thomas.shaffer@LIGO.ORG - posted 13:18, Sunday 13 December 2015 - last comment - 17:27, Sunday 13 December 2015(24181)
Lockloss 21:15
Really similar to alog24151 from yesterday. Saw the oscillation buid up and had no idea how to stop it.
We've left the ETMX ISI on 45 mHz blends in both X and Y on ST1, so I was worried that these locklosses could be reappearance of the problem described in 23674 . At least this one seems to be a different problem, this is a pitch oscialtion at around 0.4 Hz that shows up in all test mass oplevs, and seems to be in common soft if all the signs on these oplevs are right. It rings up over the last 2 minutes of the lock or so. It doesn't show up in any of the arm ASC control signals. It does show up in SRC1 (AS36I->SRM)