40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 169 of 339  Not logged in ELOG logo
ID Date Author Typeup Category Subject
  6669   Wed May 23 21:32:15 2012 SureshUpdateIOOWFS didn't turn off automatically

Quote:

I just sat down in the control room, and discovered the PMC (and everything else) unlocked.  I relocked the PMC, but the MC wasn't coming back.  After a moment of looking around, I discovered that the WFS were on, and railing.  I ran the "turn WFS off" script, and the MC came back right away, and the WFS came on as they should.

We need to relook at the WFS script, or the MC down script, to make sure that any time the MC is unlocked, no matter why it unlocked, the WFS output is off and the filter histories are cleared.

    The only script that can currently take this action is the MC autolocker.  If that is disabled first and the PMC unlocks later, the WFS will not be turned off.  During the last round of discussions we had about the autolocker script, sometime last Nov, we decided that too much automation is not desirable and that the autolocker should be kept as simple as possible.

 

  6670   Thu May 24 01:17:13 2012 DenUpdateCDSPMC autolocker

Quote:

 

  • SCRIPT
    • Auto-locker for PMC, PSL things - DEN

 I wrote auto-locker for PMC. It is called autolocker_pmc, located in the scripts directory, svn commited. I connected it to the channel C1:PSL-PMC_LOCK.  It is currently running on rosalba. MC autolocker runs on op340m, but I could not execute the script on that machine

op340m:scripts>./autolock_pmc
./autolock_pmc: Stale NFS file handle.

I did several tests, usually, the script locks PMC is a few seconds. However, if PMC DC output has been drift significantly, if might take longer as discussed below.

The algorithm:

       if autolocker if enabled, monitor PSL-PMC_PMCTRANSPD channel
       if TRANS is less then 0.4, start locking:
               disengage PMC servo by enabling PMC TEST 1
               change PSL-PMC_RAMP unless TRANS is higher then 0.4 (*)
               engage PMC servo by disabling PMC TEST 1
       else sleep for 1 sec
 

(*) is tricky. If RAMP (DC offset) is specified then TRANS will be oscillating in the range ( TRANS_MIN, TRANS_MAX ). We are interested only in the TRANS_MAX. To make sure, we estimate it right, TRANS channel is read 10 times and the maximum value is chosen. This works good.

Next problem is to find the proper range and step to vary DC offset RAMP. Of coarse, we can choose the maximum range (-7, 0) and minimum step 0.0001, but it will take too long to find the proper DC offset. For that reason autolocker tries to find a resonance close to the previous DC offset in the range (RAMP_OLD - delta, RAMP_OLD + delta), initial delta is 0.03 and step is 0.003. It resonance is not found in this region, then delta is multiplied by a factor of 2 and so on. During this process RAMP range is controlled not to be wider then (-7, 0).

The might be a better way to do this. For example, use the gradient descent algorithm and control the step adaptively. I'll do that if this realization will be too slow.

I've disabled autolocker_pmc for the night.

  6671   Thu May 24 02:55:36 2012 DenUpdatePEMacoustic noise in MCL

Mic in the PSL showed that fluctuations in the MCL in the frequency range 10 - 100 Hz are due to acoustic noise. I've measured MCL, MCL / PSL mic coherence 2 times with interval 300 seconds.

Surprisingly, acoustic noise level did not change but MC sometimes is more sensitive to acoustic noise, sometimes less.

audio_noise.png

  6672   Thu May 24 10:10:04 2012 steveUpdateIOOPMC locked

 The PMC  behavior is not changed.

 

Attachment 1: pmc4d.png
pmc4d.png
  6673   Thu May 24 12:23:00 2012 DenUpdateGeneralconnection error monitor for the website

The main page of connection error monitor can be a scheme of computers and models with connections. If there is an error in connection, the corresponding arrows turns from green to red.

errors_overview.png

 

Each arrow is a line to a more detailed information about the channels.

errors.png

  6674   Thu May 24 13:28:38 2012 DenUpdatePEMHEPA

HEPA filter was running at 90% of max. I reduced it to 20%. Acoustic noise moved down

psl_acoustic.png

The range of MCL oscillations has also decreased but fluctuations in the frequency range 10-100 are still present.

MCL is much more stable now.

mcl_90.png        mcl_20.png

 

  6677   Thu May 24 16:13:05 2012 yutaUpdateComputersASS scripts on new ubuntu machines

[Den, Yuta]

Background:
 ASS and many other scripts don't work on new ubuntu machines.

What we did:
1. Installed C-shell on rossa and rosalba(Ubuntu machine).
  sudo apt-get insall csh

2. Find out that
  /opt/rtcds/caltech/c1/scripts/AutoDither/alignY

runs, but
  /opt/rtcds/caltech/c1/scripts/medmrun /opt/rtcds/caltech/c1/scripts/AutoDither/alignY

doesn't run. It gives us the following error messages.

ezcawrite: error while loading shared libraries: libca.so: cannot open shared object file: No such file or directory
ezcaswitch: error while loading shared libraries: libca.so: cannot open shared object file: No such file or directory

Result:
 ASS scripts run on rossa and rosalba, but not with medmrun.
 At least ASS scripts run on pianosa(ubuntu machine) with medmrun. So we decided to wait for JAMIE to fix it.

  6678   Thu May 24 16:39:47 2012 steveUpdateGeneralsteve's webpage example

3 strip charts monitoring on 24 hours time scale: Vac,  PSL-IFO,  SUS and 10 channel video monitoring inside - outside  of 40m lab

Attachment 1: 05241201.PDF
05241201.PDF
  6679   Thu May 24 19:39:18 2012 SureshUpdateIOOMC and WFS alignment adjusted

[Yuta, Suresh]

We found that the MC was not locking and that the alignment between PSL and MC was too poor to obtain a TEM00 mode in the MC.   To correct the situation we went through the following steps:

1) We burt restored the MC alignment slider values to their values at 3:07 AM of today

2) We turned off the MC-autolocker and the ASC signal to the coils.   Then aligned the PSL beam into the MC (with the MC servo loop off) to obtain the TEM00 mode.  We had to adjust the zig-zag at the PSL output by quite a bit to maximise MC transmission.

3) We then centered the spot on the MC2 face and centered the transmitted beam on the MC2_TRANS_QPD

4) Next, we centered the beams on the MC_WFS sensors.

5) Turning on the WFS loops after this showed that everything works fine and WFS loops do not accumulate large offsets.

 

 

  6680   Fri May 25 02:56:44 2012 DenUpdateSUSMC3 local damping

I've terminated input to AA filters and measured signal to coils C1:SUS-MC3_??COIL_OUT.

DSC_4305.JPG

 

I compared this noise to the signal when OSEM are connected to ADC.

    osem_noise.png

 

I made BNC -> LEMO board such that all LEMOs have the same signal equal to BNC signal. I provided excitation of 50 mV as white noise to the input of the AA filter and measured coherence between excitation and MC3 coil driver. The path is

AA -> ICS 110 -> Pentium -> Pentek -> AI -> Univ Dewhitening -> Coil Driver

As all inputs have the same signal, matrices that recombine the signals should not affect coherence. But what I got for coherence between AA IN / Dewhitening OUT is

osem_coil.png

  6681   Fri May 25 13:24:48 2012 DenUpdateSUSMC3

AA IN -> COIL DRIVER IN transfer function for MC3

freq_resp.png

I've provided excitation to the AA input, the same for all OSEM channels. In the digital domain coherence between C1:SUS-MC3_ULSEN_INMON / C1:SUS-MC3_ULCOIL_INMON and other channels OSEM -> COIL is 1 starting from 0.1Hz.

test_dig.png

The only thing left to understand is why the coherence AA IN / COIL DRIVER IN measured in the analog domain is not 1 in the frequency range 0.1 - 1 Hz. It does not look like just SRS noise. I've connected Ch 1 and 2 to the source, coherence is close to 1.

  6682   Fri May 25 16:10:53 2012 KojiUpdateGeneralStripTool on Zita restored

ssh -X pianosa

On pianosa

StripTool PSL.strip&
StripTool IOO.strip&
StripTool seismic.strip&

 

  6684   Fri May 25 17:50:38 2012 JamieUpdateComputersASS scripts on new ubuntu machines

Quote:

[Den, Yuta]

Background:
 ASS and many other scripts don't work on new ubuntu machines.

What we did:
1. Installed C-shell on rossa and rosalba(Ubuntu machine).
  sudo apt-get insall csh

2. Find out that
  /opt/rtcds/caltech/c1/scripts/AutoDither/alignY

runs, but
  /opt/rtcds/caltech/c1/scripts/medmrun /opt/rtcds/caltech/c1/scripts/AutoDither/alignY

doesn't run. It gives us the following error messages.

ezcawrite: error while loading shared libraries: libca.so: cannot open shared object file: No such file or directory
ezcaswitch: error while loading shared libraries: libca.so: cannot open shared object file: No such file or directory

Result:
 ASS scripts run on rossa and rosalba, but not with medmrun.
 At least ASS scripts run on pianosa(ubuntu machine) with medmrun. So we decided to wait for JAMIE to fix it.

