Transport AC Losses in Soldered Joint of the YBCO-Coated Conductors

Abstract

In this paper, we present a direct measurement of the transport AC loss in solder joint of the YBa 2 Cu 3 O 7−xcoated conductor (YBCO CC) at liquid nitrogen temperature. The method is based on measuring the temperature rise of the thermally insulated joint which is fabricated by soldering the YBCO CC samples face to face without removing the metallic stabilizer. The contact resistances in these joints are in the range of 10 to 40 n . It is found that (1) the AC losses in the sample with lap joint dependence of I/I c can be described by use of a third-order power law, where I and I c denote the transport current peak and critical current of the YBCO CC sample, respectively. (2) The loss in sample with joint is greater than that of the original YBCO CC sample in case of I/I c < 0.6, while there are no much in the loss in two kinds of sample when I /I c is in the range from 0.6 to 0.7. Once I/I c > 0.7, the loss in sample with joint is less than that in the original tape.