Speaker
Description
Newtonian noise, or gravitational fluctuations from local moving mass, is a low Fourier frequency noise source that will limit next-generation ground-based gravitational-wave detectors. At the Australian National University, we are developing an opto-mechanical torsion pendulum sensor for direct detection of Newtonian noise, consisting of two suspended orthogonal pendulums that rotate differentially in response to local gravity fluctuations [1]. This sensor concept also offers potential applications in earthquake early-warning [2] and, with minor design modifications, may enable searches for certain classes of dark-matter interactions [3].
The sensor has undergone significant upgrades, including the implementation of a multi-stage seismic isolation suspension and operation within a vacuum environment to reduce environmental impacts. The sensor’s optical readout system has also been improved with active laser frequency noise stabilization [4] and opto-mechanical damping to suppress suspension resonance coupling. We will present the latest status of the upgraded sensor, including latest sensor characterisation and measurement results.
[1] Chua et al, Appl. Phys. Lett. 122, 201102 (2023)
[2] Chua et al, in preparation (2026)
[3] Qin et al, in preparation (2026)
[4] Kulur Ramamohan et al, Opt. Express, 32(22) (2024)
| I am the presenting author | No |
|---|---|
| If you are not the presenting author, please give the presenting author's name: | Bram Slagmolen |