[Cheryl, Giacomo]
The IMC is flashing again.
We did restart alignment almost from scratch, through the following main steps:
- Beam centered on the top periscope mirror on the PSL table, usign the bottom periscope mirror and the mirror before that
- Beam centered on the HAM2 periscope, using the top periscope mirror. This did NOT recover the original input beam pointing, as the spot reflected off of the input viewport into the external PSL wall are slightly offset. However, it did look nice as input beam alignment.
- Beam centered on the irises in front on MC1 and MC2 using the actuated and non-actuated steering mirror, respectively.
- Beam centered on the iris in front of MC3 using MC2
- Round trip closed using MC3 and MC1... and IMC flashing!
The MCx offsets are as follows (in um on the alignment offset sliders):
| MC1 | MC2 | MC3 | |
| Pitch | 500 | -125 | 395 |
| Yaw | -790 | 200 | -955 |
It's good to see that the big (and a bit worrying) offsets in yaw of MC1 and MC3 are gone...