AI Insight
Researchers developed and experimentally validated a combined position sensor and actuator system designed for seismic isolation in gravitational wave detectors. The Linear Variable Differential Transformer (LVDT) position sensor and voice-coil (VC) actuator were tested using a precision measurement setup and compared against finite-element simulations, showing excellent agreement with only 1.3% difference for displacement measurements and 0.6% for force output. The device demonstrated high linearity over a ±5 mm range with measurement uncertainties below 2.3%, confirming its suitability for low-frequency suspension control in next-generation gravitational wave observatories like the Einstein Telescope.
Why it matters
This validation provides a critical component for improving seismic isolation systems in gravitational wave detectors, which must suppress ground vibrations to detect incredibly faint spacetime ripples from cosmic events. The established measurement framework can now be used to optimize sensor and actuator designs for future gravitational wave observatories, potentially enhancing their sensitivity to detect more distant astronomical phenomena.
arXiv:2603.06209v2 Announce Type: replace
Abstract: A detailed characterisation of a combined Linear Variable Differential Transformer (LVDT) position sensor and voice-coil (VC) actuator designed for seismic isolation systems in gravitational wave detectors is presented. A dedicated experimental setup and a finite-element simulation framework were developed to measure and model a representative Einstein Telescope pathfinder Type-A LVDT+VC assembly. The setup employs a precision translation stage and balance to quantify LVDT displacement response and VC force output under controlled conditions. We found a good agreement between experiment and simulation: the measured LVDT response was determined with an uncertainty of 0.5% and differed by only 1.3% from the model prediction, demonstrating high linearity over a $pm$5~mm range. In addition, the VC force measurements agreed within the total uncertainty: the maximum normalised force was determined with a precision of 2.3% and matched the simulated value with only 0.6% discrepancy. These results validate the combined sensor-actuator design and our measurement methodology. The demonstrated linear response and stable actuation confirm that this LVDT+VC device can be used for low-frequency suspension control. Our framework therefore provides a validated tool to optimise existing sensor and actuator designs, and to study novel prototypes for next-generation gravitational wave detectors.