LSC Fellow at LIGO Livingston Observatory

38 Hz noise

aLOG entry

Lockloss trigger

LIGO T-document

Data Quality shift

LIGO wiki entry

I worked as an LSC Fellow at LIGO Livingston Observatory between January-April 2020, which was a great expreience and I had the opportunity to familiarize myself with the inner workings of the LIGO subsystems and the data characterization methods. I was working on a couple of different topics while being there.

I have investigated and found the source of a new noise arising at ~38 Hz a couple of times every day. After finding the source we were able to mitigate its effect on the data output. I have also worked on implementing a lockloss trigger which shuts down the internal sensing and control related outputs in case of a lockloss even when computer errors are experienced. The trigger activates ~1 s earlier than the guardian, i.e. ~0.05 s after the pick off power value starts to fall, which makes it really effective in protecting the sensitive optics of the detector. I was on data quality shift the last week of the O3 observing run. The task of the DQ shifter is to assess the quality of data coming out of the interferometer by using a variety of detector characterization tools, to write a report about the findings and present it to the detector characterization group of the LIGO-Virgo Collaboration.