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  40m Log, Page 138 of 335  Not logged in ELOG logo
ID Date Author Type Category Subject
  9932   Thu May 8 17:00:56 2014 rana, QSummaryLSCREFL_DC handoff didn't work last night

Last night after checking cabling and turning on ISS, we tried several times to handoff to REFL_DC but it didn't work at all.

Some issues:

  1. The ISS was injecting a lot of very low frequency power fluctuations because of bad AC coupling.
  2. The SR560 @ LSC rack was saturating a lot with the x10 gain that Jenne and Rana put in; we turned it back to G = 1.
  3. The ISS was also saturating a lot. We turned it off around 4 AM, but still no success.
  4. The ALS sequence for finding the Red Resonance takes too long (~2 minutes), so we're trying a faster scheme tonight.
  9931   Thu May 8 15:55:43 2014 jamieUpdateCDSpython issues

Quote:

On pianosa: The ezca.Ezca class somehow initializes with its prefix set to "C1:", even though the docstring says the default is None. This makes existing scripts act wonky, because they're looking for channels like "C1:C1:FO-BLAH".

In ligo/apps/linux-x86_64, I ran ln -sfn cdsutils-old cdsutils to get the old version back for now, so I don't have to edit all of our up/down scripts.

Also, Chiara can't find the epics package when I try to load Ezca. It exists in '/usr/lib/pymodules/python2.6/epics/__init__.pyc' on pianosa, but there is no corresponding 2.7 folder on chiara.

I just pushed a fix to ezca to allow for having a truly empty prefix even if the IFO env var is set:

controls@pianosa:~ 0$ ipython
Python 2.6.5 (r265:79063, Feb 27 2014, 19:43:51) 
Type "copyright", "credits" or "license" for more information.

IPython 0.10 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object'. ?object also works, ?? prints more.

In [1]: import ezca

In [2]: ezca.Ezca()
Out[2]: Ezca(prefix='C1:')

In [3]: ezca.Ezca(ifo=None)
Out[3]: Ezca(prefix='')

In [4]: ezca.Ezca(ifo=None).read('C1:LSC-DARM_GAIN')
Out[4]: 0.0

This is in cdsutils r232, which I just installed at the 40m.  I linked it in as well, so it's now the default version.  You will have to make a modification to any python scripts utilizing the Ezca object, but now it's a much smaller change (just in the invocation line):

-ca = ezca.Ezca()
+ca = ezca.Ezca(ifo=None)

 

  9930   Thu May 8 14:37:02 2014 JenneUpdateASCPOP ASC QPD power

I was thinking about POP today, and wanted to know if there was something to be done to allow us to use the PRCL ASC for at least a little bit farther into arm power buildup.

Anyhow, I checked, and while PRMI is locked on sidebands (ETMs misaligned), POP DC is about 80 counts, and the power measured by the Ophir power meter is 24 microWatts. 

We were on the 3rd gain setting for the QPD's power amplifier.  I turned it down to the "2" option.  (When at 4, the front panel light indicates saturation).

It's not clear to me what the gain settings mean exactly.  I think that "1" means 4*10^3 V/A, and "6" means 4*10^6 V/A (On-Trak OT301 info site), but I don't know for sure how the gain changes for the settings 2-5.  Anyhow, I have changed the digital gain for the ASC to be -0.063 from -0.023 for both pitch and yaw.

  9929   Thu May 8 02:03:51 2014 ranaUpdateISSISS: fuse was blown, repaired, loop back on

Back in November, Nic and Evan turned on an SR560 based ISS. It uses the PMC TRANS PD as the error signal and makes an AC coupled loop with 2 SR560's and then it drives the RF amplifier which drives the AOM upstream of the PMC.

This was the saturating SR560 under the PSL table that Steve found this week*. Tonight I found that the +24 V rack fuse for this was blown. I replaced the previous 2A fuse with a new 2A fuse (turned off the +/24 V Sorensens during this operation). I think all of the servo settings are basically the same as before, except that I'm using a gain of 10000 instead of 50000 on the first SR560. It was saturating otherwise. My guess is that the fuse blew many months ago and no one has noticed...

 I checked the out of loop performance in MC_TRANS and in the IFO REFL_DC and there's some high frequency improvement with the loops on.

The main improvement, however, was in lowering the HEPA fan speed. This should only be turned up to Hurricane when you are working on the table. Similarly, those of us trying to lock at night, can't really trust that the HEPA is set to its nominal low setting of 20%. The whole difference in the MC_TRANS from 5-50 Hz is from this however, so we can use this ISS reference .xml as a way to see if the HEPA is up too high.

If we want to do better for RIN from 100-1000 Hz for improving the REFL_DC/CARM noise, we would have to think of how to improve the PMC_TRANS PD RIN.

 

* Steve gets +1 point for finding this, but then -3 points for not elogging.

  9928   Thu May 8 01:33:21 2014 ericqUpdateCDSpython issues

On pianosa: The ezca.Ezca class somehow initializes with its prefix set to "C1:", even though the docstring says the default is None. This makes existing scripts act wonky, because they're looking for channels like "C1:C1:FO-BLAH".

In ligo/apps/linux-x86_64, I ran ln -sfn cdsutils-old cdsutils to get the old version back for now, so I don't have to edit all of our up/down scripts.

Also, Chiara can't find the epics package when I try to load Ezca. It exists in '/usr/lib/pymodules/python2.6/epics/__init__.pyc' on pianosa, but there is no corresponding 2.7 folder on chiara.

