An Elemental Powder Approach for High Performance Nb3Sn Superconductors

70684 For high energy physics applications, Nb3Sn superconductors are the main material used to construct magnets that operate at magnetic fields greater than 12 Tesla. However, future applications will require higher performance and lower manufacturing costs. Specifically, the targets of 3000 A/mm2 at 12T, effective filament diameter 10 km have been established for the Very Large Hadron Collider (VLHC). This project will develop a process that utilizes elemental powders of Nb, Sn, and Cu to produce a non-copper critical current density that meets these targets. The use of elemental powders in a powder in tube approach should provide a cost effective process to reach high perfromance. In Phase I, powders of Nb, Sn and Cu will be processed by a powder-in-tube method to form a multifilamentary composite wire. The Nb and Sn will deform during processing to form a fine scale mixture. Heat treatment studies will be conducted to determine the time and temperature required to react these fine layers to obtain good performance. Metallography and electrical characterization will be completed on the reacted samples. Commercial Applications and Other Benefits as described by the awardee: A successful conductor should find commercial applications in high field Nuclear Magnetic Resonance (NMR) applications for chemical analysis to take advantage of the high upper critical current and strain tolerance. A Nb3Sn conductor also could find application in Magnetic Resonance Imaging (MRI) imaging devices where the high critical temperature of the superconductor might allow helium-less conduction cooled magnets.