A Study on Critical Current of Twisted Soldered-Stacked-Square (3S) HTS Wire with 1mm Width

Abstract

In high temperature superconducting (HTS) applications, the external magnetic field affects the performance of the critical current and the AC loss. To improve the performance, a novel soldered-stacked-square (3S) HTS wire is developed through narrowing, stacking and soldering processes using 2G narrow wires with 1 mm width. In this paper, the narrowing process of the wire with 4 mm width was showed and the stacking and soldering processes were also presented. The 3S wire was made of three narrow HTS tapes and four brass strips. For the 3S HTS samples, the typical electrical and mechanical properties have been tested. Based on that, single 3S wire and double 3S wires were twisted. Then the critical currents of the samples were tested at different twist pitches. The test results showed that the measured critical currents of 3S wire samples were between 120 A and 150 A. The critical current of the single 3S wire at average twist pitch of 50∼70 mm was about 8% lower than that of the original wire. And the critical current of double 3S wires was about 10% lower than the original critical current at a twist pitch of 65 mm.