[Louis, Jenne, TJ, Ryan S., others in control room]

Since GV20 was closed Wednesday afternoon, taking the x-arm out of commission, I started to look into revisiting our efforts to get longer DRMI locks.

- We locked the y-arm in green to make sure the ITMY alignment was good.
- Then we ran INPUT_ALIGN on the yarm (ALIGN_IFO::INPUT_ALIGN_YARM). I moved IM4 and PR2 manually to bring the INP error signals closer to zero and maximize LSC-TR_Y. 
- Then moved on to MICH dark (10 W input) and had to manually adjust the beamsplitter to maximize the fringes in AS_A. This entire thing was tricky because we confirmed that moving the BS also affects the alignment of IM4 and PR2 to the arms and, which is evident in the INP error signals. This isn't normally a concern when performing input_align with the xarm. Doing this with the y-arm introduces a new constraint with the BS alignment. We decided to move forward anyway, hoping that our moves brought the BS, IM4, and PR2 all /close enough/ to where they need to be.
- We moved on to PRX_LOCKED and adjusted the PRM to improve the PRC1 and PRC2 error signals.
- Then we moved on to SRY and adjusted the SRM by hand. We found that the SRC1 and SRC2 loops fight each other and run away pretty quickly. We were able to enable SRC2 on its own without it running away. Once we bring in SRC1 the alignment runs away. Maybe the AS_{A,B}_RF45_Q readbacks need to be rephased? 


Tentative plan for tomorrow is to check the phasing of AS_{A,B}_RF45_Q then move on to trying to lock full DRMI.