Study on Physical Mechanisms of Dynamical Characteristics of Residual Gases in Inertial Sensors Applied into Gravitational Wave Detection

As the core system for gravitational wave detection in space, the analysis of the noise interference inducing mechanism of inertial sensors during in-orbit operation is a key scientific problem that needs to be solved urgently. The residual acceleration noise of the test mass (TM) in the inertial sensor is the largest noise source limiting the sensitivity of the detector. As a direct characterization of the residual gas noise, the analysis of the escape time dynamics of gas molecules under the complex topological configuration of inertial sensors needs to be solved urgently. In this paper, we firstly consider the differences in material properties and outgassing characteristics between the test mass block and the surrounding wall in a narrow space, and establish a mathematical model of inertial sensors under the complex topology of heterogeneous space; secondly, we analyze the quantitative constraints between the residual gas noise and escape time of gas molecules, and extract the core factors affecting the escape time; subsequently, we use Monte Carlo simulation as the entry point to obtain the dynamic characteristics of gas molecules diffusing out from the plate under the constraints, and then we use Monte Carlo simulation as the entry point for the analysis. Subsequently, Monte Carlo simulation technique is used as an entry point to obtain the simulation solutions for the escape time and the number of collisions required for the gas molecules to diffuse out from the plate. This paper finds that: different gas compositions and wall properties have a large impact on the residual gas noise; considering the retention time of gas molecules on the wall will substantially increase the escape time and decrease the collision frequency.