Development of High Field, High Current Density Nb3Sn Conductor with Engineered Microstructures

50765-98-I Development of High Field, High Current Density Nb3Sn Conductor with Engineered Microstructures--Supercon, Inc., 830 Boston Turnpike, Shrewsbury, MA 01545-3301; (508) 842-0174 Mr. Terence Wong, Principal Investigator Ms. Elaine Drew, Business Official DOE Grant No. DE-FG02-98ER82676 Amount: $75,000 In order for the next generation high energy physics particle accelerators to reach higher collision energy levels, there is a need for higher field dipole magnets. This in turn demands superconductors that have higher critical current densities at high fields than can typically be reached with NbTi. Thus Nb3Sn conductors are the conductor of choice for the next generation dipole magnets (=15Tesla). Further improvements in Nb3Sn conductors are necessary if this goal is to be met. The objective of this research is to develop a high critical current density Nb3Sn conductor that uses the additions of dopants to the Nb3Sn phase. The dopants will refine the Nb3Sn microstructure to reduce the average grain size and increase the grain boundary pinning force in order to reach higher critical current densities. This project will investigate the feasibility of fabricating a Nb3Sn conductor by the powder-in-tube (PIT) method with additions of Zr as a dopant to control the microstructure during heat treatment. A multifilamentary assembly will be drawn to sample size, heat treated, and then tested for superconducting properties. Comparison of the Zr addition to a control sample will allow evaluation of the PIT method as a means of incorporating dopants into Nb3Sn conductors. Commercial Applications and Other Benefits as described by the awardee: The principle application of a higher performing Nb3Sn conductor would be in high field dipole magnets. However, other uses would be found in magnetic confinement systems for fusion reactors and nuclear magnetic resonance (NMR) systems for chemical analysis._