Apparently the environment was not being properly inherited by the scripts launched from medmrun.  We modified the medmrum script so that it executes things with an interactive shell ("bash -i -c ...") and this fixed the problem (by assuring that it sources all the interactive environment configs (i.e. ~/.bashrc)).  I'm still not sure why we were seeing different behavior on pianosa, but at least the solution we have now should be robust.

As a reminder, all scripts launched from MEDM should use medmrun:

/opt/rtcds/caltech/c1/scripts/medmrun
  6685   Fri May 25 17:52:08 2012 JamieUpdateComputersallegra now running Ubuntu 10.04

The last of the control room machines is now upgraded.

  6688   Fri May 25 23:11:50 2012 SureshUpdateIOOMC spot positions measured

[Koji, Yuta, Suresh]

We measured the MC spot positions after re-aligning the MC.  The spot positions are listed below:

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
    3.9073    6.6754    2.8591   -7.6985   -0.9492    7.0423

 

Procedure:

1) In the directory /opt/rtcds/caltech/c1/scripts/ASS/MC  we have the following scripts

      a) mcassUp:    This sets up the MCASS lockins to excite each of the MC mirrors at a different frequency

      b) mcassOn:    This sets the MCASS output matrix to actually send the excitation signals to the mirrors

      c) senseMCdecenter:  This sequentially introduces a 10% offset into the coil gains of each mirror degree of freedom.   It also sends the lockin output data to the screen. 

      d) sensemcass.m :  This is a matlab file which digests the data gathered by the senseMCdecenter script to print a couple of plots and compute the spot positions.

      e) MCASS_StripTool.stp:  This is a set-up file for the StripTool which allows us to see the MCASS-lockin_outputs.  It is nice to see the action of senseMCdecenter  script  at work.

 

2) So the series of commands to use are

      a) ./StripTool  <-- MCASS_StripTool.stp

      b) ./mcassUp

      c) ./mcassOn

      d) ./senseMCdecenter | tee Output_file

       e) ./mcassOff

      f) ./mcassDown

       g) matlab <-- sensemcass.m  <---- Output_file

 

  6689   Sat May 26 00:08:41 2012 DenUpdateIOOMC_F low frequency noise

 MC_F low frequency noise might be due to local damping electronics. I did not measure OSEM noise, but even without it electronics (AA -> ICS 110 -> ADC) provide sufficient amount of noise. 

These 2 image show electronics noise and coherence between OSEM signal / seismic

osem_noise.png           gur_suspos_coh.png

From these 2 plots we might think that SNR > 10 and coherence OSEM / GUR is high at the frequency range 0.1 - 10 Hz and this is not a big problem.

However, at low frequencies the length of seismic waves becomes large enough and relative oscillations of MC2 and MC13 decrease.

For 1 wave ( u(MC2) - u(MC1) ) / u(MC2) = sin(2 * pi * L  * f  / c), L - distance between MC1 and MC2 where 2 seismometers are located. So MC123 move according to seismic motion and electronics noise is not seen unless we look at MC Length. Here this noise is seen, because mirrors move in a synchronistic manner. 

To check this I measured seismic noise with 2 guralps at distance 12 meters - at MC1 and MC2. Then I've computed the difference between these signals. And indeed at low frequencies, relative motion is much less.

Green, blue - GUR1,2_X

Red - differential motion GUR1_X - GUR2_X

dgur.png

 

The following plot illustrates how electronics noise effects MC_F. Green is the signal to coils. Red - electronics noise. Blue, black, cyan - simulated contribution to MC_F for different seismic waves speed. Most probably seismic waves have waves in the range 50 - 800 m/s, others are deep. The plot shows that electronics noise is big enough to disturb coherence between MC_F and seismic noise. 

mc_noises.png

Here is a rough calculation of the seismic waves speed. The following plot shows the ratio of psd of differential MC2-MC1 motion to MC2 motion.

ratio.png

If seismometers would be very far, ratio would be 1 if we neglect the difference in transfer function SEISMOMETER -> ADC for each channel. The drift of the ratio from 1 to 1.3 demonstrates this effect. Ratio starts to decrease at 15 Hz according to sin (2*pi*L*f/c) ~ 2*pi*L/c * f. So 2*pi*L/c * f_0 = pi/2 => c = 4 * L * f = 600 m / sec.