 

  9927   Thu May 8 00:40:39 2014 ericqUpdateLSCBNC vs. 2pin LEMO for AO

 I've checked that the 2pin lemo connector that was run some time ago from the LSC rack to the MC board does indeed transmit signals. To try and evaluate its suitability I did the following:

  • Generated a 5mVpp 1.3kHz signal with an SR785 and fed that into CM board In1, all boosts off, 0dB AO gain. 
  • Both BNC and LEMO connected to CM servo out
  • One of BNC or LEMO connected to IN2 of MC servo, input gain of 30dB but disabled, OUT2 switched to AO and fed to Agilent spectrum analyzer. 
  • Terminated MC IN2 for comparison. 

No real difference was seen between the two cases. The signal peak was the same height, width. 60Hz and harmonics were of the same amplitude. Here are the spectra out to 200k, they are very similar. 

AOcablesWide.pdf

Mode cleaner was locked during this whole thing. This may interfere with the measurement, but is similar to the use case for the AO path. If ground loop / spurious noise issues keep occurring, it will be worthwhile to examine the noise of the CM and MC servo paths, inputs and outputs more carefully. 

  9926   Wed May 7 23:30:21 2014 jamieUpdateCDScdsutils should be working now

Should be fixed now.  There were python2.6 compatibility issues, which only show up on these old distros (e.g. ubuntu 10.04).

controls@pianosa:~ 0$ cdsutils read C1:LSC-DARM_GAIN
0.0
controls@pianosa:~ 0$ cdsutils --version
cdsutils 230
controls@pianosa:~ 0$ 
  9925   Wed May 7 23:09:06 2014 rana, jamieSummaryComputer Scripts / ProgramsOttavia back on network

After Jamie fixed the third party repo issue with Ottavia, he was able to upgrade it to Ubuntu 12.04 Precise Pangolin. But its network stopped working.

I tried to fix its issues by ifconfig and GUI, but what it really wanted was for me to put the network cable back into its eth0 slot. The eth1 network card appears not be working anymore.

All seems fine now. Next I will mount the shared user disk from linux1 and put in a .bashrc.

  9924   Wed May 7 22:47:33 2014 ranaUpdateCDScdsutils updated to version 226: not working on pianosa or rossa

 controls@rossa:~ 0$ cdsutils read C1:LSC-DARM_GAIN
Traceback (most recent call last):
  File "/usr/lib/python2.6/runpy.py", line 122, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.6/runpy.py", line 34, in _run_code
    exec code in run_globals
  File "/ligo/apps/cdsutils-226/lib/python2.6/site-packages/cdsutils/__main__.py", line 57, in <module>
    imp.load_module('__main__', f, pathname, description)
  File "/ligo/apps/cdsutils-226/lib/python2.6/site-packages/cdsutils/read.py", line 32, in <module>
    print ezca.Ezca(prefix).read(rest, as_string=args.as_string)
  File "/ligo/apps/linux-x86_64/cdsutils-226/lib/python2.6/site-packages/ezca/cached.py", line 17, in __call__
    key = (args, tuple(kwargs.viewitems()))
AttributeError: 'dict' object has no attribute 'viewitems'

  9923   Wed May 7 17:10:59 2014 ranaUpdateCDScdsutils updated to version 226

 This upgrade from Jamie has given us the new apps (avg, servo, and trigservo). We should figure out if there's a way to integrate Masayuki's work, so that we can have a 'cdsutils demod' function too.

  9922   Wed May 7 16:31:12 2014 jamieUpdateCDScdsutils updated to version 226
controls@pianosa:~ 0$ cd /opt/rtcds/cdsutils/trunk/
controls@pianosa:/opt/rtcds/cdsutils/trunk 0$ svn update
...
At revision 226.
controls@pianosa:/opt/rtcds/cdsutils/trunk 0$ make
echo "__version__ = '226'" >lib/cdsutils/_version.py
echo "__version__ = '226'" >lib/ezca/_version.py
...
controls@pianosa:/opt/rtcds/cdsutils/trunk 0$ make ligo-install
python ./setup.py install --prefix=/ligo/apps/linux-x86_64/cdsutils-226
...
controls@pianosa:/opt/rtcds/cdsutils/trunk 0$ ln -sfn cdsutils-226 /ligo/apps/linux-x86_64/cdsutils
controls@pianosa:/opt/rtcds/cdsutils/trunk 0$ exit
...
controls@pianosa:~ 0$ cdsutils --version
cdsutils 226
controls@pianosa:~ 0$ 

  9921   Wed May 7 14:01:36 2014 steveUpdateLSCTRY 60Hz noise hunt

Quote:

This is an effort to get rid of our ground loops  by isolating the electronic components from the optical table.

Aluminum mounting base plates of Thorlabs BA2 and Newport B-2 were replaced by plates or post made out of delrin material.

This is an insulator. DELRIN base plates were installed 6 places. The oplev-qpd has Nylon base plate.

The NPRO and HE/NE lasers are not isolated from the table. S8 and S9

I'm not sure about the doubling oven S10 

The optical table is grounded at G11  through  ~1 Mohms to the ETMY chamber.

Alignment touch up needed   at all D-marked component!

 

 Attachment appendix:

 

D: component delrin isolated

N: component nylon isolated ( or Delrin )

S: component shell is shorting to optical table (except oven)

G:  optical table ground

 

I failed to maximize TRY the pds.

