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ID Date Author Type Categoryup Subject
  5751   Fri Oct 28 03:12:37 2011 SureshUpdateIOOMC2 realigned to align MC to PSL

Around 6PM on the 27th, I found that the C1:IOO-MC_RFPD_DCMON had risen to about 2.5V.   I checked the trend of MC2 sensors and found that  between 2PM and 6PM, MC2 had drifted in a strange way.  And also that the alignment had grown worse over several days.   I also noticed that the spot on the MC2F camera had shifted to the left.

I attempted to correct the alignment (decrease the C1:IOO-MC_RFPD_DCMON to ~0.5V ) by just moving the MC2 and succeeded!! So it is quite likely that most of the slow MC drift is arising due to MC2 table drift.

MC2_Drift_20111027.png

 

I decided to try and close the MC2_TRANS QPD to MC2 loops separately to see if MC alignment becomes stable  But several screens needed to be fixed before we could try anything.   So I fixed C1IOO_WFS_MASTER,  C1IOO_WFS_INMATRIX and ...OUTMATRIX screens.  Deleted the older ones to avoid confusion.

In this process I noticed that the directory of $screens$/c1mcs/master contains copies of older C1SUS_MC1 , 2. and 3 screens which look very similar to the new autogenerated screens.  Some of the links in the WFS screens were pointing to the old screens.  I have redirected the links and I will delete these in a couple of days, if no one objects.

 

 

 

  5761   Sat Oct 29 02:35:39 2011 SureshUpdateIOOWFS_MASTER screen and lockin screens fixed

I have fixed the WFS_MASTER screen and several of the subscreens such as the MCASS and MC_WFS_LKIN.

Since MC_WFS_LKIN uses six demodulators and single oscillator I could not use the automatically built Lockin screens. 

I built one using the compact filter banks mentioned earlier

The phases in the WFSlockins have yet tp be set.

  5768   Mon Oct 31 09:42:12 2011 steveUpdateIOOPMC locked

The PMC HV drops off more offen lately.

Attachment 1: pmcHV.png
pmcHV.png
  5799   Thu Nov 3 17:19:54 2011 SureshUpdateIOOMC realigned to center the spots on actuation nodes

Several activities in the past week (elog1, Mirko's rough realignment of MC and adjustment of the PSL zig-zag on Monday and elog2 ), had led to an MC state where the spots were not centered on the actuation nodes.

The change in the C1IOO model part dealing with MC_ASS led to the disappearance of all MC_ASS filter definitions in the lockins.  I have fixed all that, remade the screens and scripts for making the MC Decenter measurements.

I have just completed the re-centering of the spots on the MC and this of course will lead to some change in the input pointing. 

The MC_REFL beam also was recented on the WFS and the MC2_TRANS QPD.

Will add the mc-decenter measurement in a few mins

  5803   Thu Nov 3 22:32:48 2011 SureshUpdateIOOMC realigned to center the spots on actuation nodes

Quote:

Several activities in the past week (elog1, Mirko's rough realignment of MC and adjustment of the PSL zig-zag on Monday and elog2 ), had led to an MC state where the spots were not centered on the actuation nodes.

The change in the C1IOO model part dealing with MC_ASS led to the disappearance of all MC_ASS filter definitions in the lockins.  I have fixed all that, remade the screens and scripts for making the MC Decenter measurements.

I have just completed the re-centering of the spots on the MC and this of course will lead to some change in the input pointing. 

The MC_REFL beam also was recented on the WFS and the MC2_TRANS QPD.

Will add the mc-decenter measurement in a few mins

 The current MC spot decentering is given below:

spot positions in mm:

MC1P     MC2P     MC3P      MC1Y     MC2Y     MC3Y

0.4089    0.4800   -0.1266   -1.4095    0.3808   -1.7517

 

The yaw measurement probably has the wrong scale factor in the conversion to mm.  It could be under estimated by a factor 2.65/2.00 since the 10% step in coil gains produces a 2mm offset rather than the expected 2.65mm.  See the figures below.  I will check this during the next iteration when another mode clearner alignment comes up.

As I had to redefine all the MC_ASS lockin filters it is possible that Lockin phase might have changed by a few degrees giving rise to a change in the scale factor.

20111103_1.png    20111103_2.png

  5813   Fri Nov 4 16:23:41 2011 SureshUpdateIOOMC spot decenter measured

After Kiwamu adjusted the MC2 PIT to accommodate the limited range of the PZT1 ( elog ),  I remeasured the spot positions today.  

  MC1P MC2P MC3P MC1Y MC2Y MC3Y
Yesterday 0.1354 -0.2522 -0.1383 -1.0893 0.7122 -1.5587
Today 4.0411 4.4994 3.5564 -1.4170 -0.2606 -1.7109

 

As expected there is a translation of the beam axis to one side (Up? Down?) .  

I wonder how a beam translation by 5mm solved the PZT1 angular range limitation problem (?!)

  5819   Sat Nov 5 01:10:29 2011 SureshUpdateIOOWFS output matrix measured (open loop)

 

The scripts and screens needed to make the MC WFS ouput matrix are once again functional

I corrected the WFS lockins' phases to ensure that the Q outputs are minimised.  Since all the lockins have the same relative phase with respect to the oscillator I found that the same phase works for all of them.  About 90 deg in this case.

The scripts used to make the WFS outmatrix measurement live in /cvs/cds/rtcds/caltech/c1/scripts/MC/WFS

1) setupWFSlockins:   This script makes sure that all the ASC, WFS_ LKIN and WFS_servo filter banks used in this measurement are set up properly.  It also sets the WFS_lockin oscillator to 10 Hz.  There are filter modules in the SIG filter bank of the WFS demodulators. 

2) senseWFSoutMATRX:  This script cycles through the various MC actuators ( MC 1 2 3 : PIT and YAW ) and measures the response of the various ASC sensors (WFS and MC2_TRANS QPD).

3) The data collected by the sensWFSoutMATRX can be analysed with a matlab file called " wfsmatrix3.m " located in a subdirectory under WFS called 'matlab'.   I have added some comments in this file to make it easier to follow.   The output of this file, at the moment, gives only the " Actuation Vectors " for WFS1P, WFS2P, WFS1Y and WFS2Y.  It ignores the MC2TransQPD for now. 

