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Controlling and Calibrating Interferometric Gravitational Wave Detectors


Cahillane, Craig Russell (2021) Controlling and Calibrating Interferometric Gravitational Wave Detectors. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/76jj-mr73.


In September 2015, the Advanced LIGO detectors made the first direct detection of gravitational waves from a binary black hole merger [1]. Since then, around fifty total gravitational wave detections have been reported by Advanced LIGO and Advanced Virgo over three dedicated gravitational wave observation times, known as observing runs.

Observing run three (O3) ran from April 2019 to March 2020, with higher sensitivity and more stable operation of the Advanced LIGO detectors [2]. In the first half of O3, thirty-nine gravitational wave events were detected [3], as opposed to eleven in all of observing runs one (O1) and two (O2) [4]. The higher rate of detections is due primarily to the increased detector sensitivity to gravitational waves.

Although the Advanced LIGO detectors are more sensitive to gravitational waves than any detector in history, they have not yet achieved design sensitivity. Work continues to push the detectors to their fundamental limit of sensitivity. The work in this thesis partially covers the effort to improve the sensitivity of the LIGO Hanford detector prior to O3.

Calibration of the Advanced LIGO interferometer is the conversion of raw detector data into gravitational wave strain data. This process is crucial to an accurate and precise understanding of astrophysical sources of gravitational waves. The calibration uncertainty pipeline for characterizing the strain uncertainty during O1 and O2 is discussed in detail [5].

This thesis covers topics in long-baseline interferometric gravitational wave detector technology, including an overview of the performance of the detector in O3, commissioning tasks done to increase the sensitivity of the detector for O3, overall calibration uncertainty in the gravitational wave data, and methods for robust estimation of spectral quantities from LIGO data.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Gravitational waves, LIGO, experimental gravity, astrophysics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Weinstein, Alan Jay
Thesis Committee:
  • Adhikari, Rana (chair)
  • Chen, Yanbei
  • Reitze, David H.
  • Kirby, Evan N.
  • Weinstein, Alan Jay
Defense Date:26 January 2021
Record Number:CaltechTHESIS:05102021-070729581
Persistent URL:
Related URLs:
URLURL TypeDescription Itemgitlab thesis repository uncertainty for Advanced LIGO's first and second observing runs - Article adapted for Chapter IV of the Advanced LIGO detectors for the discovery of the binary black-hole merger GW150914 - Article adapted for Chapter IV and performance of the Advanced LIGO detectors in the third observing run - Article adapted for Chapter III and Chapter V
Cahillane, Craig Russell0000-0002-3888-314X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14139
Deposited By: Craig Cahillane
Deposited On:21 May 2021 23:38
Last Modified:28 Oct 2021 16:27

Thesis Files

[img] PDF (Final thesis draft) - Final Version
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