Detecting quence of superconducting magnet by optical fiber

我们开发了一种双芯光纤的猝灭检测技术，该光纤在一根光纤中有两个单模光芯。我们进行了基础实验，并证明该双芯光纤在4.2 K下可以检测到1.0 K的温升，通过使用更长的光纤和更灵敏的干涉光纤位移检测器可以提高该技术的灵敏度。使用这种技术，证明了淬火是可检测的。置于磁体中的光纤在磁体绕组中受到电磁力的应力。由于电磁应力的作用，干涉条纹有可能发生位移。实验还证明了电磁力-应力对干涉条纹不产生位移。采用这种光学方法的猝灭检测器不受电磁噪声的影响，也不受高压张力的干扰。讨论了将该技术应用于大型磁体时出现的问题和可能的改进技术。

We have developed a quench detecting technique with a dual-core optical fiber< The fiberf has two single-mode optical cores in one fiber.We performed a basic experiment and demonstrated that a temperauture rise of 1.0 K could be detected at 4.2 K by this dual-core optical fiber Sensitivity of this technique can be improvel by using a longer fiberf and a more sensitive detector of the interference fiber shifts. Using this technique, it was demonstrated that a quench was detectbable. The optical fiber placed in a magnet in a magnet winding is subject to stresses by electromagnetic force. There is a possibility that the interference fringes shift due to the electromagnetic stress. In the experiment, it was also demonstrated that the electromagnetic force-stress did not shift the interference fringes.A quench detector using this optical method is immune from electromagnetic noises and free from troubles caused by high voltage tension. Porblems arising when applying this technique to a large scale magnet and a possible improving technique in the instrumentation are discussed.