Recent improvements in the superconducting performance and technical maturity of high-temperature-superconductors (HTS) lead to considerations of using HTS in future fusion magnets in addition to the presently used low-temperature superconductors (LTS). Compact high field magnet systems entirely made of HTS for compact tokamaks, hybrid HTS-LTS magnets for enhanced operational capabilities (e.g. larger flux swing) in conventional tokamaks and future stellarator devices with HTS magnet systems are presently investigated. An overview of recent concepts, developments and designs of HTS-based future fusion magnet systems is given and a number of physical and technical challenges will be addressed, too: In particular, the so-called second generation HTS Rare-Earth-Barium-Copper-Oxide (REBCO) shows an excellent superconducting performance over a wide range of magnetic fields and temperatures. The layered architecture of these technical REBCO conductors and the ceramic nature of REBCO lead to mechanical challenges at high Lorentz forces, which is relevant for cable-in-conduit-conductors (CICC) of future fusion magnets due to the high currents and high field strengths. Different high-current cable concepts for future fusion magnets are discussed. High loads are not only a challenge for potential future HTS conductors but also for the conductor jackets and the coil casing of the magnet systems. An increase of the numbers of load cycles on the path towards a future fusion power plant requires superior mechanical strength. The high critical temperature of HTS materials allows to design HTS CICC with a noticeably higher minimum quench energy and temperature margin compared to LTS conductors – but leads inevitably to substantially slower quench propagation velocity and challenges related to quench detection. Recent results from numerical modeling and experimental investigation of quench in high-current HTS CrossConductor (HTS CroCo) based CICC are addressed.

中文翻译：

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用于聚变应用的高温超导体和 HTS CroCo 导体设计的新发展

近年来，高温超导体（HTS）的超导性能和技术成熟度不断提高，除了目前使用的低温超导体（LTS）之外，人们还考虑在未来的聚变磁体中使用HTS。目前正在研究用于紧凑型托卡马克的完全由高温超导材料制成的紧凑型高场磁体系统、用于增强传统托卡马克操作能力（例如更大的通量摆幅）的混合高温超导-低温磁体以及具有高温超导磁体系统的未来仿星器装置。概述了基于高温超导的未来聚变磁体系统的最新概念、开发和设计，还将解决许多物理和技术挑战：特别是所谓的第二代高温超导稀土钡铜-氧化物（REBCO）在广泛的磁场和温度范围内表现出优异的超导性能。这些技术 REBCO 导体的分层架构和 REBCO 的陶瓷特性导致高洛伦兹力下的机械挑战，由于高电流和高场强，这与未来聚变磁体的电缆导管导体 (CICC) 相关。讨论了未来聚变磁体的不同高电流电缆概念。高负载不仅对未来潜在的高温超导导体构成挑战，而且对磁体系统的导体护套和线圈外壳也构成挑战。未来聚变发电厂的负载循环次数的增加需要卓越的机械强度。与 LTS 导体相比，HTS 材料的高临界温度允许设计具有明显更高的最小失超能量和温度裕度的 HTS CICC，但不可避免地会导致失超传播速度大幅减慢以及失超检测相关的挑战。基于数值模拟和基于高电流 HTS CrossConductor (HTS CroCo) 的 CICC 失超实验研究的最新结果得到了解决。