4)  The lockin outputs are given below ( the 'reduceddata' )

             wfs1p      wfs2p      mc2tp      wfs1y      wfs2y     mc2ty

mc1p    0.2926   -0.4086    0.2926    0.0340    0.0064    0.0001
mc2p   -0.2830   -1.3060   -0.2833    0.0628    0.1171   -0.0003
mc3p   -0.3283   -0.3455   -0.3288   -0.0456    0.0275    0.0000
mc1y    0.0440    0.0261    0.0429    0.7204    0.9351   -0.0008
mc2y   -0.1006    0.0850   -0.1036   -1.5509   -0.3882    0.0165
mc3y     0.0150   -0.0832    0.0144    0.1114   -1.0573    0.0006

5) The actuation vectors are given below

Pitch WFS1P WFS2P
MC1 1.00 -0.86
MC2 -0.12 -1
MC3 -0.72 0.09

 

Yaw WFS1Y WFS2Y
MC1 0.16 0.59
MC2 -1.00 0.20
MC3 0.51 -1

6) This measurement was performed with the WFS servo loops open. I will try to close the loops with this matrix and run the script again to measure the output matrix in closed loop.

7) This a.vectors obtained above are significantly different from that obtained a while ago (elog 5668) before the lockin demod phases (relative to each other) were fixed.  This could also be because both are open loop measurements and we might have wandered into the nonlinear regime of the WFS sensors.

 

 

 

  5826   Mon Nov 7 08:08:24 2011 steveUpdateIOOPMC locked

The PMC acted like it was sleeping. The HV slider was dead. The MC locked instantly as the PMC had transmission.

Attachment 1: pmcHV.png
pmcHV.png
  5834   Mon Nov 7 15:49:26 2011 jamieUpdateIOOWFS output matrix measured (open loop)

Quote:

 The scripts used to make the WFS outmatrix measurement live in /cvs/cds/rtcds/caltech/c1/scripts/MC/WFS

 I assume you mean /opt/rtcds/caltech/c1/scripts/MC/WFS.

As I've tried to reitterate many times: we do not use /cvs/cds anymore.  Please put all new scripts into the proper location under /opt/rtcds.

  5839   Tue Nov 8 10:34:42 2011 SureshUpdateIOOMC spot decenter measured

Quote:

After Kiwamu adjusted the MC2 PIT to accommodate the limited range of the PZT1 ( elog ),  I remeasured the spot positions today.  

  MC1P MC2P MC3P MC1Y MC2Y MC3Y
Yesterday 0.1354 -0.2522 -0.1383 -1.0893 0.7122 -1.5587
Today 4.0411 4.4994 3.5564 -1.4170 -0.2606 -1.7109
8Nov2011 4.7341 4.8794  4.3907 1.3542 -3.0508 -1.7167


As expected there is a translation of the beam axis to one side (Up? Down?) .  

I wonder how a beam translation by 5mm solved the PZT1 angular range limitation problem (?!)

 The MC alignment was bad and I wondered if it is because MC shifted or because the input PSL beam shifted.   So I remeasured the spot positions and find that MC2 Yaw has shifted a lot.   Todays measurements are in Cyan boxes above. The shift in MC3P is probably an associated shift due to some pit--yaw coupling.  So I am going to move MC2 and try to align the MC to the PSL.

  5840   Tue Nov 8 12:07:08 2011 SureshUpdateIOOMC WFS Servo: suppression of WFS error signals below 3Hz

I switched on the WFS servos with the output matrix (open loop) determined last Friday.  Only the WFS1Pit, WFS2Pit, WFS1Yaw and WFS2Yaw servo filters are now on.   I then adjusted the gains to obtain maximum suppresson of error signals without oscillations in the loops

I now proceed to determine the output matrix again.

WFS_servo-20111108.png

  5857   Wed Nov 9 21:21:30 2011 SureshUpdateIOOMC WFS: Output matrix determined with loops closed.

With the loops closed I ran the $SCRIPTS/MC/WFS/senseWFSoutMATRX script and analysed the lockin outputs with $SCRIPTS/MC/WFS/matlab/wfsmatrix3.m.  I had to edit both the setupWFSlockins and the sensWFSoutMATRX scripts because in the past we used to switch on / off the ASC filter bank GAINs on the MC suspensions to start / stop the lockin excitation.  We cannot do this any more since these the WFS feedback signals have to get through these filters while the WFS loops are closed.  So the current, more sensible, scheme is to set the appropriate elements to 1 / 0 in the C1IOO_LKIN_OUT_MTRX.

Note:  The senseMCdecenter script will also have to be ammended in the same manner.

The lockin outputs measured are (reduceddata):

             wfs1P    wfs2P       mc2tP        wfs1Y     wfs2Y       mc2tY

MC1P  -10.3694    7.0642  -10.2133   -0.1025    0.4653   -0.0000
MC2P    8.2838   21.5141    8.4102   -0.2215    0.0734    0.0000
MC3P    9.4804    6.0835    9.6346   -0.0080    0.0366   -0.0000
MC1Y   -0.7339   -1.4498   -0.6175  -11.7502  -13.0480    0.0004
MC2Y    0.9004    0.6645    1.0554   25.6083    7.3399   -0.0046
MC3Y   -0.2914    2.1573   -0.1829   -2.1130   14.3038   -0.0000
 

After inverting and normalising a subset of the above matrix ( done in the wfsmatrix3.m )  we obtain the following output matrix coefs:

  WFS1P WFS2P
MC1P -1.0 0.82
MC2P 0.15 1.0
MC3P 0.62 0.02

 

  WFS1Y WFS2Y
MC1Y -0.11 -0.56
MC2Y 1.00 -0.17
MC3Y -0.62 1.00

 

Apart from a negative sign (introduced by the negative gains in the WFS servo filters ) these values are quite close to the actuation vectors determined in open loop.

I have plugged these values into the WFS output matrix.  Will determine the open loop gain later when there arent so many people stomping around the MC.

 


 

  5859   Wed Nov 9 21:48:43 2011 SureshUpdateIOOWFS Servo included into the MC_Autolocker

The WFS servo loop will come on 5 seconds after the MC is locked

 

I have uncommented the lines in the mcup script which turn on the WFS servos.  But I shifted their location to the part after the MC is locked.

  5866   Thu Nov 10 20:20:57 2011 SureshUpdateIOOMC Spot positions have shifted after accelerometer installation on MC2 chamber

[ Jenne, Suresh ]

We were tying the fix the WFS and noticed that the PSL --> MC alignment was poor.   The PMC output was also at about 0.5 instead of its optimal 0.86 .   So Jenne started by first realinging the PMC input and pushed the PMC ouput to about 0.8  

Then we decided to fix the PSL--> MC alignment by using the zigzag.  After Jenne finished that, we realised that it was probably not the best thing to do since the MC2 might have shifted after the accelerometer installation on the MC2 chamber.

