We propose a new flux pump driven non-soldering closed-loop (NSCL) high temperature superconducting (HTS) magnet free of any soldering joints throughout the magnet for persistent current mode (PCM) operation. All the superconducting parts of the magnet are wound directly with HTS closed-loop ring split from an 8 mm REBCO tape using our new cutting scheme free of any soldering requirements. The magnet contains two single-pancake coils connected in series forming a closed circuit through two parallel bridge branches. Two thermal switches set on the two bridge branches control the on–off of the two bridges. A copper coil with iron core installed around one of the bridges is employed as the flux pump to drive the HTS magnet. An electromagnetic-thermal semi-analytical modelling method is proposed to analyse the pumping process by which the transport current in the magnet is calculated. The theoretical limit equation of the saturation current is improved as well. The proposed method can predict the current of the NSCL HTS magnet during the pumping process and provide results that are close to experiments. Experiments verify both the feasibility of the proposed flux pump driven NSCL HTS magnet and the modelling method. The results show that the NSCL HTS magnet works well in the PCM, which provides inspiration to the design of PCM operation of high field HTS magnets. The proposed modelling method also helps guide the design of different forms of HTS magnets and the flux pumps driving them.

中文翻译：

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磁通泵驱动的非焊接闭环高温超导磁体及其电磁热半解析建模方法


我们提出了一种新型磁通泵驱动的非焊接闭环（NSCL）高温超导（HTS）磁体，整个磁体中没有任何焊接点，可实现持续电流模式（PCM）操作。磁体的所有超导部件均使用我们新的切割方案直接缠绕在 HTS 闭环环上，该 HTS 闭环环从 8 毫米 REBCO 胶带上分离出来，无需任何焊接要求。磁铁包含两个串联连接的单薄饼线圈，通过两个并联桥分支形成闭合电路。两个桥支上设置的两个热敏开关控制两个桥的通断。采用安装在其中一个桥周围的带有铁芯的铜线圈作为磁通泵来驱动高温超导磁体。提出了一种电磁热半解析建模方法来分析泵浦过程，通过该方法计算磁体中的传输电流。饱和电流的理论极限方程也得到了改进。该方法可以预测泵浦过程中 NSCL HTS 磁体的电流，并提供接近实验的结果。实验验证了所提出的磁通泵驱动 NSCL HTS 磁体和建模方法的可行性。结果表明，NSCL高温超导磁体在PCM中工作良好，这为高场高温超导磁体的PCM操作设计提供了启发。所提出的建模方法还有助于指导不同形式的高温超导磁体及其驱动磁通泵的设计。