High-Precision Capacitive Displacement Sensor for Gravitational Wave Detection: Sensitive Probe Modeling, Analysis, and Optimization
Jiawen Lan, Liangqi Gui, Liang Lang, Hong Ma, Sheng Zhu, Quanliang Huang
Abstract
Gravitational wave (GW) detection is an important topic in fundamental scientific research. Studying high-precision capacitive displacement sensor (CDS) is crucial for capturing weak GW signals. However, existing research primarily focuses on noise analysis and optimization of the front-end and back-end circuits of CDS, with limited articles specifically studying the sensitive probe (SP). Therefore, this article focuses on the modeling, analysis, and optimization of the SP in CDS. We establish a general model of the SP in COMSOL and extract the capacitance matrix to derive the displacement–capacitance curve between the displacement of each degree of freedom and the differential capacitance. By analyzing the capacitance matrix, we propose an equivalent circuit for the SP and verify its accuracy. Additionally, we optimize the structure of the SP and innovatively explore the impact of different electrode sizes on injection efficiency and induction efficiency. Overall, the works in this article provide new perspectives for the design of high-precision CDS and serve as a theoretical basis and reference for practical engineering design in GW detection.