Speaker
Description
Novel ultrafine jelly roll Nb3Sn ultrafine wires, i.e. ~50 μm diameter, offer the potential of building Nb3Sn magnets using the react-and-wind approach with high-Jc wires. The high flexibility of these wires due to their small diameter, the ability to assemble multiple of them in Rutherford cables, and the long unit lengths that have recently been manufactured motivates further studying the performances and behavior of these ultrafine wires.
A heat treatment study of individual ultrafine jelly roll Nb3Sn wires will be presented. A qualitative and quantitative observation of phase and microstructure evolution during the heat treatment by electron microscopy will be presented. The residual resistivity ratio (RRR) results of the wires after heat treatment to study Cu-matrix contamination from over-reaction in regions not visible in the analyzed cross-sections will also be summarized.
This work is supported by the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics under DOE National Laboratory Program Announcement Number LAB 24-3200. The work performed at Lawrence Berkeley National Laboratory was also supported by the Office of High Energy, U.S. Department of Energy, under contract No. DE-AC02-05CH11231.
