"A Cost Effective, Tube Extruded Nb3Sn Superconductor

The high energy physics (HEP) community requires the development of superconducting wires for use in magnets generating magnetic fields greater than 12 T. Currently, Nb3Sn is the only commercially available superconductor capable of operating at such high fields. However, its technical and cost performance does not meet the demands for next generation magnets. This project will develop an economical process for the fabrication of Nb3Sn conductors that will meet the requirements. In particular, the Internal Tin (IT) process will be further developed to produce high performance ternary A15 superconducting wire for HEP applications. The process improvements consist of (1) developing tube extrusion as a cost effective route for fabricating multifilament sub-elements used in the IT process, and (2) the addition of a thin tantalum diffusion barrier around each individual sub-element, thereby removing any heat treatment constraints and maximizing current density. Commercial Applications and other Benefits as described by the awardee: High performance multifilamentary Nb3Sn should find applications in high energy physics particle accelerators and magnetic confinement fusion machines. Commercially, such a conductor should find application in high frequency NMR magnets, by taking advantage of the higher critical current density in order to reduce the size and overall cost of the magnet system.