High-temperature superconducting coated conductors (CCs) are considered an enabling ultra-high field (UHF) tape-conductor technology due to their extremely high engineering current densities at very high magnetic fields and low temperatures, and high mechanical strength. A major challenge is however related to induction of problematically large superconducting screening currents (as an effect of the large width-to-thickness ratio) when the wide tape conductors are exposed to strong transverse magnetic fields above 20 T, which is the case in many UHF magnet systems. Subdividing the superconducting layer into narrow parallel decoupled filaments has been shown to effectively reduce superconducting screening currents by a factor comparable to the number of filaments. The filamentization is however not effective until the induced coupling currents flowing across the filaments have decayed. The effectiveness of the multifilamentary structure in suppressing coupling currents and reducing the decay time constants is directly linked to potential current paths between filaments. Very recent experimental and numerical studies have examined both the challenge of magnet precision, caused by screening-current-induced fields, and the fatal consequences of local uneven tape stresses exceeding the irreversible limits for commercial CCs. These studies have conclusively revealed that screening currents must not be ignored in the mechanical design and other studies have introduced multifilamentary CCs as a viable solution. This paper aims to review the efforts made in developing and investigating multifilamentary CCs for ultra-high field applications focusing on the screening-current-related mechanisms, critical system-level effects, effectiveness of filamentization in UHFs, fabrication and large-scale analysis of multifilamentary CCs, in addition to providing cost estimates of previously studied filamentized CC fabrication techniques.

高温超导涂层导体 (CC) 被认为是一种实现超高场 (UHF) 带状导体技术，因为它们在非常高的磁场和低温下具有极高的工程电流密度以及高机械强度。然而，当宽带状导体暴露于 20 T 以上的强横向磁场时，一个主要的挑战是与有问题的大超导屏蔽电流的感应有关（作为大宽厚比的影响），这在许多情况下都是如此。超高频磁铁系统。已证明将超导层细分为狭窄的平行去耦细丝可以有效降低超导屏蔽电流，其系数与细丝数量相当。然而，在流过灯丝的感应耦合电流衰减之前，灯丝化是无效的。复丝结构在抑制耦合电流和减少衰减时间常数方面的有效性与灯丝之间的潜在电流路径直接相关。最近的实验和数值研究已经检验了由屏蔽电流感应场引起的磁体精度挑战，以及局部不均匀胶带应力超过商业 CC 不可逆极限的致命后果。这些研究最终表明，在机械设计中绝不能忽略屏蔽电流，其他研究已经引入多丝 CC 作为可行的解决方案。