面向高场应用的ReBCO超导导体电磁热应力下性能表征及其高场下性能衰退机理研究

多重介质、多芯多层级不规则绞缆形成的螺旋结构的ReBCO电缆和CICC导体在国际上得到广泛研究并在加速器超导磁体上进行了一定的应用，也为未来聚变用高场超导导体提供了具有应用前景的候选技术方案。但循环加载的电磁及热应力下超导临界性能的退化是ReBCO导体广泛应用于高场(>12T)磁体系统的制约。其结构的复杂性，使数值方法难以准确地进行精细应力分析和临界性能对应力敏感性的模拟。本项目旨在通过理论模型和实验相结合的方法，探究ReBCO导体结构设计、电缆绞制、导体制造及低温高场运行对导体性能的影响。本项目的研究结果，将精确表征ReBCO超导电缆和导体在电磁热应力以及循环负载下的临界性能，并进一步揭示ReBCO导体的高场高负载下的退化机理，提出面向于聚变和对撞机加速器用的高场下高性能ReBCO导体结构设计、电缆制造技术及低温高场下运行性能分析方法，及为高场磁体领域的广泛应用打下坚实的基础。

CORC-like ReBCO cable and conductor cabled spirally with tapes have been investigated world widely and applied in accelerator magnet, also provide a promising technical solution and candidate for Fusion high field magnet. Critical performance degradation of the ReBCO cable and conductor due to electro-magnetic and thermal stress as well as cycle loadings, is the main issue to be understood and solved, thus can be applied widely in the high field applications like Fusion and Accelerator. The spiral structure caused by irregular cabling with multiple composites is complex and difficult to be simulated by analytical models. . The objective of this project aims to investigate and figure out the performance degradation mechanism of ReBCO cable and conductor by theoretical model together with numerical method and experiments, serving conductor design, conductor manufacture, and performance prediction in magnet operation. The electrical and mechanical properties of the ReBCO tape and its different materials are studied first as a database. Various cable and conductor samples with different designs and manufacture processes are planned for measurement and analysis. Combined with theoretical analysis, experiments (Ic vs different fields of 7, 10, 12 and 15T, and transverse loads at 4.2K), numerical model and coding, NDE (Non-Destructive Examination) and micro-imaging method for cracks, a systematic approach is developed and applied to figure out and understand the degradation mechanism and the irreversible limit in terms of strain （εirr）or mechanical load. Consequently, the work can characterize the critical performance of ReBCO cable and conductor under electro-magnetic and thermal stress as well as cycle loads, reveal the degradation mechanism. That will provide a solid basis for both design and manufacture of high field ReBCO CICC, and further for its high field application in Fusion and Accelerator，as well as high field MRI improving its commercialization and thus the high-end medical standard and people’s health. It can also be referenced for other tape-shaped HTS conductor like Fe-based superconductor.