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Reports until 16:47, Friday 27 March 2015
H1 DetChar (DetChar, ISC)
daniel.hoak@LIGO.ORG - posted 16:47, Friday 27 March 2015 - last comment - 19:01, Friday 27 March 2015(17537)
mHz resolution spectrum, with known features

Using the latest BRUCO results, I've annotated a hi-res spectrum from last night's lock.  Peaks, bumps, and so on are labeled with the largest coherent channels.

There are a few peaks, at 46, 166, 420, and 689Hz, that are coherent with PRCL/SRCL, and they have changed since the blue reference (Mar 19th at 18:00).  This might be due to the POP --> POPAIR switch.

The source of the 300Hz lines has been identified, it's the BS violin modes.  The frequency is given in Mark Barton's table of predicted violin resonances (thanks Jeff!).

We turned off all the ring heater power supplies yesterday; this got rid of a line at ~74Hz but didn't change the 55Hz line and its harmonics.  These lines are certainly due to some electronics in the EX racks.

Features coherent with the IMC WFS and the PSL persicope are probably the same thing (input beam jitter), hopefully from the same source (PSL PZT mount).

Images attached to this report
Comments related to this report
rich.abbott@LIGO.ORG - 16:52, Friday 27 March 2015 (17538)ISC
As I think is known, there is a filter solution for the ring heater driver to eliminate the fan noise.  It is the same basic design as was used in the Seismic Coil Driver fans.  We just need to make these available for installation soon.  Added this to my to-do list.
gabriele.vajente@LIGO.ORG - 16:52, Friday 27 March 2015 (17539)

The 160 and 420 Hz peaks are moving in frequency with a timescale of some minutes. The moves in a coherent way, in the sense that the frequencies seem pretty much to maintain a ratio of 2.5

See my previous log entry for an analysis of the line wandering.

daniel.hoak@LIGO.ORG - 19:01, Friday 27 March 2015 (17544)ISC, TCS

It turns out the 55Hz line is actually a 57Hz line, and it's the Hartmann camera.   This was explored in detail at LLO a long time ago, I should have remembered.

I have turned off the HWS box in the EX electronics rack.  This eliminated the 57Hz line and harmonics from the rack magnetometer, but for some reason the overall noise floor has increased, see attached.  Probably turning off the camera is a better solution, as Aidan recommends in the LLO log.  We'll see if this affects the noise.

Images attached to this comment
H1 General
nutsinee.kijbunchoo@LIGO.ORG - posted 16:26, Friday 27 March 2015 (17536)
Daily Ops Summary

== Activities ==

7:40 Cris to LVEA

8:00 Cris out of LVEA

9:00 Lock Loss

        Kiwamu to EY to reset ETMY ESD

9:22 Kiwamu back

11:14 Jodi to Mid X and Mid Y

14:50 Kyle back from mid stations (No notes of when he went out... Kyle and Jodi together?)

 

Best lock range at LHO ever. Happy Friday.

LHO VE
kyle.ryan@LIGO.ORG - posted 15:03, Friday 27 March 2015 (17534)
Shortened (tube cutter, solder caps) chilled water 1/2" copper lines in X-mid VEA
Kyle, Gerardo 

Pressurized lines -> no leaks.  

Attempting to clear a path for under tube pallet jack traffic and ease 3IFO storage and also to eliminate need for overhead crane.  

Instrument air and copper grounding cable still need to be re-routed off of the floor
LHO VE
bubba.gateley@LIGO.ORG - posted 13:57, Friday 27 March 2015 (17533)
Beam Tube Washing
Scott L. Ed P. Chris S.

The crew was able to complete tube cleaning to the X-1-7 double doors. 
Results are posted here.
The afternoon will be spent doing P Ms on the equipment and relocating to the next section to be cleaned.
  

