A method with scanning electron microscopy （SEM） is presented to measure the density inhomogeneity of the stainless steel （SS316） sphere prepared for measuring G using time-of-swing method. The experimental result...A method with scanning electron microscopy （SEM） is presented to measure the density inhomogeneity of the stainless steel （SS316） sphere prepared for measuring G using time-of-swing method. The experimental result shows that the relative density inhomogeneity of the sphere is better than 5.9 × 10^-4 over the volume of 0.272 ×0.234× 0.005 mm^3. If we assume that the density inhomogeneity of the spheres used in our G measurement is the same as that of the sphere destroyed in testing, it will contribute to G value with an uncertainty of less than 0.034 ppm in our G measurement. Furthermore, the mass centre offset from the geometric centre of the sphere will be less than 4.3× 10^-4 μm due to this inhomogeneity.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2003CB716300, and the National Natural Science Foundation of China under Grant No 10121503.
基金Supported by the National Basic Research Programme of China under Grant No 2003CB716300, and the National Natural Science Foundation of China under Grant No 10121503.
基金Supported by the National Basic Research Program of China under Grant No 2010CB832801, the National High-Tech Research and Development Program of China under Grant No 2008AA12A215, and the National Natural Science Foundation of China under Grant No 10805021.
文摘在我们有 time-of-swing 方法的 G 测量的本地变化时间的磁场的效果被放大磁场在摆钟的时期引起一个可察觉的变化学习。在到磁场的时期的变化的系数是 37 的试验性的结果表演(1 ) 并且 12 (1 ) 在二个水平方向的 ms/gauss 分别地，它意味着系统的无常由于本地磁场是在我们的 G 测量的不到 0.4ppm。[从作者抽象]
基金Supported by the National Basic Research Programme of China under Grant No 2003CB716300, the National Natural Science Foundation of China under Grant No 10121503. The authors thank the Center for Analysis and Testing of Huazhong University of Science and Technology, the FEI-Quanta 200 SEM used in the experiment is provided by the Centre.
文摘A method with scanning electron microscopy （SEM） is presented to measure the density inhomogeneity of the stainless steel （SS316） sphere prepared for measuring G using time-of-swing method. The experimental result shows that the relative density inhomogeneity of the sphere is better than 5.9 × 10^-4 over the volume of 0.272 ×0.234× 0.005 mm^3. If we assume that the density inhomogeneity of the spheres used in our G measurement is the same as that of the sphere destroyed in testing, it will contribute to G value with an uncertainty of less than 0.034 ppm in our G measurement. Furthermore, the mass centre offset from the geometric centre of the sphere will be less than 4.3× 10^-4 μm due to this inhomogeneity.
