TJ, Camilla. After we found both CO2 output powers have been changing since the timing master swap 74025, we recalibrated the CO2 rotation stages this morning ~ 16:20UTC. Last done in September 72961.
Followed the README.txt file in /opt/rtcds/userapps/release/tcs/h1/scripts/RS_calibration/. We did this with annular masks in. I'd previously tried this without using the matlab fitting code and hadn't been able to make a good fit.
tcs_nom_annular_pwr = {'X': 1.7,
'Y': 1.7}
Maximum power measured out of each laser:
| Annular Mask | Central Mask | |
| CO2X | 6.6W | 3.8W |
| CO2Y | 5.5W | 3.7W |
Plot attached, Aidan noted that we expect to get more power through the central mask than annular. We plan to check the mode matching going into the masks in the next couple of weeks.
TJ noticed some strangeness with the CO2X rotation stage not going back to the same place, over ~minutes. Turned H1:TCS-ITM{X,Y}_CO2_LASERPOWER_FINEADJUST to False, as PSL RS uses. And re-tuned the attached calibration, this could do with more work but will leave alone as we are relocking.
I've added some bootstrapping to the CO2 power guardians to approximate the adjusted power request after it reaches the initial request. This will only bootstrap on the way up, not when finding minimum power. Something that should be added is to not bootstrap if close enough, we've noticed the rotation stage will do some odd moves when very small angle changes are requested.
adjusted power request = (initial request)^2 / current power
