Cost Reduction Techniques for Producing NbSn2 Intermetallic Powder for Application in PIT Processed Nb3Sn Superconductor

65411 The high energy physics community requires the development of superconducting wires for use in magnets that generate magnetic fields of 15T and above. Currently, Nb3Sn is the only commercially available superconductor capable of operating at such high fields. Powder-In-Tube (PIT) Nb3Sn conductor has shown attractive performance and good strain resistance. However, cost is a major drawback, particularly powder costs. This program seeks to reduce the cost of the PIT process. This project will investigate alternative powder fabrication routes for NbSn2 powder for eventual application in PIT Nb3Sn conductor development. These alternative processing routes have the promise of producing high quality powder in a single step and at greatly reduced cost. In Phase I, alternative processing routes to produce NbSn2 powder were explored through changes in reaction heat treatment parameters and choice of raw material. Samples were analyzed by scanning electron microscopy to determine degree of NbSn2 formation. The indirect melt diffusion and chopped niobium wire processes were found to be practical, scaleable, and cost efficient processes by which to manufacture phase-pure NbSn2. In Phase II, these processes will be scaled up to handle production size lots. Ultimately PIT Nb3Sn conductor will be fabricated, and its superconducting properties will be tested and optimized. Commercial Applications and Other Benefits as described by the awardee: A low cost multifilamentary Nb3Sn superconducting wire with high current carrying capacities in high magnetic fields should find many applications in accelerator, fusion, and NMR magnets.