Study of Transverse Compressive Stress Effects on the Critical Current of Bi-2223/Ag HTS Tapes

Bi-2223/Ag high-temperature superconducting (HTS) tapes have been widely used in superconducting magnet. For fusion magnets, transverse loads are introduced in HTS tapes, caused by mechanical, thermal and electromagnetic stress during manufacturing, winding and operation which leads to a remarkable degradation of critical current (I-c), thus cause the performance degradation of superconducting magnet. In this study, the I-c of Bi-2223/Ag HTS tapes under transverse compressive stress will be studied. An analytical model based on Weibull distribution was optimized and experiment was carried out to fit the model parameters. It is shown that the optimized analytical model agrees well with experimental data. Furthermore, to analyze the electro-mechanical behavior of Bi-2223/Ag HTS tapes, a numerical model was built based on the optical micrograph of tape's cross-section, and the distribution of transverse stress and I-c degradation was discussed.