So I measured the spot positions and find that the MC2Y has shifted by about 3.6mm and  MC2P has shifted by about a mm.  There is also a shift of 2mm in MC3P, but hopefully it will go away when we adjust the MC2

 

    MC1P MC2P MC3P MC1Y MC2Y MC3Y
03Nov2011   0.1354 -0.2522 -0.1383 -1.0893 0.7122 -1.5587
04Nov2011   4.0411 4.4994 3.5564 -1.4170 -0.2606 -1.7109
08Nov2011   4.7341 4.8794  4.3907 1.3542 -3.0508 -1.7167
10Nov2011 ........ 3.9944 3.7676 6.1001 -1.3058 -3.8087 -1.6418

 

I am going to adjust the MC2 to recover its nominal position as marked above in green

  5878   Fri Nov 11 22:07:43 2011 SureshUpdateIOOTried to recover the MC alignment of 4th Nov: partial success, PSL beam clipping

I have recovered the yaw values pretty much .  As the PZT1 rails in this direction perhaps this is the more relevant of the two alignments.  The beam is translated in the vertical direction, but this can be easily corrected by changing the pitch of MC2

However note that if the WFS are switched on .. MC is going to follow the PSL beam. 

 

 

 Date  #### MC1P MC2P MC3P MC1Y MC2Y MC3Y
03Nov2011   0.1354 -0.2522 -0.1383 -1.0893 0.7122 -1.5587
04Nov2011   4.0411 4.4994 3.5564 -1.4170 -0.2606 -1.7109
08Nov2011   4.7341 4.8794  4.3907 1.3542 -3.0508 -1.7167
10Nov2011    1   3.9944 3.7676 6.1001 -1.3058 -3.8087 -1.6418
11Nov2011    1  3.8542 3.6831 3.0418 -0.8383 0.1550 -2.3841
11Nov2011    2    3.6876 2.7429 2.7830 -1.6250 -0.0386 -1.6346

 

 

  5883   Sat Nov 12 03:46:55 2011 SureshUpdateIOOMC WFS Servo: Open loop gain

[Mirko, Suresh]

I closed the WFS loops and measured the transfer function from IN2 to IN1 testpoints on the WFS1_PIT filterbank. 

We looked at the filter shape consisting of

1) Integrator: zpk([0.8],[0],0.8,"n")

2) zpk([0.8],[100,100],1,"n")

3) zpk([1:10],[3,30],1,"n")

The combined filter shape (along with an added pendulum filter, zpk([ ],0.8,1,"n")  ) is given below

WFS1_PIT_servo_filtershape_20111111_1.png

 

The OL Transfer function measured for WFS1_PIT loop is

WFS1_PIT_servo_OLG_20111111_1.png

 The blue reference is a measurement  without the third "45 deg" filter in the list above.  Without it the UGF is around 1.5Hz and increasing the gain results in additional noise from the servo bump seen in the earlier elog .  With it the UGF is around 3Hz.

The supression of the error signal is shown here

 Error_signal_WFS1_PIT_20111111_1.png

The other WFS loops are expected to have a similar behaviour with the exception of the MC2 QPD channels.  I will measure their OLTF shortly and then proceed with the inclusion of the QPD sensors into the WFS system.

 

 

  5884   Sat Nov 12 08:09:47 2011 ranaUpdateIOOMC WFS Servo: Open loop gain

Somehow, I generically don't like the idea of lead filters for the WFS loops. We don't really need so much bandwidth. I think you should include with the servo measurements, a servo model ( on the same plot ) that matches the loop shape.

For example, this means including the 28 Hz ELP in the MC1/3 hardware and MC2 ASCPIT/YAW digital filter banks. BY comparing the model v. measurement we can determine if the cross-coupling due to imperfect output matrix is very serious or not.

In the measurements, the loop with the most low frequency gain looks the most promising.

  5891   Tue Nov 15 00:00:15 2011 SureshUpdateIOOMC was realigned to remove beam clipping and to accommodate PZT1 range

[Kiwamu, Suresh]

The MC was realigned to readjust the input beam direction in pitch such that the clipping of the beam at the PSL table reduced and the railing of the PZT1 is avoided.

The current spot positions are given below on the last row:

 

 Date  #### MC1P MC2P MC3P MC1Y MC2Y MC3Y
03Nov2011   0.1354 -0.2522 -0.1383 -1.0893 0.7122 -1.5587
04Nov2011   4.0411 4.4994 3.5564 -1.4170 -0.2606 -1.7109
08Nov2011   4.7341 4.8794  4.3907 1.3542 -3.0508 -1.7167
10Nov2011    1   3.9944 3.7676 6.1001 -1.3058 -3.8087 -1.6418
11Nov2011    1  3.8542 3.6831 3.0418 -0.8383 0.1550 -2.3841
11Nov2011    2    3.6876 2.7429 2.7830 -1.6250 -0.0386 -1.6346
14Nov2011    1 5.9412 2.7658 5.4806 -4.7676 0.7778 2.2053

 

We have quite a lot of decentering in the MC which we must try to remove by parallel transporting the beam in Pitch and Yaw..

At the current settings we might be clipping on the Faraday Isolator as we had estimated that we can allow atmost a 2mm offset in spot positions due to this constraint.

 

 

 

  5892   Tue Nov 15 01:44:36 2011 SureshUpdateIOOMC WFS Servo: Open loop gain

Quote:

Somehow, I generically don't like the idea of lead filters for the WFS loops. We don't really need so much bandwidth. I think you should include with the servo measurements, a servo model ( on the same plot ) that matches the loop shape.

For example, this means including the 28 Hz ELP in the MC1/3 hardware and MC2 ASCPIT/YAW digital filter banks. BY comparing the model v. measurement we can determine if the cross-coupling due to imperfect output matrix is very serious or not.

In the measurements, the loop with the most low frequency gain looks the most promising.

WFS1_PIT servo replotted with foton data overlaid:

I included the following filters in foton:

1) Integrator: zpk([0.8],[0],0.8,"n")

2) zpk([0.8],[100,100],1,"n")

3) zpk([1:10],[3,30],1,"n")

4) ELP28

I have unwound the phase by adding or subtracting 180 to portions of the phase data.

And here is the plot for WFS1_PIT.  I will repeat this process for the other three WFS loops tomorrow.

WFS1PIT_OL_gain.png

 

  5899   Tue Nov 15 19:59:41 2011 SureshUpdateIOOWFS output matrix measured (open loop)

Quote:

Quote:

 The scripts used to make the WFS outmatrix measurement live in /cvs/cds/rtcds/caltech/c1/scripts/MC/WFS

 I assume you mean /opt/rtcds/caltech/c1/scripts/MC/WFS.

