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Reports until 11:17, Friday 29 July 2016
LHO VE
kyle.ryan@LIGO.ORG - posted 11:17, Friday 29 July 2016 (28728)
more Y-end RGA leak testing 
see also https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28644

Today I further torqued the RGA analyzer to protective nipple flange that was "gappy" from the factory.  The factory supplied fasteners are an inadequate alloy and limit the factory assembler's ability to achieve the desired "flange-to-flange" joint (it is 2016, why can't they just use silver plated A-286 like the rest of the free world?).  Anyway, I was able to improve the situation and further close this joint using metric wrenches (arghh! again with the "it is 2016...free world") and elbow grease but couldn't go as far as I would have liked.  I again leak tested this joint (7 x 10-9 torr*L/sec baseline) and, again, found it not to be leaking but the real proof will be after it goes through the upcoming bake cycle.  Additionally, I opened the Nitrogen and Krypton isolation valves so as to allow leak testing of their double sided 1.33" CF joints.  No leaks (6 x 10-9 torr*L/sec baseline) here either.  Next up will be to bake everything (will likely start Wednesday, Aug. 3rd during HAM6 vent activities).  

Leaving area with Nitrogen and Krypton isolation valves closed, local turbo off and isolated and leak detector off and decoupled.
H1 General
edmond.merilh@LIGO.ORG - posted 11:03, Friday 29 July 2016 - last comment - 14:44, Friday 29 July 2016(28729)
DBB Scans FAMIS# 6583

File extensions - .001= 35W path .002=200W

RPN - 35W; no changes worth mentioning.

          200W; noise is higher in the 300Hz-2k range.

FRQ - 35W; seems to hav a higher degree of error correction. Resonances that aren't noticible in recent past scans appear starting at ~7Hz/20Hz and seem to have harmonics out to ~100Hz

         200W; These same resonances mentioned above seem present in this path as well. Last weeks scan by comparison show these resonances propogating out as far as 200Hz

PNT - 35W; This looks much better than last weeks which had 2x and 2y higher than the rest by a factor of two from 1Hz-30Hz.

         200W; This weeks scan looks almost identical to last weeks scan with the outliers being 2x and 2y all the way out to 2K

MSC - 35W; HOM ct/ mode matching looks pretty good with the exception of TEM10 mode which is a bit higher than reference. Significantly better looking scan than last week.

         200W; Mode matching looks a  little sloppy. No change from last week.

Non-image files attached to this report
dbb_rpn-001.pdf
dbb_pnt-001.pdf
dbb_frq-001.pdf
dbb_msc-001.pdf
dbb_rpn-002.pdf
dbb_frq-002.pdf
dbb_pnt-002.pdf
dbb_msc-002.pdf
iss_rpn-001.pdf
Comments related to this report
jason.oberling@LIGO.ORG - 14:44, Friday 29 July 2016 (28739)
Link

Should also add that the out-of-loop PD in the ISS in iss_rpn-001.pdf (PDB in this case, the blue trace) is seeing roughly an order of magnitude more noise than the reference.  This is the 3rd time the ISS scan has been run since we resurrected the DBB after the HPO turn on, and the other scans match this one.  What is odd is is not a RPN noise increase of this magnitude in either the FE or HPO RPN scans.  Unknown at this time where the noise is coming from.

H1 SEI
nutsinee.kijbunchoo@LIGO.ORG - posted 10:04, Friday 29 July 2016 - last comment - 11:24, Friday 29 July 2016(28727)
H1 ISI CPS Noise Spectra Check - Weekly

Note that there are people in the LVEA during this measurement.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 11:24, Friday 29 July 2016 (28731)
Link

It is not HUGE, but the ETMY V2 and ITMX H3, have higher levels than in previous measurements.

H1 SEI
hugh.radkins@LIGO.ORG - posted 08:52, Friday 29 July 2016 (28725)
WHAM6 HEPI Locked onto Hard Stops

Locked down the HEPI on its hard stops while Isolated.  Positions kept as close as possible.  Here is where it ended up wrt the nominally servo position:

dof delta
X 5.4um
Y 3.7um
Z -7.2um
RX 4.6urad
RY -0.6urad
RZ 4.6urad

You can also see these on the HEPI CART BIAS medm accessed from the OVERVIEW; look for DC BIAS.

