My detailed DQ shift report for August 27th - 30th can be found here:

https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20150827

Highlights:

• Overall very low glitch rate (almost as low as it can get)
• Range in the 65-70 Mpc range
• Overall very constant performance
• Only one CBC trigger with newSNR>8.

Main oustanding issues:

• PEM-EY_MAG_EBAY_SUSRACK_X_DQ seems to be associated with a good number of glitches, often with relatively high SNR
• Something may be wrong with PRM damping loops, as pointed out by Kiwamu here.
• on Aug 28, Kleinewelle reported (among others) 4 loud glitches all very well aligned at about 100 Hz. Origin is unknown, but may be common.
• on Aug 29th, a lock loss likely happened because of high winds, but the immediate cause has not (yet) been identified
• on Aug 30th, calibration lines appeared to be unstable throughout the day (including science segments)

In addition, many glitches picked up by Omicron or similar tools could use some further investigation, that I did not have the time to perform. I plan on following up on a few of them in the coming days.

The "noisemon pringle" actuator noise measurement from LLO alog 19853 has been calibrated to meters, and extended to the L1 and L2 stages of all test masses.

Total noise from these stages is estimated to be ~1e-20 m/rtHz around 30 Hz.  This includes driver noise, DAC noise, and glitches (to the extent they were present during the measurement).

A hierarchical noise budget PDF is attached. Here's how things look for ITMX L2:

From this plot you can see the following:

• Length control signal projections from the DAC drive and from the noisemon readback match well. (This is a calibration consistency check.)
• The pringle noise seems to closely approach DARM below 20 Hz, but this is due to contamination from ASC pitch signals (which has been present in DARM also).  Noisemon pitch and yaw are projected (using the length TF) to show the subtraction. The bottom of the roll bandstop suggests the true noise floor is consistent with the slope of the curve above 30 Hz.
• The DAC noise model from G1401399 is plotted for comparison. The model matches at high frequency but apparently underpredicts the noise below 200 Hz (though some of this band is subtraction-limited).

The calibration of these signals is approximate, based on the coil driver and suspension models -- not the precise measurements people have been taking during the past week. There may be some discrepancies especially in the L1 (UIM) stage.  The ETMY L1 plot definitely shouldn't be trusted, because its noisemons appear to be broken (see attached plot).

Scripts have been checked in to the NoiseBudget SVN.

(All time in UTC)

15:00 Jim has been having trouble locking DRMI all night. So I work on PRMI.

15:32 Managed to get pass DRMI_LOCKED, lockloss at REDUCE_CARM_OFFSET. Saturation alarm complained about PRM.

16:17 Hugh to end stations

16:29 Robert to CER and LVEA

16:40 SR3 is totally unresponsive to Gurdian. See alog 21057.

          DAC recalibratio and DAC restart.

16:53 Hugh back

17:05 Robert back

17:45 Begin initial alignment after several locklosses at random places.

          burtrestored the alignment to last night lock

18:20 Karen/crew to change room and optics lab for cleaning.

19:36 Since there's an operator training going on, Evan insisted I switch the Operating Mode to TRAIN.

21:39 Jeff/Evan to restart PR3, PRM satellite amplifier.

22:00 Jeff back

22:26 Gerado to LVEA hunting for parts.

22:28 Jeff K. brings IMC_LOCK Guardian to OFFLINE

22:39 Gerado back

This afternoon, Richard and Fil tried various hardware diagnostics of the cabling and boxes out on the floor for the shared PRM/PR3 chain noise.  While swapping sat boxes and reterminating cables a few times, the PRM RT TOP BOSEM flopped between flatlining, or being super noisy multiple times after they made connections.  There was additional confusion in the fact that the PRM misaligned state moves the PRM a huge amount in YAW, thus sending the RT BOSEM signal to near zero - we thought this meant it "died" a few times during our troubleshooting.  Long story short, the troubleshooting of the electronics this afternoon didn't seem to improve the noise much.

To be continued...

C. Cahillane, D, Tuyenbayev, E, Hall

I have discovered the difference between Plot 1 and Plot 7 in aLOG 20974.
To recap, Plot 1 was strain uncertainty calculated from actual ER7 data, and Plot 7 was strain uncertainty calculated from sensing, digital, and actuation transfer functions only.
One issue was the dewhitening filters were incorrect.  Evan taught me to locate the correct filters based on the GPS times and channel names.  (They can be found in /opt/rtcds/lho/h1/chans/filter_archive/h1calcs/  The shortcut terminal command is "chans")
Another issue was I was using only the ASD of DARM_ERR and DARM_CTRL for my calculations, and ignoring the phase information.  I have corrected this in my code, but not in my uncertainty document T1400586.