  6690   Sat May 26 01:28:58 2012 KojiUpdateGeneralClipping improvement

The beam at the dark port was largely clipped.
The arm transmissions (TRX/TRY) were ~0.6 no matter how you try to align.

The PZT1/2 X was scanned and TRX/TRY are now both ~0.9.
This means that the beam was mostly clipped in or after the mode mathing optics.

FPMI contrast is (2.45-0.02)/(2.45+0.02) = 98%
Not so bad although it does not tell anything about clipping before the IFO.

In the next opportunity, we should try to "pin" the beam axis on the arm mirrors using A2L.

1. I am not sure exactly where the clipping was. It means that a small clipping might still be there.

2. I am afraid that the beam is still clipped in the faraday. The beam can be scanned using the steering on the PSL table.

 

Attachment 1: Untitled.png
Untitled.png
  6691   Sat May 26 15:59:19 2012 DenUpdateIOOGuralp noise is high

As I've mentioned in yesterday's elog MC mirrors start to move in a synchronistic manner. I've plotted DELTA_GUR = GUR1_X - alpha * GUR2_X, where alpha = const to make the transfer functions SEISMOMETER -> ADC equal for each channel. I've noticed that DELTA_GUR decreases below 10 Hz compared to GUR1_X as theoretically predicted. But starting from 1 Hz DELTA_GUR starts to increase. I decided that this is Guralp noise floor. Today I checked this, this is indeed the case.

In the frequency range 0.01 - 1.5 Hz Gur noise is comparable to the signal DELTA_GUR. For that reason we see low coherence between MC_F and GUR1_X in this frequency range. 

gur_noise.png    MCF_GUR.png

Guralp noise floor was determined by placing 2 seimometers close to each other and subtracting by Wiener filtering.

DSC_4306.JPG

Conclusion: To filter seismic noise out of MC_F we need more sensitive seimometeres.

 

  6692   Sat May 26 20:40:48 2012 DenUpdatePEMexperiments with seismic noise

I measured relative motion of 2 seismometers separated by 4, 18 and 38 feet.

DSC_4307.JPG         DSC_4308.JPG

Relative motion for difference distances between seismometers is presented below.

    psd_distance.png        ratio.png

 

Al frequencies f < fcrit relative motion becomes smaller then motion of each point. At these frequencies, the ratio relative / absolute motion can be approximated as ratio = C fa . The following table summarizes fcrit, C and a for different length between seismometers.

 

L, ft fcrit, Hz
C a
4 45 0.0074 1.30
18 30 0.0057 1.52
38 15 0.0208 1.43

Using this approximation we can estimate the desired noise floor of the seismometer to subtract seismic noise from MC_F

sim_delta.png

Desired seismometer noise should be 100 times less then Guralp's. ADC noise is still less then this level, so this will not be a problem.

Note: for longer cavities condition for seismometer noise becomes more week as fcrit decreases with length.

  6693   Sat May 26 23:57:11 2012 DenUpdatePEMGuralp noise

I've looked through the Guralp manual to figure out what noise do they declare. They present it in acceleration units in dB relative to 1 m2 / s4 / Hz. I've converted my measurements to this units and got

noises.png

They declare much better noise. May be linoleum makes an effort. Do we have any isolation boxes?

  6695   Sun May 27 23:15:22 2012 DenUpdatePEMexperiments with seismometers

I wondered if linoleum is a reason of high Guralp noise. I measured Guralp noise in 3 cases: they stand on a very soft piece of paper, linulium and stone.

DSC_4309.JPG               DSC_4310.JPG                  DSC_4311.JPG

I've calibrated the noise to units m/s/sqrt(Hz). Using soft paper we get the worst noise, stone - the best, but noises do not differ that much and still much worse then declared noise in the manual.

loc_noise.png

  6696   Tue May 29 00:35:57 2012 DenUpdatePEMguralp readout box

I measured the frequency response of the Guralp readout box and noise by providing sin signal of amplitude 50 mV at 15 Hz for channels 1-3.

1_3.png

It turns out that the gain is ~250, while my liso model simulated it to be 200. This is because it is hard to approximate AD620 amplifier.

Noise of the box does not seem to be too bad at low frequencies.

  6697   Tue May 29 00:39:52 2012 DenUpdatePEMGuralp noise

I've connected Guralp output to the ADC without readout box. I've got the same noise at low frequencies and even worse noise at high frequencies. However, readout box was still used as DC supply and the signal was read from INPUT test points. I'll do the same experiment without touching readout box at all.

in_out.png

  6698   Tue May 29 00:48:51 2012 DenUpdatePEMsts readout box

STS readout box seems to be partly broken. I've terminated inputs from the seismometer and measured the output. I could not do this for vertical channel because it outputs 7 V DC + 500 mV AC signal. All the switches work fine, 5 V DC is indeed shown when auto zero, calibration, 1 sec resp, sig select are enables. The box has AC power supply that seems to work ok, all measured DC values are equal to the labels. Something is wrong with amplification.

