The influence of tensile strain to critical current of Bi2223 composite tape

✍ Scribed by Y. Mukai; J.K. Shin; S. Ochiai; H. Okuda; M. Sugano; K. Osamura

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 558 KB
• Volume: 468
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2008.05.088

✦ Synopsis

As the stress-induced damage evolution is different from position to position in the sample, the local critical current is scattered in a sample, affecting on the overall current. The present work aimed to describe the distribution of local critical current and its relation to overall critical current under tensile stress for Bi2223/Ag superconducting composite tape. In the experiment, seven voltage probes were attached in a step of 10 mm. The local critical current and n-value at 77 K under various applied stress levels were measured for a voltage probe distance 10 mm and the overall ones for a probe distance 60 mm. Main results are summarized as follows. The overall critical current and n-value were described well by using the voltage summation model in which the sample was regarded as a one dimensional series circuit. For the low applied stress, the distribution of local critical current was described with the three parameter Weibull distribution function. Using the measured distribution of the local critical current, an experimental relation of critical current to n-value and the voltage summation model, and applying the Monte Carlo method, the overall critical current was predicted, which was in good agreement with the experimental results. Based on these results, the sample length dependence of critical current of the sample damaged by tensile stress was discussed.