Non-image files attached to this report
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 12:12, Friday 27 March 2015 (17531)
CDS Overview MEDM, new buttons

I have added two buttons to the CDS OVERVIEW MEDM screen:

Press All Diag Reset Buttons

The name says it all. It opens an xterm window, and then sequences through all running models pressing the DIAG_RESET button on the GDS_TP screen

EDCU disconnected channels

This is a small yellow button, labeled with an exclamation mark,  next the the EDCU status LED. When the LED is purple, pressing the button will open an xterm and list the EDCU channels which are disconnected. The xterm is held open so you can read it at your leisure, please close it when you are done with it.

H1 CAL
kiwamu.izumi@LIGO.ORG - posted 11:55, Friday 27 March 2015 - last comment - 16:09, Monday 06 April 2015(17528)
Notes on the calibration with the low noise ETMY ESD

Here are some notes on the recent DARM calibration for future reference.

 


(A) We intentionally do not switch the simulated ETM actuators in the CAL-CS model when we switch to ETMY for low noise in the DARM control.

Even though we switch the actuator from ETMX to ETMY for the LSC DARM control to achieve low noise, the calibration filters for the actuators in CAL-CS remain using the *ETMX simulated actuator path*. Since we adjusted the ETMY ESD digital gain such that the response of ETMX and ETMY ESDs are the same with a precision of 10 % in frequency band from 20 to 60 Hz, the calibrated spectrum after the ETMY transition should be still valid with a precision of 10 %. In other words, we forced the actual ETMY ESD to be identical to that of ETMX so that we don't have to manipulate the filters in CAL-CS. In fact, when we transition from ETMX to ETMY, we do not see visible reduction or increment in the DARM spectrum at low frequencies below 100 Hz, which convinced us that the calibration remained consistent. Then, once we decrease the ETMX ESD bias all the way to zero, we see noise reduction in 20-100 Hz band due to lower ESD noise.

The adjustment of the ETMY ESD digital gain was done on the last Tuesday, Mar-24th (alog 17411). The following is some detail of what I did for the adjustment. First, I measured the transfer function from ETMX_L3_LOCK_L_IN1 to LSC-DARM_IN1 in 20-60 Hz band by swept sine while the interferometer stayed fully locked on DC readout. Then I measured the same transfer function but with the ETMY ESD driven. So the transfer function I took was from ETMY_L3_LOCK_L_IN1 to LSC-DARM_IN1. At this point, I noticed that the ETMY ESD response was weaker than that of ETMX by an overall scale factor of 1.25. Note that both ESDs use the linarization. So I increased the ETMY ESD gain by the same factor in ETMY_L3_LOCK_L_GAIN. So this gain is now 1.25 and this is already coded in the ISC_LOCK guardian. Then in order to check how good the matching is between ETMX and ETMY, I ran another swept sine on ETMY with the new gain. However this still gave me a bit too-weaker ETMY ESD by 10% (I attach the dtt xml file). Since we knew that the overall scaling factor of our calibration is already uncertain by the same level (on the order of 10%, see for example alog 17082), I did not try to get better matching between them. We will revisit the ETMY calibration at some point.

(B) The DARM spectrum below 2 Hz is not trustable.

There are two reasons.

  1. We have not calibrated the L1 stages yet, the calibration below the cross over frequency (which must be somewhere between 0.5 and 2 Hz) is uncertain.
  2. We intentionally do not engage two of the simulated suspension digital filters for the L1 stage (i.e. the ones simulating low frequency boosts in ETMX(Y)_L1_LOCK_L, specifically FM1 (zpk([0.3], [0])) and FM2 (zpk([0.1] [0])) ). This makes the calibration inaccurate below 0.3 Hz in such a way that the DARM spectrum becomes too good. Enabling one or both filters tends to accumulate a large DC offset over some time and eventually causes a spill over envelope into the DARM spectrum even if the DC component is subtratced in diaggui.
Non-image files attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 16:09, Monday 06 April 2015 (17708)
By how much is the calibration off at low frequencies because we do not include the low-frequency control filters, i.e. Kiwamu's point (B)2? 

See attached. This is the (driven) transfer function from the DARM_CTRL input of the CAL CS model (actually H1:CAL-CS_DARM_FE_ETMX_L3_ISCINF_L_EXC) to the output of the actuation function chain (actually H1:CAL-CS_DARM_DELTAL_CTRL_WHITEN_IN1).

