Naoki, Camilla, Eric, Vicky

While looking through some old FDS/FDAS data, we noticed that the spectra taken on March 17 2024 seemed to have the flattest antisqueezing spectra seen during ER16 (to be discussed in upcoming log post).  The PSAMS were adjusted between March 17 and March 20th, and since that date we have seen sizeable frequency dependence in our antisqueezing spectra.  Several other changes were made around this time as well, so the story isn't completely clear, but the PSAMS seem a likely suspect. 

The PSAM strain gauge values from March 17 (7.5,0.5) were not covered during our recent scans.  Shortly before the observing run this afternoon, we moved our PSAMS to (7.5,0.5), realigned, and took quick FDS and FDAS datasets.  Indeed we see that the spectra appear to have less frequency dependence.  More thorough analysis with classical noise subtraction and careful normalization/calibration will be performed in the coming days to quantify the change.  For now, we have reverted back to the old PSAM values (8.8,-0.7) for the observing period. 

It seems that our overall level of antisqueezing is a bit lower than in previous days, but there are other likely causes for this besides the PSAM settings.  We will come back to this PSAM setting later on and try to optimize further to see if we can match or exceed our best ever spectra. 

Datasets:

• 9/4/2024 22:33:00-22:38:00 UTC:  FDAS at (7.5,0.5)
• 9/4/2024 22:44:00-22:49:00 UTC:  FDS at (7.5,0.5)