H1 General
cheryl.vorvick@LIGO.ORG - posted 08:51, Friday 29 July 2016 - last comment - 11:29, Friday 29 July 2016(28724)
Morning Meeting: OMC is down, plans being made for venting next week

OMC / Vent plans

 

- OMC is down, we're venting HAM6 and going in next week

 

- Spare OMC needs some attention before it can be installed - may not be ready by Tuesday

 

- we may go into HAM6 on Monday to diagnose the situation

 

- HAM6 is locked down

 

- cleanrooms around HAM6 being turned on today and will be on all weekend

 

Tasks:

 

- CDS - Richard - taking advantage of down time to 

 

- EY - Kyle wants to bake RGA installed on BSC6, not valved in, next week

- EX - Kyle wants to bake RGA installed on BSC6, not valved in, next week

 

- PSL - Peter and Jason next Monday and Tuesday - have PSL for alignment and calibrations

 

- Rich Abbott is here and has a film crew here for today and tomorrow (related to chip manufacturer)

--- in LVEA up to 10AM

 

- JeffK - getting transfer functions of HAM6 optics for reference

 

- EY BRS is off - see morning update and Jim's alog from last night

 

- Hugh - HAM6 guardian is off and needs to stay off - screenshot of HAM6 HEPI and HAM6 ISI attached

Comments related to this report
hugh.radkins@LIGO.ORG - 11:29, Friday 29 July 2016 (28732)
Link

Regarding the HAM6 Guardian.  The HAM6 SEI chamber manager is paused so it will not try to isolate HEPI.  HEPI will not isolate and should be kept READY.  The ISI is fine and should be kept isolated by responding to trips at the watchdog as usual.  Be sure to use the ISI Guardian and not the HAM6 SEI chamber manager if guardian attention is needed.

H1 General (OpsInfo, SEI)
cheryl.vorvick@LIGO.ORG - posted 08:26, Friday 29 July 2016 (28723)
Ops Morning Update:

State of H1: IMC is locked, guardian in Down state, Hugh in LVEA at HAM6, LVEA is laser safe

Attached: screenshot of current state of BRS, also see Jim's alog 28703

Images attached to this report
H1 AOS
peter.king@LIGO.ORG - posted 07:57, Friday 29 July 2016 (28722)
LVEA transitioned to LASER SAFE 
The LVEA is now LASER SAFE.

At this point in time, please do not remove viewport covers, or the tubes connecting
the table enclosure(s) to their relevant viewports.
H1 General
edmond.merilh@LIGO.ORG - posted 21:02, Thursday 28 July 2016 (28720)
Shift Summary - Evening
TITLE: 07/29 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Aquisition
INCOMING OPERATOR: Aug
SHIFT SUMMARY:
LOG:
3:00 PI Mode 2 rang up. I was able to damp it by flipping the gain phase.
3:10 As mode 2 rang down, mode 17 begaan to rise a little and hold steady. Gonna watch it.
3:20 Kiwamu informs me that this mode 17 can't be damped unles we are in Low Noise Mode. 
4:01 Just waiting for the lock to break due to PI that I can't damp. :/. Heading home.
LHO VE
kyle.ryan@LIGO.ORG - posted 19:07, Thursday 28 July 2016 - last comment - 12:11, Friday 29 July 2016(28719)
Pressure bump at Y-end 
The pressure change seen in the attached is typical of the Y-arm gauges with PT410 responding first followed by subsequent responses in time as it propagates toward the CS.  Looks like a real change and occurs 15 mins or so after a seismic system change was made at the Y-end (Jim W?) or not.  IP9 has not changed voltage -> Will monitor from home.
Non-image files attached to this report
Yend_pressure_bump.pdf
Comments related to this report
chandra.romel@LIGO.ORG - 11:20, Friday 29 July 2016 (28730)
Link 

Y2-8 IP is not pumping. Controller doesn't power past 350 V and 430 mA. Gerardo & Chandra reseated cable at both ends and rebooted controller. Next Gerardo & Richard will test HV cable. The controller initially read back an error code 02. Gerardo contacted Gamma for troubleshooting and waiting to hear back (their online screens are currently not available).
chandra.romel@LIGO.ORG - 12:11, Friday 29 July 2016 (28734)
Link 

UPDATE:  bad HV cable
H1 ISC (DetChar, ISC, SEI)
michael.antia@LIGO.ORG - posted 18:50, Thursday 28 July 2016 (28715)
Impact of high wind on ASC loops during O1

Michael Antia, Paul Altin, Jess McIver

 

Summary: High winds are impacting ASC control loops, manifesting as an increase in noise for three distinct frequency bands and glitches at 5 Hz.

 

This is a follow up to a study initiated by Paul Altin, that confirms the increase of ASC loop noise during periods of high wind.

The lock stretches analyzed pertain to O1 and contain periods of both high and low wind.

The effect of high wind is evidenced by an increase in amplitude for the ASD (see GIFs by clicking the link at the end) at three distinct frequency bands which are:

·      0 – 1 Hz

·      4 – 20 Hz * Glitches occur in this band (see attached spectrogram.png)

·      20 – 40 Hz

The ASD for Oct 9th 2015 shows an increase in noise in 4 – 20 Hz as can be seen in the four figures in the ASD.png attachment. The four channels chosen are representative of behavior seen for CARM control, DARM control and transmitted light at the end stations. The soft modes for CARM and DARM appear to be the most reactive.

The four figures in ASD.png each contain an ASD averaged over 30 minutes. Blue is the reference time during low wind. Red is related to the period of high wind.