At these low frequencies, the formulation of DELTA L EXTERNAL is entirely dominated by the actuation function times the control signal, A * DARM_CTRL. So, any discrepancies between what we believe is the most accurate reconstruction of A and the real A is by how much that calibration is off. To give a few frequency points in words, at 0.1 [Hz] the discrepancy is roughly an order of magnitude too low, and at 0.02 [Hz] is almost two orders of magnitude off. In other words, any plots of DELTA L EXTERNAL is *under* estimating the displacement by ~10 at 0.1 [Hz] and by 100 at 0.02 [Hz].

This transfer function comparison also reveals (maybe?) what problems that Kiwamu mentions in (B)2. One can see *without* the low frequency compensation, the TFs clean. *With* the low frequency filters engages, the transfer function becomes ratty both at low and high frequencies. Maybe this is a problem with numerical precision in the filter computation?
Non-image files attached to this comment
H1 CAL (CAL)
richard.savage@LIGO.ORG - posted 10:51, Friday 27 March 2015 (17525)
Xend Pcal commissioning and calibration

SudarshanK, RickS

Yesterday, we adjusted the transmitter module optical layout to address the s-pol light downstream of the AOM (see notes appended below).

We then calibrated the system using Working Standard WS1.  The details are in LIGO-T1500129.

The calibration of the TxPD output (H1:CAL-PCALX_TX_PD) is  8.517e-13 *1/f^2 (m/V).

The calibration of the RxPD output (H1:CAL-PCALX_RX_PD) is  6.799e-13 *1/f^2 (m/V).

 

Notes:

LHO Xend calibration

As found:
With servo output railed at ~1.5V
 
Total power downstream of AOM 1.37 mW
Diffracted power 1.09 W
80% Diffraction efficiency
OFS PD 1.32 mW; -9.0 V with NE01A-B filter
TxPD  6.64 mW; 2.72 V without filter
 
Beam seemed to be slightly clipping the transducer in the AOM
Moved the beam away from the transducer approx 1/2 turn on 4 axis mount
 
Now (without the polarizer)
Total power 1.55 W
diffracted poer 1.14W
75% efficiency
 
Moved wedge about one inch farther downstream to decrease incidence angle
 
Found that wedge roll angle was not well set.  OFS PD too high.
Used IRIS set right in front of wedge, then adjusted vertically so iris is centered on input beam.
Then, used iris in Tx and OFS beams to adjust roll angle of wedge such that both beams are level.  Note that one needs to adjust the pitch angle of the wedge for the Tx beam after making a roll angle adjustment.
 
After centering beams on PDs, then installing lens in OFS PD path and recentering.
Installed NE06A-B on OFS PD.  6.12 mW on OFS PD.Output was -14 V.  With an additional NE01A-B we have -10.8V
Tx PD (without any filters) 12.3 mW on Tx PD. 5.1 V
 
Installed PBS downstream of AOM and rotated in yaw to minimize reflected light with AOM drive switched off.  ~4 mW
With AOM drive on at max level 23 mW.
 
Measured OLTF (see attached photo).  UGF 100 kHz with gain set to 37 dB.  Phase margin 61 deg.
Images attached to this report
H1 ISC (DetChar, ISC)
gabriele.vajente@LIGO.ORG - posted 10:46, Friday 27 March 2015 (17524)
Coherences

Every time commissioners improve the sensitivity, I have to run again my brute force coherence. Luckily, it's fast enough now. Here is the sumamry page:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1111482016/

MICH is dominant between 20 and 150 Hz (first plot). PSL periscope peaks are prominent (third plot). Intensity noise is a factor of few below DARM at frequencies above 100 Hz (fourth plot). There are many lines coherent with suspension or environmental signals, too many to list all of them here.

SRCL and PRCL show a broad band coherence basically everywhere (second plot), giving a noise projection a level of few below the DARM signal. This is the usual thing we already saw, and I believe is due to the IMC locking offset, somehow converting frequency noise into intensity noise. Still to be proven though.

