In this paper we present design, construction, and preliminary results of a proof-of-concept prototype of high-temperature superconductor (HTS) shim coils operated at 77 K and energized, for the first time among all shim coils, by a flux pump, here called digital flux injector (DFI). Although the prototype shims were wound with 2-mm wide REBCO tape, and DFI with Bi2223 and REBCO tapes, the HTS Z1 and Z2 shims to be installed in the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) currently under construction and operated at 4.2 K will be wound with reinforced Bi2212 wire and DFI with Nb$_3$Sn tape. The paper concludes with two sets of Bi2212 Z1 and Z2 shims for 1.3G.

中文翻译：

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由通量泵为 MIT 1.3 GHz LTS/HTS NMR 磁体供电的 HTS 匀场线圈：概念验证原型的设计、构造和结果

在本文中，我们介绍了高温超导 (HTS) 匀场线圈概念验证原型的设计、构造和初步结果，该原型在 77 K 下运行，并且在所有匀场线圈中首次由磁通泵通电，此处称为数字磁通注入器 (DFI)。尽管原型垫片是用 2 毫米宽的 REBCO 胶带缠绕的，而 DFI 是用 Bi2223 和 REBCO 胶带缠绕的，但 HTS Z1 和 Z2 垫片将安装在目前正在建造的 MIT 1.3 GHz LTS/HTS NMR 磁体 (1.3G) 中，并且在 4.2 K 下工作时将使用增强 Bi2212 线和含 Nb 的 DFI 缠绕$_3$锡带。本文最后给出了用于 1.3G 的两套 Bi2212 Z1 和 Z2 垫片。