  9920   Wed May 7 04:01:44 2014 rana, jenneUpdateLSCPRFPMI: Common Mode servo using REFL_DC ON, CARM offset still non-zero
  1. With REFL_DC coupled into the CM board through an SR560 (with an offset subtractor), we were able to transition to use it as the CARM error signal.
  2. We reduced the CARM offset until the arm powers went up to ~13.
  3. We had the AO path turned on and the MCL/AO crossover was ~150 Hz.
  4. We saw the double cavity pole come in from HF down to ~1-2 kHz. The lock stayed stable like this.
  5. We've set the IMC overall gain higher by +4dB in the mcup script. That's -4 dB from Eric's max gain earlier today.
  6. We have some scripts now for this scripts/PRFPMI/ :   camr_cm_down.sh and carm_cm_up.sh
  7. The sequence was ALS -> SqrtInv while digital with CARM -> MC2. Then we digital transition to REFL_DC using the CM board switch to put REFL_DC into the REFL11_I socket.
  8. REFL_DC is noisy, so we upped the SR560 gain by 10 and compensated.

Also, we found the PRM OL off and turned it back on. The ETMY was swinging a lot after lock loss, so we set its SUSPOS damping gain to match the ETMX and it stopped swinging so much.

Next up: more of the same, make this sequence more stable, turn on CARM OSC and watch the LOCKI outputs while we slowly ramp between signals.

Also, what should be the sign of the CARM offset ???

  9919   Tue May 6 19:38:13 2014 JenneUpdateLSCSet up for PRFPMI CM locking

To get ready for the PRFPMI CM trials tonight, I put AS55's cables back to their nominal state, and now have REFL11 I going to IN1 of the CM board.  The OUT1 of the CM board goes to the REFL11I whitening channel.

REFLDC was not disconnected in the last few days, so it is still set up for IN2 of the CM board, with an external offset adjust.

  9918   Tue May 6 18:32:14 2014 steveUpdateLSCTRY 60Hz noise hunt

This is an effort to get rid of our ground loops  by isolating the electronic components from the optical table.

Aluminum mounting base plates of Thorlabs BA2 and Newport B-2 were replaced by plates or post made out of delrin material.

This is an insulator. DELRIN base plates were installed 6 places. The oplev-qpd has Nylon base plate.

The NPRO and HE/NE lasers are not isolated from the table. S8 and S9

I'm not sure about the doubling oven S10 

The optical table is grounded at G11  through  ~1 Mohms to the ETMY chamber.

Alignment touch up needed   at all D-marked component!

 

  9917   Tue May 6 17:58:44 2014 ericqUpdateLSCfarther into CM

 I took a look at the MC OLTF and AO path TFs with the fast agilent analyzer. 

I played with the relative gain of the EOM and PZT, but couldn't really change the MC OLTF shape much without making the PC Drive RMS angry. 

However, it turns out we have plenty of phase headroom to up the MC UGF from ~100kHz to ~180, with about 40 degrees of phase margin and ~7dB of gain margin. As I write this, PC drive RMS is around 1.1, and FSS Fast at 5.6, so I think the extra gain is fine for now. 

This pushes up and smoothens out the gain peaking in the AO path; see this figure:

AOTFs.pdf

(why does ELOG hate my python plots?! argggg)

Rana's rule of thumb was "We need at least +3dB MC loop gain at our CM servo UGF," so it looks like high tens of kHz bandwidth may be doable from the AO standpoint.

RXA: No, no, no, no, no, noooo. Rana said we need a gain of 3-10 at the CM UGF, not +3 dB.

  9916   Tue May 6 10:31:58 2014 jamieUpdateCDSc1ioo dolphin fiber

Quote:

I put label  at the dolphin fiber end at 1X2 today.   After this I had to reset it, but it failed.

 If by "fail" you're talking about the c1oaf model being off-line, I did that yesterday (see log 9910).  That probably has nothing to do with whatever you did today, Steve.

  9915   Tue May 6 10:22:28 2014 steveUpdateCDSc1ioo dolphin fiber

Quote:

Steve and I nicely routed the dolphin fiber from c1ioo in the 1X2 rack to the dolphin switch in the 1X4 rack.  I shutdown c1ioo before removing the fiber, but still all the dolphin connected models crashed.  After the fiber was run, I brought back c1ioo and restarted all wedged models.  Everything is green again:

green.png

 I put label  at the dolphin fiber end at 1X2 today.   After this I had to reset it, but it failed.

  9914   Tue May 6 09:46:50 2014 steveUpdatePEMcleaning day

 Keven and Steve,

We cleaned around the Vertex chambers, PSL and MC2 floor areas.

 

  9913   Tue May 6 03:17:15 2014 ranaUpdateLSCfarther into CM

Yes, we still need to do these things, day team. Please tune up the MC loop first, before anything else.

Quote:

Next steps:

  • Check CM board boosts turn on politely (Transients, TFs)
  • Use fast spectrum analyzer to check MC loop gain out to a few MHz. (The bump in the tens of kHz should be fixed / moved higher)
  • Think about noise performance of, say, REFLDC, ASDC, RF AS signals, etc. in the PRY case, figure out which one to use first. 
  • We may want to first focus on directly locking the arm on an RF signal, figure out gains etc. and then figure out how to do DC->RF handoff nicely, or if high bandwidth DC signal control is even feasible.  

