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Reports until 21:02, Thursday 28 July 2016
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 CDS
david.barker@LIGO.ORG - posted 17:27, Thursday 28 July 2016 (28712)
power cycled h1oaf0 IO Chassis to reset NGN ADC

Jenne, David M, Jim, Nutsinee, David B:

As part of the NGN signal problem investigation, at 13:46 PDT this afternoon we power cycled the IO Chassis for h1oaf0 (which runs the h1ngn model). Sequence was: stop models, power down h1oaf0, power cycle IO Chassis (powered down for at least 30 secs), powered up h1oaf0.

The TCS chillers did trip out soon after the power down, Nutsinee recovered them.

H1 SEI
jim.warner@LIGO.ORG - posted 16:41, Thursday 28 July 2016 (28710)
Monthly HEPI Trends

 Attached are trends for 45 days of HEPI pressure signals. All corner station signals look pretty similar. To my the EX signals look somewhat noisier than EY, but I think this is a know issue. This closes FAMIS task 4522.

Images attached to this report
LHO General
patrick.thomas@LIGO.ORG - posted 16:24, Thursday 28 July 2016 (28709)
Ops Day Summary 
14:42 UTC Jeff B. to LVEA to check clean rooms near HAM6
14:50 UTC Jeff B. back
15:04 UTC Jeff B. to OSB optics lab
15:09 UTC Jeff B. back
15:16 UTC David M. to LVEA to tape down cables
15:21 UTC PRMI locked, aligned BS in YAW. PRMI to DRMI transition failed.
15:26 UTC DRMI locked
15:27 UTC lock loss in DRMI locked
15:41 UTC Stopped at ENGAGE_SOFT_LOOPS
16:35 UTC Rich A. to HAM6
16:52 UTC Rich A. back
17:10 UTC David M. back
17:13 UTC Filiberto and Dave M. to LVEA to check NN array
17:32 UTC Filiberto and Dave M. back
17:38 UTC Bubba to mechanical rooms in mid stations to work on fans (WP 6011)
18:20 UTC Kyle and Gerardo to LVEA to start purge air compressor (WP 6027)
18:53 UTC Filiberto to LVEA to untrip ITM ESD HV power supply
19:05 UTC Jim W. adding state to SEI guardian
19:09 UTC Rich A. walking around LVEA
19:51 UTC Rich A. back
19:55 UTC Filiberto to LVEA to start pulling cable (WP 6028)
20:04 UTC Rich A. to observation deck and driving down arm
20:41 UTC Corey to optics lab
20:45 UTC Jenne and Jeff B. to look at seismometers in LVEA
20:46 UTC Kiwamu to ISCT6 to realign OMC REF camera
20:47 UTC Gerardo to LVEA to look for viewport protector
20:48 UTC Dave B. powercycling h1oaf
21:03 UTC Dave B. done
21:11 UTC Gerardo back
21:13 UTC Nutsinee to LVEA to turn TCS lasers back on
21:22 UTC Nutsinne back
21:37 UTC Kiwamu back
21:49 UTC Kiwamu back to table
22:26 UTC Filiberto done
H1 General
edmond.merilh@LIGO.ORG - posted 16:11, Thursday 28 July 2016 (28708)
Shift Summary-Evening Transition
TITLE: 07/28 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Unknown
OUTGOING OPERATOR: Patrick
CURRENT ENVIRONMENT:
    Wind: 13mph Gusts, 7mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.06 μm/s 
QUICK SUMMARY:
H1 CDS
patrick.thomas@LIGO.ORG - posted 13:25, Thursday 28 July 2016 (28707)
Powered Conlog off 
WP 6026

I powered h1conlog1-master and h1conlog1-replica off.

The disks were almost at capacity. I will remove and give them to LDAS to archive.

Unfortunately this means that there is no Conlog until the next version is installed.
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 ISC (ISC, SUS)
filiberto.clara@LIGO.ORG - posted 12:39, Thursday 28 July 2016 (28705)
ITM HV Power Supply

The positive HV power supply for the ITM ESD was found in the off position. Unit most likely tripped, this is something we have seen at the end stations. Unit was powered on and the output settings were set to V = 430V, I = 80mA. Time unit was power back on ~12:00PM.

