Determining Optimal Analysis Techniques for Characterizing Dust Distributions in Virgo Clearnooms

One of the primary contributors to noise in the optical benches of LIGO and Virgo is stray light. Stray light differs randomly in phase and adds noise to the measured phase after recombining with nominal light. A main cause of stray light in optical systems is particulate matter that contaminates clean surfaces and serves as a mechanism for scattering. Impacts of stray light can be calculated with tools like simulational analysis, however parameters necessary for simulations must be calculated for each specific environment. We present progress towards developing an imaging and analysis procedure that accurately produces values for particle characteristics that can be used to calculate such parameters. Optical elements that had been purposefully contaminated by particles with known values were analyzed, allowing us to take images with different settings and determine which combination was the most accurate. Our results showed that an aperture of 5.6 with an exposure time of 40 milliseconds produces accurate values with more regularity and less uncertainty than any other combination of settings. As this project is the first of its kind within the EGO collaboration, our results and procedures have the potential to be applied to numerous optical systems in Virgo, LIGO, and beyond.