  9912   Tue May 6 02:48:50 2014 JenneUpdateLSCAO path engaged with AS55 as error signal for Yarm locking

[Rana, Jenne]

This evening, we were able to lock the Yarm through the common mode board, using AS55 as our error signal.  Our final UGF is about 5kHz, with 60 degrees of phase margin.

Before dinner, Rana switched the input of the CM board's REFL1 input to be AS55I rather than POY11Q, in the hopes that it would have better SNR.  Demod phase of AS55 was measured to be 14 deg for optimum Yarm->I-phase and has been set to 0 degrees.  Since the POY demod phase had been 90 degrees, which puts in a minus sign, and now we're using 0 deg which doesn't have a minus sign, we're using the plus (instead of minus) polarity of the CM board.

We re-allocated gains to help lower the overall noise by moving 15dB from the CM board AO gain slider to the MC IN2 gain slider, so we weren't attenuating signals.

We see, by taking loop measurements even before engaging the AO path (so, just the digital loop portion) that we've gained something like 20 degrees of phase margin!  We think that about 5 degrees is some LSC loop re-shaping of the boost filter.  We weren't sure why there was a hump of extra gain in the boost filter, so we've created a new (FM8) boost filter which is just a usual resonant gain:  resgain(16.5,7,50)

The cm_down and cm_step scripts in ..../scripts/PRFPMI/ were modified to reflect the settings below, and their current states are included in the tarball attached.

Also, throughout our endeavors this evening, the PC fast rms has stayed nice and low, so we don't suspect any EOM saturation issues.


Now our Yarm digital servo has a gain of -0.0013, with FMs 2, 4, 5, 7, 8 engaged (2, 7, 8 are triggered). 

Our final CM board settings are: 

REFL1 gain = +22dB

offset = -2.898V

Boost = enable

Super Boost = 0

option = disable

1.6k:79 coupled cavity compensator = enabled

polarity = plus

option = disable

AO gain = 15dB

limiter = enable

MC board:  IN1 gain = 18dB, IN2 gain = 0dB.


Here is a measurement of the Common Mode MCL/AO crossover.  The purple/orange trace here is after/before the boost was engaged.

out.pdf

We also have a measurement of the total loop gain, measured with the SR785.  The parameter file, as well as the python script to get the data, are in the tarball attached.  Noteably, the excitation amplitude was 500mV, whereas Q and Rana yesterday were using 5 or 8 mV.  We aren't sure why the big change was necessary to get a reasonable measurement out.  This measurement is with the boost enabled.

TF3_5May2014_BoostON_UGF5kHz.png

Finally, here is a measurement of the MC error point spectra, with the CM boost on, after we reallocated the gains.  There's a giant bump at several tens of kHz.  We need to actually go out with the fast analyzer and tune up the MC loop.

CM_TP2A_140506_boostON_realloc.png

  9911   Mon May 5 19:51:56 2014 jamieUpdateCDSc1oaf model broken because of broken BLRMS block

I finally tracked down the problem with the c1oaf model to the BLRMS part:

/opt/rtcds/userapps/release/cds/common/models/BLRMS.mdl

blrms-hot-mess.pngsddefault.jpg

Note that this is pulling from a cds/common location, so presumably this is a part that's also being used at the sites.

Either there was an svn up that pulled in something new and broken, or the local version is broken, or who knows what.

We'll have to figure how what's going on here, but in the mean time, as I already mentioned, I'm leaving the c1oaf model off for now.

 RXA: also...we updated Ottavia to Ubuntu 12 LTS...but now it has no working network connection. Needs help.  (which of course has nothing whatsoever to do with this point )

  9910   Mon May 5 19:34:54 2014 jamieUpdateCDSc1ioo/c1ioo control output IPCs changed to PCIE Dolphin

Now the c1ioo in on the Dolphin network, I changed the c1ioo MC{1,2,3}_{PIT,YAW} and MC{L,F} outputs to go out over the Dolphin network rather than the old RFM network.

Two models, c1mcs and c1oaf, are ultimately the consumers of these outputs.  Now they are picking up the new PCIE IPC channels directly, rather than from any sort of RFM/PCIE proxy hops.  This should improve the phase for these channels a bit, as well as reduce complexity and clutter.  More stuff was removed from c1rfm as well, moving us to the goal of getting rid of that model entirely.

c1ioo, c1mcs, and c1rfm were all rebuild/installed/restarted, and all came back fine.  The mode cleaner relocked once we reenabled the autolocker.

c1oaf, on the other hand, is not building.  It's not building even before the changes I attempted, though.  I tried reverting c1oaf back to what is in the SVN (which also corresponds to what is currently running) and it doesn't compile either:

controls@c1lsc ~ 2$ rtcds build c1oaf
buildd: /opt/rtcds/caltech/c1/rtbuild
### building c1oaf...
Cleaning c1oaf...
Done
Parsing the model c1oaf...
YARM_BLRMS_SEIS_CLASS TP
YARM_BLRMS_SEIS_CLASS_EQ TP
YARM_BLRMS_SEIS_CLASS_QUIET TP
YARM_BLRMS_SEIS_CLASS_TRUCK TP
YARM_BLRMS_S_CLASS EpicsOut
YARM_BLRMS_S_CLASS_EQ EpicsOut
YARM_BLRMS_S_CLASS_QUIET EpicsOut
YARM_BLRMS_S_CLASS_TRUCK EpicsOut
YARM_BLRMS_classify_seismic FunctionCall
Please check the model for missing links around these parts.
make[1]: *** [c1oaf] Error 1
make: *** [c1oaf] Error 1
controls@c1lsc ~ 2$ 

I've been trying to debug it but have had no success.  For the time being I'm shutting off the c1oaf model, since it's now looking for bogus signals on RFM, until we can figure out what's wrong with it. 

