An Innovative Low Cost, High Strength Stabilizer for High Field Bi2212 Superconductors

78216S High Energy Physics requires the development of superconducting wires for use in magnets that generate fields greater than 15 tesla for such applications as the interaction region quadrupoles for the planned Large Hadron Collider luminosity upgrade. Although niobium-tin conductors are currently meeting the requirements of the accelerator magnet community, improvements in Bismuth 2212 superconductors have shown promise as a potential alternative that might allow even higher magnetic fields to be reached. However the cost, current capacity and mechanical performance of these wires do not meet target values. This project seeks to improve the mechanical strength, increase the engineering critical current density, and lower the cost for Bi2212 wires. To accomplish this, a low cost, high strength, matrix material will be developed to replace the pure silver used in current Bi2212 wires. In Phase I, a silver-based composite will be fabricated using two experimental approaches. The composite matrix material will be evaluated for fabricability and compatibility with the melt processing heat treatments used for Bi2212 superconductors. Composite tubes will be fabricated and used to produce superconducting monofilaments, which will be drawn to fine wire diameters and then melt processed. Mechanical, scanning electron microscopy, and electrical testing of the superconducting behavior will be conducted to evaluate the novel composite matrix. Commercial Applications and Other Benefits as described by the awardee: A high performance, lower cost Bi2212 superconductor should find primary application in accelerators for high energy physics and magnetic confinement fusion systems. The conductor also should find application in high field nuclear magnetic resonance systems, to take advantage of the high upper critical field, and magnetic resonance imaging, to take advantage of the high critical temperature.