TITLE: 07/25 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 53Mpc
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
    Wind: 5mph Gusts, 4mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.10 μm/s
QUICK SUMMARY:  No issues handed off.  Lock is 19.5 hours old.

TITLE: 07/25 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 53Mpc
INCOMING OPERATOR: Travis
SHIFT SUMMARY:
LOG:

J. Kissel

Still hunting for what's limiting our range, we took Valera's suggestion to drive stage 2 (ST2) the test masses' BSC-ISIs to check for, among other mechanisms,
  (a) scattered light problems, 
  (b) charge coupling issues, or
  (c) mechanical shorting / rubbing

The measurements indicate that ETMX and ITMY are the worst offenders, in that their ambient noise falls as ~1/f^{1/2} between 10 and 100 Hz, with some resonant features at 70 and 92 Hz. The features are presumably the first few cage bending modes, for which we have Vibration Absorbers that have already knocked down the Q of the ~70 Hz modes, thankfully.

I've used the measurements to "calibrate" the error point of the ISI's ST2 Isolation Loops, and project the ambient noise to equivalent DARM displacement noise (a.k.a. primitive noise budgeting), see first attachment.
Each come within a factor of 3-5 at their worst parts during ambient conditions; too close for comfort.
Also, of course, there should be no such coupling at all if the cage were properly isolated from the suspension, and this appears to be a straight-forward linear coupling.
Note that the precision of the projection is not great -- I did not try hard to get it right. There are addendum plots that show the residual between model and measurement.

I don't think this is a / the limiting source now, since there is little coherence during ambient conditions, but this will certainly be a problem in the future if the coupling remains this bad for ETMX and ITMY. It definitely deserves a more careful calibration, further study with other degrees of freedom, and mapping out a broader frequency band. Perhaps we should check the coherence with these ST2 ISI channels after Jenne's subtraction of jitter (see LHO aLOG 37590) -- though the slope doesn't quite match up (from eye-ball memory).

ITMX's coupling is about 1/2 as bad, and ETMY does not show any visible signs of bad coupling at this excitation level (which is damning evidence that it's related to charge, since ETMY has the largest effective bias voltage at the moment).

%%%%%%% Details %%%%%%%%
Measurement Technique (all while in nominal low noise):
- choose obvious, simply to imagine coupling degrees of freedom: the longitudinal axis for the optics in the arm cavity (X for ETMX and ITMX, Y for ETMY and ITMY)
- measure ambient error signals in those directions using DTT.
- In the same DTT template, create a band-passed excitation where you suspect you're having problems (10-100 Hz), shape it to look roughly like that ambient spectra you see. I used
    ellip("BandPass",4,1,40,10,100)zpk([0.1],[1; 10],1,"n")gain(0.159461)gain(1e-4)
copied and pasted to the 4 excitation banks (thanks Daniel!) so that I can pick and chose what I'm driving, and with what amplitude.
- Grab a bunch of relevant response signals; the excitations, the error signals, the calibrated displacement (the pre-calibrated SUSPOINT signals are especially nice -- though the suffer from spectral leakage up to above 10 Hz).
- Slowly creep up the drive (I started with 0.001 [ct] to be extra careful) until you start to see hints of something / coherence.
- In case the coupling is non-linear, record the results at three different drive levels (I chose factors of three, 500 ct, 1500 ct, and 4500 ct, filtered by the above band-pass.)

