https://doi.org/10.1140/epjs/s11734-024-01358-1
Regular Article
Experimental studies of critical currents and joint resistance of HTS twisted stack slotted-core cables
1
Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 230031, Hefei, People’s Republic of China
2
University of Science and Technology of China, 230026, Hefei, People’s Republic of China
3
Hefei International Applied Superconductivity Center, 230071, Hefei, People’s Republic of China
b
shiyi@ipp.ac.cn
j
liuhj@ipp.ac.cn
Received:
14
May
2024
Accepted:
29
September
2024
Published online:
15
October
2024
As the high critical current at high field, the representative second-generation high-temperature superconductor (2G HTS) REBCO-coated conductor serves as a good candidate for the future China Fusion Engineering Test Reactor (CFETR) with a magnet field exceeding 15 T. The Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) is engaged in the R&D activities of REBCO-based HTS Twisted Stack Slotted-core Cables (TSSC) with the objective of validating the feasibility of cable-in-conduit conductor (CICC). Two 1.3-m-long TSSC samples, each comprising 32 3-mm-wide REBCO-coated conductors and 56 copper tapes, have been manufactured and successfully tested at 77 K and self-field, followed by a joint resistance test at 4.2 K. The critical current of the both TSSC specimens at 77 K was tested to be 2830–2886 A with an n-value of approximately 30, which is similar to the simulation value, demonstrating no significant degradation occurred during fabrication. Nevertheless, current transfer between cables is carried out through joints, and the manufacturing process of the joint terminals can seriously affect the capability to achieve current transfer with a low resistance. Therefore, an oil-bath heated melting solder method was presented to prepare the joint terminals for HTS TSSC cables, as well as resistance measurements being evaluated. At 77 K, the terminal resistance was measured to be in the tens of nano-ohms, in comparison to about 0.68 nΩ at 4.2 K. The findings of this study offer valuable insight into the conductor preparation process and provide a foundation for future developments in large-scale fusion magnet applications.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.