Homogenous BSCCO-2212 Round Wires for Very High Field Magnet Applications

With the drive towards higher-field dipole magnets, the material requirements for superconductors are becoming stringent. Compared to existing metallic superconductors, high-critical-temperature ceramic materials have the very significant advantage of extremely high critical field values. For this reason, the ceramic superconductor, bismuth strontium calcium copper oxide (BSCCO-2212), in the form of a multi-filamentary Ag alloy composite, is beginning to attract the interest of the DOE for future extremely high-field magnets or magnet-insert coils for 4.2K operation. This project will produce a commercially viable BSCCO-2212/Ag composite, multi-filamentary round wire with a Jc value exceeding 2100 A/mm2 and Je value equal to or exceeding 600 A/mm2 at 12T and 4.2K. Furthermore, the project also will determine the powder processing conditions for BSCCO-2212 powder, in order to maximize the uniformity Jc and Je throughout the length of the composite wire. In Phase I, several calcining conditions will be investigated and the effects of these conditions on the microstructure of the BSCCO-2212-based conductor, formed in tape and wire samples after melt processing, will be determined. Commercial Applications and other Benefits as described by the awardee: The BSCCO-2212/Ag composite wire should find application in high field magnets for high energy physics experimentation. The technology also should have applicability wherever high field magnets are required, such as in medical MRI.