[Keita, Louis, Jenne, Elenna, others in CR]
We have locked both arms on green! Proof.
Jenne started running baffle PD scripts for TMSX and ITMX with Keita. There is some issue with ITMX baffle script, so Keita and Jenne walked through the process by hand (hopefully one of them will describe). Jenne was able to lock the green arms after aligning ETMX by hand. We don't think the slow controls are working, so we couldn't move beyond the "locking" state in the guardian.
While Louis and Jenne were running the y arm baffle scripts, there was a power glitch that tripped both end station HEPIs. We stood down while Ryan and Huyen went to reset them.
Louis had a hard time with the ITMY baffle PD script. I was able to move ITMY a large amount to find the March 5 2026 setting Jenne found here. This allowed Louis to finally find the beam on the baffle PDs. After a few iterations by hand and with the script, we settled on a setting that moved ITMY by 110 urad in pitch and 56 urad in yaw.
We could not see green flashes at ISCT1 from the y arm, because the beamsplitter is now very misaligned between the two ITMs due to the large ITMY move. First, I misaligned the Y arm and checked for the red beam on ISCT1 refl camera. I had to move IM4 to find it there. Then, Louis and I tried to move the beamsplitter around. We found that by putting ITMY back to its slider setting before the baffle PD script was run, we could move ITMY a bit towards the correct direction and follow with the beamsplitter. We also had to touch up SR2 to keep the beam on the AS AIR camera and roughly centered on AS_C.
We completed an initial alignment. Oddly, IM4 and PR2 didn't need to be moved at all for input alignment, depsite the fact that we put IMs1-3 in their desired locations for ISS QPD and IM4 trans. However, I did move IM4 earlier to find the red retroreflection from ITMX during our green alignment work, so maybe this makes sense after all.
We have locked PRMI again, and the OLGs look good. This includes BS feedback to M3! Screenshot of OLGs. Camera looks terrible, but no BS or PRM touch up helped. We are using oplev damping on the beamsplitter and then disengaging it as soon as PRMI locks.
We are now trying to lock DRMI with little luck despite the good flashes.
After failing to lock DRMI for a bit, I decided to check the SRY olg. I noticed that there was quite a bit of gain peaking in the loop, so I turned off the 30 Hz low pass. This made the SRY olg much better, but then I learned that maybe this has no effect because the ISC DRMI guardian doesn't engage this filter.
The screenshot below shows the blue reference trace in the template, the green trace is the OLG I measured with SRCL FM8 LP30 on, the ref trace is with FM8 off.
