Strain-tolerant cable using Bi-2212 superconductor

The high strain sensitivity of Bi-2212 is a major obstacle for its use as a practical conductor in high-field magnet applications. Most efforts to improve the mechanical behavior of Bi-2212 focus on strengthening the silver matrix by means of alloying. We are reporting the design and preliminary testing of a strain-tolerant Bi-2212 cable that takes a different approach: Instead of reinforcing the conductor, it channels mechanical stress and strain away from it by prudent design of a Cable-in-Conduit (CIC) assembly. Six strands of Bi-2212 are cabled around a thin-walled Inconel X 750 tube and then sheathed in an outer armor that is drawn onto the 6-on-1 cable configuration.