Images attached to this report
H1 SEI (CDS, GRD)
hugh.radkins@LIGO.ORG - posted 10:32, Friday 27 March 2015 (17523)
LHO SEI SDFs all Clear (Grey)

Updated all the BSC ISI snaps to reflect Jim's current Blends.  Elliptical blends have been added to and turned on to all the St2 for the 4 DOFs we are isolating.  I also had to edit unchanged filter banks due to the FE/SDF mapping of SW2 down onto SW1.  This was an issue just at the ETMs and seems related to the blend switching for the winds (45 vs 90mhz, what's up with that?)  Safe.snaps committed to svn.

H1 SEI
jim.warner@LIGO.ORG - posted 10:11, Friday 27 March 2015 - last comment - 10:27, Friday 27 March 2015(17521)
HAM Blends: Same trick, different dog

Similar to my mods at ETMX in alog 17488, I thought I would try add some low pass filters to one of the HAM's CPS blend filters. So far I've gotten mixed results. HAM6 shows a pretty clear improvement, HAM5 is about 50/50 good and bad. First plot shows HAM6, second is HAM5, solid is before, dashed is after, black is ground, blue is CPS, red is GS13. HAM6 shows improvement between  1 hz and 10, but HAM5 is better up to 3 or 4 hz, then worse. At least the HAM 5 data shows nothing worse below a HZ, the HAM6 data was taken really quick so I didn't get the low frequency part.

Not really sure what is going on. Maybe insufficient loop gain or something?

Images attached to this report
Comments related to this report
jim.warner@LIGO.ORG - 10:27, Friday 27 March 2015 (17522)

Adding plots of the blend filter change. Red is stock, blue is the added filter, green is the product.

Images attached to this comment
H1 SEI
hugh.radkins@LIGO.ORG - posted 09:43, Friday 27 March 2015 - last comment - 09:59, Friday 27 March 2015(17519)
Looks like the BS Stage2 Isolation can survive the lock loss-- We need the guardian!

Previously posted as comment to 17504.

 

Note that ISI Stage2 was a State3 trip meaning that the Damping Loops were still functional.  It would be nice to know when/why the stage tripped.  But I'd guess that the Guardian was set to fully isolated before the ~0700utc short lock and was untripped during the short lock, likely triggering during acquisition and then triggering again at the trip.  That is what I first thought.

See attached--It looks like the stage2 when isolated survived the IFO lock loss but not the MICH reacquisition.  This means, we can use the Guardian to transition the ISI between Isolated Damped and Fully Isolated with tripping nor requiring operator intervention.

This is a 50 minute stretch so the IFO lock Loss is only a couple minutes before the St2 WD trigger but there may be enough time to deisolate stage2.  Looking at a zoomed in full data, looks like a full 70+ seconds after lock loss based on this CAL_DELTAL channel.  The second lock loss had even more time so I don't think it is tied to the lock loss but more to the reacquisition.

 

Of course, we also need to show that turning Stage2 Isolation loops on is a positive thing.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 09:59, Friday 27 March 2015 (17520)

When I look at the MASTER_(local-drive)DRIVE_DQ, there isn't actually a data point(full data) that exceeds the trigger threshold.  These are the channels the watchdog plotting scripts display.  However, when I look at the OUTF_SATURATION totalizers, I see that indeed H1 had 2 saturations (I've set this counter threshold to 31000cts.)  All the other drives had no saturations at the lock loss.  I wonder if there is a way we could ride this out?  Of course if we hadn't shut off the Isolation, we probably would have a lot more.

H1 ISC (CAL, CDS, DetChar, GRD, INS, IOO, ISC, SEI, SUS, SYS)
jeffrey.kissel@LIGO.ORG - posted 08:58, Friday 27 March 2015 - last comment - 07:47, Saturday 28 March 2015(17515)
Great sensitivity all night long!
J. Kissel, J. Warner, J. Romie, H. Radkins, N. Kijbunchoo, K. Izumi, G. Moreno

SUMMARY: We just finished ~7 HOUR lock stretch at our best sensitivity ever, between 32 and 34 [Mpc]!

