Sheila measured the CARM gain during vent recovery at a thermalized time (84944), and it seemed low, so today we plugged in the SR785 and measured the CARM OLG at the start of lock.
Right at the beginning of lock, the UGF was 14.4 Hz, which is fine except that we will lose gain from thermalization. I bumped up the gain by 1 dB on each REFL A and B slider ("H1:LSC-REFL_SUM_{A,B}_IN2GAIN") and remeasured, and the UGF was about 14.3 Hz. Then, I increased the gain another 2 dB each on each slider and remeasured, 16 kHz. This is where we want to be, although I imagine it will decay more as we thermalize.
This means that in NLN, we want our CARM gain settings to be 15 dB on each slider, which I accepted in SDF. However, I have not yet put them in the guardian because I am trying to figure out where that actually should be adjusted.
I have attached the three measurements I took. The title of the first one is misleading since I used the wrong template, but the time stamps on all are accurate.
Second measurement, both gains up +1 dB
Third measurement, both gains up +2 dB more
Procedural notes for future me to measure the OLG and plot the measurement:
> cd ligo/gitcommon/psl_measurements/templates
> conda activate psl
> python ../code/SRmeasure.py carm_olg_template.yml
> python ../code/quick_tf_plot.py ../data/carm_olg/[filename]
I unplugged the SR785 before observing.
I see now, with Keita's help, that I changed the "wrong" gain sliders, because I should have adjusted the "H1:LSC-REFL_SERVO_IN{1,2}GAIN" sliders. However, jsut based on how things are connected, I don't think it is having an overall different effect right now. But, to do this properly, I am updating the guardian code on line 5882: