The simple excuse might be that apparently not all the Isolation Gains were zero.

Okay, HEPI and ISI tripped from a HEPI Pump Station VFD OU3 fault.  Upon trying to recover, operator was unable to untrip the WD.  The T240 was riled up and touching the 32k limit and pressing the WD Reset button just tripped the platform again immediately with T240.  Additionally, JeffK noticed that the H1:ISI-ETMX_ST1_WD_MON_CURRENTTRIG was not RED(on T240) even when the T240 was still banging on the rail [indicating the T240 was being ignored although I can't say I know that based on model.]

Checking the model as a refresher, if all the ISO gains are zero, the ST1 ISO STATUS is zero and the T240 is ignored (text read, not my understanding of the model logic at this time although I believe it to be true from experience.)

So looking at ISO gains & WD signals, first plot, 10 minutes: You see the three attempts where the WD_MON_STATE goes to 1 and immediately tripping back to damp only (state3) and the first trigger remains 2 (T240.)  So even though the ISO GAINs are zero and the ISO STATUS remains zero, attempts to clear the WD trips it back blaming the T240s.

The fourth attempt to clear the watchdog state succeeds but shows a situation I do not understand.  You see all the ISO gains going to 0.1 with the ISO status switching to 1 and then back to zero when the gains go back to zero, as expected.  Did the Guardian do this?  The first step of the ISO gain ramp up is to 0.01, not 0.1; you can see this on the gains toward the end of the traces.

My second plot shows the 6 horizontal T240 signals (the verts never hit 32k) and I checked overlying the curves that no attempt to clear the WD was made when none of the signals were at 32k.  The last attempt to clear the WD was after all the T240s are off the rail and while the weird brief gain switch to 0.1 occurred, the WD state remained 1 and recovery succeeded.

So why did the gains step up to 0.1?  That may be an aside study.  And, why did the WD fail to clear while the T240s were hitting the rail even though the T240 should have been out of the 'loop?'

I'll keep looking.  Is it related to the HEPI tripping?  That was kinda why the T240 MON was developed.  In this case, HEPI was reset and had completed its isolation steps.  Was the WD circuit not getting the ignore the T240 signal?  Work ongoing, guess I should do an FRS.

TITLE: 08/22 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
INCOMING OPERATOR: Jeff
SHIFT SUMMARY:

Most of Maintenance was complete around noon.  Around 1pm started on an InitialAlignment, & unfortunately, the Y-arm was a bit off and this took me a long time to get back (but Sheila helped out).  Finally after getting ALSy back, the 

Had several tours today.

HEPI Pump Controllers died.  Hugh & I brought them back (he had to drive to both end stations).

TCSx flow rate trippped TCSx laser.  Rebooted interlock box & reset the servo relock the laser.  (Peter & Thomas)

Made a pseudo LVEA Sweep post-Maintenance Day (Turned OFF lights and confirmed WAP was OFF).
H1 to NLN at 23:22utc & Sheila is currently running a quick measurement.

LOG:

Maintenance Activities:

• 15:00-15:10 BSC ISI broadband injections
• 15:00 Cleanroom work (Bubba Chris)
• 15:05- Karen cleaning EY
• 15:08 ISI Sensor Correction OFF
• 15:09 Charge Measurements 
• 15:17 Tour (Paul)
• 15:20 TMDS at EX (Kyle & group)
• 15:20-15:45 IM4 in yaw (Kissel)
• 15:24 Apollo chiller yard EY trouble shooting CWP1
• 15:35 LN2 Insulation Activity (contractor & Chandra)
• 15:45 Cintas (mats) onsite.
• 1554 EX cleaning (christina)
• 16:31-16:47 HPO diode current (Jason)
• 16:33-19:00 Squeezer table prep (Fil)
• 16:38 LVEA cleaning (karen)
• 16:48 LN2 Delivery on X-arms CP8 at EX.
• 17:15 Moogega Tour (Amber)
• 17:33-17:50 3IFO work (hugh)
• 17:50 LN2 truck at CP6 at MX.
• 18:45 Restarted ETMy Hartman code (it was dead).
• 18:57 EX/EY HEPI Pump Controller died (OU3 [over voltage] error?)
  • Heading to EX first (Hugh)

here is a 12 hour, minute trend plot of the outside temperatures at LHO in degF. The time axis is centered around the time of the eclipse.

