Georgia, Craig, Danny, Sheila
Here are some updated noise budget plots, made for 9:30 UTC March 5th, when there was no squeezing injected.
Some notes:
- shot noise: Although the pcal monitors at this time suggest that kappa_c (scale factor for optical gain) is and that the DARM cavity pole, I found that the shot noise is more accurate based on the cross correlation with a cavity pole of 440 Hz, and kappa c of . For the last few weeks I have consistenly been using cavity poles higher than the pcal monitors have said and optical gains lower than what the pcal monitor says.
- The OMC length noise is Geogira's measurement posted here: 47286
- The frequency noise is based on Craig's projection 46864 Note that we are doing a pretty generous interpolation here, sometime we would like to get better frequency resolution for the measurement.
- 73 Hz line: This was a time before the grounding change at EX got rid of 73 Hz line and some features around 280 Hz, so those peaks which are unexplained in this budget are no longer in DARM. 47323
- MICH P: The MICH P ASC noise is very small in this noise budget, but will need to be updated again. We are rethinking this loop 47352 since we found that it was causing a lot of motion at 0.5Hz and contributing to the sidebands on the 60Hz line.
- The centering loops haven't been re-measured so they aren't included here yet. neither is the SRC1 (AS 72 to SRM loop).
- MICH LSC coupling has been changing a bit while things thermalize, the ones that are included here are measured a few hours into a lock.47333
Dan, Craig, Georgia
We git-committed the noise budget templates used here, and have rerun the noise budget templates for MICH_P, DHARD_P, DSOFT_P (increased the excitation by a factor of 30 to make it visible in DARM). We still need to re-run the CSOFT_P template to make the ASC contribution to the noise budget up-to-date. We have added DC centering loop templates to the folder however the excitation level needs to be tuned.
A preliminary look at the ASC budget, with the old CSOFT_P measurement, (attached figure) shows we've won a in the <15 Hz region, and we still have some sensitivity to gain by improving DHARD.
Dan, Danny, Alexi
To include the DC centering in the noise budget we excited the DC1 and DC2 pitch and yaw centering loops and DC3 yaw. It took large amplitudes for us to see coherence in DARM that was mainly below 10 Hz.
We also injected into the SRC1 yaw excitation point and didn't seem to see anything in DARM even with large amplitudes.
Not sure if we are doing this right. Might be worth revisiting. We have templates made up for these. They live in /ligo/gitcommon/NoiseBudget/simple-noise-budget