We've all been pleasantly surprised this morning to see that the lock stretch that Sheila Evan, Dan and Lisa started last night lasted the entire night. Unfortunately, as of ~10 minutes ago (~8:40a PDT, ~15:40 UTC), there are GIANT glitches and non-stationarity that keep popping up, spoiling the sensitivity. There's no one in the LVEA, so we're not at all sure what's caused the sudden change in behaviour. Wind seems fine at ~5 [mph], ground motion is still pretty low, the 1-3 [Hz] hasn't even come up yet.

Anxious to explore things, Jim installed some low-pass filters in the HAM5 and HAM6 ISIs at around 8:45 to try to reduce scattering / acoustic coupling to the ISI, and Kiwamu began exploring MICH coupling to DARM. 

But, as I write this log, we lost lock. However, for DetChar purposes, one can assume the detector was undisturbed from March 27 9:00 UTC to March 27 ~15:00 UTC.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 09:17, Friday 27 March 2015 (17516)
K. Izumi, J. Kissel

For the record: Kiwamu drove down to the EY end station to check: *this* lock loss did *not* cause the EY ESD Driver to trip. Huh.
gabriele.vajente@LIGO.ORG - 11:21, Friday 27 March 2015 (17526)DetChar, ISC

Looking at spectrograms of DARM during the first hour of lock (first plot) and the last hour (second plot), it seems to me that the noise is more or less stationary, but there are huge glitches. They are so big that you can even see them easily in time domain (third plot). A zoom in is visible in the fourth plot. They look like bursts of oscillations at about 5.5 kHz.

Images attached to this comment
kiwamu.izumi@LIGO.ORG - 13:44, Friday 27 March 2015 (17532)

We now believe that the glitches we had in the lock stretch from this morning was due to the ISS which repeatedly unlocked. This is a typical behavior of the ISS when the diffraction power is too low. Indeed the diffracted power had been 4% on average during the time when the interferometer was locked. There was clear correlation between arm cavities' power and the ISS diffracted power. See the attached trend of some relevant channels. Elli adjusted the diffracted power in this after noon so that the diffracted power is now at 8% with only the inner loop closed.

Images attached to this comment
thomas.massinger@LIGO.ORG - 18:24, Friday 27 March 2015 (17540)DetChar

Looking at glitch-to-glitch coupling between auxiliary channels and DARM shows a large number of glitches in the > 1kHz range that are coincident with glitches in CARM, REFL 9 PIT/YAW, and REFL 45 PIT. Interestingly, CARM is highly correlated with high frequency glitches until about 12:00:00 UTC, at which point REFL 45 PIT becomes the stronger veto.

It looks like REFL 45 Q PIT was offset by about 2500 counts during the lock, is it possible that intensity fluctuations on an uncentered WFS are showing up as alignment glitches? I've attached a time series covering 2 hours of the lock from 11 UTC to 13 UTC.

We're currently running code to see if the lower frequency (50-200 Hz) glitches are caused by zero-crossings in the 18-bit DACs.

I've attached an Omicron glitchgram for the whole day, it seems as if the higher frequency glitches and the glitches populating the 50-200 Hz region are the two dominant populations right now. There are also a few high SNR glitches scattered around in the 100-400 Hz region that we'll follow up individually.

Images attached to this comment
joshua.smith@LIGO.ORG - 07:47, Saturday 28 March 2015 (17555)DetChar

-2^16 Crossings in ETMY L3 ESD causing many of the glitches in this lock:

In addition to the arches reported in 17452 and 17506 we found DAC glitches in this lock when ETMY L3 ESD DAC outputs were crossing -2^16 counts. Attached is a PDF with a few examples that were lined up by hand. We will follow up more closely to see if other suspensions and penultimate stages also add glitches. Note: At Livingston, SUS MC2 M3 DACs were also a problem. 

If you'd like to see the primary culprits from this long lock, here is a tar file of omega scans (thanks to Joe Areeda) of the loudest 100 glitches between 30 and 200Hz. The vertical lines that repeat are DAC glitches, the crazy wandering features are the arches described in the pages linked above, those two mechanisms account for most of the glitches we see.   

