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ID Date Authorup Type Category Subject
  5392   Tue Sep 13 03:18:14 2011 kiwamuUpdateLSCY arm locking prep

(Preparation of Y arm locking)

(A) The f2a filters were newly designed and applied to ETMY (see the attachment)

(B) Once the Y arm is aligned such that the TEM00 mode flashes, the transmitted light is visible on the ETMYT CCD camera.

(C) With the newly installed resonant EOM circuit the PDH signal from AS55 looks healthy.

 

(some notes)

(A) To design the f2a filters there is a handy python script called "F2A_LOCKIN.py" in /scripts/SUS.

The script measures the coil imbalance at high frequency and low frequency using a LOCKIN module and then gives us the information about the imbalance.

The script hasn't yet been completed, so it doesn't return the intuitive answers but returns something non-intuitive. I will modify it.

 

(B)  To see the transmitted light from the Y arm I was going to align the CCD camera on the Y end table.

However I found that once the green light is blocked, the transmitted light can be visible on the camera without any re-alignment.

Therefore I haven't rearranged anything on the Y end table, but I just blocked the green light.

Perhaps we still need to align the photo diodes for the transmitted light.

 

(C) While Suresh was working on MC, I looked at the signal from AS55 with all the optics misaligned except for ITMY, ETMY and BS.

The signal from the Y arm looked very PDH signal, and the demodulation phase seemed to be about 45 deg to maximize the I signal.

I tried locking it by feeding the signal back to ETMY but failed due to a too much POS to angle coupling in the ETMY actuators.

I was momentarily able to capture a higher order mode with a negative gain in LSC-YARM_GAIN, but it was quite difficult to keep it locked.

This was because once I increased the gain to make it stable, the angle instability became more significant and lost the lock immediately.

This was the reason why I had to do the f2a filter redesign. Tomorrow we can try locking the Y arm.

  5398   Tue Sep 13 19:31:09 2011 kiwamuUpdateLSCY arm locking prep

The Y arm has been locked with AS55.

A next thing is to check the spot positions on the ETMY and ITMY mirrors so that we can evaluate the recent beam pointing.

 

- - - parameter settings - - -

C1:LSC-YARM_GAIN = -0.03

AS55 demod phase = 0.2

WF gains = 21 dB

C1:LSC-TRY_OUT = 0.57 (maximized by steering PZT2)

Quote from #5392

This was the reason why I had to do the f2a filter redesign. Tomorrow we can try locking the Y arm.

 

  5400   Wed Sep 14 01:17:51 2011 kiwamuUpdateLSCmeasurement of spot position on Y arm

The spot positions on ITMY and ETMY were measured using the LOCKIN modules in C1ASS when the Y arm stayed locked.

The beam was successfully aligned such that it hits the center of the ETMY mirror.

However on the other hand the angle of the beam is pitching and it's going upward as the beam propagates to ETMY.

 

/***** RESULTS ******/

Here is a summary of the measurement :

  amount of off-centering [mm]
ETMY_PIT  0.0032
ETMY_YAW  -0.13
ITMY_PIT  -12
ETMY_YAW  0.91

  

Also a cartoon is shown below.

The scale is not quite true, but at least it gives you a 3D information of how the beam is pointing down to the Y arm.

 misposition.png


  /***** MEASUREMENT *****/

 In order to measure the spot positions the standard technique, namely A2L, was used.

Since the C1ASS model was made for doing the A2L measurements on each arm cavity, the LOCKIN modules in C1ASS were used.

First the Y arm was locked with AS55 (#5398), and then the C1ASS was activated by calling some scripts from C1ASS_QPDs.adl.

In order to calibrate the signals from LOCKINs, an intentional coil imbalance was introduce.

This is the same calibration technique as Valera explained before (#4355) for measurement of the MC spot positions.

Quote from #5398

The Y arm has been locked with AS55.

A next thing is to check the spot positions on the ETMY and ITMY mirrors so that we can evaluate the recent beam pointing.