Below I have replotted the carpet plots from aLOG 20974 in the same order.  Now you can see very good agreement between New Plot 1 and New Plot 7.
The next step is to discover why the data is so glitchy at high frequency.  I believe it is due to interpolation of the data to fit our ER7 transfer function frequency vector.  
Darkhan has been working on the ER8 DARM model and has made every element into an LTI object.  This will make getting the ER8 transfer functions into any frequency vector very easy, so this is the next step for this project.

The step after that is to begin calculating the error bars themselves. I will have to revisit my Mathematica notebooks to recalculate uncertainty in strain magnitude σ_{|h|} and strain phase σ_{φ_h} with phase info from DARM_ERR and DARM_CTRL included.

Noticed HVE-EX:75IPBSC9_511LOG red on the vacuum main screen, the ion pump appears to have railed around 12:51 pm today.  I drove to End X and found the ion pump connected and powered on, controller shows all LEDs on.

Attached is 1 day trend data.

J. Kissel, Nutsinee

Dan found glitches in SR3 T2  last night and it seems like we have been having trouble locking ever since so we investgated. SR3 T2 problem started right before Aug 31 09:23 lockloss and never go away. DAC recalibration this morning didn't solve the issue and the power glitch didn't cause it. The noisy/glitchy feature looks just like what happened before the drive swap back in Aug 18.

The LHO SITEMAP MEDM was modified to add two new MAIN catagories: generic seismic (SEI) and Observing Run related screens (O-1).

I have added Hugo's generic SEI_SAT_OVERVIEW to the SEI button. I have added my new H1CDS_O1_OVERVIEW_CUST to the O-1 list. The new CDS OVERVIEW MEDM must always be GREEN. Any deviation from the O1 configuration will show as RED. Hopefully nothing will be red for long on this screen during O1.

h1nds1 (the default NDS) daqd process died this afternoon. This was a more drastic failure, the computer locked up and had to be reset. The last messages in the log files are different from yesterday to today:

Sunday 30 Aug 15:29:

Retry expired; requesting again

....

Packet buffer is full

Moday 31st Aug 15:58:

[date-time] Ask for retransmission of 15 packets; port 7097

....

Have to skip 15 packets (packet buffer limit exceeded)

The times of the restarts of h1sush2a and h1sush56 are summarized below.

2015_08_31 09:13 h1iopsush2a
2015_08_31 09:15 h1susmc1
2015_08_31 09:15 h1susmc3
2015_08_31 09:15 h1suspr3
2015_08_31 09:15 h1susprm
2015_08_31 10:09 h1iopsush56
2015_08_31 10:09 h1susomc
2015_08_31 10:09 h1sussr3
2015_08_31 10:09 h1sussrm

As per alog 21036, Evan dropped the absurd precision in the WFS_offset_* scripts which set the dark offsets.  I reran it now since the IFO is down, confirmed that none of the 80 offsets changed by very much, and then accepted them in SDF.  Now at only 4 sig didgits, SDF was able to write them into the SAFE.snap when I hit ACCEPT all.

ER8 Day 14

model restarts logged for Sun 30/Aug/2015
2015_08_30 15:30 h1nds1
2015_08_30 15:31 h1nds1

both restarts unexpected.

J. Kissel, K. Izumi, S. Dwyer, N. Kijbunchoo

While trying to being the h1sush56 SUS (SR3, SRM, and OMC) to safe for DAC calibration of all cards in that chassis (see LHO aLOG 21048), we had great trouble with the SUS_SR3 guardian node. This node is not managed, but it was entire unresponsive to requests to change its state, to load, to pause, to stop, anything. Sadly, this was all true and the guadian node screen did *not* turn red indicating its in error.

Looking at the guardian log, there was a message:

epicsMutex pthread_mutex_unlock failed: error Invalid argument
epicsMutexOsdUnlockThread _main_ (0x3e7a0f0) can't proceed, suspending.

This is after requesting the ISC_LOCK guardian to DOWN. Note, we also had the SR3_CAGE_SERVO guardian still running, because, though this is managed by the ISC_LCOK guardian, it does not turn it OFF in the DOWN state. Probably not the issue, but it gathered our attention because it had gone nuts and was driving the M2 stage into constant saturation.

See first attachment for screenshot of the broken situation.
For the record this has happened on a smattering of guardian nodes in the past, see LHO aLOGs 17154 and 16967.