For a more detailed visualization on the evolution of noise as wind speed increases, please see the link at the end.

Figures in the spectrogram.png attachment show recurring glitches during transition from low wind to high wind. This indicates that for the 4 – 20 Hz band, the increase in amplitude seen in the spectra GIFs is at least in part due to glitches.

Further study: The glitches will be further analyzed for the possibility of scattered light saturating the photo detector. In addition, we will investigate whether high wind causes lingering effects on ASC loop noise.

 

For more details, please see the study at the following link: https://wiki.ligo.org/DetChar/LHOWindASCStudies

Images attached to this report
H1 ISC
koji.arai@LIGO.ORG - posted 17:59, Thursday 28 July 2016 (28714)
3rd OMC inspection ~ epoxy delamination

[Betsy, Koji]

We brought the OMC to the bonding lab for inspection. We found some of the EP30-2 joints between the main glass breadboard and the invar mounting brackets showed sign of delamination. Dennis, Calum, and Garilyn have been notified and are woking on the counteraction.

Attachment 1: 40% delamination. This piece is holding one side of a balance mass holding bracket.

Attachment 2: 80% delamination. This piece is holding one side of a balance mass holding bracket.

Attachment 3: 40% delamination. This piece is holding one side of a balance mass holding bracket.

Attachment 4: 80% delamination and this piece is supporting one of the DCPD housing at the bottom side.

Attachment 5: 30% delamination and this piece is supporting the other DCPD housing at the bottom side.

Images attached to this report
LHO VE
kyle.ryan@LIGO.ORG - posted 17:30, Thursday 28 July 2016 (28713)
Problem with Corner Station purge/vent air supply 
Kyle, Gerardo

Upon being notified of the upcoming (unscheduled) vent of HAM6 on Monday, we thought that it would be prudent to run the Corner Station purge air supply sooner rather than later do demonstrate its readiness.  Though this unit is well maintained and hasn't had functional issues of late, it is 20 years old now and we no longer assume that it won't develop issues while sitting idle.  As such, we found that it tripped off a few minutes after startup with the alarm "2nd STAGE SUCTION OVER TEMPERATURE".  Restarted and same problem etc ->  The water lines supplying the intercooler were colder than ambient suggesting chilled water flow to the components of interest (Yes John the booster pump is on!) -> The displayed temperature of interest was intermittently alternating between an expected value and a bogus high value which resulted in the shut down response -> We switched the terminations between the 2nd stage suction RTD and discharge RTD and noted that the problem did not follow the temperature sensing device but rather remained "2nd STAGE SUCTION OVER TEMPERATURE" -> Gerardo noticed that when the bogus 2nd stage suction temperature value was occurring, that all of the other displayed temperatures also changed to the same value suggesting a logic and/or common connection issue.  Correspondence with Roger's Machinery (original equipment provider) revealed that the Siemens PLC unit used in our Kobelco had known issues that could sometimes be resolved by lifting then re-landing the wires (of which there were many!) on its terminal strips -> We did this and the unit seems to be happy now -> We are leaving it run over night but isolated from the LVEA so as to reduce air demand and minimize loading cycles. 

All of the Roger's Machinery field service technicians are booked solid through this weekend but I will be updating them at 0800 tomorrow morning as an emergency service call isn't out of the question should we need it.
H1 AOS (SEI, SUS)
thomas.shaffer@LIGO.ORG - posted 13:16, Thursday 28 July 2016 - last comment - 09:00, Friday 29 July 2016(28706)
Opitcal Lever 7 Day Trends

Attached are screenshots for the past 7 days optical ever trends for PIT, YAW, and SUM.

This completes FAMIS 4686

Images attached to this report
Comments related to this report
jason.oberling@LIGO.ORG - 09:00, Friday 29 July 2016 (28726)
Link

Everything looks normal with these trends.  The large step in the ETMy SUM trend is due to the laser swap (here) and the large steps in the ITMx and ITMy SUM trends are due to the increase in whitening gain (here).

H1 PEM (PEM, SEI)
david.mcmanus@LIGO.ORG - posted 11:01, Thursday 28 July 2016 - last comment - 18:10, Thursday 28 July 2016(28696)
NN array channel 7 I/O Chassis Problems

David.M, Filiberto.C

Yesterday I was looking at the NN array output channels to check everything was working and noticed that the 7th NN channel (H1:NGN-CS_L4C_Z_7_OUT) was producing a noisy output about 3 orders of magnitude higher than expected. I thought potentially the L4C might be busted, so I went into the LVEA this morning and swapped it out for another one that we tested earlier (L41429). The problem remained even with the new sensor and also even when the sensor was unplugged. We went into the CER to diagnose where the problem was. Turning off the L4C interface chassis and the AA chassis both didn't fix the problem, which seems to indicate that the large noise level in this channel is caused by a problem in the I/O Chassis.