 

  5405   Wed Sep 14 14:06:44 2011 kiwamuUpdateGeneralminutes of 40m meeting : plans
+ Optical lever (Steve/Paul)
+ LSC demod board (Keiko)
+ DRMI locking (Keiko / Anamaria)
+ Modulation depth (Mirko)
+ ALS (Katrin)
+ MC WFS (Suresh)
+ OAF (Jenne/Mirko)
+ MC_F acquisition (Jenne/Mirko)
+ SUS, free swinging (Jenne)
+ CDS (Jamie)
+ vent plan (Jamie)
+ EOM (Kiwamu)
+ PZT-HV (Kiwamu/Koji)
  5406   Wed Sep 14 15:00:00 2011 kiwamuUpdateLSCmeasurement of spot position on Y arm

Forgot to attach a picture of the ITMY's face camera when it was locked.

The horizontal position of the spot looks good, but the vertical position is apparently too low, which agrees with the A2L result.

DSC_3408_small.jpg

Quote from #5400
  amount of off-centering [mm]
ETMY_PIT  0.0032
ETMY_YAW  -0.13
ITMY_PIT  -12
ETMY_YAW  0.91

 

 

  5410   Wed Sep 14 21:18:45 2011 kiwamuUpdateLSCY arm locking prep

Although we did some of the Input Matrix diagonalization, we have not yet actually used this knowledge. As a result all of the optics are shaking all over the place.

Sunshine Task: Set the input matrices to their calculated values and then adjust the OSEM damping gains for all optics so as to get a Q ~ 5.

  5417   Thu Sep 15 15:11:38 2011 kiwamuUpdateSUSf2a filters on BS and PRM

The f2a filters were newly designed and installed on BS and PRM.

So the lock of PRMI will be more stable .

Once the SRM oplev project settles down, I will adjust the f2a filters on SRM too.

  5435   Fri Sep 16 16:29:05 2011 kiwamuUpdateSUSf2a filters on SRM

New f2a filters were installed on SRM.

The lock of DRMI should be more stable than last night.

Quote from #5417

Once the SRM oplev project settles down, I will adjust the f2a filters on SRM too.

 

  5439   Fri Sep 16 17:46:13 2011 kiwamuUpdateSUSSome screens fixed

The bad medm screens have been fixed. There are no blank fields and all the links are correct.

Quote from #5409

I've found that a few of the screens still have Whited-Out fields due to naming changes (OL SUM and ALS-> TM OFFSET). I attach a screen shot of it.

The OL screens have the wrong SUM names and the IFO ALIGN screen is pointing to the wrong SUS screens.

 

  5444   Fri Sep 16 23:22:36 2011 kiwamuUpdateSUSETMX input matrix : bad YAW-SIDE coupling

With the new input matrix, it looks like YAW and SIDE are not quite decoupled on ETMX.

It needs one more kick and free swinging test.

 

- - - details

 To see what exactly is going on, I changed the input matrix from the default to the new one, which Jenne computed (#5421) on ETMX.

I started putting the elements of the input matrix from POS through SIDE, one by one.

It seemed that POS and PIT worked fine. However the YAW signal looks containing a lot of the SIDE signal.

Similar to YAW, SIDE also interact with the YAW motion and somehow rings up both YAW and SIDE signals as Jenne reported ( #5438).

So right now the YAW and SIDE rows are partially reburted to the default elements in order to avoid ringing up.

Quote from #5438

but ETMX and BS were not good at all.  ETMX was ringing up when I turned on the damping. 

 

  5446   Sat Sep 17 02:07:10 2011 kiwamuUpdateSUSETMX input matrix : bad YAW-SIDE coupling

Excited all the optics. They will be automatically back after 5 hours.

Sat Sep 17 02:02:07 PDT 2011
1000285342

Quote from #5444

It needs one more kick and free swinging test.

 

  5452   Mon Sep 19 01:07:32 2011 kiwamuUpdateSUSf2a filters on ITMs and ETMX

The f2a filters were installed on ITMs and ETMX.

Now all of the suspensions has the f2a filters.

  5453   Mon Sep 19 01:38:00 2011 kiwamuUpdateLSCtoday's locking activity

[Anamaria / Kiwamu]

 The incident beam pointing was improved by using PZT1 and PZT2. 

With some triggers the lock of PRMI became smoother.

For the DRMI lock, the MICH and SRCL signals on AS55 are not quite decoupled, so we should find cleaner signals for them.

 

(what we did)

 + locked the Y arm

 + aligned incident beam by using PZT1(#5450) and PZT2. The spot positions on ITMY and ETMY are now well-centered.

