Reports until 15:53, Friday 15 November 2024
H1 SQZ (SQZ)
victoriaa.xu@LIGO.ORG - posted 15:53, Friday 15 November 2024 (81300)
More low pass filtering for ADF SQZ readbacks

Sheila, Vicky. 

We changed the low pass filtering on the ADF SQZ angle servo to be lower, going from 1 Hz low pass to 0.1 Hz low pass on the ADF I/Q demod filter banks. I think this reduced the sqz angle readback noise a bit (trends before/after). It didn't make a huge impact on the control signal that goes to the CLF_RF6 demod phase (bottom purple trace), and it might be worth considering low pass filtering that control signal too. I accepted the SDFs for this filter bank LPF change.

Images attached to this report