Comments related to this report
david.mcmanus@LIGO.ORG - 18:10, Thursday 28 July 2016 (28716)
Link

This problem was not fixed with an I/O chassis power cycle,  so it may be a problem with the ADC card.

H1 ISC
daniel.sigg@LIGO.ORG - posted 17:08, Wednesday 27 July 2016 - last comment - 18:37, Thursday 28 July 2016(28683)
OMC

We have a serious issue with the OMC. Even after a day of trying, we are unable to resonate a 00 mode.

Comments related to this report
kiwamu.izumi@LIGO.ORG - 17:17, Wednesday 27 July 2016 (28684)
Link

Many people,

(Anyone, please add comments if I am missing something or inaccurate)

The OMC does not seem to resonate a 00 mode any more.

One hypothesis is the OMC with damaged cavity mirrors.

[Time line]

The interferometer was locked with a 50 W PSL last night (28670) with the DC readout. At around 8:13 UTC (1:13 local), the interferometer was unlocked due to an human error where an integrator of the OMC LSC servo in the digital system (FM2 of OMC-LSC-SERVO) was accidentally disengaged. 20-30 msec after the disengagement of the integrator, the laser power in HAM6, according to ASAIR_A_LF, went up to at least 150 W for a short duration of roughly 50 msec. Since ASAIR_A saturated, this power is a lower limit of the actual laser power in HAM6. In terms of energy, it is about (50 msec) * (150 W) =   7.5 J at least. According to OMC-LSC_SERVO_OUT, the OMC seemed to have escaped the resonance before the laser pulse arrived. Therefore it is unclear how much energy was actually deposited to the cavity mirrors of the OMC from this particular lockloss. 

No locking attempt was made until 16:00 UTC (9:00 AM local) in this morning. Later, the interferometer was locked with a 2W PSL with the RF readout. We noticed that the OMC were unable to acquire a 00 carrier mode at all. After one hour or so of investigation, the interferomter was intentionally unlocked. We started investigating the OMC with a single bounce configuration.

 

[The symptom]

No matter how we changed the length offset, the OMC did not show a visible 00 mode in the OMC trans camera. Instead, resonance the OMC went across appeared to be higher order modes with some airy disk-type halos around. In fact, we could not get a visible 01 or 10 mode either. Keita studied the effect of the OMC SUS and OM tip-tilts alignment and he was able to get a visible TEM11 mode though.

We do not think this symptom is due to some kind of misalignment --- we steered the OM mirrors and OMC suspension around by more than several 100 urad typically, but were never able to get visible 00, 01 or 10 mode in the camera. The PZT2 DC voltage monitor told us that the PZT2 was getting correct voltage.

The beam shape of OMC REFL at ISCT6 visually looked fine -- it appeared to be a gaussian beam. We steered the input optics back to where they used to be (28670) before Jenne moved them.

 

[Shutters were not functioning]

Daniel discovered that neither mechanical shutter nor PZT shutter had been working in the past months after the HAM6 vent on April. Richard and Daniel found that the shutter trigger box had a wrong cabling. So for the reason, we believe that the OMC and the DCPDs have been exposed to high intensity light at every lockloss. They fixed the cable and now the shutters should be triggered as intended.

Images attached to this comment
jenne.driggers@LIGO.ORG - 18:03, Wednesday 27 July 2016 (28686)
Link

We are going to try going forward with high power work tonight using RF instead of DC readout.  There is a new value in lscparams.py, "use_dc_readout".  It is currently set to zero, so guardian will not try to transition to DC readout.  When we're ready, we should just have to flip this to 1.

koji.arai@LIGO.ORG - 19:06, Wednesday 27 July 2016 (28688)
Link

The plot shows that the shutters were not triggered since Apr 4, 2016.

Images attached to this comment
koji.arai@LIGO.ORG - 19:28, Wednesday 27 July 2016 (28689)
Link

(Stefan was working on this but I extended it to look at the other lock losses)

Plots of ASAIR_B and DCPD_SUM for last 4 lock loss

Jul 27, 2016
lockloss1: 3:48
lockloss2: 5:38
lockloss3: 6:15
lockloss4: 8:15 (Last one)

These tell us that the last one was not particular lock loss. We regularly had the similar level lock losses.

Images attached to this comment
daniel.sigg@LIGO.ORG - 19:56, Wednesday 27 July 2016 (28690)
Link

The mode which give us ~10% of transmitted light thru the OMC doesn't look like a mode of a misaligned cavity. There are multiple concentric rings around the center spot, more reminiscence of a fringe pattern with a central aperture.

This would be compatible with a worst case scenario where we have an OMC optics with a damaged coating. The DCPDs look healthy without any indication of elevated dark current. This counters our intuition where the DCPDs are most vulnerable.

keita.kawabe@LIGO.ORG - 22:55, Wednesday 27 July 2016 (28691)
Link

We tried mode scan using a single shot beam with QPD alignment and no sensible mode was visible at all. The maximum transmission measured by DCPD_SUM was about 0.7mA or so when we expect O(100mA) for 00.

