arXiv subjects

Emilia Chick

Publications and source records attributed to Emilia Chick.

3 recordsLinked to original sources

arXiv2026

Extending Ground-Based Gravitational-Wave Sensitivity to 5 Hz

Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active platform stabilization down to 10 mHz. Our laser position sensors reach a sub-pm/$\sqrt{\rm Hz}$ sensitivity above 10 mHz, independent of the input light polarization, representing a 100-fold improvement over the current LIGO position sensors. In addition, our inertial sensors provide at least a factor of 5 improvement in low-frequency sensitivity compared to state-of-the-art commercial seismometers. We integrate these technologies into a LIGO-like interferometer model and predict a low-frequency sensitivity improvement of up to an order of magnitude at 10 Hz, with enhanced linearity and calibration stability. This extension increases the detection horizon for intermediate-mass black hole binaries of mass $10^3 M_\odot$ by a factor of 3. Our results provide the first experimental demonstration of a practical pathway to sub-10 Hz operation of terrestrial gravitational-wave detectors and establish key technologies for next-generation observatories such as Cosmic Explorer and Einstein Telescope.

astro-ph.IM↗

arXiv2024

Demonstration of the minimal coupling of horizontal accelerations to rotations in a torsion balance suspended from three wires

The Cavendish torsion balance is the instrument of choice for measuring weak forces, such as gravity. Although torsion balances have extremely high sensitivity for measuring forces over ranges of a few cm and more, their dynamics make it difficult to extend this range to much less than fractions of mm. In particular forces such as the Casimir force are usually studied using atomic force microscopes. We present results of our studies of a simple torsion balance with a 3-wire suspension. This device should be able to maintain parallelism between flat plates of areas of a few $\sim\mathrm{cm^2}$ at separations of much less of 10's of $\mathrm{\mu m}$. In this paper we describe our experimental investigation into the coupling of ground tilt to the torsional rotation of the novel device. We show that, like the Cavendish torsion balance, the 3-wire torsion balance is highly insensitive to tilts. We also demonstrate that this tilt sensitivity is itself insensitive to shifts in the centre of mass position of the suspended mass. We discuss simple models of the 3-wire torsion balance that show that it is only the static wire lengths that determine the coupling of tilts and horizontal accelerations. We also discuss designs of torsion balances where sensitivity and noise rejection to tilts are optimised.

physics.ins-det↗

arXiv2024

Sensitivity and control of a 6-axis fused-silica seismometer

We present a pair of seismometers capable of measurement in all six axes of rigid motion. The vacuum-compatible devices implement compact interferometric displacement sensors to surpass the sensitivity of typical electrical readout schemes. Together with the capability to subtract the sensitivity-limiting coupling of ground tilt into horizontal motion, our seismometers can widen the sensing band towards mHz frequencies. This has notable applications across a range of fields requiring access to low-frequency signals, such as seismology and climate research. We particularly highlight their potential application in gravitational-wave observatories (LIGO) in improving their observation capability of intermediate-mass black holes ($\sim 1000\,M_\odot$). The sensors are based on a near-monolithic fused-silica design consisting of a fused-silica mass and fibre, showing improved stability and robustness to tilt drifts, alignment, and control compared to all-metal or mixed metal-silica designs. We demonstrate tilt sensitivity that surpasses the best commercial alternatives in a significantly reduced footprint compared to our previous iterations of these sensors.

physics.ins-det↗