There's some evidence that something strange is happening in the ETMY drive electronics and it's associated with the range drops. The ETMY L2 coil monitors (the noisemons) get quieter by about a factor of two around the same time as the range drops, but there's also excess noise that's not accounted for by the drive signal.

The correlation of strange behavior of the noisemon is not perfectly correlated with the drops in range, and the excess noise in the noisemon does not have the same shape as the excess in DARM and is not coherent with it. However, this does point to further problems with drive problems at EY. So would it be possible to switch control over to EX as Sheila suggested before? The range loss due to this problem is dropping the event rate by at least a factor of 2 (20% range loss cubed), so we should do anything with a chance of solving it. Power-cycling the EY electronics might also help, or checking any fast readbacks of the driver (the version in frames go only up to 1 kHz so if there's high-frequency junk we can't see it.

Attached are three plots. The first is a comparison of the noisemon during the reference (Jan 13 1 UTC) and the bad time (Jan 13 14:45 UTC). The second is a comparison of the noisemons with the drive signals (L2 MASTER UL) subtracted. The transfer function is measured from the data, since it is clearly changing. The transfer functions have the same shape and phase, but are different by a scale factor, about 0.42. There's excess noise during the bad time that is clearly above the noise floor of the coil monitor. The final plot is the RMS of the monitor channel during Jan 13 (ending at the last lock), showing that it starts to drop around the same time as the range. On Jan 8, the RMS is steady for the whole day, while on Jan 12 it also shows a drop during a time when the DARM range drops.

Lost lock in POWER_UP, same as Ed reported. Something seems wrong with the ISS (see previous alog). I have stopped at DC_READOUT while I investigate, but I'm not making much progress. I have left a message with Keita and Peter.

Could this be a sign of a problem related to the lock losses on POWER_UP? See attached.

TITLE: 01/14 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
    Wind: 2mph Gusts, 1mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.22 μm/s 
QUICK SUMMARY:

IFO is at down. Going to start an initial alignment.

Unfortunate turn of events considering the trouble I'm having.

Bubba turned on heater 3A yesterday to help deal with the cold conditions. You can see in the plot that the heater is cycling, probably on a protective temperature switch.

Nutsinee reported some misbehavior in the LVEA 10-30 Hz seismic activity.

I'm not sure there is any correlation between these two events but someone might look at this. The heater is likely ~25kw so there is some significant EMI from the contactor opening and closing. 

Re-locking has been a daunting task to say the least. PRC gave me a really hard time trying to get it locked. Upon getting it locked and the control signals converged, DRMI alignment still looked pretty terrible. BS alignment was checked repeatedly but to no avail to the alignment. I then decided to do a complete initial alignment. The IMC became unstable while trying to re-align the arms and I had to clear he WFS and re-align the optics. After letting the loops have the alignment for tuning during a brief break I continued with the initial alignment. Locking attempts following have been more sucesssful but not completely successful. So far, the farthest I've gotten is DC Readout.

4.8M Indonesia

Was it reported by Terramon, USGS, SEISMON? Yes, Yes, No

Magnitude (according to Terramon, USGS, SEISMON): 4.8, 4.8, NA

Location: 56km ENE of Taniwel, Indonesia

Starting time of event (ie. when BLRMS started to increase on DMT on the wall): ~06:30 UTC

Lock status? Caused lockloss.

EQ reported by Terramon BEFORE it actually arrived? Yes

Note: There were multuple earthquakes happened around the same time. It's not neccessary that this one in particular caused the lockloss. But the timing reported by Terramon matches.

TITLE: 01/14 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC

STATE of H1: Earthquake

INCOMING OPERATOR: Ed

SHIFT SUMMARY: The range was awfully low but the IFO stayed locked until an earthquake knocked us out. Otherwise nothing exciting.

LOG:

07:19 Lockloss. There were several earthquakes happened right around the same time but the arrival time of the 4.8M Indonesia earthquake is closest to the peak time observed in the control room. The peak reached 0.4 um/s on the 0.03-0.1Hz FOM.

About 2 hours into this lock stretch the range started to drop very fast. About the same time 10-30 Hz seismic activity (LVEA vertex) is behaving funny. I don't believe that it's real (no one is out there). I don't see funny things in magnetometers. Still looking for more clues. Electronics related?

It's been set to KILL since Jan 4th. Are we leaving it at KILL on purpose?