Overcoming Controls and Noise Challenges for High Power Interferometric Gravitational-Wave Detectors
Date of Award
5-12-2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics
Advisor(s)
Stefan Ballmer
Keywords
gravitational wave detectors;gravitational waves;interferometer
Subject Categories
Physical Sciences and Mathematics | Physics
Abstract
In August 2017, the Advanced LIGO and Advanced Virgo detectors made the first coincident detection of gravitational waves from a binary neutron star merger, GW170817. This multi-messenger detection, measured with both gravitational wave detectors and electromagnetic telescopes, emphasized the ability of ground-based gravitational-wave detectors to make exciting astrophysical discoveries that revolutionize understanding of the universe. In this new era of gravitational-wave astronomy, high detector sensitivity and reliable operation are required to enable more of these exciting detections. Ground-based gravitational-wave observatories are generally limited in sensitivity at low frequency by technical noise, at mid frequency by coating thermal noise, and at high frequency by quantum shot noise. This dissertation covers efforts to study and improve the controls scheme of Advanced LIGO to reduce low frequency technical noise and increase the operating power of the detector to improve the shot-noise-limited sensitivity. Reliable modeling of the alignment controls is presented, which enabled an increase to the highest detector operating power ever achieved with Advanced LIGO. Improvements in detector noise and operational stability summarized in this work also enabled the highest detector sensitivity ever achieved at the LIGO Hanford Observatory, more than doubling both the detector's sensitive volume and gravitational-wave detection rate. This dissertation also summarizes work to study lower thermal noise optical coatings, making use of an improved analysis method for multimodal measurements. Preliminary results of the coating thermal noise of a novel amorphous coating mixture are presented, with a proposal for next steps. Finally, this work considers future detector operation and noise impacts based on current generation detector experiences. Future gravitational-wave detectors target increased sensitivity by building on technologies of current detectors. By analyzing current detector limitations, design requirements for future detectors are proposed that will enable exciting astrophysics in the new age of gravitational-wave astronomy.
Access
Open Access
Recommended Citation
Capote, Elenna, "Overcoming Controls and Noise Challenges for High Power Interferometric Gravitational-Wave Detectors" (2024). Dissertations - ALL. 1973.
https://surface.syr.edu/etd/1973
