Program for Analysis of Filament Homogeneity in Bi2Sr2CaCu2O8-x (Bi-2212) and Nb3Sn superconducting wires

Abstract

Superconductors are materials that can carry electricity without resistance at cryogenic temperatures, which is useful for large magnet applications such as particle accelerators. Bi2Sr2CaCu2O8-x (Bi-2212) is a superconductor capable of producing very large magnetic fields (>20 Tesla), but processing the Bi-2212 into usable, filamentary round wire forms is challenging. The fluctuations in the size and shape of Bi-2212 filaments in a composite wire can affect processing capability and wire performance. The focus of this project was to create a programmed application that would simplify the image analysis process. The program takes as input a series of black-and-white thresholds of transverse wire cross-sections. The program then returns as output a spreadsheet with filament measurements and basic statistical data on the filaments over the series of images. The key measurements of a filament are its area and circularity. The key statistical data of a filament is its coefficient of variation, which provides information about its homogeneity along the wire. Previously, this analysis took up to 5 hours of manual analysis and data manipulation. Using the new program has reduced this time to up to 5 minutes of automatic analysis, improving productivity by 60 times.