Later I found that when I misalign the OMC enough, I recover some of the sensible-looking higher order modes, but only the ones with the node at the center. We were never able to visibly identify any mode that doesn't have the node at the center.

In the attached, OMC suspension was YAWed considerably, OMC automatic alignment was disabled, and PZT was scanned a bit more than the FSR.  X axis is the PZT2 voltage, Y axis is DCPD_SUM.

Two modes visibly identified were plus-shaped HG11 type mode (i.e. 2nd order, about 8mA) and LG3 type mode (i.e. 3rd order, 6 bright spots, about 6.5mA), these both have a node at the center. These are both O(10%) of the power coming to the OMC.

We were also able to see what is arguably HG10-type mode, but one of the two bright spots was more like an ugly blob with a lot of structures in it. And this HG10-type thing is very broad compared with HG11 and LG3 type peaks.

Everything else was kind of hard to identify, but the transverse mode spacing tells us the positions of 00, 4th and 5th HOM.

It seems like 00 peak is tiny, and  even broader than the first order mode.

Images attached to this comment
stefan.ballmer@LIGO.ORG - 11:45, Thursday 28 July 2016 (28701)
Link

Attached is a trace of ASAIR_B_LF_OUT, calibrated in Watt out of HAM6. The top panel is the fatal lock-loss, the bottom one is the one before.

Images attached to this comment
kiwamu.izumi@LIGO.ORG - 18:37, Thursday 28 July 2016 (28718)
Link

For the OMC REFL light; we have realigned the gigE camera and took some pictures to quantitatively assess how Gaussian the beam is.

  • 1st attachment: OMC REFL camera image.
    • white dashed line is the intersection where I checked the beam profile (see the 3rd attachment).
  • 2nd attachment: ASAIR camera image.
  • 3rd attachment: beam profile of the OMC REFL image.
    • The fitting function is Gaussian + offset
  • 4th attachment: beam profile of the ASAIR image.

The measurement was done with a 2 W PSL in a single bounce configuration (with ITMY misaligned). The OMC was in a non-resonant state where I see almost no light in the OMC trans camera. The OMs and OMC SUS was initially servoed to the nominal operating points using the ASC DC loops and the OMC SUS QPD loop.

Clearly, the OMC REFL showed some discrepancy from a pure Gaussian, but not a lot. It is unclear what optic introduced the distortion form the image. Moving the OMC REFL camera around did not improve the beam quality in the camera.

The last attachement is a tar.gz of the images in numpy npz format.

Images attached to this comment
Non-image files attached to this comment
H1 DetChar
keith.riles@LIGO.ORG - posted 21:20, Tuesday 12 July 2016 - last comment - 08:01, Thursday 01 September 2016(28364)
Narrow lines in ER9 H1 DARM 
Executive summary: 

* Good news - as expected, the 16-Hz comb due to the OMC length dither is gone (at least at this sensitivity level)
* Bad news - low-frequency 1-Hz combs remain, and some new low-frequency combs & lines have appeared 

Some details:

    

  •  I initially looked at 15 hours of 30-minute FScan DELTAL_EXTERNAL SFTs (30 SFTs) generated during ER9 and was aghast at how bad the low-frequency spectrum looked, with a pervasive 0.485308-Hz comb ranging up to its 446th harmonic at 216.4 Hz, but when I exclude the three hours of SFTs when the 2-second ALS- glitches were present, things don't look quite so bad (see figure 1 for a sample without removal and figure 4 with removal). I dewhiten according to the new 6-pole / 6-zero, 0.3 / 30 Hz algorithm.

  •  The infamous 16-Hz comb due to the OMC length dither tracked down and killed here is gone (at least at this sensitivity level and these SFT statistics). As a result the high-frequency band (up to 2 kHz) is remarkably smooth with only violin modes and sporadic isolated artifacts.

  •  The 1-Hz comb with 0.5-Hz offset remains pervasive, but other prior 1-Hz or near-1-Hz combs with different offsets (e.g., 0.25 Hz) are not strong.

  •  On the other hand, there is a new near-1-Hz comb (0.996798-Hz spacing) visible to its 204th harmonic at ~203.3 Hz.

  •  There is also a new near-2-Hz comb (1.999951-Hz spacing) visible on approximate odd-integer-Hz frequencies, starting from ~9 Hz and visible up to ~175 Hz. This is likely the same 2-Hz comb reported in May by Bryn Pearlstone (which Ansel Neunzert kindly reminded me about today). 