  9909   Mon May 5 19:26:43 2014 JenneUpdateLSCOverride ability for whitening triggering

 Today I finally implemented a feature in the whitening triggering that I should have a long time ago:  an override button.

Now, on each RFPD's phase rotation screen, there is a button to either allow triggering for that PD (both quads) or to be in manual mode.  

If you are allowing triggering, they will behave as they have for the last ~year.....if any degree of freedom is using either quadrant of that PD, and that degree of freedom is triggered, then engage analog whitening and digital de-whitening.

If you chose manual mode, then you can engage or disengage the whitening as you please.  (The analog whitening and digital de-whitening are still tied together).

  9908   Sun May 4 22:28:54 2014 ericqUpdateLSCfarther into CM

 [Rana, ericq]

Today, we got a ~2kHz bandwidth lock of the YARM with the AO path. We weren't able to turn any boosts on, due to POY noise. 

Rana and Koji have written scripts (/scripts/PRFPMI/cm_step and cm_down) that work very reliably. 

Here is an OLTF. (Violin filter was off, the crap around 600Hz goes away with them on)

 OLTF.png

My MATLAB modeling was useful is predicting the features of the loop shape, and the dependence on AO gain/crossover. Still, I need to check it out, because there is nonzero discrepancy between reality and my model (this may be hiding in the non flat MC AO response, i.e. the bump at ~35kHz. Alternatively, the crossover frequency is a free parameter...)

In any case, we have confidence that the CM board is mostly working predictably. We presume that our current obstacle is the very noisy nature of POY, and thus it's not worth spending more time in this configuration. 

Upcoming plans:

  • Use the CM board to control the Y arm coupled with the PRM. ("PRY"?)
  • Determine the game plane for high BW control of CARM. 

Next steps:

  • Check CM board boosts turn on politely (Transients, TFs)
  • Use fast spectrum analyzer to check MC loop gain out to a few MHz. (The bump in the tens of kHz should be fixed / moved higher)
  • Think about noise performance of, say, REFLDC, ASDC, RF AS signals, etc. in the PRY case, figure out which one to use first. 
  • We may want to first focus on directly locking the arm on an RF signal, figure out gains etc. and then figure out how to do DC->RF handoff nicely, or if high bandwidth DC signal control is even feasible. 

RXA: we should also use AS45 instead of POY11. It has better SNR and I think our whole problem is too little light on POY.

  9907   Sun May 4 14:20:04 2014 ericqUpdateIOOPMC relocked

The PMC has been unlocked for ~23 hours. FSS slow was at ~-1.5 V. I zeroed it, and relocked the PMC, transmission is ~0.81V. MC with WFS came back fine.

  9906   Fri May 2 19:03:13 2014 JenneUpdateLSCALS out of loop spectra

I have taken out of loop spectra for both arms, by looking at POX/POY while the arms were controlled with ALS.

To do this, I put the POY11 Q signal directly to the whitening board, which meant that I removed the cable coming from the common mode board.  (Now that we're doing CM stuff again, I have put it back, so POY is still in the slightly weird "going through the CM slow path" situation). 

For the locking, both arms had FMs 1, 2, 3, 5, 6 engaged.  Yarm had a gain of +17, Xarm had a gain of -17. 

Y beatnote was 98.6MHz with a peak height of -22 dBm.  X beatnote was 45.0MHz with a peak height -11 dBm.

I drove ITMY at 503.1 Hz with 100 counts.  I drove ITMX at 521.1 Hz with 25 cnt. 

Koji helped me match up the peak heights between the FINE_PHASE_OUT_HZ calibrated signals and the PDH signals. 

The out of loop noise is definitely below 1kHz rms now, which is better than it was!  Hooray!

ALS_OutOfLoop2_2May2014.pdf

  9905   Fri May 2 14:31:26 2014 KojiUpdateLSCALS Y beat setup aligned

Please check the X&Y ALS out-of-loop stability. Use fine resolution (BW0.01). Calibrate the POX/POY in Hz.

  9904   Fri May 2 13:03:30 2014 JenneUpdateLSCALS Y beat setup aligned

I touched up the alignment of the Ygreen on the PSL table.

  9903   Fri May 2 11:14:47 2014 jamieUpdateCDSc1ioo dolphin fiber nicely routed

Quote:

This C1IOO business seems to be wiping out the MC2_TRANS QPD servo settings each day.   What kind of BURT is being done to recover our settings after each of these activities?

(also we had to do mxstream restart on c1sus twice so far tonight -- not unusual, just keeping track)

I don't see how the work I did would affect this stuff, but I'll look into it.  I didn't touch the MC2 trans QPD signals.  Also nothing I did has anything to do with BURT.  I didn't change any channels, I only swapped out the IPCs.

  9902   Fri May 2 10:38:29 2014 steveUpdatePSLthin window AR measured

Quote:

CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS  S polarization beam was used with an other 1/2 wave plate and PBS.

W2-PW1-1004-C-633-1064-0   This 0.045" thick window has 0.7- 0.8 % reflected beam on each sides at 5 degrees of incidence, P polarization.

The specification is  R avg <0.5 % per surface at 0 degree

Rana wants The device would be useless with such a high R, but R 0.1% is OK so I will get V coating.

