Since we may want to close up tomorrow, I did the following prep work:
- Cleaned up Y-end suspension eleoctronics setup, connected the Sat Box back to the flange
- The OSEMs are just sitting on the table right now, so they are just seeing the fully open voltage
- Post filter insertion, the four face OSEMs report ~3-4% lower open-voltage values compared to before, which is compatible with the transmission spec for the filters (T>95%)
- The side OSEM is reporting ~10% lower - perhaps I just didn't put the filter on right, something to be looked at inside the chamber
- Suspension watchdog restoration
- I'd shutdown all the watchdogs during the Satellite box debacle
- However, I left ITMY, ETMY and SRM tripped as these optics are EQ-stopped / don't have the OSEMs inserted.
- Checked IMC alignment
- After some hand-alignment of the IMC, it was locked, transmission is ~1200 counts which is what I remember it being
- Checked X-arm alignment
- Strictly speaking, this has to be done after setting the Y-arm alignment as that dictates the input pointing of the IMC transmission to the IFO, but I decided to have a quick look nevertheless
- Surprisingly, ITMX damping isn't working very well it seems - the optic is clearly swinging around a lot, and the shadow sensor RMS voltage is ~10s of mV, whereas for all the other optics, it is ~1mV.
- I'll try the usual cable squishing voodoo
Rather than try and rush and close up tomorrow, I propose spending the day tomorrow cleaning the peripheral areas of the optic, suspension cage, and chamber. Then on Thursday morning, we can replace the Y-arm optics, try and recover the cavity alignment, and then aim for a Thursday afternoon pumpdown. The main motivation is to reduce the time the optics spend in air after F.C. peeling and going to vacuum. |