Analysis Techniques
- Remember, to calibrate DELTA L EXTERNAL, one must apply the transfer function from
     /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Scripts/ControlRoomCalib/caldeltal_calib.txt
i.e. copy and paste that file into the "Trans. Func." tab of the calibration for the channel, after creating a new entry called (whatever) with units "m".
- For calibrated transfer functions of ISI displacement in local meters to DELTA L in global differential arm meters, just plot transfer functions between SUSPOINT motion (which comes pre-calibrated) and DELTA L EXT.
- Store the transfer function between the ISI ST2 ISO error point and DELTA L EXT for the loudest injection
- For "good enough" calibration of the error point, make a foton filter (in some junk file) that looks like the transfer function of error point to DELTA L EXT, and install into DTT calibration for that channel. Guess the gain that makes the driven error-point spectra line up well with the DELTA L spectra. For ETMX this was
    foton design: resgain(70 Hz, Q=8, h=8) * resgain(92 Hz, Q=30, h=10) * zpk(100,1,1)
    equiv zeros and poles: z=[10.6082+/-i*69.1915, 3.42911+/-i*91.9361, 100], p = [4.2232+/-i*69.8725, 1.08438+/-i*91.9936, 1], g = 1
    dtt calibration: 
        Gain: 1e-14 [m/ct]
        Poles: 4.2232 69.8725, 1.08438 91.9936, 1
        Zeros: 10.6082 69.1915, 3.42911 91.9361, 100
For ITMY this was the same thing, but without the 92 Hz resonant feature:
    foton design: resgain(70 Hz, Q=8, h=8) * zpk(100,1,1)
    equiv zeros and poles: z=[10.6082+/-i*69.1915, 100], p = [4.2232+/-i*69.8725, 1], g = 1
    dtt calibration:
        Gain: 1e-14 [m/ct]
        Poles: 4.2232 69.8725, 1
        Zeros: 10.6082 69.1915, 100
This calibrates the channel, regardless of if there's excitation or not (assuming all linearity and good coherent original transfer function) --- in the region where your transfer function is valid, then this will calibrate the ambient noise.

Since I didn't take enough data to really fill out the transfer function, I only bother to do this in the 10-100 Hz, and did it rather quickly -- only looking for factors of ~2 precision for this initial assessment.

So as to not confuse the main point of the aLOG, I'll attach supporting plots as a comment to this log.

H1 locked for 16 hrs @ 52Mpc. Nothing to report other than some commissioning work that took place.

23:56 a2l/commissioning work

01:05 Intention bit "Undisturbed"

There is evidence of the NPRO trip and current tweaking from last week. Head flows/pressures are being monitored closely on a regular basis, currently. Also included, for your entertainment is a plot of the power stability into the IFO from the rotation stage from the previous 12 hours of lock. Gerardo was questioning the "bouncy" (+/- .1W) numbers of the input power showing on the Ops overview, so we trended it.

23:54 as a segue into some commissioning work. LLO was notified.

TITLE: 07/24 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 51Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    Wind: 10mph Gusts, 5mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY:

TITLE: 07/24 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 50Mpc
INCOMING OPERATOR: Ed
SHIFT SUMMARY: 11.5 hour lock at 50Mpc, not much else going on.
LOG:

• 18:26 Corey to MY
• Dave starting WP7083 
• 18:46 Corey Back

model restarts logged for Sun 23/Jul/2017 - Mon 17/Jul/2017 No restarts reported

John, Bubba, Dave:

WP7083

the cell phone alarm system was reconfigured and restarted to add the CS, EX and EY water pump status channels. In the  FMCS EPICS database there is a CALC record which performs an inclusive OR on the pump status. If at least one pump is running, the STATUS is ONE. If no pumps are running, the STATUS is ZERO. The alarm levels are HIGH=1.5, LOW=0.5. There is no delay in sending the cell phone texts when an alarm is triggered. This completes this WP.

The full report can be found on the detchar wiki: https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20170720

Below I summarize the main highlights of this shift:

-The duty cycle was 78.5%, the range was stable around 53Mpc.
-We went to out of observation intentionally at 19:13UTC to dump violin mode on Thursday.
-The glitches around 20Hz at 10:00 UTC seem to be due to overflows in all of the test mass L2 coils
, perticularly the pitch motion of soft mode in cavity, similarly at 8:00UTC on Thursday.
-GRB alert occured at 01:49 UTC, 02:48 UTC, 04:31 UTC, 16:16 UTC and 21:11UTC.

