Development and Characterization of High Temperature Superconducting Wire for Superconducting Cable System

In order to improve the properties of high-temperature superconducting wire for superconducting cable system, we optimized the electro-polishing (EP), ion-beam assisted deposition (IBAD), superconducting (SC) layer, and baking (heat) treatment. The buffer layer was deposited on electro-polished substrate with RMS roughness (R RMS ) less than 5 nm. The IBAD process was carried out at V beam : 1100 V and V accel : 850 V that resulted in highly crystalline film of LaMnO 3 . Chemical composition of SC layer is key to higher critical current, and we found that composition can be determined by surface color of SC layer. We adopt a proprietary contorl system based on RGB analysis of the surface and achieved critical current of 150 A/4 mm-width. The proposed baking treatment resulted in decreasing of about 10% of fraction defects.