Joint technology is one of the key technologies for the application of second-generation high-temperature superconducting (2G HTS) tapes. The simplicity of the joint fabrication method and the excellence of the electrical and mechanical properties of the joints significantly impact the performance of REBCO in large-scale applications. Copper bonding joint technology, a new type of solder-free,...
The solder layer in electronic systems has been the subject of a vast number of studies in the field of reliability assessment due to the weakness of this layer and the large difference between its mechanical characteristics and those of the rest of the system. Among these characteristics, the difference in the coefficient of thermal expansion drives the generation of thermal stress, which can...
Rare-Earth Barium Copper Oxide (REBCO)-based High-Temperature Superconductor (HTS) tapes are used for large-scale applications, which typically require spools longer than those currently produced. Therefore, several joints are often needed for a single project, emphasizing the importance of low-resistivity, mechanically strong, and repeatable joints. Currently, soldering is one of the most...
High-Temperature Superconducting (HTS) magnets, composed of multiple pancake coils made from Second Generation (2G) HTS tapes, offer significant advantages due to their superior performance in elevated magnetic fields and temperatures compared to traditional low-temperature superconductors. A critical aspect of manufacturing these magnets is creating reliable joints, which transfer current...
To achieve a controllable operating temperature for superconducting magnet devices, the development of cryocooler-cooled superconducting magnets has garnered significant attention. Typically, the excitation current of commercially available cryocooler-cooled superconducting magnets ranges from approximately 100 to 200 A. However, increasing the excitation current of superconducting magnets is...
The concept of a rotating cryocooler for superconducting rotating machines eliminates the need for cryogenic liquids in the cooling loop, thereby simplifying and compacting the cooling system. This approach enables the development of extremely lightweight machines with high torque density. However, at high rotational speeds (e.g., >3000 rpm), operational conditions often limit the...
In the United States, a NASA University Leadership Initiative program with The Center for Cryogenic High-Efficiency Electrical Technologies for Aircraft (CHEETA) and a separate ARPA E Connecting Aviation By Lighter Electrical Systems (CABLES) program have been developing 2 kA-rated, medium voltage, and lightweight quick connectors for aerospace. These quick connectors will also permit a...
The fabrication of high-temperature superconductor (HTS) magnets often involves manual soldering joints, which relies on operator skill and causes performance variations. To address these challenges, this study presents the design, fabrication, and experimental evaluation of a roller-shaped HTS coil joint apparatus for soldering rare-earth barium copper oxide (REBCO) tapes. The apparatus was...
In this study, different types of joints (lap joint and bridge joint) using commercially available second-generation (2G) high-temperature superconductor (HTS) tapes from two manufacturers were prepared, and their I-V characteristics were studied at 77 K, liquid nitrogen temperature. Both types of joints were prepared by taking each sample of HTS tapes with effective overlapping lengths...