As I've tried to reitterate many times: we do not use /cvs/cds anymore.  Please put all new scripts into the proper location under /opt/rtcds.

 Yes the files are in /opt/rtcds/caltech/c1/scripts/MC/WFS.

I just went to wherever the 'scripts' alias takes me, found the 'pwd' and did a cp+paste of the path.   I checked to be sure that 'scripts' takes me to /opt/rtcds/caltech/c1/scripts/.

So why does the pwd show /cvs/cds.... instead of /opt/rtcds  ?

 

  5904   Wed Nov 16 08:57:08 2011 SureshUpdateIOOMC WFS Servo OLG data and fits

I measured the Transfer Functions between from IN2 to IN1 on the WFS1PIT, WFS2PIT, WFS1YAW and WFS2YAW servo loops. 

Then I used the foton filter profiles of the servo filters in the loop and added another one to simulate the pendulum to generate a reasonable fit to the data.  Only the pendulum filter was hand tweaked since the PIT and YAW pendula have different resonant frequencies.

The filter modules included are:

1) Integrator: zpk([0.8],[0],0.8,"n")

2) Phase lead: zpk([0.8],[100,100],1,"n")

3) 45 deg filter: zpk([1:10],[3,30],1,"n")

4) ELP28: ellip("LowPass",5,1,50,28)

5)Pendulum: zpk([ ],0.03+i*0.82;0.03+i*0.82;],1,"n"  (for YAW)

5)Pendulum: zpk([ ],0.05+i*0.68;0.05+i*0.68;],1,"n"  (for PIT)

The data and fits are below.   The UGF is around 2 to 3 Hz and there is no servo bump at this gain setting.  The fits are poor at and below the resonance because the coherence was poor at these frequencies.  I will have to do a swept sine measurement for these low frequencies.

WFS1PITservo.png  WFS2PITservo.pngWFS1YAWservo.png  WFS2YAWservo.png

  5905   Wed Nov 16 09:21:56 2011 SureshUpdateIOOMC2 Shifted in Pitch, corrected by adjusting the pitch bias

[Steve, Suresh]

    Steve went over to the MC2 walkway and stepped over the barrier to pick up some stuff there.  MC2 stack shifted and MC2 pitch as off.  MC unlocked and could not relock till the MC2 pitch bias was readjusted

previous MC2PIT reading: 3.6235           current MC2PIT reading:  3.9565

Without the WFS the MC to PSL alignment is poor, but it is largely due to a shift in the MC and not a shift in the PSL beam.  We know this 'coz the shift in the DC spot positions on WFS (when the MC is unlocked) is not significant nor is the shift on the C1:IOO-QPD.  When WFS loops are engaged the MC optics are turned to optimise the PSL to MC alignment, but the shift is large at the moment.

(Sorry Mirko your measurement could not be completed.  The MC unlocked in the middle)

Please Note:  If you need to access the blocked off area near MC2 stack, do not step over the barrier.  The disturbance is too great and the MC2 stack will shift.  Instead please move the barrier aside and walk as gently as possible near it, taking care not to touch the MC2 Chamber.

  5906   Wed Nov 16 10:08:17 2011 SureshUpdateIOOEffect of turning on the MC2_TRANS_PIT and YAW loops in ASC

I turned on the two remaining loops in the ASC system to see if we can lock.   I put in some ones into the WFS_OUTPUT matrix

WFS_OUTMATRIX.png

and locked the MC2_TRANS_PIT and MC2_TRANS_YAW loops.

The effect of doing so is visible in the error signals.  The black loops are with all ASC loops off, Blue traces are with the WFS1 and 2 loops locked and Red traces are with all loops locked.  I took the red traces to a lower frequency to see if the suppression of the error signals at low frequencies is disturbed by the switching on of the MC2_TRANS loops.  They seem to be working fine without adding any perturbation above the UGF.

WFS_servo_err_20111115.png

I measured the  Transfer Function coefs (at 10Hz using the WFS Lockins)  with MC2_TRANS loops locked in this rudimentary fashion

  WFS1P WFS2P MC2TP WFS1Y WFS2Y MC2TY
MC1P -23.8541 15.2501 -24.3470 -3.3166 -2.0473 -0.1202
MC2P 29.7402 54.7689 29.5102  -0.2922 -17.4226 0.0310
MC3P 34.3612 10.7279 33.9650 6.6582 -4.0892 0.2333
MC1Y 0.9510 -6.3929 0.8722 -98.2414 -82.9129 -4.2802
MC2Y 12.0673 6.1708 11.9502 237.1172 20.7970 14.6480
MC3Y -0.8498 2.8712 -1.4195 -20.6031 111.2531 -1.5234

 

The green and blue bits are the only relevant parts since we ignore the off diagonal parts.  And most of these off diagonal coefs are indeed quite small (<5% of the max).  I have marked the not-so-small ones in yellow.

I then calculated the output matrix elements in two different ways.

a) Using a null vector in the place of MC_DoF --> MC2_TRANS transfer coefs.  The output matrix we get is

 

  WFS1P WFS2P Null Vector
MC1P -1.0000 0.8271  -0.8880
MC2P 0.0962 1.0000  0.4431
MC3P 0.9306 -0.2913  -1.0000

 

  WFS1Y WFS2Y Null Vector
MC1Y -0.2340 -0.5840 1.0000
MC2Y 1.000o -0.1551  0.4714
MC3Y -0.3613 1.0000 0.6571

 

b) Without using the null vector.  i.e. using the MC_DoF --> MC2_TRANS transfer coefs and inverting the full matrix.  The output matrix we get is

 

   WFS1P WFS2P  MC2TP
 MC1P  0.1471  -0.8880  0.8655
 MC2P  1.0000  0.4431  -0.4369
 MC3P  -0.7634  -1.0000  1.0000

 

  WFS1Y WFS2Y MC2TP
MC1Y 0.1401 1.0000 -1.0000
MC2Y 0.1449 0.4714 -0.3627
MC3Y 1.0000 0.6571 -0.6775

 

I plan to try out these two output matrices and measure the OL TFs of the MC2_TRANS and see if we can include these into ASC in a useful fashion.

Attachment 1: WFS_OUTMATRIX.png
WFS_OUTMATRIX.png
  5910   Wed Nov 16 10:53:35 2011 SureshUpdateIOOMC2 Shifted in Pitch, corrected by adjusting the pitch bias

Quote:

[Steve, Suresh]

    Steve went over to the MC2 walkway and stepped over the barrier to pick up some stuff there.  MC2 stack shifted and MC2 pitch as off.  MC unlocked and could not relock till the MC2 pitch bias was readjusted

previous MC2PIT reading: 3.6235           current MC2PIT reading:  3.9565

Without the WFS the MC to PSL alignment is poor, but it is largely due to a shift in the MC and not a shift in the PSL beam.  We know this 'coz the shift in the DC spot positions on WFS (when the MC is unlocked) is not significant nor is the shift on the C1:IOO-QPD.  When WFS loops are engaged the MC optics are turned to optimise the PSL to MC alignment, but the shift is large at the moment.

