基于嵌入式FBG的脉冲强磁体应变测量研究

Study on strain measurement inside high-energy pulsed magnets using embedded FBG

针对传统的电类传感器因易受电磁干扰而无法实现对线圈内部应变的测量,本文利用光纤Bragg光栅(FBG)不受电磁干扰和体积极小的优势,通过实验研究,成功地将3个FBG嵌入到磁体线圈由内到外3个不同的线层中。液氮环境下对磁体线圈1 000V放电实验结果显示,3个FBG测得磁体内部不同线圈层产生的最大应变分别为34、63和13με,应变分布规律与相关的仿真研究结果一致。实验表明,通过嵌入FBG研究脉冲强磁体励磁过程中应变分布及变化的方法可行有效。

The strain generated at the moment of excitation and its distribution are important parameters in the research of pulsed magnetic field. Traditional sensors are sensitive to outside magnetic interference. The method using fiber Bragg grating （FBG） embedded inside the pulsed magnet coil to accomplish strain measurement in liquid nitrogen is proposed. Three FBGs are embedded inside the three different layers of the pulsed magnet and 34 uε, 63 uε , and 13 uε are the corresponding strains that are measured at the moment of 1000 V excitation. The results of experiment show that the condition of strain variation fits the previous simulation results. The method using embedded FBG sensors can be an effective tool for the strain measurement inside the pulsed magnet under cryogenic environment.