低温超导位移传感中的磁场干扰研究

A STUDY OF MAGNETIC FIELD INTERFERENCE IN THE LOW TEMPERATURE SUPERCONDUCTING DISPLACEMENT SENSING

低温超导位移传感技术是分辨率最高的位移探测技术之一,在重力梯度测量和引力波探测中有重要应用。在基于低温超导位移传感技术的引力测量实验中,各种磁场干扰是提高实验精度的严重制约因素。文章在液氦温度研究了各种磁场对加速度测量的影响及其作用机制;测量了引力源通过磁场与探测器耦合的刚度系数;测量了超导体检验质量剩磁并分析了其特性;测量了超导磁屏蔽层对外界磁场的屏蔽效率;分析了磁场引起残余差分加速度扰动的机制;为实验改进提出了合理建议。

The low temperature superconducting displacement sensing is one of the most sensitive methods of detecting displacement,and an important technology in gravity measurement and gravitational waves detection.In gravity measurement experiments based on low temperature superconducting displacement sensing,magnetic field disturbances are serious constraints to improve the accuracy.This paper studies the influence of various magnetic fields on the acceleration measurement and their mechanisms at liquid helium temperature,measured the coupling stiffness between the gravity source and detector,and the shielding efficiency of the superconducting magnetic shield to the external magnetic field.The mechanism of residual differential acceleration perturbation caused by magnetic field is studied;and we propose reasonable suggestions to improve the experiment.