Displaying report 1-1 of 1.
Reports until 17:23, Wednesday 13 June 2018
H1 AOS
thomas.vo@LIGO.ORG - posted 17:23, Wednesday 13 June 2018 (42510)
More ITMY HWS Work

TJ, TVo

Feeling like we should try to capture the positions of the alignment from alog-42507, we attempted center the HWS QPDS but we had an incredibly difficult time finding the beam because it was so dim returning from the ITM and the sensitivity of the QPDs were not very good. I'm not sure if this is an old issue but we eventually gave up on this.  The motivation behind this was because the current position of SR3 to get the ALS green beam onto the HWS table requires that SR2's alignment to come close to railing when trying to get the main IFO beam down to HAM6.  If we move SR3, we'll have to adjust the HWS injection alignment with the periscope mirrors but it is not clear how much we can compensate before we start clipping.  I think the current plan is that we'll try to wait until the ISC alignment crew (Sheila+Georgia+Hang) is happy with their spot positions with respect to the y-arm and see how much SR3 adjusted can be fixed with.

One interesting thing worth mentioning is that we removed the Hartmann plate in preparation for this alignment work and noticed that the beam did not look the same as it did yesterday even though we didn't move anything.  This could be due to the SR3 drift mentioned in alog-42507 and wasn't noticed because the plate was on. There's a bit more prominent clipping on the right side and the top, but I suspect this can be easily fixed by adjusting the periscope mirrors.

Images attached to this report
Displaying report 1-1 of 1.