Dan, Kiwamu,

We had trouble locking the interferometer tonight and therefore did not reach full lock.

It seems that the recycling gain is very low for some reason tonight. It seems as low as 19. Therefore the CARM reduction did not work as intended. In fact, REFL_LF dropped below 40% or less even when we were at the CARM_15PM state. Every time when we moved onto CARM_10PM it lead to lock loss. Not good. We even tried to transition to TR_REFL mutilple times by skipping a few CARM reduction steps since the REFL9 seemed passing the turn-around point. However this did not work either. Sad.

We co-aligned both red and green light in the Y arm in order to improve the recycling gain, but this did not seem to help. I am thinking of starting from the baffle PDs tomorrow in both arms just to make sure alignment is reasonable. In the course of the Y arm alignment tonight, we had to realign the ALS diff beatnote once because it went lower than -10 dBm.

PRC2 ASC loop still does not work only in yaw as reported by Dan (alog 18109).