Keita, TVo
In Keita's previous alog-33547 , he checked the free swinging ITMs for rubbing by comparing the angular response to the SUS M0_TEST drives during initial alignment by the operators. Looking at the shifts from the norm of the responses as a function of time could signal rubbing as was shown in his aLOG.
In trying to investigate the 10-80Hz noise, we tried to run this script again from June 27th 00:00:00 to July 14th 00:00:00. Picture 1 shows the results:
1) The first plot is the range, operators only run initial alignment out-of-observing.
2) The second plot is the response of the individual optics, you can see that even after the earthquake, they don't change much as a function of time.
3) The third plot shows the ITMY vertical position and a guess at what the rubbing threshold could be based off of Keita's alog above.
4) The fourth plot shows ITMX vertical position.
I tried editing the script to run a similar measurement for ETMs, but the results are much more scattered and will require more investigation. It is possible that the ETM responses are different because they undergo different actuation during initial alignment than the ITMs.
Here is a similar plot for ETMs except using the Oplev/M0_test in order to compare the responses before and after the earthquake. There doesn't seem to be much of a difference in response except at about Day 14.4 in EY Yaw but then it goes back to what it was before.
