Alignment into JAC was not great. Since JAC wasn't thermalized yet (heater was turned on merely 30minutes or so before we started aligning) and the fringes weren't staying put relative to the PZT voltage, I injected more than 250Vpp (with an appropriate offset) into JAC PZT to make sure that more than FSR is scanned and manually aligned JM1 and PSL PZT until 10/01 mode became less than 10% of 00 mode. Didn't bother to refine further. Attached shows the JM1 and PSL PZT alignment offsets.
I zero-ed the dark offset of JAC_REFL_A_RF43.
We had to turn on FM10 ("W_in_HAM2" which is not calibrated in reality) which was disabled at some point.
JAC guardian was able to lock JAC after the above.
We are able to see flashing in MC TRANS camera now, seems like it's mainly off in yaw but we can see 00 mode once in a while. Nothing in MC REFL camera, we'll work on IOT2L next.
IOT2L alignment 1st round (Jennie, Elenna, Keita)
Without doing any fine alignment, IMC REFL diode was centered using the steering mirror after the bottom periscope mirror. Shifted one of the beam dumps a bit as I felt like one of the beam dumps for blocking the wrong polarization beams (or maybe AR reflections) was too close to the main beam.
IMC WFS sensors were centered using pico mirrors.
IMC REFL camera was centered using the last steering mirror.
After this, we found that JM3 needed to be rotated in PIT (which means YAW in the IMC coordinate) to roughly align the JAC output into IMC.
| before I started | after roughly aligned | |
| H1:SUS-JM3_M1_OPTICALIGN_P_OFFSET | -54 | 85 |
| H1:SUS-JM3_M1_OPTICALIGN_Y_OFFSET | 297 | 297 |
Attached video shows how the MC REFL beam goes dark when IMC is locked for a few seconds. As you can see the alignment is already pretty reasonable. This is just manual lock via fast path, no boost no feedback to MC2 no nothing. IMC guardian doesn't want to lock IMC (yet).
I disabled all ASC output to mirrors and set the H1:IMC-WFS_GAIN to zero so LOCK state should not confuse you about the alignment even if ASC is "turned on".
Jennie and I continued trying to lock the IMC for a bit this evening after Keita's attempts, but weren't successful.
We did discover, however, that an MC2 length excitation was left running, which may have confused some of the locking attempts when using the Guardian. We killed this excitation and tried the Guardian again, but still no luck. Jennie also discovered when browsing SDFs that the IMC-L gain had been stepped from 1.0 to 0.1 then 0.01 at around 00:30 UTC. We assumed this was part of Keita's locking attempts, but since it was not mentioned as necessary in any logs and it had been 1.0 for several years, we put the gain back to 1.0 and tried the Guardian once more. Sadly, this didn't seem to help either. We're leaving the IMC-L gain here and if someone else deems it should be different, they're welcome to change it back.
MCL gain was me (sorry).
Excitation was me, too (sorry again) but it was 1 ct pk-pk and has zero effect on locking.