I have compiled the results of in-air measurements during installation and in-vacuum measurements from the alogs; 14231 LLO (including corrections mentioned in alogs 21652 and 27901) and 17610 at LHO (including corrections mentioned on the comments).

In the case when a frequency split is shown on in-vacuum measurements we have taken the average of both frequencies. I have grouped these numbers per front and back fibres, then per test mass and then per detector, finally I obtained the difference as (in-vacuum – in-air) including the sign:

We notice that in most cases the frequency difference is always positive, so frequency increases when moving the suspension to in-vacuum.

The increase in frequency is always a few hundred mHz (mean of 0.3Hz and median of 0.4Hz), with a clear outlier on LLO_ITMY_FL (which as explained here seems to be involved with uncertainty in the identification).

There is not clear difference in frequency variation between front and back fibres (especially no sign difference) which would indicate pitch effect.

However, notice that as per the Technical document T1700399 the expected increase in frequency due to buoyancy is of 0.14Hz, and the variation in frequency due to pitch angles of 2mHz is of 0.33Hz (although that would be an opposite sign change between front and back fibres). Therefore while the observed changes cannot be explained through pitch and buoyancy alone, they are of the same order.

Didn't catch when this happened, but see on the Seismon (compact) medm window that "SEISMON DEAD".  The "Keep Alive" is flashing on both Seismon screens.

This morning I completed the weekly PSL FAMIS tasks.

HPO Pump Diode Current Adjustment (FAMIS 8436)

With the ISS OFF, I adjusted the operating current of the HPO diode boxes.  All currents were increased by 0.2 A, changes summarized in the table below:

I did not adjust the operating temperatures of the DBs.  The ISS is now back ON and the HPO is outputting 155.0 W; I have attached a screenshot of the PSL Beckhoff main screen for future reference.  This completes FAMIS 8436.

PSL Power Watchdog Reset (FAMIS 3664)

I reset both power watchdogs at 16:34 UTC (9:34 PDT).  This completes FAMIS 3664.

TITLE: 08/22 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: Jim
CURRENT ENVIRONMENT:
    Wind: 4mph Gusts, 2mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.10 μm/s
QUICK SUMMARY:

Maintenance Day!

Jumping headlong into Maintenance day.  Have a pretty full board.  Full steam ahead!

TITLE: 08/22 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 52Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Quiet shift, 1 lockloss, PCAL lines turned off briefly
LOG:

12:30 Lockloss, no apparent cause, back to observing 13:00

14:20 Turned off PCALX lines for a measurement, back on 14:35

Adam Mullavey called and said he needed to run a measurement for today's maintenance. His measurement needed the PCAL X lines turned off, so he had me turn the amplitudes on those lines down to 0. Unfortunately, he ran into some permissions issues and couldn't do his measurement. LHO was out of OBSERVE from 14:21 to 14:34 for this, but as far as I know the only differences during that time were from turning off the pcal lines. Attached screen shot shows the settings we were running while observing. All the oscsin and osccos amplitudes were zero'd for the planned measurement. I've reverted them to the pictured settings now.

The end Y BRS is continuing it's slow drift and is getting close to going out of range, but should survive through the end of the run. It's possible, however, if it gets rung up by people working in the area, it could cause a problem for the damping loops and leave the BRS in an unusable state. 

TITLE: 08/22 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 50Mpc
INCOMING OPERATOR: Jim
SHIFT SUMMARY: 39.5hr lock, many tours for the eclipse party. Quiet shift overall.

A. Urban, on behalf of the calibration group

The C00 vs. C01 comparison pages have been updated and include all C01 data from 2016-11-30 through 2017-08-01.

As part of this analysis, I've got updated PCAL-to-DARM ratio trends at 36.7, 331.9 and 1083.7 Hz (attached below).

Plots of both magntidue and phase residual timeseries trends are attached. These trends are computed by demodulating 300-second segments at each PCAL line frequency, then averaging to get a magnitude and phase out of each channel. In practice, I break up each 300-second segment into overlapping 100-second chunks, apply a Kaiser window, and then average over chunks to get a less noisy measurement. (It's basically Welch's method, except I'm demodulating rather than computing a PSD.) Finally, I remove most outliers that are due to locklosses and loud transient glitches. The same analysis was done on Livingston data; see L1 aLOG 35501.