 CVI V-AR coating at 1064 nm, 0 degree,  catalog item is R< 0.25% on each sides,

 R <0.1 % is custom at much higher prices.

This custom order should go with other  orders that has similar need.

From CVI: 5-6-2014

I checked the trace info on the W2-PW1-1004-C-633-1064-0, BBAR coated window that you received.  It is side 1, 0.42%R & side 2, 0.53%R @ 1064nm.  And with the shift, I’m not too surprised you ended up with 0.7%.  A V coat would start with <0.25% (and more typically coming in at ~0.1%) per surface.  As far as stock options, I have a 1”dia x 4mmT, fused silica window that is recorded as side 1, R=0.09 and Side 2, R=0.08% @ 1064.  Is this too think or will it work for you?

 

 

  9901   Fri May 2 08:38:07 2014 SteveUpdateIOOthis typical morning

 

 c1sus needed reset.

  9900   Fri May 2 08:15:54 2014 steveUpdatesafetysafety audit 2014

 

 Late adition: CHECK all viewport covers.

A, transparent Lexan sheet is protecting glass windows in a horizontal position

B, metal housing protection is required on each viewport except signal ports

C, signal ports should be shielded by optical table enclosure

 

We have to cover this window-camera with implosion proof cover or just remove it and blank it.

Question number 2: Do our vertically positioned windows with flip able covers require protective lexan ? NO 5-5-2014

  9899   Fri May 2 03:51:29 2014 ranaUpdateLSCfarther into CM

Rana, Q

After some more matlab loopology (see Qlog), we turned on the AO path successfully. The key was to turn on the 300:80 filter in the MCL path so that it could cross stably with the AO. Then we ramp up the AO gain via the newly AC coupled AO path into the MC servo board.

The POY11 signal looks nice and smooth. For the final smoothness after the overall common gain is ramped up, I turned on a FM7 pole at 300 Hz so that the MC path would keep falling like 1/f^2 and not interfere with the AO path around 1 kHz.

There's not enough gain yet to be able to turn on the Boost. PCDRIVE is ~3 V. Earlier tonight we were seeing the EOM saturation effect maybe, but we re-allocated the gain more to the front end and its all fine now. I think we can get another ~10-15 dB of gain by using the POY whitening gain slider + the CM AO slider. Then we can get the Boost on and take some TFs with the SR785 (as long GPIB allows).

Good Settings:

CM REFL1 = +31 dB, AO = +16 dB, MC IN2 = +16 dB. SUS-MC2_LSC = FM6, FM& ON

 

** Everything has been pretty stable tonight except some occasional MC/EOM locking oscillations. This means that its been easy to keep trying some different CM steps since the Y-Arm relocks using MCL within seconds.

  9898   Fri May 2 02:22:56 2014 rana, QUpdateIOOMC alignments

We were having unstable MC locking so we did some physical alignment touch up. Use MC suspension bias to have good MC alignment. Unlock MC and align DC beams to center on WFS. Re-lock and things are now stable.

Someone had been feeding bad info to Eric about MC alignments; we do not center the MC WFS beams with the MC locked.

However, in any case, today the MC2-TRANS servo was not being good so I turned it off. We need the real matrix measurement to bring it back.

  9897   Fri May 2 01:58:52 2014 ranaConfigurationComputer Scripts / ProgramsupdateDB configured to index NFS during CRON daily

I wanted to use locate to find some files today, but found that it doesn't index any of our NFS mounted files (i.e. the whole /cvs/cds/ and /opt/rtcds/ ).

So I went into /etc/updatedb.conf and edited it like so, so that it no longer ignores NFS type file systems:

controls@rossa:/etc 0$ diff updatedb.conf updatedb.conf~
4c4
< PRUNEFS="nfs4 rpc_pipefs afs binfmt_misc proc smbfs autofs iso9660 ncpfs coda devpts ftpfs devfs mfs shfs sysfs cifs lustre_lite tmpfs usbfs udf fuse.glusterfs fuse.sshfs ecryptfs fusesmb devtmpfs"
---
> PRUNEFS="NFS nfs nfs4 rpc_pipefs afs binfmt_misc proc smbfs autofs iso9660 ncpfs coda devpts ftpfs devfs mfs shfs sysfs cifs lustre_lite tmpfs usbfs udf fuse.glusterfs fuse.sshfs ecryptfs fusesmb devtmpfs"

The CRON.daily on ROSSA only should run each morning at 6:25 (under the ionice class 3 protocol as usual). If this seems OK after a week or so, we can do the same for the other CDS workstations (remembering to adjust their cron.daily times so that not every one hammers the NFS at the same time).

  9896   Fri May 2 01:01:28 2014 ranaUpdateCDSc1ioo dolphin fiber nicely routed

This C1IOO business seems to be wiping out the MC2_TRANS QPD servo settings each day.   What kind of BURT is being done to recover our settings after each of these activities?

(also we had to do mxstream restart on c1sus twice so far tonight -- not unusual, just keeping track)

  9895   Thu May 1 17:14:36 2014 steveUpdatePSLthin window AR measured

CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS  S polarization beam was used with an other 1/2 wave plate and PBS.

W2-PW1-1004-C-633-1064-0   This 0.045" thick window has 0.7- 0.8 % reflected beam on each sides at 5 degrees of incidence, P polarization.

The specification is  R avg <0.5 % per surface at 0 degree

Rana wants The device would be useless with such a high R, but R 0.1% is OK so I will get V coating.

  9894   Thu May 1 17:00:05 2014 ranaUpdateLSCYarm locking with CM board

 I think that's about halfway there. Since this needs to be a precise comparison, we cannot use so many approximations.

We've got to include the digital AA and AI filters as well as the true, measured, time delay in the system. Also the measured/fitted TF of the CM board with the 79:1.6k filter engaged. We want an overall phase accuracy between Jenne's measured TF from last night and this model (i.e. on the same plot with the residual plotted).

Is there a cavity pole in the model? Should be at ~1.6 kHz.

  9893   Thu May 1 16:41:35 2014 ericqUpdateLSCYarm locking with CM board

 (Edited this post; Forgot to account for the FMs other than 4 and 5... it now agrees better!)

I did some quick MATLAB simulation of the relevant loops to try and understand what was going on. I put the digital UGF around 200Hz, and then brought in the AO path with both signs. 

In these plots, blue is digital only, green is AO+digital with the crossover happening at the UGF, and red is the AO gain set to five times of what it was in the green curve. 

 AOsignsSame.pdfAOsignsOpposite.pdf

Based on the phase curves in the loop measurements, I would be inclined to say the pink -AO case corresponds to the opposite sign plot, and the +AO case to the same sign plot. 

This correspondence also holds for the appearance of the peaks in the noise curves, the Opposite sign case has a dip in loop gain at ~50Hz (pink curve, -AO), same sign around ~30Hz (brown curve, +AO). 

However, both of these look like they become unstable at some point in the transition! This agrees with our experience last night...

I'll fiddle around and try to come up with some compensating digital filter that will make the Opposite sign scenario work. 

The MATLAB code I used to make these plots is attached. 

  9892   Thu May 1 14:45:44 2014 JenneUpdateLSCMC board back in

Quote:

Quote:

To fix this, I am going to put a 6.8uF cap in series with R30 in the MC board, which is part of the crossbar switch where the IN1 and IN2 get summed.  This should AC-couple the output of the IN2 slider before the summing node.

 MC board is out, so don't be surprised that the MC isn't locking.

 MC board is back in place, MC is locked.

If I disable all of the AO path bits of the CM servo (disable switch, and also gain slider to -32dB), and then move the MC IN2 slider around, the MC does not get an offset anymore (as seen by reduced transmission and increased reflected power), so I think the DC coupling is working.  I do lose lock of the MC if the slider goes above ~22 dB in this situation, but I don't see any effect before then, whereas we were able to see a steady increase in the reflected power as we moved the slider around last night.  So, it seems like things are good with the DC coupling of the IN2 slider.

Here are some photos from before I modified the board (front, back, and zoom of the area I was working in):

IMG_1394.JPG

IMG_1395.JPG

IMG_1398.JPG

And here is my modification, putting the 6.8uF cap in series with (a new) 2k thin film resistor, in the spot for R30:

IMG_1402.JPG

The board is https://dcc.ligo.org/DocDB/0004/D040180/001/D040180-C.pdf

[Edit, 20140721: It looks like this is actually D040180 rev B, not rev C. —Evan]

  9891   Thu May 1 13:03:34 2014 JenneUpdateLSCMC board pulled for AC coupling

Quote:

To fix this, I am going to put a 6.8uF cap in series with R30 in the MC board, which is part of the crossbar switch where the IN1 and IN2 get summed.  This should AC-couple the output of the IN2 slider before the summing node.

 MC board is out, so don't be surprised that the MC isn't locking.

  9890   Thu May 1 10:23:42 2014 jamieUpdateCDSc1ioo dolphin fiber nicely routed

Steve and I nicely routed the dolphin fiber from c1ioo in the 1X2 rack to the dolphin switch in the 1X4 rack.  I shutdown c1ioo before removing the fiber, but still all the dolphin connected models crashed.  After the fiber was run, I brought back c1ioo and restarted all wedged models.  Everything is green again:

green.png

  9889   Thu May 1 03:23:07 2014 ericqUpdateLSCYarm locking with CM board

Quote:

POY is going from its demod board to the CM board, and then the slow output of that is going to the POY channel of the whitening, and then on to the ADC.  So, with no AO path engaged, this is basically like regular Yarm locking.  

Just to be clear, the normal POY signals are not currently present, so the restore POY script will not result in the arm locking. POY11_I is turned off, POY11_Q is the output of the CM board, which can be used to lock the arm, as we did tonight. 

The POY digital demos angle went -56 -> 90, to get all of POY11_Q_IN1 to POY11_I_ERR

Miscellaneous things:

  • Right now, the cable from CM board ->MC board is a BNC. There appeared to be a differential 2-pin lemo hanging around for this purpose, but it didn't seem to be transmitting the signal. However, we will want something better than a BNC to keep this signal clean. 
  • I took SR785 TFs of the CM board from IN to the slow and fast outs. They looked reasonable, and will be posted in time. 
  • We enabled the 79:1.6k filter in the CM screen (though it is unclear if these are the actual values...), and put in its inverse in the digital path. I.e. we only want this shape in the AO path, to give it 1/f shape in the vicinity of the crossover. This is only necessary in the uncoupled cavity case. 
  9888   Thu May 1 03:15:03 2014 JenneUpdateLSCYarm locking with CM board

[Rana, EricQ, Jenne]

We locked the Yarm by using the CM board this evening. 

POY is going from its demod board to the CM board, and then the slow output of that is going to the POY channel of the whitening, and then on to the ADC.  So, with no AO path engaged, this is basically like regular Yarm locking. 

