Advanced Silver Sheathed 2212/Ag Wire for High Field Magnets

Solid Material Solutions (SMS), in collaboration with the Applied Superconductivity Center (ASC) at Florida State University, will establish the feasibility of an innovative, silver sheathed Bi2Sr2Ca1Cu2Ox (2212/Ag) High Temperature Superconducting (HTS) wire design that enables much higher wire current densities, adding to the advances achieved by recent powder and over pressure (OP) process developments, and propelling Bi2212 into the position to provide broad - based utility in commercial high field magnet applications. This novel wire design, combined with thermal – mechanical densification and OP processes, will enable vital improvements in the performance of a variety of large accelerator type magnets, as well as NMR and other field boosting magnet systems. Additionally, it is a promising candidate for use in next- generation large-scale commercial applications in the electric power industry, such as high-powered but lighter-weight and more efficient wind generators. The Phase 1 program will establish the feasibility of achieving much higher current density, round and rectangular 2212/Ag wire, by using uniform one bundle architectures that eliminate the wasted space that occurs in double bundle architectures, and that, combined with our improved silver chemistry, will enable more uniform 2212 densification, with better texturing and 2212 formation during OP. Additionally, these designs have the potential to be produced at lower cost than present Bi2212/Ag wires. The approach for producing these wires and achieving these results will be established by building on our experience in the design and manufacture of high Je Bi2223/Ag (1G) tapes, specifically, 1) increasing the amount of the Bi2212 in the wire to about 35% from 25%, 2) modifying the chemical composition of the silver sheath adjacent each filament so the Bi2212 chemistry is not changed in OP, and 3) greatly decreasing variability of filament cross-sectional shapes and longitudinal variability.