Reducing Magnetization AC Loss in Twisted-Stacked HTS Cables

Due to the high critical current density and isotropic properties of stacked-tape high-temperature superconducting (HTS) conductors, they become potential candidates for fusion magnets. However, when used in fusion magnets, significant magnetization ac loss can generate heat, burden the cooling system, and even lead to quench. Therefore, evaluating and optimizing the magnetization ac loss of twisted stacked-tape cables (TSTCs) is crucial. The total magnetization ac loss of twisted stacked HTS cables was measured using the nitrogen boil-off method with various frame materials and twisting angles subjected to an alternating magnetic field, thereby optimizing the structure of TSTCs to reduce magnetization ac loss. In addition, twisted stacked-tape cables were simulated using a 3D T-A equation, whose results were compared with the measurements. This article comprehensively explained the effect of the twisting angle in magnetization ac loss, and proposed a new structure of the twisted stacked-tape conductor to further reduce magnetization ac loss. The novel structure design and optimization methods can be beneficial for designing future HTS conductors for fusion magnets.