X1 DTS
david.barker@LIGO.ORG - posted 12:27, Thursday 28 July 2016 (28704)
Testing minimal DAQ data which can be sent from 64kHz front end model

Jim and I tested for the minimal data which can be sent from a 64kHz model to the DAQ. We used x1ioppsl0 as the test model.

Background: When we installed the first SUS PI model on H1 last year the users wished to write two of the channels to the DAQ at 2kHz, this  caused runtime errors. I fixed the errors by adding two other channels at the full 64kHz rate, similar to what RCG does if there are no DAQ channels selected. Since it is not possible to set acquire=0, I set the data to zero to maximize compression.

Rolf mentioned that the rule of two channels at full rate has been removed. To see what the minimum rate is, I created a DAQ block on x1ioppsl0 and tried various combinations of one and two channels at various rates.

The mimimum DAQ configuration is one channel at 8192Hz. If the data content on MX is 4096 or less, the model will not run and the dmesg error "DAQ size too small" is shown. This is also true if two 2048Hz channels are selected, as was the case with the PI model. We suspect adding a third 2kHz channel would have avoided the problem.

Because acquire=1 will be selected for the 8kHz channel, the trick of ensuring the data is zero should be used to minimize impact on the frame size.

H1 OpsInfo (SEI)
jim.warner@LIGO.ORG - posted 12:18, Thursday 28 July 2016 - last comment - 17:09, Thursday 28 July 2016(28703)
BRSY will probably be down for the weekend

The BRS-Y has been continuing it's (already known) drift toward the end of its light sensor. So, some time we should probably turn the sensor correction off on Friday. I have added a state to do this in the SEI_CONF guardian, called WINDY_NO_BRSY. Krishna and Michael are already planning on coming over to address this on Tuesday.

There is a test for both BRSes in the Diag guardian node, so we should either wait for the notification for BRSY to come up or make the change last thing Friday night. If commissioners or operators don't want to risk an ISI trip, there is no problem with making the switch right now.

It should be noted that since both BRSes have been installed, this drift has been the only issue effecting the robustness of the BRS. Otherwise, we have been runing them as part of our nominal configuration for a couple months now.

Images attached to this report
Comments related to this report
jim.warner@LIGO.ORG - 17:09, Thursday 28 July 2016 (28711)
Link

I looked at the BRSY closer and it's getting close enough that a diurnal swing could take the spot position out of range. I've switched the SEI_CONF state, it should be left in the WINDY_NO_BRSY state unless the microseism comes up ~about an order of magnitude over the weekend.

H1 ISC
evan.hall@LIGO.ORG - posted 12:01, Thursday 28 July 2016 - last comment - 11:48, Friday 29 July 2016(28702)
Locking with different macroscopic SRC lengths

Hugh, Evan

Over the course of several locks, we moved the HAM4 HEPI in the y direction by several hundred microns in order to see the interferometer behavior at 2 W with the SRC locked on different fringes.

For a 1.1 mm shift in the HEPI position (i.e., a 2.2 mm shift in the one-way SRC length), there is no discernible trend in the rf sideband buildups or in the DARM pole frequency.

We would like to repeat this test with SR2 offsets as well.

Images attached to this report
Non-image files attached to this report
ham4_move.pdf
ham4_move.py
DcDarm_HVHN_Ham4.xml
Comments related to this report
rana.adhikari@LIGO.ORG - 11:48, Friday 29 July 2016 (28733)
Link

Craig C, Rana

We've been looking at the Gouy phase in the LHO SRC to understand the mode hopping, matching, etc.

The attached PDF shows something like the diagonal elements of the Jacobian: the change in the round trip Gouy phase as a function of each of 4 distances and 4 Radii of Curvature. The goal for the RT Gouy was 38 deg assuming a 50 km thermal lens.

 

In the plots the zero position on the x-axis is the nominal position of each optic according to (E1400205) the IAS as-built numbers OR the RoC according to the specs/measurements in optics database (galaxy.ligo.caltech.edu/optics).