  •  There is a "new" 56.8406-Hz comb visible to its 11th harmonic at ~625.25 Hz, which in hindsight I can see was buried in the O1 spectrum (I overlooked the pattern and indicated the teeth as isolated lines). This time the pattern was strong enough to jump out at me and to jog my memory that this comb was seen in  H2 1-arm data in 2012 in both the arm feedback channel and a quiet sensor-noise-dominated OSEM channel. This seemed to indicate a DAQ system problem at the time. I can see from O1 NoEMi line lists that this comb is pervasive in ISI, SUS and PEM channels at the corner station and both end stations.

  •  The old "K" comb-on-comb (0.088425-Hz fine comb attached to teeth of a coarse 76.3235-Hz comb) has more 11 more fine teeth visible on the lowest-frequency coarse-tooth comb.

  •  The old calibration line at 35.9 Hz has been moved to 35.3 Hz. The new excitation lines at 33.7 and 34.7 Hz are easily visible, but not as strong as the primary calibration lines. I found these changes documented here.

  •  There are sporadic new isolated lines here and there (indicated in line list - see below)

  •  There is a "crab-killer" broad bump centered at about 58.6 Hz which degrades sensitivity in the Crab Pulsar band of interest (~59.3 Hz). On the other hand, the whole noise floor is elevated w.r.t. O1, anyway. So it may be premature to worry about the bump.



Figure 1 - spectrum for 50-100 Hz when the 3-hour 2-second-glitches stretch is included (~0.5 Hz lines marked with 'h' for 'half')
Figure 2 - 0-2000 Hz (removing 3-hour bad stretch from here on)
Figure 3 - 20-50 Hz sub-band 
Figure 4 - 50-100 Hz sub-band 
Figure 5 - 100-200 Hz sub-band
Figure 6 - 1300-1400 Hz sub-band (illustration of how clean the high-frequency band is)

Also attached are a larger set of zipped sub-band spectra and a lines list (excluding the bad 3-hour stretch). Note that because the statistics here are two orders of magnitude smaller than used for the full O1 run report, I am not yet removing lines seen then that may yet re-emerge with more accumulated post-O1 data. So many of the line labels in these figures are buried in the noise fuzz for now.

Line label codes in figures:

b - Bounce mode (quad suspension)
r - Roll mode (quad suspension)
Q - Quad violin mode and harmonics
B - Beam splitter violin mode and harmonics
C - Calibration lines
M - Power mains (60 HZ)
O - 1-Hz comb (0.5-Hz offset)
o - weaker 1-Hz and near-1-Hz combs (various offsets, including zero)
H - 99.9989-Hz comb
J - 31.4127 and 31.4149-Hz combs
K - 0.088425-Hz comb-on-comb
t - 1.999951-Hz, 2.07412-Hz and 2.07423-Hz combs
D - 56.8406-Hz comb
x - single line (not all singlets in the vicinity of quad violin modes are marked, given the known upconversion)
Images attached to this report
Non-image files attached to this report
subband_spectra_ER9-Cleanedtar.zip
Lines_H1-CAL-DELTAL-EXT_ER9-Cleaned.txt
Comments related to this report
duo.tao@LIGO.ORG - 12:04, Monday 25 July 2016 (28619)DetChar
Link

I analyzed the 56.8406Hz comb with coherence tool and here are the results. The same structure is found to be significant in 35 channels in ER9, distributed in ISI, SUS, PEM and LSC subsystems. Among all the 35 channels, 22 of them does not have a range up to its 11th harmonic, 625.25 Hz.

 

Keith indicated in his slog entry that a DAQ malfunction is suspected to be the ultimate source of this, and these findings suggest it's in an EX electronics crate.

 

Here are a few interesting observations:

  • The 9th harmonic at 511.56Hz is the weakest in most channels, sometimes buried in noises.

  • In some PEM channels, there are missing lines at low frequency (< 200 Hz) and high frequency (> 500 Hz).

  • In PEM and ISI channels, there seems to be another comb structure with a frequency slightly larger than 56.8406Hz coexists. That one is usually most significant at its third harmonics.

  • Generally, the structure is more clearly seen in LSC, SUS and ISI channels

 

Sample plots from each subsystem:

Figure 1: We can see the 56.8406Hz comb structure exists with its 9th harmonic weakest in ISI.

Figure 2: PEM channels have more noises and, as in ISI channels, the other comb structure coexists.

Figure 3: SUS channels do not have enough range up its 11th harmonic but we can see its first and second harmonic here.

Figure 4: There is only one channel from LSC but the structure is very clear.

 

All plots and a list of channels are attached in the zip file.

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Non-image files attached to this comment
nelson.christensen@LIGO.ORG - 11:14, Tuesday 26 July 2016 (28642)DetChar, PEM
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Just to be clear. Here are the channels that the coherence tool is finding the comb. This is what is supporting Keith's assumption that the problems could be in an EX electronics crate.

