ISI was locked by Jim in the morning.
Before doing anything, EY alignment slider [PIT, YAW] = [142.0, -75.1], TMSY = [116.6, -20.0], EY OPLEV=[-39, -15]-ish.
Transitioned to laser hazard, moved EY such that the green return beam hits the center of the relf PD: EY [PIT, YAW]=[207.4, -75.1]
- Krytox on beam diverter in situ: Good.
Everything went well as per yesterday.
- QPD strain relief: Good-ish.
Unlike TMSX, it turns out that all QPDs were already equipped with a make-shift strain relief using stainless steel cable clamps, the same clamps used for fixing the cables on the TMS ISC table, but the cables were without kapton tubes. We decided to install the right strain relief anyway.
In the end, we were able to install the right ones on three out of four QPDs. As for the remaining one (Green QPDB), we weren't able to install it as the 1/4-20 Allen key to attach the PEEK strain relief to the QPD base would have interfered with the YAW knob of one of the QPD sled mirror holders (M102 in D1201458). The stainless steel strain relief was left as is.
After this work, we checked if QPDs still work and they did (used green beam for the green QPDs and a flashlight for IR QPDs).
- TMS balancing: Good.
After the work, we checked the balace of the TMS table with the green light injected to the chamber. The vertical alignment was found to be already good and therefore we did not make any mechanical adjustment. Similarly, the horizontal was also good and giving an extra digital bias of +13 urad (resulting in -7.0 urad in OPTICALIGN_OFFSET) made the return beam well-centered on ALS-REFL_PD. So the balance is good.
After everything was done: EY slider [PIT, YAW] = [142.0, -75.1] (back to the original), TMSY = [116.6, -7.0], EY OPLEV=[-24, -31]-ish.
Seems like EY moves around by 15urad-ish both in PIT and YAW, so TMS alignment could be only as good as 15urad-ish.
Here are photos from EY TMS work today: https://ligoimages.mit.edu/?c=1616
This is the picture of the stainless steel strain relief in resource space.
The certificate for ligoimages.mit.edu has expired, so this site is currently not accessible.