Laser Status:
SysStat is good
Front End Power is 33.94W (should be around 30 W)
HPO Output Power is 154.9W
Front End Watch is GREEN
HPO Watch is GREEN

PMC:
It has been locked 5 days, 23 hr 37 minutes (should be days/weeks)
Reflected power = 17.22Watts
Transmitted power = 57.55Watts
PowerSum = 74.77Watts.

FSS:
It has been locked for 0 days 6 hr and 20 min (should be days/weeks)
TPD[V] = 2.354V (min 0.9V)

ISS:
The diffracted power is around 2.8% (should be 3-5%)
Last saturation event was 0 days 6 hours and 20 minutes ago (should be days/weeks)

Possible Issues:
PMC reflected power is high

Need some commissioning time today. New items from DetChar and old items that they didn't have time for last week.

Virgo engineering run coming up soon. They will most likely be on GraceDb, not GraceDb-test for this run.

Went over Tuesday Maintenance activities tomorrow, see whiteboard for complete list. New items:

• Bubba will be running the well pump in the morning to fill the fire tanks
• Dozen or so UW students in for tour tomorrow, would like to go into LVEA
• PCAL might want to go to EY for line investigation
• Sudarshan may want to do a PCALX spot move test
• Jim wants to do a HAM4 SRCL FF TF
• Jeff K to run rubbing TFs on CS optics
• CDS on floor taking measurements for future squeezer equipment

Update on Raven/Crows/Black Birds LN2 lines:

• Chandra will bring a company out to insulate the lines.
• Not sure of timeline yet.

The glitchy periods at 10 UTC today, and 8 UTC on July 20, seem to be due to overflows in all of the test mass L2 coils. The cause of the overflows looks to be CSOFT pitch.

The attached plots show timeseries of CSOFT pitch and ITMX L2 master for one quadrant, then a spectrogram of the coil signal. It looks like most of the power is in the 2.8 Hz pitch mode of the test masses. From the summary pages, it looks like the RMS of CSOFT pitch has crept up over the last few months.

When the coil drive goes over 131,072 counts, the DAC overflows and the coil glitches. It's possible that I have things backwards, and the glitch comes first and the overflow is a symptom, but that doesn't seem to match the behavior of the RMS at non-glitchy times.

Is there a way to get CSOFT pitch lower, or maybe suppress some of the feedback at 2.8 Hz (which I think is the biggest contributor)?

aLOG 37666

Looked at the BS UR signal as reported by Jenne. Disconnected noise monitor outputs of coil driver and shorted the inputs to the AA chassis. From here we could see that UR has ~10dB gain difference than the other channels. Power cycled both the AA and coil driver, transfer function showed no change. Coil driver S1000355 in SUS-C6 slot U26 was replaced with S1100039. Transfer function for all signal outputs the same.

F. Clara, J. Driggers, R. McCarthy

Keita pointed out that we have only been using OMC DCPD B for at least the last lock.  I trended the relative gains of DCPD A and DCPD B, and it looks like we've been in this situation since 16July2017 at around 05:30 UTC.

The attached is a 5 day trend of the gains.  The 2 spikes earlier are when we were either adding or removing a layer of whitening, due to the violin modes being too high.  On the 16th, it looks like the guardian was started to switch the whitening, but then maybe got stopped halfway.  This explains why it has looked like the shot noise was too high the last few days.

Clearly we need to write into the READY_FOR_HANDOFF OMC lock state to ensure that the 2 gains are both at their nominal values.  Also, it looks like someone accepted the wrong values into the Observe SDF file, so we've been able to go to Observing with the wrong values :(  No good.  The safe SDF file was correct.  I'll fix the Observe file.

EDIT:  Looking through the guardian log file, it looks like the code gets a bit confused when you try to use these states before we're using the DCPDs for DARM.  So, now if we're at DC_Readout_Transition or before (and don't need to do any gain ramping), we skip the gain changes and just change the whitening.  If we're on DC_Readout or after, the change will happen as before.  Either way, at the end of the state is now a check to see if the DCPD gains are equal (they should both be 1000).  The new code is in the svn and has been reloaded, although not actually used.