL MAKE A STRAND FOR INCORPORATION INTO A HIGH FIELD CABLE-IN-CONDUIT CONDUCTOR (CICC). PHYSICAL VAPOR DEPOSITION (PVD) EQUIPMENT, SUITABLEFOR THE DEPOSITION OF LONG LENGTHS OF NBN, HAS BEEN DESIGNEDAND IS AVAILABLE, AND PRELIMINARY ATTEMPTS TO STABILIZE THE DEPOSITED FILAMENTS HAVE BEEN STARTED. IN PHASE I IT IS INTENDED TO CONCENTRATE ON THE DEVELOPMENT OF A METHOD OF CONTINUOUSLY OPENING AND CLOSING THE TOW OF FILAMENTS THAT IS COMPATIBLE WITH EXISTING EQUIPMENT CAPABLE OF PERFORMING THESE OTHER STEPS. THE PROPERTIES OF SAMPLES MADE ON THE FILAMENT TOW WILL ALSO BE INVESTIGATED TO DETERMINE WHICH OPERATIONS NEED FURTHER DEVELOPMENT. IN PHASE II THE SEVERAL STEPS WILL BE CONSOLIDATED TO PRODUCE LONG LENGTHS OF STABILIZED NBN STRANDS FOR USE IN A HIGH FIELD CICC.