(Sorry Mirko your measurement could not be completed.  The MC unlocked in the middle)

Please Note:  If you need to access the blocked off area near MC2 stack, do not step over the barrier.  The disturbance is too great and the MC2 stack will shift.  Instead please move the barrier aside and walk as gently as possible near it, taking care not to touch the MC2 Chamber.

 

Apparently the MC2 stack had not finished shifting.   The MC unlocked while Steve was working on the PSL table installing the mirror for IOO_QPD and then it could not relock.  So I moved the MC2 once again in Pitch.  The current status of the sliders is here

C1IOO_MC_ALIGN.png

 

Yesterday I fixed the yellow buttons on the MC_ALIGN and MCLOCK screens.  They use the new updatesnap script  .  Could we also add a couple of lines to this script so that eveytime we save a snap shot the various values are written(appended) to a text file?  That way we do not need to depend solely on the conlog, which is quite slow.

 

  5913   Wed Nov 16 17:03:19 2011 KojiUpdateIOOMC2 Shifted in Pitch, corrected by adjusting the pitch bias

MC was not locked for more than 5 hours because of the misalignment.

Noticed that MC2 WFS feedback filters had big outputs (particularly in Pitch).
They were reset to zero.

MC2 was aligned and recovered the lock. Once the WFS is engaged, the transmission returned to the uisual value.

  5915   Wed Nov 16 17:40:48 2011 MirkoUpdateIOOMC unlocked and misaligned.

MC fell out of lock and was then quite badly misaligned. Mostly in pitch. I realigned it and it locked ok.

Turns out the MC falls often out of lock when the WFS servo comes on. I think the MC2_Trans history is not cleared on lockloss. I cleared it manually and realigned. Seems fine for now.

  5916   Wed Nov 16 18:14:09 2011 KojiUpdateIOOMC unlocked and misaligned.

Actually, do we need to reset the filter history at every lock loss of the MC?

Those DC offsets were necessary to keep the alignment good just until the MC is unlocked.
So if we keep the history, we can maintain the good alignment.

  5917   Wed Nov 16 20:30:27 2011 not KojiUpdateIOOMC unlocked and misaligned.

Quote:

Actually, do we need to reset the filter history at every lock loss of the MC?

Those DC offsets were necessary to keep the alignment good just until the MC is unlocked.
So if we keep the history, we can maintain the good alignment.

 I suspect the integrators get fed a huge wrong signal on lockloss. Clearing the history on the trans DOFs when the MC was badly aligned gets it nicely aligned again. I switched off the alignment transmission DOFs for now.

  5925   Thu Nov 17 13:58:12 2011 SureshUpdateIOOMC unlocked and misaligned.

Quote:

Quote:

Actually, do we need to reset the filter history at every lock loss of the MC?

Those DC offsets were necessary to keep the alignment good just until the MC is unlocked.
So if we keep the history, we can maintain the good alignment.

 I suspect the integrators get fed a huge wrong signal on lockloss. Clearing the history on the trans DOFs when the MC was badly aligned gets it nicely aligned again. I switched off the alignment transmission DOFs for now.

I have modified the 'mcwfson' and 'mcwfsoff' scripts to include the Clear History step for the MC2_TRANS_PIT and _YAW filters.  

These scripts can be run, by hand, from LOCKMC screen or from the WFS_MASTER screen.  Use the 'Turn WFS ON/OFF' button. 

The mcautolockmain script will now clear history on all ASC filter banks when the MC unlocks.

I have turned on ASC loops on the MC2_TRANS (= alignment transmission DOFs of the above elog) paths.

 

 

  5928   Thu Nov 17 17:03:28 2011 MIrkoUpdateIOOMC noise projection

Another go at the noise projection from MC1-3 pit/yaw to MC length. This time injecting into the MC autoalignment FB (e.g. C1:IOO-WFS1_PIT_EXC ).

LTPDA is working now, but still the NDS server is not so cooperative.

Summary: Alignment fluctuations of the MC mirrors don't significantly contribute to MC length changes up to at least 3.5Hz. Especially they can't explain the lack of coherence between seismometers and MC length below 1Hz that we worry about for the OAF.

At high frequencies >= 10Hz you can see angle to length coupling as is evident in Sureshes spot position measurements.

Whiteish noise injection:

Injection from 0.1-20Hz.Filtered by the servo filters and zp:[1],[1] , Gain = 1 @ 2Hz

 MCLengthToAngleCouplingNoiseProjection.png

Look at the coherence plots for the quality of the measurement:

Coherence_WFS1pit.png

Coherence_WFS2pit.png

 

Coherence_WFS1yaw.png

 Coherence_WFS2yaw.png

Injection details:

DOF      Amplitude[counts]        UTC Time (duration always 4mins)
WFS1p  70                               22:28
WFS1y  55                               22:03
WFS2p  70                               22:13
WFS2y  70                               22:18
None      -                                 22:23

Fixed sine injections:

To get some better SNR at low frequencies I did a fixed sine noise injection at 0.3Hz. See attached files.

DOF      Amplitude[counts]        UTC Time (duration always 4mins)    Lower limit of SNR MC length via mirror misalignment
WFS1p  4                                  00:05                                                29.3
WFS1y  4                                  00:14                                                22.0
WFS2p  4                                  00:19                                                18.5
WFS2y  4                                  00:25                                                18.0

Attachment 2: WFS1pit.png
WFS1pit.png
Attachment 3: WFS1yaw.png
WFS1yaw.png
Attachment 4: WFS2pit.png
WFS2pit.png
Attachment 5: WFS2yaw.png
WFS2yaw.png
Attachment 7: Coherence_WFS2pit.png
Coherence_WFS2pit.png
Attachment 11: NpWfs.pdf
NpWfs.pdf NpWfs.pdf NpWfs.pdf NpWfs.pdf NpWfs.pdf
  5933   Thu Nov 17 23:38:40 2011 DenUpdateIOOMC unlocked

MC is unlocked to measure the free swing of the MC mirrors with the local sensors.

Autolocker is disabled.

  5934   Thu Nov 17 23:44:48 2011 DenUpdateIOOMC1_SENSOR

We've found that one of the  MC1_SENSORS does not work properly.

See the figure.

