The FSS RefCav TPD has been falling, so this morning I tweaked the beam alignment into it from the Control Room. With the IMC off the TPD was ~0.745 V, and after the alignment tweak the TPD was ~0.813 V (see attached plot). I also attached a screeshot of the PSL Quad Display after the alignment tweak. Corey relocked the IMC, and with the IMC locked the RefCav TPD is ~0.810 V (it's normal for there to be a slight difference in RefCav TPD with the IMC locked and unlocked).
This TPD is not as high as Ryan was able to get on June 11th, when this was last done. Further, the RefCav Refl spot is different from that time as well (lower left image on the Quad Display picture). This likely means things on the table are moving, which tends to happen when the weather changes. The TPD is looking good for now, but we will continue to monitor this over the coming weeks; an on-table FSS beam alignment may be necessary in the near future, depending on how things change.
A reminder that the PSL FOM image is archived every hour (https://lhocds.ligo-wa.caltech.edu/cr_screens/archive/png/2025/). The PSL FOM can be found under MM/DD/HH/nuc21-1.png
Attached shows PSL FOM at midnight and 11am today.
Note to operators: the LVEA lights can be seen on the PSL Anteroom camera coming through the wall vents, could be useful as a check the lights have been turned off.
