高精度惯性传感器是空间引力波探测中的核心和关键技术，其测量精度与直接作用在检验质量上的非引力扰动密切相关，检验质量周围残余气体分子的碰撞是一项主要的扰动源。人们了解到惯性传感器中的残余气体主要来自材料本身的放气，且放气规律与材料本身特性密切相关，目前尚无完善的理论对其进行预测，只能用实验手段测量。由于检验质量与周围电容极板之间间距很小，残余气体分子会多次碰撞检验质量使得其扰动规律与自由空间的撞击模型存在差异，因此，研究其影响规律及其抑制方法对空间引力波探测而言意义重大。本项目拟采用高Q值悬丝悬挂并结合差分波前传感技术，构建一套力矩噪声低至10^{-15}Nm/Hz^{1/2}的扭摆，在此基础上对惯性传感器中的残余气体扰动进行深入研究，得到残余气体释放的规律，总结出有限空间内气体分子对检验质量扰动的特性，同时积极探索其扰动影响的抑制方法，为研制空间引力波观测计划中的高精度惯性传感器提供依据。

Precision inertial sensor is one of the most important payload in space gravitational wave detection. Its resolution is related to the direct non-gravitation disturbance on the test mass. The collision of the residual gas surrounding the test mass is the major contribution of the non-gravitational disturbance. It has been recognized that the residual gas mainly come from the out-gassing of the material surface and the rate of out-gassing have close correlation with the characteristics of the material. However, there is no detailed theoretical method to predict the out-gassing effect nowadays. It can only be measured by experiments. Beside of this, the gas molecules collide the test mass lots of times because of the limited gap between the test mass and the wall surrounding it, so the disturbance of residual gas is quite different from what in infinite volume. The investigation about this difference is significant. In this project, we plan to develop a torsion pendulum whose noise is lower to 10^{-15} Nm/Hz^{1/2}, with the advantages of high Q suspension fiber and DWS interferometer applied. Then the disturbance from residual gas including the gas release and collision in precision inertial sensor can be investigated in detail. The achievements of this project can provide some instuctions for the development of the inertial sensor for gravitational wave detection missions.