Attachment 1: MCSENSORS.pdf
MCSENSORS.pdf
  5935   Thu Nov 17 23:47:43 2011 DenUpdateIOOMC1_SENSOR

The most interesting plot did not uploaded in the previous elog.

Upload now local MC1_SENSOR signals.

Attachment 1: MC1SENSOR-crop.pdf
MC1SENSOR-crop.pdf
  5939   Fri Nov 18 01:27:04 2011 DenUpdateIOOMC locked

[Mirko, Den]

While the MC was unlocked (and the local damping off) we've measured the coherence between GUR1_X and OSEM sensors. It was rather high, close to 1 at frequencies 0.1 - 1 Hz. That means that stack does not kill all coherence between seismic noise and mirror motion.

Then we've turned on the local damping and measured the coherence again between GUR1_X and OSEM sensors. It decreased due to some noise and was on the level of ~0.5. We did reduced the motion between the mirror and the frame by local damping but it is not obvious that we lost some coherence due to this effect. Probably, actuator adds some noise.

When we locked the MC, we did not see any coherence at 0.1 - 1 Hz between GUR1_X or STS1_X and OSEM sensors of MC1 and MC3 but we did see with MC2. The MC1 sensor was fixed by Suresh.

 

Attachment 1: cohnolocalpumping-crop_4.pdf
cohnolocalpumping-crop_4.pdf
Attachment 2: cohlocalpumping4-crop.pdf
cohlocalpumping4-crop.pdf
Attachment 3: cohlock4-crop.pdf
cohlock4-crop.pdf
  5941   Fri Nov 18 01:51:37 2011 KojiUpdateIOOStochmon update

Update of the stochmon status

[Attachment 1: Circuit diagram]

- The new stochmon has a low noise amplifier (MAR-6SM) inside.
The RFAM signal from the PD has the power of -60~-50dBm, which is almost at the bottom of the sensitivity for the power detector.

- The band pass filters were doubled.

- I've suffered from some RF coupling from the power line as the power detector is quite sensitive to it.
The situation has been largely improved by the EMI filters in the power supply path, although the problem is still present.
The worst remaining problem is that we can not close the aluminum lid as it cause a huge sprious coupling.

 

[Attachment 2: Calibration result]

- The outputs were calibarted with Marconi. They showed the signals linear to dBm for the input powers between -70dBm and -10dBm.

- The calibration result was fitted with the empirical fit function. The function and the results are shown in the attachment.

[Attachment 3: Detection limit]

- The attached figure shows the power spectrum of the PD output. This measurement gives us the amount of the RF power given from the PD noise when there is no RF signal.

11MHz out passband noise: −72.7dBm ===> V11 = 2.0483
30MHz out passband noise: −64.6dBm ===> V30 = 1.9333
55MHz out passband noise: −71.2dBm ===> V55 = 2.0272

- Now 11MHz and 55MHz outputs seem indicating the power correctly, but the 29.5MHz output never provides useful information.
It is a constant value independent from the state of the incident beam. Strangely this problem disappears if the marconi is used
for the RF source. Thus this issue is not seen in the calibration measurement.

- So far, 11MHz, 29.5MHz, 55MHz, and DC outputs appear in the channels C1:IOO-RFAMPD_33MHZ, C1:IOO-RFAMPD_133MHZ, C1:IOO-RFAMPD_166MHZ, and C1:IOO-RFAMPD_199MHZ.
They will be renamed.

Attachment 1: stochmon.pdf
stochmon.pdf
Attachment 2: stochmon_calib.pdf
stochmon_calib.pdf
Attachment 3: RFAM_PD_noise.pdf
RFAM_PD_noise.pdf
  5942   Fri Nov 18 02:50:10 2011 kiwamuUpdateIOORF generation box : power switch malfunction

[Suresh / Kiwamu]

 The power switch button of the RF generation box is not properly working

For tonight we are leaving it as it is but it needs to be fixed at some point.

 

(the Story)

While I was working around the green broad-band RFPD, I noticed that the RFPD was detecting the 25 MHz modulation signal.
To confirm if it really comes from the modulation source, I switched OFF the RF generation box by pressing the blue LED power button on the rear side of it.
The 25 MHz signal in the RFPD disappeared. So it was indeed the 25 MHz modulation signal.
Then I pressed the LED button again to bring it ON, but the switch didn't stay in the clicked position.
Keeping pressing the button could make it ON but once I released my finger from it it became OFF.
So the mechanical thing in the LED button is not properly working.
I removed the box from the 1X2 rack to take a look at it.
With a help from Suresh we somehow managed to keep it ON after several trials of pressing it.

The temporary solution we decided is to leave it ON so that we can survive tonight.

The box was back in place. The MC is find and 11 MHz and 55 MHz seem okay.

 

Please be aware of it.

 

broken_power_switch.png

This is a picture showing the rear view of the RF generation box. The red arrow is pointing the blue LED switch button.

  5943   Fri Nov 18 08:29:35 2011 SureshUpdateIOOHEPA air-flow effect on WFS.

[Koji, Suresh]

    We investigated the effect of airflow from the HEPA filters on the PSL beam fluctuation and the resultant noise injected into the WFS loops.   The hint that the WFS are injecting PSL beam jitter into MC mirror motion lies in the MC2_TRANS_PIT and YAW signal's power spectrum shown here.  First, in the blue trace, which shows the spectrum when the WFS loops are off, we see that the WFS1 and WFS2 error signals have a different shape from that of MC2_TRANS.  Since WFS are affected by the PSL beam jitter while the MC2_TRANS_QPD is not, the WFS spectrum contain excess noise, while the MC2_TRANS signals show only the mirror motion.  Next, upon switching on the WFS1 and WFS2 loops, we notice that the MC2_TRANS  spectra acquire the same shape as the WFS spectra.  This shows that the excess noise from the beam jitter has been injected into the MC2 motion, and shows up in the MC2_TRANS spectra.

   To confirm these conclusions we repeated the above measurement with the HEPA fans at 0% (Blue trace), 20% (Red), 30% (Brown) and  100% (Green).   The plots are shown below.  We can see that there is no difference between 0 and 20% levels but beam jitter is visible at 30% HEPA level.  The WFS loops were ON during this time and we can can see the PSL noise injected in to MC2 motion (Green).

WFS_err_HEPA.png

 

The HEPA filter fans are now at 20%.  How can we be sure that they are really working at 20%, since we cannot see any difference between 0 and 20%?

Now that we have this quiet situation, we also investigated the effect (or lack thereof) of switching on the MC2_TRANS loops.  The figure below shows the spectra with all the loops turned off (Blue), with the WFS1 and WFS2  loops turned on (Green)  and with everything turned on (Red).   With the current output matrix, which is the same simple one as the one in this elog, we see some low frequency suppression.  But it also seems to add some noise into the other WFS loops.  I am not sure of this result, due the long duration of this measurement, the seimic noise level may have changed over the course of this measurement.

