Study on the influence of welding process of YBCO CICC conductor terminal on conductorqs current 7 carrying performance

The welding process is one of the key technologies for making connector terminals of YBCO CICC conductors with uniform current distribution and good performance. It is an important factor to ensure the long-term stable operation of YBCO CICC conductors at low temperatures and high fields. This paper describes the soldering process for making YBCO CICC conductor connector terminals by the solder filling method. To verify the influence of the welding process on the conductor current-carrying performance and process reliability, a 150 mm long YBCO tape of each layer was intercepted from the end of the conductor connector, and the critical current of each layer was tested at 77 K. Test results show that the critical current of the tape at the end of the conductor’s joint is maintained within 168 ± 15 A, with no degradation in current-carrying performance. The solder filling method of the welding process has no effect on the conductor end performance, the process is reliable and meets the experimental needs. The solder-filled welding process can provide key technical support for the preparation of YBCO CICC conductors and their application in future large-scale fusion devices.