 

sts_box.png

 

  6699   Tue May 29 00:53:57 2012 DenUpdateCDSproblems

I've noticed several CDS problems:

  1. Communication sign on C1SUS model turns to red once in a while. I press diag reset and it is gone. But after some time comes back.
  2. On C1LSC machine red "U" lamp shines with a period ~5 sec.
  3. I was not able to read data from the SR785 using netgpibdata.py. Either connection is not established at all, or data starts to download and then stops in the middle. I've checked the cables, power supplies and everything, still the same thing.
  6700   Tue May 29 10:08:21 2012 steveUpdateIOOcentered IOO monitoring qpds

IOO Angle & IOO Position QPDs centered.

Attachment 1: 40dtrendIOO.png
40dtrendIOO.png
Attachment 2: IOOcentered.png
IOOcentered.png
  6701   Tue May 29 14:58:28 2012 JenneUpdateLockingETMX trans camera

...will be helpful for acquiring lock after the vent.  We should install a camera at ETMX.

  6702   Tue May 29 14:59:39 2012 JenneUpdateIOOPMC, MC alignment are shit

[Yuta, Jenne]

PMC and MC alignment are both shit, although with the WFS on, the MC is pretty good.  We're leaving it for now, so that (a) we don't mess up Koji's work, and (b) we can work on the Xarm.  Steve is doing Yarm oplev stuff, so we'll do Yarm later.

  6703   Tue May 29 15:29:16 2012 JamieUpdateComputerslatest pynds installed on all new control room machines

The DASWG lscsoft package repositories have a lot of useful analysis software.  It is all maintained for Debian "sqeeze", but it's mostly installable without modification on Ubuntu 10.04 "lucid" (which is based on Debian squeeze).  Basically the only thing that needs to access the lscsoft repositories is to add the following repository file:

controls@rossa:~ 0$ cat /etc/apt/sources.list.d/lscsoft.list 
deb http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze contrib
deb-src http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze contrib

deb http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze-proposed contrib
deb-src http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze-proposed contrib
controls@rossa:~ 0$ 

A simple "apt-get update" then makes all the lscsoft packages available.

lscsoft includes the nds2 client packages (nds2-client-lib) and pynds (python-pynds).  Unfortunately the python-pynds debian squeeze package currently depends on libboost-python1.42, which is not available in Ubuntu lucid.  Fortunately, pynds itself does not require the latest version and can use what's in lucid.  I therefore rebuilt the pynds package on one of the control room machines:

$ apt-get install dpkg-dev devscripts debhelper            # these are packages needed to build a debian/ubuntu package
$ apt-get source python-pynds                              # this downloads the source of the package, and prepares it for a package build
$ cd python-pynds-0.7
$ debuild -uc -us                                          # this actually builds the package
$ ls -al ../python-pynds_0.7-lscsoft1+squeeze1_amd64.deb
-rw-r--r-- 1 controls controls 69210 2012-05-29 11:57 python-pynds_0.7-lscsoft1+squeeze1_amd64.deb

I then copied the package into a common place:

/ligo/apps/debs/python-pynds_0.7-lscsoft1+squeeze1_amd64.deb

I then installed it on all the control room machines as such:

$ sudo apt-get install libboost-python1.40.0 nds2-client-lib python-numpy   # these are the dependencies of python-pynds
$ sudo dpkg -i /ligo/apps/debs/python-pynds_0.7-lscsoft1+squeeze1_amd64.deb

I did this on all the control room machines.

It looks like the next version of pynds won't require us to jump through these extra hoops and should "just work".

  6704   Tue May 29 15:48:31 2012 KojiUpdateIOOPMC, MC alignment are shit

The followings are a kind of daily check. Do this without any notice:

- Align PMC.

- Check MC spot position with the script (where is it located?). Ignore MC2 result as it can be arbitrary set.

- If the MC1/MC3 spots have moved it means that the PSL beam has moved. If the beam has moved, we should have some discussion what we should do.

- If the spot positions are about the same as before, align the MC mirrors. This should be done by nulling the WFS feedback. (Someone should make a simple script for this WFS offloading.)