-----------------------
Here's what we did to solve the problem:
- Tried to restart the guardian node from a work station,
guardctrl restart SUS_SR3
No success.
- Tried to destroy the guardian node from a work station,
guardctrl destroy SUS_SR3
No success. 
Both report
stopping node SUS_SR3...
timeout: run: SUS_SR3: (pid 3042) 23232015s, want down, got TERM
(see second attachment).

- Tried logging into guardian machine, h1guardian0, and began to kill process IDs sound on the machine related to SUS_SR3, (see third attachment).
- Curiously, as I killed the first two processess,
runsv SUS_SR3 and
svlogd -ttt /var/log/guardian/SUS_SR3
as soon as I killed the latter, the guardian log came alive again, and the the SUS_SR3 node became responsive.

- At Kiwamu's recommendation, I killed all processes simultaneously, destroyed the node, and restarted the node, just to make sure that all bad joojoo had been cleared up.
----------------
The problem is now solved, and we've moved on.

Unsure what to do about this one in the future other than the same successively agressive restarting techniques...

This is a follow-up on alog alog20541 and alog20717

I took some time to study Robert's noise injections in more details. The result attached below. Quick conclusion: Human jumps in the change room and car sudden breaks near 2k electronics building and high-bay seems to couple into DARM.

At the request of Richard M and Nutsinee, I restarted the models on h1sush2a to force a recalibration of the 18bit DAC cards.  All cards reported successfull calibration.

Nairwita Mazumder, Rich Abbott

A few days back Jim noticed  (alog ) that the "Bumbling line" which varies over a large frequency range is again back on ETMX seismic channels . This was first noticed on March and disappeared before ER7 and again was seen from 4th August. One can see the lines at all the horizontal and vertical sensors on ETMX. 

I have attached a pdf containing some follow up work done during Rich's recent visit to LHO. The first plot in the pdf is the spectrogram of ETMX GS13 on 26th August. It can be seen that there are multiple wandering lines having a fixed offset.  We were suspecting that some magnetometers at the End X might be the culprit (as we could not find any correlation between temperature fluctuation  with the line ). 

The second and third plots are the spectrum of H1:PEM-EX_MAG_EBAY_SEIRACK_Z_DQ and H1:ISI-ETMX_ST2_BLND_Z_GS13_CUR_IN1_DQ for 2nd August and 26th August respectively. The red one is for 2nd August when the bumbling line could not be found and the blue one is the recent data (26th August). It is clear that the peaks appearing on  ISI-ETMX_ST2_BLND_Z_GS13 after 3rd August are correlated with the peaks of the spectrum (which also appeared around the same time) of SEIRACK magnetometer .

The plots on the second page shows the coherence between GS13 and the magnetometers in the VEA and SEIRACK. It looks like  the magnetometer on the SEI rack has stronger coherence with GS13 sensors than the magnetometer located at VEA .  I have marked two points (blue and red cross)  in the coherence plots to highlight two of the many peaks.

Kiwamu, Nutsinee

As we were trying to relock the ifo after several locklosses due to high wind (50mph), we noticed the sideband signals wiggled a lot before another lockloss at DC_READOUT (wind speed ~35-40 mph). We found a coherence between POP18, POP19, POP_A_LF, AS90 and PRM, SRM, BS which indicates that the DRMI was unstable. The BS ISI Windy blends weren't turned on. 

J. Kissel, K. Kawabe, S. Karki

We've broken observation mode such that we can enable the DAC DuoTone timing readbacks on the front ends that are responsible for DARM control, i.e. h1lsc0, h1susex, and h1susey. We needed to take the IFO down for this because the last channel on the first DAC cards for the end station SUS are used for top-mass OSEMs for damping the suspensions. If the damping loops get a two sign waves at 960 and 961 [Hz] instead of the requested control signal for one of the OSEMs, then we get bad news.

Here are the times when the DAC DuoTone switches were ON for the following front ends:

h1susex and h1susey --- 19:04 to 20:04 UTC (12:04 to 13:04 PDT)
h1lsc0 --- 19:16 to 20:06 UTC (12:16 to 13:04 PDT)

Though all relevant channels (ADC_0_30,  ADC_0_31, DAC_0_15) are free on the h1lsc0 front end, we elected to turn the DAC DuoTone off, so that we aren't in danger of an oscillitory analog voltage being sent around the IO chassis that's used to measure the OMC DCPDs.

Data and analysis to come. 

The IFO will be staying down for a few hours, while we finish up some electronics chain characterization of the OMC DCPD analog electronics (along with some other parasitic commissioning measurements).