Influence of Oxygenation in Copper Stabilized Multifilamentary 2G HTS Tapes Made by Selective Electroplating and Laser Ablation

Abstract

Striation and selective electroplating of copper stabilizer layer has been proven to be an effective way of reducing the hysteretic AC loss of second generation high temperature superconducting (2G-HTS) tapes. This method consists of a top down laser material removal (ablation) followed by post-oxygenation to create resistive oxide layer on the grooves and selective electroplating of a thick Cu stabilizer layer on the filaments. In such a filamentization technique, scalability, the degree of coupling loss contribution and critical current (I c ) degradations are the main concerns. In this study, we have investigated the post-oxygenation temperature effect on the I c degradation and coupling loss contribution. The results showed that post-oxygenation temperature has immense effect on the I c degradation and also alters the coupling loss contribution to the total magnetization AC losses. The coupling loss contribution was found to be less in samples oxygenated at higher temperatures; however, the degradation of I c was found to be higher. In addition, preliminary experiments were conducted to scale-up this newly-developed technique. Initially, 10 m long fully-filamentized tape with thick Cu stabilizer layer was fabricated and at least 5 times reduction in AC loss was observed.