------------

Then, start locking both arms

Quote:

[Yuta, Jenne]

PMC and MC alignment are both shit, although with the WFS on, the MC is pretty good.  We're leaving it for now, so that (a) we don't mess up Koji's work, and (b) we can work on the Xarm.  Steve is doing Yarm oplev stuff, so we'll do Yarm later.

 

  6705   Tue May 29 15:49:02 2012 KojiUpdateLockingETMX trans camera

Quote:

...will be helpful for acquiring lock after the vent.  We should install a camera at ETMX.

 Do that.

  6706   Tue May 29 15:55:22 2012 steveUpdateSUSETMY oplev spot size reduced

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

There was no IP-ANG coming out of the chamber at this time!

Attachment 1: ETMYoplev.jpg
ETMYoplev.jpg
Attachment 2: IMG_1243.JPG
IMG_1243.JPG
  6707   Tue May 29 17:40:45 2012 JenneUpdateIOOPMC, MC alignment are shit

Quote:

[Yuta, Jenne]

PMC and MC alignment are both shit, although with the WFS on, the MC is pretty good.  We're leaving it for now, so that (a) we don't mess up Koji's work, and (b) we can work on the Xarm.  Steve is doing Yarm oplev stuff, so we'll do Yarm later.

 [Yuta, Jenne, Suresh]

We pushed on the MC SUS connectors at the back of the rack, and that helped bring MC3 back to where it should be.  Then we looked at MC RFPD DC, and adjusted the optics with the WFS off, so that the refl is ~0.56.  Then when we turn the WFS on, the alignment doesn't really change, so we have offloaded the WFS. 

Now we're measuring the spot positions to check where the MC is.  Then we'll align the arms, and align the green to the arms.

  6708   Tue May 29 19:50:01 2012 JenneUpdateIOOPMC, MC alignment are shit

Quote:

The followings are a kind of daily check. Do this without any notice:

- Align PMC.

Quote:

[Yuta, Jenne]

PMC and MC alignment are both shit, although with the WFS on, the MC is pretty good.  We're leaving it for now, so that (a) we don't mess up Koji's work, and (b) we can work on the Xarm.  Steve is doing Yarm oplev stuff, so we'll do Yarm later.

 

 [Keiko, Jenne]

PMC aligned.  Suresh is fixing the measure MC spot positions script, then we'll remeasure MC spot positions.

  6709   Tue May 29 21:05:30 2012 yutaUpdateIOOPMC, MC alignment are shit

Quote:

  [Keiko, Jenne]

PMC aligned.  Suresh is fixing the measure MC spot positions script, then we'll remeasure MC spot positions.

 [Suresh, Jenne, Yuta]

We measured the MC spot positions twice tonight. Procedure for measuring them is in elog #6688.
The results were;

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
    3.3359    3.9595    2.3171   -7.7424   -0.8406    6.4884

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
    3.2681    4.0052    2.2808   -7.3965   -0.7624    7.1302

The spot moved by about 0.5 mm since May 25, but we concluded that this displacement is negligible and difficult to be fixed by aligning PSL beam.

We'll align Y arm and X arm next.

  6710   Tue May 29 21:34:08 2012 JenneUpdateSUSETMY oplev spot size reduced

Quote:

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

 Flipped the sign on the ETMY oplev servo gain, since it was wrong.  (It was "-" for both, now it is "+" for both)

  6711   Tue May 29 21:50:21 2012 JenneUpdateLockingYarm error spectra

The ~16Hz bounce mode of some optic is showing up in the Yarm error signal. 

MC is kind of 'windy' looking, so maybe it's from that? (Yuta's guess).

We need to make sure that the SUS damping and oplev paths both have notches at the correct bounce mode, not the old, old MOS frequency.  If that doesn't work, may need to put a resgain in Yarm path.

Attachment 1: LSC_POY_11_I_ERR_29May2012.pdf
LSC_POY_11_I_ERR_29May2012.pdf
  6712   Tue May 29 22:48:37 2012 DenUpdatePEMGuralp noise

I've checked whether the Guralp noise that we see comes not from seismometer but from ADC or readout box. I did 2 separate measurements . First, I've split 1 signal from Guralp into 2 before the input to AA board and subtracted one from another using Wiener filter. Second, I've connected inputs of channels 1 and 4 of the seismometer readout box and put the signal from seismometer to channel 1.

split_noises.png

The plot shows that ADC and readout box do not contribute too much to the Guralp noise.