The first page of the PDF shows the situation in the nominal warm state (ITM thermal lens with 50 km focal length). The second page is with no thermal lens. I have ignored the curvature of the CP as well as the cold lens in the ITM due to index inhomogeneity; assuming for now that these effects are small.

As you can see by flipping between pages 1 & 2, the ITM thermal lens stabilizes the SRC by increasing the round trip phase shift by ~15 deg.

 

So, is the LHO mode hopping problem due to a 0.05% RoC increase of SR3? Or is the LLO SRC more stable because it has a short RoC?

Is it possible that the alignment trouble with the LHO SRC can be mitigated by increasing the Gouy phase shift? If so, perhaps we could determine this by translating the HAM4/5 HEPI as well as pushing on the M1 stages of the SUS. If it goes in the right direction, perhaps we can make a bigger correction using the screws on HAM4 and get more like a 1 cm motion of the SR3-SR2 length without venting the main volume.

 

Uncertainties:

  • The placement of the SR2 and the SR3 has a small uncertainty in the x & z axes, but the y-direction (the important one for the SRC) has an uncertainty of +/- 1.5 mm since the measurement method is different.
  • The RoC uncertainty on the SR3 is ~15 mm or dRoC/Roc ~ 0.05%. This corresponds to a Gouy phase deficit of  ~15 deg.
  • The RoC uncertainty of the SR2 is the next most important parameter, but even a 0.1% error (standard off-the-shelf tolerance) would not be so bad.
  • We are very insensitive to the distance between the ITM and SR3, as well as the SR2-SRM distance.
  • Similarly, there is no conceivable distortion of the SRM temporary mirror which could destabilize the SRC.
Non-image files attached to this comment
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.

Images attached to this comment
Non-image files attached to this comment
nelson.christensen@LIGO.ORG - 11:14, Tuesday 26 July 2016 (28642)DetChar, PEM
Link 

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
Link

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?


Images attached to this comment
duo.tao@LIGO.ORG - 00:15, Friday 29 July 2016 (28721)
Link

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.

Images attached to this comment
Non-image files attached to this comment
duo.tao@LIGO.ORG - 08:01, Thursday 01 September 2016 (29431)
Link

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

H1 SEI (PEM, SEI)
david.mcmanus@LIGO.ORG - posted 15:19, Wednesday 22 June 2016 - last comment - 12:00, Thursday 28 July 2016(27919)
L4C Huddle Testing

David.M, Jenne.D

Yesterday I set up the sensors for the Newtonian noise L4C array in the beer garden. There are 31 sensors there in total (30 for the array and 1 spare), I arranged them in a huddle beneath the stairs near the STS-2. 20 of them are plugged into the two chassis located in the beer garden which correspond to the first 20 L4C channels. The other chassis is located external to the beer garden next to HAM2, I only connected two sensors to this rack because of a lack of long cables. The channels with these two sensors are L4C channels 26 and 30. I've attached a table which states which serial number L4C is connected to which channel for reference. Also attached are a photo of the current sensor huddle as well as an initial plot of the sensor spectrums calibrated to the STS-2 (thick black line).

The sensors themselves are each only touching the floor (despite what it looks like in the photo), although each wire touches many other wires and don't have any proper strain relief yet. The sensors currently being recorded are the ones more closely huddled together in the photo. The ones which are seperated slightly off to the left are the currently unrecorded L4Cs.

Images attached to this report
Comments related to this report
david.mcmanus@LIGO.ORG - 12:00, Thursday 28 July 2016 (28700)
Link

A second huddle was performed by swapping out channels 11 to 18 with the 8 sensors that had not yet been tested. This swap occured on 6/28/16, the sensors listed on those channels for the original huddle were swapped out on that date and replaced with the new L4Cs. The table attached to this comment lists all L4C serial numbers along with the channel number they were connected to during the huddle (3rd column, the 5th column is the current channel for the array), and also the start and stop dates for when that L4C was connected in the huddle. If the L4C was never swapped out, both dates on this range are blue. The date 6/28/16 is in red to make it obvious that the L4C was swapped in or out on that date.

Non-image files attached to this comment
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