[Cheryl, Giacomo, Greg]
Using only IM1 and IM2 (under the assumption that the alignment done before the power outage was still good), we realigned the beam coming out of the (flashing) IMC to the fiducials we had downstream of IM2.
We initially used just the input and output aperture of the FI, obtaining these offsets
IM1 Pitch: 3000
IM1 Yaw: -1000
IM2 Pitch: -1410
IM2 Yaw: -1300
Then, we refined the alingment using IM1 to center on the iris past PRM, and IM2 to center on the iris in front of PR2. These were the offsets at the end of the process:
IM1 Pitch 2730
IM1 Yaw -170
IM2 Pitch -1380
IM2 Yaw -300
With this alignment:
- the parking beam reached the hole n the parking baffle with the same offset values for PRM (pitch = 2500, yaw = 50).
- the refl beam goes all the way back and easily clears the last baffle before entering HAM1
-the input aperture on the FI magnet is centered
- the centering into the AOE2 baffle is good (i.e. slighly off-centered, as neeed)
We are thus confident that we have realigned the beam out of the IMC to the beam we used before the power outage, and so all the resst of the alignment should be reasonably good.
Note that the beam appears to be slightly off-center (between 0.5~1 beam radii) on the output aperture of the FI, but we have no memory of how well that was centered before the power outage.
We then checked that the beam coming back from PR2 is reasonable centered on PR3. because the beam was scarcely visible and bigger than our target, we just scanned PR2 pitch and yaw to find the limit of visibility of the beam on the target, and then took the average. Our best estimate for PR2 the send the beam back to PR3 are:
PRM pitch = 1400
PRM yaw = 900
We then:
- re-centered the IMC REFL in the periscopes
- placed reference dog-clamps ad remove all the irises
- adjust a few baffles on IM2
- remove all loose/temporary IO hardware from HAM2.
We also went to remove the black glass from AROM RH6 in HAM3 (planning to either quikly find a way of cutting it, or just leave it out) to discover that the black glass had never been installed in the first place.