  6713   Wed May 30 01:35:15 2012 yutaUpdateGreen Lockingaligned Y arm green beam

[Jenne, Yuta]

We aligned the Y arm for IR (C1:LSC-TRY_OUT is now ~ 0.9), and aligned the green beam from the ETMY table. The Y arm green is now resonating in TEM00 mode, but we need some monitors (green trans or green refl) to maximize the coupling.

We noticed that the MC beam spot are oscillating at ~ 1 Hz, mostly in YAW.  This wasn't observable before the PMC realignment (elog #6708). We should find out why and fix it.

  6714   Wed May 30 13:24:08 2012 JenneUpdateLockingYarm error spectra

Quote:

The ~16Hz bounce mode of some optic is showing up in the Yarm error signal. 

MC is kind of 'windy' looking, so maybe it's from that? (Yuta's guess).

We need to make sure that the SUS damping and oplev paths both have notches at the correct bounce mode, not the old, old MOS frequency.  If that doesn't work, may need to put a resgain in Yarm path.

 Made the Bounce notch in the BounceRoll filter (ITMY OLPIT, ITMY OLYAW)  wider, so it actually spans the peak we see in the error spectra.  When we next lock the arm later today, I'll retake this spectra to see if the ETMY oplev fix (Koji, Yuta) and this notch fix both helped.

  6715   Wed May 30 15:51:22 2012 yutaUpdateIOOMC beam spot oscillation

[Koji, Suresh, Jenne, Yuta]

Background:
  We noticed that the beam spots on MC mirrors are oscillating in ~ 1 Hz yesterday. It means MC mirrors are actually oscillating. This was observable even if the WFS servo is off.

What we did:
  1. By measuring the spectra of OSEM sensor outputs, we found that MC3 is the one that is oscillating.

  2.  Oscillation at ~ 1 Hz only happened when the local damping using OSEMs are on (see Attachment 1; REF is when the damping is on).

  3.  We found that this oscillation came from insufficiency in phase margin in SUSPOS loop. So, we increased the gain, C1:SUS-MC3_SUSPOS_GAIN, from 95 to 200. It helped a little, but oscillation is still there.

  4.  We measured openloop transferfunctions of SUSPOS, SUSPIT, SUSYAW, SUSSIDE loop, and concluded that diagonalization some how went wrong. The amplitude of the oscillation (peak height in the OSEM spectra) changed by pushing the MC SUS connectors.

Plan:
  - Fix the connectors so that we don't have to push them any more.
  - Redo the diagonalization of the MC suspensions.

Attachment 1: specMC3_onoff_localdamping.pdf
specMC3_onoff_localdamping.pdf
  6716   Wed May 30 18:08:40 2012 JamieUpdateLSCc1lsc: add error point pick-offs, moved ctrl pick-offs after feedforward

I made some modifications to the c1lsc model in order to extract both the error and control signals.

I added pick-offs for the error signals right before IFO DOF filter modules.  These are then sent with GOTOs to outputs.

I also modified things on the control side.  The OAF stuff was picking off control signals before feedforward in/outs.  After discussing with Jenne we decided that it would make sense for the OAF to be looking at the control signals after feedforward.  It also makes sense to define the control signal after the feedforward.  These control signals are then sent with GOTOs to another set of outputs.

Finally, I moved the triggers to after the control signal pickoffs, and right before the output matrix.  The final chain looks like (see attachment):

input matrix --> power norm --> ERR pickoff --> DOF filters --> FF out --> FF in --> CTRL pickoff --> trigger --> output matrix

The error pickoff outputs in the top level of the model are left terminated for the moment.  Eventually I will be hooking these into the new c1cal calibration model.

The model was recompiled, installed, and restarted.  Everything came up fine.

Attachment 1: LSCchain.png
LSCchain.png
  6717   Wed May 30 18:16:44 2012 JamieUpdateLSCskeleton of new c1cal calibration model created

[Jamie, Xavi Siemens, Chris Pankow]

We built the skeleton of a new calibration model for the LSC degrees of freedom.  I named it "c1cal".  It will run on the c1lsc FE machine, in CPU slot 4, and has been given DCUID 50.

Right now there's not much in the model, just inputs for DARM_ERR and DARM_CTRL, filters for each input, and the sum of the two channels that is h(t).

Tomorrow we'll extract all the needed signals from c1lsc, and see if we can generate something resembling a calibrated signal for one of the IFO DOFs.

 

  6718   Wed May 30 19:27:38 2012 yutaUpdateIOOMC beam spot oscillation

[Koji, Yuta]

We found that C1:SUS-MC{1,2,3}_TO_COIL_3_4_GAIN was somehow changed to -1, and feedback signal for SIDE was fedback to LLCOIL, which is apparently not correct.
We checked the snapshots on May 25 and confirmed that it was used to be 0, so we fixed it.
We suspect that it happened during the beam spot measurement, because the measurement changes the TO_COIL matrix gains.