Non-image files attached to this comment
H1 ISC (ISC)
lisa.barsotti@LIGO.ORG - posted 02:12, Friday 27 March 2015 - last comment - 12:17, Friday 27 March 2015(17504)
30 is the new 20!

Evan, Sheila, Dan, Lisa

We made it to 34 Mpc by managing to do at the same time all of the things we have tried before (low noise ESD on ETMY, low noise coil drivers for all the optics, POPAIR for vertex length DOF, more aggressive SRCL cut-off), plus some more ASC cut-offs. Implementing all of these things at the same time happened to be more challenging that expected because of a few problems that slowed us down today:

Some more details

Final IFO & Guardian state

We leave the interferometer locked at 34 Mpc, starting at March 27 9:00 UTC

Comments related to this report
evan.hall@LIGO.ORG - 02:17, Friday 27 March 2015 (17505)

Spectrum attached.

Images attached to this comment
fred.raab@LIGO.ORG - 07:41, Friday 27 March 2015 (17509)
Great work! I will update our slides for the quarterly briefing.
albert.lazzarini@LIGO.ORG - 08:40, Friday 27 March 2015 (17511)
Excellent progress!
david.reitze@LIGO.ORG - 08:47, Friday 27 March 2015 (17514)
Nice work.  Great headline, too.
hugh.radkins@LIGO.ORG - 09:38, Friday 27 March 2015 (17518)

Note that ISI Stage2 was a State3 trip meaning that the Damping Loops were still functional.  It would be nice to know when/why the stage tripped.  But I'd guess that the Guardian was set to fully isolated before the ~0700utc short lock and was untripped during the short lock, likely triggering during acquisition and then triggering again at the trip.  That is what I first thought.

See attached--It looks like the stage2 when isolated survived the IFO lock loss but not the MICH reacquisition.  This means, we can use the Guardian to transition the ISI between Isolated Damped and Fully Isolated with tripping nor requiring operator intervention.

This is a 50 minute stretch so the IFO lock Loss is only a couple minutes before the St2 WD trigger but there may be enough time to deisolate stage2.  Looking at a zoomed in full data, looks like a full 70+ seconds after lock loss based on this CAL_DELTAL channel.  The second lock loss had even more time so I don't think it is tied to the lock loss but more to the reacquisition.

Images attached to this comment
evan.hall@LIGO.ORG - 12:17, Friday 27 March 2015 (17530)

Noise budget attached, with new the anticipated ETMY ESD noise. We have many other traces to add here: intensity coupling, frequency coupling, auxiliary dofs, etc.

I believe the 10 W quantum noise and the DAC→ESD noise alone limit us to no more than 60 Mpc, although based on the previous performance of the ETMX ESD, the ESD trace here may be an overestimate.

Non-image files attached to this comment
H1 SUS
sheila.dwyer@LIGO.ORG - posted 00:57, Friday 27 March 2015 - last comment - 11:33, Friday 27 March 2015(17501)
EX PUM watchdog

Earlier in the evening we tripped the RMS watchdog on ETMX, and had to drive out the end station to power cycle the coil driver.  

This wasn't obvious from the control room.  Three things that would help are to 

1) add this to the OPS overview screen

2) add it to the SYS_DIAG gaurdian

3) add it to the SUS guardians

Comments related to this report
thomas.shaffer@LIGO.ORG - 11:33, Friday 27 March 2015 (17527)

They are now in SYS_DIAG.

H1 ISC
filiberto.clara@LIGO.ORG - posted 09:53, Thursday 26 March 2015 - last comment - 16:04, Friday 27 March 2015(17484)
Shutter Controller EY
Replaced Shutter Controller S1203610 with S1203612. Daniel reported CH1 on S1203610 is not functioning, thus we were controlling the shutter with CH2. I reconnected the shutter to CH1 of the new unit and changed the jumper settings to VS35 on both channels.
Comments related to this report
daniel.sigg@LIGO.ORG - 16:04, Friday 27 March 2015 (17535)

Same story. Channel 1 opens and closes immediately. Next thing to check are cabling and slow controls.

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