First of all, Den and Koji back in December were concerned that they were seeing some EOM saturation in the fast path, but we don't think that's an issue.  We looked at the FSS PCDRIVE while we increased the AO gain.  In fact, it looks like the offset is coming from the MC board's IN2 slider.  Even with no input on that slider, increasing its value puts an offset into the MC.  To fix this, I am going to put a 6.8uF cap in series with R30 in the MC board, which is part of the crossbar switch where the IN1 and IN2 get summed.  This should AC-couple the output of the IN2 slider before the summing node.

We aren't sure which sign to use for the AO path of the CM board...Eric is doing some modelling to see if he can figure it out.  He's going to try to see which spectra (below) his model matches.

For the spectra, we have a reference trace with no AO path, a trace with "Plus" polarity on the CM board which started to show a peak when the value of the MC IN2 slider was at about -6 dB, and a trace with "Minus" polarity, which started to show a peak when the value of the MC IN2 slider was at about -16 dB. 

Yarm_CMlocking_spectra_30Apr2014_copy.pdf

We took loop measurements for each of the Plus and Minus cases. Something that seems a little weird is how shallow of a slope we have in both cases near our UGF.

Yarm_CMlocking_TFs_30Apr2014_copy.pdf

 

  9887   Thu May 1 00:13:21 2014 KojiUpdateLSCALS X beat setup aligned

I saw big misalignment on the GTRX camera, I went to the PSL table and aligned the beat beams.

I disconnected the RF out of the X beat PD and  connect an oscilloscope.
The beat amplitude was 15mVpp at the beginning and is 60mVpp right now.
I checked the alignment on this RF PD and the DC PD as well as the spot on the CCD.

The RF cable was connected again.

Jenne and I ran the ALS and scanned the arm cavity. We had the impression that the noise level of the ALS improved,
but I don't have correctly calibrated measurement. Let's do it tomorrow in the day time.

The Yarm beat alignment look awful. We should align this too.

  9886   Wed Apr 30 21:57:07 2014 ranaSummaryIOOMC2_TRANS QPD Servo now on for real

dolphin.pngMC2_QPD_trend.png

During a lull in Koji vs. The Arm, I switched on the MC2_TRANSQPD feedback path to check out its UGF. In the past months, when its been on, it has had a gain of ~0.03 - 0.1.

Today, I found that with the gain turned up to 11, it has a ~1 minute step response time (as you see in the above Strip chart). So its had a UGF of ~2 hours or so during the times when we thought it might be doing bad or good or magic.

I leave it on now to see if it behaves well over the next days. Let's see if Steve thinks its good or not based on his trend monitoring.

** also touched up the PMC pointing (using the PMC REFL image / please never align the beam into the PMC without this camera image)

  9885   Wed Apr 30 21:31:25 2014 ranaHowToIOOMystery Alignment again

Looks like there was some mysterious MC alignment shift around 5:30 PM today, but no elog.....?? Now things are drifting much more than this morning or yesterday. Who did what and why???

I think I'll blame Jamie since he just got back and did some computer fiber voodoo today.

http://www.lawsome.net/no-throwing-rotten-tomatoes-a-repealed-kentucky-law/

  9884   Wed Apr 30 21:16:42 2014 ranaUpdateLSCMC2 Strad

bettsreplica.jpg

I found the YARM LSC feedback going to MC2 and the MC2 violin mode (at 644.69 Hz) rung up. The existing notch was just a second order Twin-T style notch (so not a good idea) and also not turned on, since it was in the FM4 spot of LSC-MC2 and the vio triggers are ganged between all mirrors and don't touch FM4.

I copied the PRM vio bandstop into FM2 of this bank, deleted the old notch, and tuned the bandstop frequencies a little to get the violin peak into one of the zeros of the elliptic bandstop. Attached are the Y-arm / MCF spectrum with the mode rung up as well as the new filter's TF compared with the old notch.

P.S. I installed http://en.wikipedia.org/wiki/Midnight_Commander on pianosa.

  9883   Wed Apr 30 18:06:06 2014 jamieUpdateCDSPOP QPD signals now on dolphin

The POP QPD X/Y/SUM signals, which are acquired in c1ioo, are now being broadcast over dolphin.  c1ass was modified to pick them up there as well:

c1ioo-POPQPD.pngc1ass-POPQPD.png

Here are the new IPC entries:

controls@fb ~ 0$ egrep -A5 'C1:IOO-POP' /opt/rtcds/caltech/c1/chans/ipc/C1.ipc
[C1:IOO-POP_QPD_SUM]
ipcType=PCIE
ipcRate=16384
ipcHost=c1ioo
ipcNum=116
desc=Automatically generated by feCodeGen.pl on 2014_Apr_30_17:33:22
--
[C1:IOO-POP_QPD_X]
ipcType=PCIE
ipcRate=16384
ipcHost=c1ioo
ipcNum=117
desc=Automatically generated by feCodeGen.pl on 2014_Apr_30_17:33:22
--
[C1:IOO-POP_QPD_Y]
ipcType=PCIE
ipcRate=16384
ipcHost=c1ioo
ipcNum=118
desc=Automatically generated by feCodeGen.pl on 2014_Apr_30_17:33:22
controls@fb ~ 0$ 

Both c1ioo and c1ass were rebuild/install/restarted, and everything came up fine.

The corresponding cruft was removed from c1rfm, which was also rebuild/installed/restarted.

ELOG V3.1.3-