Magnetic field monitoring devices are essential for studying and operating high-temperature superconducting (HTS) magnets. Apart from conventional Hall sensor, passive optical fiber sensor is also an option for magnetic field monitoring. In this article, we proposed a novel access based on yttrium iron garnet magneto-optic (YM) sensor, which is one kind of optical fiber sensors, to measure magnetic fields generated by an HTS double pancake coil. Moreover, we used a magnetic field bypass tube made of silicon steel material to expand the measurement range of YM sensor. The test results of YM sensor in liquid nitrogen demonstrated that the YM sensor was benchmarked against Hall probe up to 24.7 mT at 77 K. Using a silicon steel tube to shield magnetic field could extend the field measurement range to 37.6 mT. YM sensor could be one of the promising methods for monitoring HTS magnet magnetic field.

中文翻译：

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基于磁光法拉第效应的高温超导线圈磁场测量新方法

磁场监测设备对于研究和操作高温超导 (HTS) 磁体至关重要。除了传统的霍尔传感器，无源光纤传感器也是磁场监测的一种选择。在本文中，我们提出了一种基于钇铁石榴石磁光 (YM) 传感器的新型通路，它是一种光纤传感器，用于测量 HTS 双薄饼线圈产生的磁场。此外，我们使用硅钢材料制成的磁场旁通管来扩大YM传感器的测量范围。YM 传感器在液氮中的测试结果表明，YM 传感器与霍尔探头在 77 K 下进行了高达 24.7 mT 的基准测试。使用硅钢管屏蔽磁场可以将场测量范围扩展到 37.6 mT。