Precision Measurement of Distribution of Film Thickness on Pendulum for Experiment of G

Distribution of film thickness coated on the pendulum of measuring the Newton gravitational constant G is determined with a weighing method by means of a precision mass comparator. The experimental result shows that the gold film on the pendulum will contribute a correction of -24.3 ppm to our G measurement with an uncertainty of 4.3 ppm, which is significant for improving the G value with high precision.     

基于迈克耳孙干涉仪光路折叠和抽真空方式测空气折射率

采用光路折叠结合气室先预抽真空后充气的实验方式，改进了传统的迈克耳孙干涉仪测量气体折射率的方法.利用折叠光路法增加激光在气室中的穿越次数达到增加气室内的光程，从而数倍地增强待测信号；采取预抽真空后缓慢向连通气室的大容积缓冲真空室内充入待测气体，使气室内气压更均匀、平稳地增长，从而实现了气体折射率的高精度测量，并验证了气压与折射率的线性关系.