Channels List:
H1:ISI-ETMX_ST2_BLND_RX_GS13_CUR_IN1_DQ_data
H1:ISI-ETMX_ST2_BLND_RY_GS13_CUR_IN1_DQ_data
H1:ISI-ETMX_ST2_BLND_RZ_GS13_CUR_IN1_DQ_data
H1:ISI-ETMX_ST2_BLND_X_GS13_CUR_IN1_DQ_data
H1:ISI-ETMX_ST2_BLND_Y_GS13_CUR_IN1_DQ_data
H1:ISI-ETMX_ST2_BLND_Z_GS13_CUR_IN1_DQ_data
H1:LSC-X_TR_A_LF_OUT_DQ_data
H1:PEM-EX_ACC_BSC9_ETMX_Y_DQ_data
H1:PEM-EX_ACC_BSC9_ETMX_Z_DQ_data
H1:PEM-EX_ACC_ISCTEX_TRANS_X_DQ_data
H1:PEM-EX_ACC_VEA_FLOOR_Z_DQ_data
H1:PEM-EX_MIC_VEA_MINUSX_DQ_data
H1:PEM-EX_MIC_VEA_PLUSX_DQ_data

H1:ISI-ETMX_ST1_BLND_Y_T240_CUR_IN1_DQ_data
H1:ISI-ETMX_ST1_BLND_Z_T240_CUR_IN1_DQ_data
H1:ISI-GND_STS_ETMX_X_DQ_data
H1:ISI-GND_STS_ETMX_Y_DQ_data
H1:PEM-EX_MAINSMON_EBAY_1_DQ_data
H1:PEM-EX_MAINSMON_EBAY_2_DQ_data
H1:PEM-EX_MAINSMON_EBAY_3_DQ_data
H1:PEM-EX_SEIS_VEA_FLOOR_X_DQ_data
H1:PEM-EX_SEIS_VEA_FLOOR_Y_DQ_data
H1:SUS-ETMX_L1_WIT_Y_DQ_data
H1:SUS-ETMX_L2_WIT_L_DQ_data
H1:SUS-ETMX_L2_WIT_P_DQ_data
H1:SUS-ETMX_L2_WIT_Y_DQ_data
H1:SUS-ETMX_M0_DAMP_L_IN1_DQ_data
H1:SUS-ETMX_M0_DAMP_P_IN1_DQ_data
H1:SUS-ETMX_M0_DAMP_T_IN1_DQ_data
H1:SUS-ETMX_M0_DAMP_V_IN1_DQ_data
H1:SUS-ETMX_M0_DAMP_Y_IN1_DQ_data
duo.tao@LIGO.ORG - 18:55, Thursday 28 July 2016 (28717)DetChar
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I chased Comb 23 (type K) in Keith’s post, shown in Keith's original post as

https://alog.ligo-wa.caltech.edu/aLOG/uploads/28364_20160712211751_CombPlots_H1-CAL-DELTAL-EXT_ER9-Cleaned_100_200_Hz.png

 

This comb has an offset of 153.3545 Hz and a fundamental frequency of 0.0884Hz. It starts at 153.3545 Hz and goes up to its 11th harmonic, 154.3272 Hz. As is listed in Keith's txt file:

Comb 23 (type K, offset=153.354500):
Frequency (offset + harmonic x fund freq) Ampl (m/rtHz)  Bar (logarithmic)
K  153.3545 (   0  X    0.0884) 1.844961e-19   ****
K  153.4429 (   1  X    0.0884) 1.949756e-19   ****
K  153.5314 (   2  X    0.0884) 2.165192e-19   *****
K  153.6198 (   3  X    0.0884) 2.181833e-19   *****
K  153.7082 (   4  X    0.0884) 2.457840e-19   *****
K  153.7966 (   5  X    0.0884) 2.243089e-19   *****
K  153.8851 (   6  X    0.0884) 2.709562e-19   *****
K  153.9735 (   7  X    0.0884) 2.499596e-19   *****
K  154.0619 (   8  X    0.0884) 2.562208e-19   *****
K  154.1503 (   9  X    0.0884) 1.945817e-19   ****
K  154.2388 (  10  X    0.0884) 1.951777e-19   ****
K  154.3272 (  11  X    0.0884) 1.703353e-19   ****

 

I found the comb structure in two channels of ISI subsystem.

Figure 1 shows the plot of channel H1:ISI-HAM6_BLND_GS13RZ_IN1_DQ. Descriptions of this channel can be found here:

https://cis.ligo.org/channel/314371

Figure 2 shows the plot of channel H1:ISI-HAM6_BLND_GS13Z_IN1_DQ. Descriptions of this channel can be found here:

https://cis.ligo.org/channel/314374

In the plots of both channels, we can see a comb structure stands out at the positions of harmonics. We are wondering about the reason for this:

 

Why these seismic isolation channels?


