jeffrey.kissel@LIGO.ORG - posted 16:17, Wednesday 29 May 2019 - last comment - 18:06, Wednesday 29 May 2019(49541)
Calibration Measurements Today: Sensing Functions In Nominal ISC Config, Some Data with More Centered ETMX Spot
J. Driggers, J. Kissel
We've gathered some new data on the DARM loop both in support of regular check-ins on the calibration as well as in prep for a potential increase in IFO power tomorrow, and further investigations in to "L to A to L" coupling in the ISC control scheme:
Standard sensing function suite:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O3/H1/Measurements/FullIFOSensingTFs/
2019-05-29_H1_DARM_OLGTF_LF_SS_5to1100Hz_15min.xml
2019-05-29_H1_OMCDCPDSUM_to_DARMIN1.xml
2019-05-29_H1_PCAL2DARMTF_BB.xml
2019-05-29_H1_PCAL2DARMTF_LF_SS_5t1100Hz_10min.xml
Some incomplete data during the spot position move:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O3/H1/Measurements/FullIFOSensingTFs/
2019-05-29_H1_PCAL2DARMTF_BB_postspotmove.xml
2019-05-29_H1_DARM_OLGTF_LF_SS_5to1100Hz_15min_postspotmove.xml
Data analysis and results to come later.
For this spot position move to investigate the L-to-ASC-to_L path, I moved the ETMX spot in pitch only, from -18.2mm (P2L gain of 4.85) to about -9.1mm (P2L gain of 2.85). It seems that something in the ASC went unstable and caused the lockloss, although I'm not sure if that's because we were starting the second cal measurement at low frequencies, or if it would have rung up anyway while we sat for a few tens of minutes at this unusual spot position.