WFS_err_mc2t_effect.png

As they are not doing any good just now.  I have turned them off by setting the gain in MC2_TRANS PIT and YAW to zero.

 

  5944   Fri Nov 18 11:16:08 2011 ranaUpdateIOOeom box

Quote:

I made a super sweet new foam box for our EOM.  It's awesome, and should be reasonably easy to duplicate.  Check out the PHOTOS!

 These are great photos and a nice box, but I fear from the photos that there's too much air getting in. How to pack it so that there's no air flow? How does the temperature sensors wires get in?

  5947   Fri Nov 18 15:35:18 2011 kiwamuUpdateIOORF generation box : power switch malfunction

Jenne gave me a spare LED power switch .

I will replace the broken one on Monday.

By the way here is a picture album of the RF generation box which I took last night.

            

Quote from #5942

 The power switch button of the RF generation box is not properly working

  5949   Fri Nov 18 15:45:11 2011 MirkoUpdateIOOMode cleaner noise projection

[Rana, Den, Mirko]

Updated the MC noise projection to include the longitudinal motion of the MC mirrors.

WholeMCNoiseProjection.png

=> Lots of OSEM - local dampling noise!

Consistent with static wiener filter showing only benefits in the 1 - 4Hz region.

Attachment 2: WholeMCNoiseProjection.fig
  5952   Fri Nov 18 19:57:19 2011 MirkoUpdateIOOMode cleaner noise projection

 

Some more info on this:
 

f > 1 Hz:

At these frequencies the pendulum should be quieter than the stacks. By quite a bit actually since there is the stack resonance at a couple Hz. 'Glueing' them together via the local control is not wise. We put an elliptic LP ( 2.5Hz, 4th order 6dB) into the C1:SUS-MC?_SUSPOS pathes and MC-F got better above 1Hz

MC_ELP.png

Added an extra LP @ 10 Hz afterwards. Doesn't make a visible difference.

f < 1 Hz:

Now here is more stuff to consider.

1. The OSEMs glue the MC mirrors to the stacks
2. The pendulum TF should be 1
3. It shouldn't matter if the OSEMs do or do not act on the mirror at these frequencies, assuming they don't add extra noise.
4. Page http://nodus.ligo.caltech.edu:8080/40m/5547 seems to indicate OSEM sensor noise is so low it can be neglected.

Reduced OSEM gain below 1Hz:

If we reduce the gain in the OSEMs by adding additional HP filters ( cheby2, HP 0.3Hz, 6dB 4th order ) the happens:

1. MC length gets a bit more noisy at low frequencies - should be looked into some more
2. Coherence between the GUR1 seismometer and MC length goes up between 1E-2 and 1E-1 Hz:

( Ref is with low OSEM gain )

WithAndWithoutHPs.pdf

Possible explanation:

The stacks might be more correlatedly moving together than the pendulums. This would be not so nice for OAF test, but really fine for actually using the MC.
Todo: Measure the OSEM to seismometer coherences with high and low OSEM gains.

For reference the seismometer coherence with one another:
SeismCoh.pdf

 

 

  5953   Fri Nov 18 23:44:33 2011 ranaUpdateIOOMode cleaner noise projection

Could use some more detail on how this measurement was done. It looks like you used the SUSPOS signal with the mirror moving, however, this is not what we want. Of course, the SUSPOS with the mirror moving will always show the mirror motion because the OSEMs are motion sensors.

Instead, what we want is to project how the actual OSEM noise in the presence of no signal shows up as MC length. For that we should use the old traces of the OSEM noise with no magnets and then inject that spectrum of noise into the SUSPOS filter bank with all the loops running. We can then use this TF to estimate the projection of OSEM noise into the MC length.

As far as improving the damping filter, the 2.5 LP is not so hot since it doesn't help at low frequencies. Instead, one can compute the optimal filter for the SUSPOS feedback given the correct cost function. To first order this turns out to be the usual velocity damping filter but with a resonant gain at the pendulum resonance. This allows us to maintain the same gain at the pendulum mode but ~3x lower gain at other frequencies.

In the past, we had some issues with this due to finite cross-coupling with the angular loops. It would be interesting to see if we can use the optimal damping feedback now that the SUS DOFs have been diagonalized with the new procedure.

  5957   Sat Nov 19 01:26:16 2011 DenUpdateIOOMode cleaner noise projection

Quote:

Instead, what we want is to project how the actual OSEM noise in the presence of no signal shows up as MC length. For that we should use the old traces of the OSEM noise with no magnets and then inject that spectrum of noise into the SUSPOS filter bank with all the loops running. We can then use this TF to estimate the projection of OSEM noise into the MC length.

That's right. The easier problem arises if we consider one of  MC mirrors. The coherence between OSEM sensors and GUR1_X in free moving regime is equal to 0.9 at frequencies 0.1 - 1 Hz. But with local dumping coherence is 0.6. We have

Mirror -> Sensor -> Satellite Module -> Whitening -> ADC -> Computer -> DAC -> Dewhitening -> Satellite Module -> Actuator -> Mirror

Somewhere we produce noise that kills part of coherence. We can use this method with the injection of spectrum of noise into the SUSPOS filter bank only for one mirror and see how the coherence between OSEM sensor and GUR1_X will change. If the change is small, we deal with something else. It the coherence will change from 0.6 to ~0.4, than we have big OSEM noise.

It might be also the problem that the amplitude of COIL_OUT signal is ~25. If it is in counts we may have noise from DAC. 

  5958   Sat Nov 19 06:04:43 2011 SureshUpdateIOOMC_WFS Servo: The MC2_TRANS_PIT and YAW loops switched ON

Without adding significant amounts of noise to other WFS loops I have engaged the MC2_TRANS_PIT and YAW loops. 

After several attempts to measure the system response and computing the output matrix, none of which gave any useful results, I gave up on that and decided to find three orthogonal actuation vectors which enable us to close the loops.  So using the last good output matrix (below left side)  as a template, I rounded it off to the nearest set of orthogonal vectors and arrived at the following matrix (right side):

WFS_OUTMx_Lastgood.png        WFS_OUTMATRIX_20111118.png

 

I also decided that WFS1 and 2 need not drive MC2.  This is just to decouple the loops and minimise cross-talk.   This (albeit heuristic)  matrix seems to work pretty well and the real matrix is probably quite close to it.

