15:29:32UTC

nsection Guardian is, and has been,set to INJECT_KILL.

H1 is in Observe Intent

1 hour stand down time is being initiated.

The SR3 oplev has a big increase in noise in sum, pitch, and yaw starting at 12:30 UTC, the same time the range decreased. There's no excess of noise in SRCL (or any other aux degrees of freedom), so it's not clear how it is affecting the range, but it seems like a clue. Or maybe the oplev noise is caused by whatever caused the range loss. We'll keep looking into it.

Here's the SR3 oplev summary page.

Temps were falling in the LVEA. I brought on 1 stage of heat at Zone 3A. I will monitor this change. 

I'm making an attempt to rectify my deteriorating range. Attached is the latest, passive, DTT coherence measurement. I'm grasping at straws but it's all I've got at the present.

It seems that what has been typical noise in the 15Hz-35Hz range has settled down to the preferred reference. That being said there seems to be a new feature (at least to me) that is occuring from approx 70Hz to around 200Hz. I took a snapshot of the DARM spectrum. I'm not certain when this began to look like this but judging by the downward trend in the BNS range it looks to be on the order of the last couple of hours. Range at this moment is 46Mpc.

• H1 hs been locked for approx 12.5 hrs.
• Environment has been quiet, seismically. Winds are calm and temps are zero/sub-zero. 
• the usual suspect dust alarms - PSL and EY .3u
• L1 has been coincidental for the last 4 hours, or so.

10:04:30UTC

Insection Guardian is, and has been,set to INJECT_KILL.

H1 is in Observe Intent

1 hour stand down time is being initiated.

Nothing noteworthy to report. Plots show normal consistencies between humidity fluctuations and front end diode powers. Incursions for FSS alignment are evident in environmental plots.

TITLE: 01/13 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 58.0094Mpc
INCOMING OPERATOR: Ed
SHIFT SUMMARY:

It's another cold night where our Temperature Sensors hit 0degF (& then go to 6553degF!).  H1 in OBSERVING the majority of the shift. 
LOG:

• 0:10 - 0:23 three of us went to the Observation Deck on the roof (this required removing blocks of snow/ice blocking the access door).
• 0:16 OBSERVING
• 0:44 PI Mode 28 rung & damped
• See alog about PI Mode 27 staying rung up for 3hrs.
• ~6:00utc  Started seeing H1 Summary Pages starting to go down.  Sent an email to Detchar group.
• ~7:00 Access Alarms for LDAS Room at the Warehouse.  Must have been Dan M since I sent out an email to detchar about the H1 Summary Pages being down.
• 7:28 PSL Dust Alarm

Have heard noises from within the Control Room.  Not sure what they can be.  We have piles of snow on the roof.  I have gone out after most of the noises to see if a pile of snow or ice has fallen, but have not found anything obvious.  As noted below, some of these bumps corresponded with a glitch seen on H1's DARM.  Here are some of the times I noticed hearing these bumps in the night:

• 2:10:25
• 4:34:12
• 5:32:50(saw glitch on DARM, but this was not as loud)
• 5:38:59 (direction over MSR east)
• 5:44:50 (direction of MSR west)
• 5:58:56
• 6:09:14 (west of Control Room & glitch on DARM, Range dropped to 48Mpc from 65Mpc)
• 6:10:05 (outside door?)
• 6:10:54 (west of MSR, not loud)
• 7:50:26 (outside Control Room, southern wall)

This morning we sat in nominal low noise without going to observing from 19:21 to 19:51 UTC (Jan 9th) in a configuration that should be much better for the 1084Hz glitches. (WP6420)  

On Friday we noticed that the 1084Hz feature is due to OMC length fluctuations, and that the glitch problem started on Oct 11th when the dither line amplitude was decreased (alog 30380 ).  This morning I noticed that the digital gain change described in alog 30380 that was intended to compensate for the reduced dither amplitude didn't make it into any guardian, so that we have had a UGF that was a factor of 8 lower than what I used when projecting OMC length noise to DARM: 30510 The first attachment shows open loop gain measurements from the 3 configurations: before oct 11th (high dither amplitude), after october 11th (lower dither amplitude, uncompensated) and the test configuration (lower dither amplitude, compensated).  

We ran with the servo gain set to 24 (to give us the nominal 6Hz ugf) and the lowered dither line amplitude from 19:21 UTC to 19:51 UTC Jan 9th.  You can see the spectrum durring this stretch in the second attached screenshot, in the test configuration the peak around 1083Hz is gone, with just the pcal line visible, and the OMC length dither at 4100Hz is reduced by more than an order of magnitude. You can also compare the glitches from this lock stretch with one from yesterday  to see that the glitches at 1084 Hz seem to be gone. This is probably the configuration we would like to run with for now, but we may try one more test with increased dither line amplitude.  

Other notes because we don't have an operator  today due to weather:

This morning all 4 test mass ISIs were tripped probably from the Earthquake last night that brought the EQ  BLRMS to 10 um/second around midnight UTC.  ITMY tripped again while it was re-isolating, no problem on the second try. 

Richard topped added 400mL to the TCSY chiller around 10:15 or 10:30 local time, since we were getting low flow alarms. The flow alarms came back a few minutes before 11am local time.  

I went through inital alingment witout problems and got to DC_readout transition. Then I measured the UGF of the OMC length loop in preparation for increasing the dither line height   From that measurement and trends it became clear that when the OMC dither amplitude was reduced, the compensation of the OMC digital gain described in didn't make it into the guardian.  This means we have been operating with a UGF in the OMC length loop that was a factor of 8 too low since mid october.  

We arrived in low noise at 19:21 UTC with the OMC ugf increased to 6Hz.  After about a half hour PI modes 27 and 28 rang up, and I wasn't fast enough to get them under control so we lost lock.