kiwamu.izumi@LIGO.ORG - posted 21:07, Friday 24 April 2015 - last comment - 23:58, Friday 24 April 2015(18061)
ITMY camera position updated
In order to check whether we have messed up the camera positions, I locked the interferometer and brought it to a recycling gain of 40 by steering ITMs. It seems that the ITMX camera position remained good while the ITMY camera postion was completly off for some reason. I updated the ITMY camera position.
pit: 302 -> 180
yaw: 434.3 -> 391
After Kiwamu found the good ITM alignment we tried for a few hours to reach low noise. We found the SRCL offset was breaking the lock, after the DRMI ASC turned on and as the offset was turned off. We increased the ramp time on the offset to 5 seconds, this seemed to work.
We observed the same oscillation just before full resonance that Sheila reported a couple of days ago. We tried to stay in REFL_TRANS and wait for it to subside, but this didn't work for a handful of attempts. As we were starting to motivate ourselves to investigate, the earthquake in Nepal struck.