Now, we don't see any MC beam spot oscillation.

Quote:

[Koji, Suresh, Jenne, Yuta]

Background:
  We noticed that the beam spots on MC mirrors are oscillating in ~ 1 Hz yesterday. It means MC mirrors are actually oscillating. This was observable even if the WFS servo is off.

 

  6719   Wed May 30 20:12:15 2012 ranaUpdateIOOMC beam spot oscillation

This is a common occurrence when diagnostic scripts are written without the ability to handle exceptions (e.g. ctrl-c, terminal gets closed, etc.).

The first thing to do is make sure that the "new" script you are writing doesn't already exist (hint: look in the old scripts directory).

If you are writing a script that touches things in the interferometer, it must always return the settings to the initial state on abnormal termination:

http://linuxdevcenter.com/pub/a/linux/lpt/44_12.html

  6721   Wed May 30 22:51:32 2012 DenUpdatePEMguralp isolation box

When I've put Guralps inside the isolation box, the signal from seismometers increased and was out of AA board range. I've reduced the gain of the readout box by a factor of 2. Now R2 for channels 1-6 is (2000, 1050, 1050, 2000, 1050, 1050) Ohm.

The signal increased in the frequency range 30-50 Hz. Guralp noise become better. That's good. However, it is still worse then in the manual.

As Yuta is dancing on the isolation box, Guralp signal is most time out of the AA board range. So I calculated the noise based on 5 min data. This may be enough, but I'll repeat the experiment later with 30 min data.

lin_box_noise.png

  6723   Thu May 31 01:20:41 2012 JenneUpdateASSASS filter outputs are non-zero with no input

I was looking a little at ASS, while Yuta was doing some Green transmitted DC PD work, and I find that the output of some filters is totally insane with no deliberate input or excitation signals.

Note in the figure that the filter (which is a 2nd order butter bandpass in the C1:ASS-LOCKIN29_SIG filter bank) is ringing a lot - this needs fixing.  But, more disconcertingly, sometimes (not every time) the arm flashes, the input to the filter bank gets a ~1 sample long spike that is ~9,000,000 counts.  9 million is a lot of counts.  This is then making the filter go crazy.

Any ideas on how this can happen, and how we can stop / fix it?  It's certainly a CDS issue, but I'm not sure where or how.

Attachment 1: ASS_Yarm_crazyOutputs_30May2012.png
ASS_Yarm_crazyOutputs_30May2012.png
  6724   Thu May 31 01:27:16 2012 yutaUpdateGreen LockingPSL and Y arm green beams aligned

[Jenne, Yuta]

We aligned the PSL green optics so that the PSL green beam and Y arm green beam interfere. 2 beams are now hitting the Y arm beat PD. The DC level from the beat PD is about 13 mV.

We didn't try to see the beat signal for today, because the temperature of the doubling crystal seemed funny. We need to look into it tommorow.

Currently, the temperature control is enabled and the set point is 36.9 deg C, but the temperature is stuck at 33.0 deg C.

  6725   Thu May 31 01:36:17 2012 yutaUpdateGreen LockingGREEN_TRX/GREEN_TRY PDs

I did the cabling for monitoring DC transmission of the green beam from the end table.
The two PDs are called GREEN TRX and GREEN TRY, and the channel names are C1:GCV-GREEN_TRX and C1:GCV-GREEN_TRY.
The two signal from the PDs go to the ADC_0 card of the c1ioo computer.

Now, C1:GCV-GREEN_TRX/Y are actually connected to the respective PDs, but green beams are not hitting on the PD. We need two pickoff mirrors.

  6726   Thu May 31 02:27:24 2012 yutaUpdateIOOscript for reliefing MC WFS

I wrote a simple script for reliefing MC WFS servo. The script is located at /opt/rtcds/caltech/c1/scripts/MC/reliefMCWFS.
It simply uses ezcaservo to minimize the offset of the WFS feedback signal using MC alignment sliders.

    ezcaservo -r C1:SUS-MC${optic}_ASC${dof}_OUT16 -s 0 -g 0.0001 -t 10 C1:SUS-MC${optic}_${dof}_COMM


I put "MC WFS relief" button on the WFS medm screen (/opt/rtcds/caltech/c1/medm/c1ioo/master/C1IOO_WFS_MASTER.adl).

ELOG V3.1.3-