I show below the suppressed error signals after tweaking the gains a bit.   The blue line is with no WFS, the green one with only WFS1 and 2 loops on, while the red is with all loops turned on.  The WFS1Yaw and MC2_Trans_pit loops might benefit from a more careful study to determine a better output matrix.

WFS_err_MC2T_on_OMx5_20111118.png

  5959   Sat Nov 19 10:41:30 2011 ranaUpdateIOOMC_WFS Servo: The MC2_TRANS_PIT and YAW loops switched ON

I'm quite sure that this is not good: since MC2 can produce a signal in WFS1 and WFS2, it cannot be removed in this way from the actuation without introducing a significant cross-coupling between the MC_TRANS and WFS loops.

Really need loop TFs measured and compared with the model.

The WFS noise model will also show that we need to have a much lower UGF in the MCT loop since that sensor is just a DC QPD: it can never have as good of a sensing noise as a good WFS. In the current case with no Whitening, this is even more so.

  5960   Sat Nov 19 12:57:55 2011 MirkoUpdateIOOMode cleaner noise projection

Quote:

Could use some more detail on how this measurement was done. It looks like you used the SUSPOS signal with the mirror moving, however, this is not what we want. Of course, the SUSPOS with the mirror moving will always show the mirror motion because the OSEMs are motion sensors.

Instead, what we want is to project how the actual OSEM noise in the presence of no signal shows up as MC length. For that we should use the old traces of the OSEM noise with no magnets and then inject that spectrum of noise into the SUSPOS filter bank with all the loops running. We can then use this TF to estimate the projection of OSEM noise into the MC length.

As far as improving the damping filter, the 2.5 LP is not so hot since it doesn't help at low frequencies. Instead, one can compute the optimal filter for the SUSPOS feedback given the correct cost function. To first order this turns out to be the usual velocity damping filter but with a resonant gain at the pendulum resonance. This allows us to maintain the same gain at the pendulum mode but ~3x lower gain at other frequencies.

In the past, we had some issues with this due to finite cross-coupling with the angular loops. It would be interesting to see if we can use the optimal damping feedback now that the SUS DOFs have been diagonalized with the new procedure.

 The measurement was done with the MC in lock and the OSEMS active.

1. I injected noise into MC1-3 SUSPOS_EXC at a level that domiated the SUSPOS output.
2. Then I calculated the coupling coefficients of the SUSPOS outputs to MC_F during the time the noise is injected.
3. Without noise injection I projected the SUSPOS outputs to MC_F by multiplying the coupling coefficients with the SUSPOS outputs.

All on 11-11-18. White noise inj. from 0.1Hz to 20Hz. Duration 4mins each.

DOF      Amplitude(counts)     Time(UTC)
MC1      200                           22:08
MC2      25                             22:25
MC3      25                             22:50

Some thoughts on this, bare with me:

As you say this does not show the dark / bright noise of the OSEMs. It shows the influence of the OSEMS output onto MC_F in normal operation of the MC. I would have expected that to be very low everywhere except at the pendulum resonance. Reason for that not to be true could either be the OSEMs having considerable gain off of the resonance, or noise intrinsic to the OSEMs knocking the mirrors around. Since we know the OSEM signal to MC_F TF we only need to compare the OSEM signal to OSEM noise to see the noise contribution to MC_F. We know from http://nodus.ligo.caltech.edu:8080/40m/5547 that the OSEM sensor bright noise is considerably below the OSEM signal above 0.1Hz in actual operation. We checked that the MC OSEM signals are above the noise in the reference above 0.1Hz by a factor 3-10.

We actually measured the cost function with the noise projection (valid to 10Hz). It's just the coupling coefficient, right?

CouplingMClengthsToMCF.pdf

 

Attachment 2: NpModeCleaner.pdf
NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf NpModeCleaner.pdf
  5961   Sat Nov 19 15:58:04 2011 MirkoUpdateIOOSome more looks into OSEM noise

[Den, Mirko]

We looked some more into the the OSEM signals and their coherence to the seismometer signals.

We were able to verify that the coherence OSEM sensor <-> seismometer signal goes down with increasing the OSEM gain. This seems to indicate that the OSEM FB add noise to the distance mirror <-> frame. We injected some noise into the OSEMs to see how the coherence behaves.

MC2 SUSPOS, 0.1Hz - 0.8Hz, 3mins each

Inj. amplitude   Time(UTC) Note

-                     21:35          Free swinging
-                     21:42          Big LF OSEM gain
-                     21:48          Small LF OSEM gain
150                     21:56          -"-
300                     22:00          -"-
900                     22:05          -"-

Free swinging:

FreeSwinging.png

High OSEM gain:


LocalDampingOn.pdf

Low OSEM gain:

LowOsemGain.pdf

LowOsemGainInj150.pdf

Low_LF_OSEM_Gain_Inj300.fig

LowOsemGainInj900.pdf

 

We left the filters that lower the OSEM gain below 0.3Hz on.

Attachment 2: High_Osem_Gain.pdf
High_Osem_Gain.pdf
Attachment 4: Low_LF_OSEM_Gain.fig
  5964   Sun Nov 20 15:11:09 2011 kiwamuUpdateIOORFAM monitoring test

DO NOT CHANGE THE IFO ALIGNMENT UNTIL TOMORROW MORNING OR FURTHER NOTICE.

Plus, MC has to be kept locked with the WFS.

 

An RFAM measurement is ongoing

 

 Since the Stochmon turned out to be tricky to calibrate the outputs, Koji and I decided to monitor the RFAMs using REFL11 and REFL55 RFPDs while the beam is single-bounced from PRM.
This is, of course, not a permanent RFAM monitor, but at least it gives us a long-term continuous RFAM information for the first time.
Before the measurement I ran the offset zeroing scripts, therefore any offsets from electronics must be tiny in the acquired REFL signals.
The measurement has begun from approximately 3:00 pm.
 
 Also I found C1LSC.ini file again became default (no channels had been acquired).
So I replaced it with an archived ini file and then restarted fb.
  5966   Mon Nov 21 12:48:00 2011 JenneUpdateIOORFAM monitoring test

I don't think I touched/adjusted/whatever anything, but I did open the PSL table ~5-10min ago to measure the size of the Kiwamu-Box, so if the RFAM stuff looks funny for a few minutes, it was probably me.  Just FYI.

  5967   Mon Nov 21 14:15:25 2011 JenneUpdateIOORFAM monitoring test

Quote:

DO NOT CHANGE THE IFO ALIGNMENT UNTIL TOMORROW MORNING OR FURTHER NOTICE.

 [Mirko,  Jenne]

We're playing with the MC OAF, so we're actuating on MC2.  Again, FYI.

ELOG V3.1.3-