In each plot below I show PCAL/strain trends for C00 (blue) and C01 (red) data. The trend shown in aquamarine applies a correction for f_cc to C01 data at the appropriate PCAL line frequency. Gray shaded regions correspond to times when we had a break in O2, once during the holiday season and once for commissioning work.

At mid and high frequencies, everything continues to be in order at the PCAL lines. You can see that in the bucket (331.9 Hz) all systematics are accounted for by f_cc and only very small (~1%) statistical fluctuations remain in C01. At high frequency (1083.7 Hz) there's a slight systematic offset at the level of 1% or so in magnitude and 1-2 degree in phase, which is consistent with Craig's error budget. However, in the C01 low frequency line there is a mounting phase offset prior to the May vent that becomes worse after the break: the offset is 2-3% in magnitude and about 2 degrees in phase from June all the way through August. I suspect this has to do with spring detuning in the signal recycling cavity, and will follow up on it soon.

J. Kissel

I've processed the data from LHO aLOG 38232, in which I was looking to see if the complex, high frequency dynamics found in the UIM (L1) stage of H1 SUSETMY (see LHO aLOG 31603).

Plots are attached; note that I've used the former 2016-11-17 data for ETMY. To guide the eye, I show the calibration group's dynamical model used during O2. Data shown with a coherence threshold of 0.75 or greater. I've not yet compared this against the unphysical, fitted update to the QUAD model that Brett developed for H1 SUS ETMY in CSWG aLOG 11197

It looks like 
- All suspensions see the "unknown" ~165 Hz resonance, though interestingly ITMY's mode appears to be split. ETMX and ITMY's are *strikingly* similar.
- only ETMY and ITMX show what Norna suspects is the "UIM blade bending mode" at ~110 Hz. ETMY's is indeed the ugliest.
- All but ETMX show evidence for resonances between 290 and 340 Hz, which are likely the (Suspension Point to Top Mass) wire violin mode fundamentals weakly excited by the UIM excitation. (see LHO aLOG 24917, T1300876)
- All suspensions show their (UIM to PUM) wire violin mode fundamentals between 410 and 470 Hz (see LHO aLOG 24917, T1300876)
- ETMY and ITMY's wire violin modes are *strikingly* similar; ITMX's modes are surprisingly low Q.
- We don't see the TOP to UIM wire violin modes likely because I didn't excite up to high enough a frequency; they're between ~500-510 Hz for ETMY (modeled at 495 Hz).


So now the question becomes -- what's the physical mechanism for this huge mystery resonance that's seen virtually identically in all QUADs? It seems quite a fundamental feature. Why is it split on ITMX?

It would be nice to have similarly detailed measurement of L1's QUADs, but all evidence from calibration measurements on L1's ETMY UIM stage point to this same feature (see the discrepancy between model and measurement for the UIM stage, e.g. in 2016-11-25_L1_SUSETMY_L1_actuation_stages.pdf LHO aLOG 29899). Further, it's *still there* before and after their Bounce/Roll mode Dampers (BRDs) have been installed (i.e. the same feature is seen in O1 and O2 CAL measurements; the above linked measurement was after BRD install). 

TITLE: 08/21 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 52Mpc
OUTGOING OPERATOR: Jeff
CURRENT ENVIRONMENT:
    Wind: 7mph Gusts, 3mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.10 μm/s
QUICK SUMMARY: 31.5hr lock, rode thorugh a few earthquakes, eclipse event tonight.

Committed the following modified files to SVN repository. 

   The minutes from the 12:00 weekly pre-maintenance meeting, usually held at 09:30. 

   Planned Tuesday Maintenance items:
   (1). The window may extend past 12:00 due to TMDS Testing at End-X
   (2). Jeff K. needs IFO up for 15 to 20 minutes after 08:00 to run BSC ISI coupling measurements
   (3). Jeff K. Running charge measurements
   (4). Jason will be making the weekly PSL Diode current adjustment
   (5). Possible cleanroom moves (WP #7116)
   (6). Filiberto will hold off in dressing new cables into HAM6 rack until next week.