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duo.tao@LIGO.ORG - 00:15, Friday 29 July 2016 (28721)
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This post is supplementary to the first post about coherence analysis result for the 56.8406Hz Comb at

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28619

The first post is addressing the 56.8406Hz comb found in Keith's original post (marked as D comb):

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28364

Information about this comb from the txt file in Keith's post:

Comb 35 (type D, offset=0.000000):
  Frequency (offset + harmonic x fund freq) Ampl (m/rtHz)  Bar (logarithmic)
D   56.8406 (   1  X   56.8406) 3.968800e-17   ***********
D  113.6811 (   2  X   56.8406) 1.773964e-17   **********
D  170.5217 (   3  X   56.8406) 7.121580e-18   *********
D  227.3622 (   4  X   56.8406) 3.232935e-18   ********
D  284.2028 (   5  X   56.8406) 1.166094e-18   *******
D  341.0433 (   6  X   56.8406) 1.007273e-18   *******
D  397.8839 (   7  X   56.8406) 5.962059e-19   ******
D  454.7245 (   8  X   56.8406) 3.752194e-19   *****
D  511.5650 (   9  X   56.8406) 2.577108e-19   *****
D  568.4056 (  10  X   56.8406) 1.964393e-19   ****
D  625.2461 (  11  X   56.8406) 1.891774e-19   ****
--------------------------------------------------------------

Besides the 35 channels found in the original post, 7 more channels are found to be relevant to the 56.8406Hz Comb. Two new subsystems, ASC and HPI are involved.

These new channels are:

H1:ASC-X_TR_A_NSUM_OUT_DQ

H1:ASC-X_TR_B_NSUM_OUT_DQ

H1:HPI-ETMX_BLND_L4C_Y_IN1_DQ

H1:HPI-ETMX_BLND_L4C_Z_IN1_DQ

H1:PEM-EX_ACC_BSC9_ETMX_X_DQ

H1:SUS-ETMX_L1_WIT_L_DQ

H1:SUS-ETMX_L1_WIT_P_DQ

So updated channel list is (42 channels in total):

H1:ASC-X_TR_A_NSUM_OUT_DQ
H1:ASC-X_TR_B_NSUM_OUT_DQ
H1:HPI-ETMX_BLND_L4C_Y_IN1_DQ
H1:HPI-ETMX_BLND_L4C_Z_IN1_DQ
H1:ISI-ETMX_ST1_BLND_RX_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST1_BLND_RY_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST1_BLND_RZ_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST1_BLND_X_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST1_BLND_Y_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST1_BLND_Z_T240_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_RX_GS13_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_RY_GS13_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_RZ_GS13_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_X_GS13_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_Y_GS13_CUR_IN1_DQ
H1:ISI-ETMX_ST2_BLND_Z_GS13_CUR_IN1_DQ
H1:ISI-GND_STS_ETMX_X_DQ
H1:ISI-GND_STS_ETMX_Y_DQ
H1:LSC-X_TR_A_LF_OUT_DQ
H1:PEM-EX_ACC_BSC9_ETMX_X_DQ
H1:PEM-EX_ACC_BSC9_ETMX_Y_DQ
H1:PEM-EX_ACC_BSC9_ETMX_Z_DQ
H1:PEM-EX_ACC_ISCTEX_TRANS_X_DQ
H1:PEM-EX_ACC_VEA_FLOOR_Z_DQ
H1:PEM-EX_MAINSMON_EBAY_1_DQ
H1:PEM-EX_MAINSMON_EBAY_2_DQ
H1:PEM-EX_MAINSMON_EBAY_3_DQ
H1:PEM-EX_MIC_VEA_MINUSX_DQ
H1:PEM-EX_MIC_VEA_PLUSX_DQ
H1:PEM-EX_SEIS_VEA_FLOOR_X_DQ
H1:PEM-EX_SEIS_VEA_FLOOR_Y_DQ
H1:SUS-ETMX_L1_WIT_L_DQ
H1:SUS-ETMX_L1_WIT_P_DQ
H1:SUS-ETMX_L1_WIT_Y_DQ
H1:SUS-ETMX_L2_WIT_L_DQ
H1:SUS-ETMX_L2_WIT_P_DQ
H1:SUS-ETMX_L2_WIT_Y_DQ
H1:SUS-ETMX_M0_DAMP_L_IN1_DQ
H1:SUS-ETMX_M0_DAMP_P_IN1_DQ
H1:SUS-ETMX_M0_DAMP_T_IN1_DQ
H1:SUS-ETMX_M0_DAMP_V_IN1_DQ
H1:SUS-ETMX_M0_DAMP_Y_IN1_DQ
 

Attached images are sample plots from ASC and HPI subsystem.

Full results are also attached.

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duo.tao@LIGO.ORG - 08:01, Thursday 01 September 2016 (29431)
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Coherence Search Results of All the Single Lines in ER9 Data

Here are the coherence search results of all the single lines in ER9 data, which are listed in Keith’s post. I found 29 of all the 198 lines on the list and posted the results on my homepage here:

https://ldas-jobs.ligo-wa.caltech.edu/~duo.tao/ER9_single_lines/index.html

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