From last night, I had some progress for the PRFPMI lock acquisition.

- The DARM loop is now closed with ETMX. Thanks to that, the ALS DARM loop UGF is now ~30 Hz and has larger gain at low frequencies.
- The PRFPMI was hold on resonance for about 10 sec. At this point, the ALS DARM signal was already removed.
- Now the ETMY angular motion is larger than before, especially 7.5 Hz pitch and 1.7 Hz yaw. I doubt the beam position on the ETMY, but I don't have enough energy to re-align today. 

PRFPMI is almost locked, although still we need some tweaking of servo filters, gain, suspension angular mption, alignment, etc. I will continue to try to lock tomorrow.