Abstract
There are high expectations for RE123 wires to be used as future commercial superconductors in the future because of their excellent performance under high magnetic fields and of low cost capabilities. ISTEC, national institutes, universities and companies are taking part in a Japanese national project on electric power devices known as, "Materials & Power Applications of Coated Conductors (M-PACC)". The target applications of the project are SMES, cables and transformers. ISTEC, Fujikura, Showa, Sumitomo and Furukawa are developing RE123 wires for mass-production using various fabrication processes. One of the most important characteristics for practical superconducting wires is, the bending-strain dependence of the critical current. The IC dependencies of RE123 wires for various bending strains were measured using the "Goldacker type" continuous bending apparatus. For tensile bending with the superconductor layer on the outside of the bend, the diameter of the 95% IC retentions was approximately 20 mm for all wires. On the other hand, for compressive bending with the superconductor layer on the inside of the bend, the IC dependencies for the bending diameter were each different. The reversibility strain under bending and straightening was also evaluated using the continuous bending apparatus. These results demonstrate that the IC dependencies for the bending diameter of all wires are suitable for the applications of the M-PACC project.
