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

With the drive toward higher-field dipole magnets, material requirements for superconductors are becoming stringent. Although the processing and application of existing metal-based materials have advanced to a significantly higher level than those of their ceramic high-critical-temperature counterparts, these counterparts have exhibited higher critical field values. Therefore, the ceramic superconductor, bismuth strontium calcium copper oxide (BSCCO-2212), in the form of a multifilamentary Ag alloy composite, is beginning to attract the interest of the DOE. This project will produce a commercially viable BSCCO-2212/Ag composite multifilamentary 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. In addition, the powder processing conditions for the BSCCO-2212 powder, needed to maximize the uniformity of the Jc and Je throughout the length of the composite wire, will be determined. In Phase I, an understanding of the effect of powder calcining conditions on the powder properties and the wire fabrication process was developed. In addition, a wire fabrication process was demonstrated, in which composite wires free of superconductor phase leakage were produced. In Phase II, the superconductor properties of the composite wire will be further improved by tailoring the powder processing method. Commercial Applications and other Benefits as described by the awardee: The initial commercial application of BSCCO-2212/Ag composite wire should be in high field magnets for high energy physics experimentation. Other uses of the technology should include medical MRI and other commercial applications where high field magnets are required.