Sheila, Kiwamu, Evan, Nergis, Alexa,

Since we got ALS diff working again, we moved onto the full lock attempt. So far we got back to a point where DRMI was locked with the arm cavities held by ALS at a off resonance. We locked DRMI twice this evening and each time DRMI dropped the lock right after the ASC loops came in. We need to look into this issue.

Even though we had aligned the DRMI before attempting the full lock, the DRMI looked misaligned a lot when we restored PRM and SRM. It seems that we ran a wrong ASC offloading script by accident in the initial alignment process which left a unneccessary offset in the M2 stage of PRM. We realigned PRM by misaligning SRM and locking PRMI while keeping the arm cavities locked. This gave us back good alignment in DRMI. However it took more than 15 minutes to get DRMI locked for some reason in both times. The DRMI unllocked right after the ASC loops came in both times. According to a brief look at the first lock loss, it seems that all three DRMI length error signals showed monotonically-increasing-oscillation for 0.5 sec before it unlocked (see the attached 0.5 -ish sec time series). Interestingly, IMC transmitted power increased at the same time by 10% or so. It is unclear what was going on at this point. Another thing is that it seems that the DRMI pulled ALS diff down when it unlocked and therefore this resulted in unlock of IMC.