Investigating temperature-induced torque noise of a torsion pendulum based on temperature modulation at different frequencies.

This article focuses on investigating the impact of environmental temperature fluctuations on the torque response of a torsion pendulum used for measuring small forces. Using a temperature-modulation method across frequencies from 0.1 to 10 millihertz (mHz), the study found that the coupling coefficient between temperature variation and induced torque varies significantly with frequency, ranging from approximately 4 × 10⁻¹⁵ N·m·K⁻¹ at 0.1 mHz to 3 × 10⁻¹³ N·m·K⁻¹ at 10 mHz. The experimental setup involved a tungsten-fiber-suspended hollow aluminum cube pendulum inside a vacuum chamber with a three-layer thermal-insulation system, and results demonstrated that passive insulation reduces but does not fully eliminate temperature-induced torque noise. This frequency-dependent characterization of temperature-induced disturbances provides a comprehensive approach to evaluating and mitigating environmental noise in torsion-pendulum experiments within their most sensitive operational band.