 + tried activating C1ASS but failed. It needs some gain changes due to the new PZT1 response.

 + locked the X arm

 + aligned the TRX PD (Thorlab signal PD) and set the trigger.

 + C1ASS also doesn't work for the X arm

 + realigned the PRM and BS oplevs. the PRM oplev was clipped at a steering mirror on the optical bench

 + locked PRMI and aligned the PRM mirror such that the optical gain was maximized

 + optimized the demod phase of AS55 and REFL11

 + checked the UGF of the MICH and PRCL lock. The UGF of MICH is about 100Hz with gain of -20, and the UGF of PRCL was 85 Hz with gain of 0.1

 + adjusted the output matrix such that the MICH control doesn't couple into the PRCL control.

 + set the triggers for the MICH and PRCL control to make the lock acquisition smoother.

 + tried locking DRMI and it was sort of locked. However the SRCL signal showed up a lot in AS55_Q, where the MICH signal is extracted.

  5454   Mon Sep 19 02:08:24 2011 kiwamuUpdateLSCfixed POP clipping

Actually the clipping of POP wasn't in the chamber but it was on the first lens on the optical bench.

So I repositioned the lens to avoid the clipping and now there are no clipping on POP.

Quote from #5445

We found that POP beam is clipped by the steering mirrors inside the tank.

 

  5455   Mon Sep 19 02:33:34 2011 kiwamuHowToGeneralPlan for this week

GOAL1:  Stable lock of DRMI

GOAL2:  Measurement of the LSC input matrix in the DRMI configuration

 

 /- - Daytime works - - /

  + Measurement of the arm lengths (Jenne / Kiwamu / volunteers)

  + Optimization of the oplev control loops (Paul)

  + Inversion and installation of the SUS input matrices (Jenne)

  + Tuning of the SUS damping gains (Steve)

  + Measurement of the modulation depths (Mirko)

  + Preparation of the green broadband PD (Katrin)

  + Fixing the Y arm green lock servo (Katrin / Kiwamu)

  + Installation of RFPDs (Anamaria)

  + Minimization of the AM sidebands (Anamaria / Keiko)

  + Preparation of a script for measuring the LSC input matrix (Keiko)

  + MC WFS (Suresh)

  + Online adaptive filtering (Mirko / Jenne)

  + Modification of C1ASS (Kiwamu)

  + Fixing IPPOS (volunteers) 

  + Auto alignment of PRCL and SRCL (volunteers)

  + Loss measurement of the arm cavities (volunteers)

  + Fixing the ETMX SIDE slow monitor (volunteers)

 

 /- - Nighttime works - - /

 + Locking of DRMI

 + Characterization of DRMI and complete the wiki page

  5459   Mon Sep 19 14:57:36 2011 kiwamuSummaryIOOIP POS is back

IPPOS is back. A cable had been disconnected at the 1Y2 rack. So I put it back to place.

The cartoon below shows the current wiring diagram. I think this configuration is exactly the same as it it used to be.

wiring.png

Quote from #5455

  + Fixing IPPOS (volunteers) 

  5463   Mon Sep 19 16:20:35 2011 kiwamuUpdateLSCAS55 whitening gain decreased

The gain of whitening filters on AS55 was decreased from 21 dB to 0 dB for the Y arm locking.

 

- - (Background)- -

Since the modulation depths became bigger from the past (#5462), the PDH signal from Y arm was saturated in the path of AS55.

Due to the saturation the lock of the Y arm became quite difficult so I decreased the gain of of the whitening filter from 21 dB to 0 dB.

In this condition, a required gain in C1:LSC-YARM_GAIN is about -0.3, which is 10 times bigger from the default number.

For the MICH locking tonight, it may need to be back to a big gain.

  5478   Tue Sep 20 13:57:44 2011 kiwamuUpdateIOOincident beam to MC aligned

Since the MC wasn't able to capture the 00 mode in this morning I aligned the incident beam going to MC.

As a result C1:IOO-RFPD_DCMON went down to 0.6. However the beam on IPPOS is almost falling off from the QPD.

  5482   Tue Sep 20 15:54:42 2011 kiwamuUpdateCamerasMC refl camera is available

[Suresh / Kiwamu]

 The MC REFL camera is now available. The camera name is "MCR" and you can call it from the videoswitch script.

 

(what we did)

 + repositioned and aligned the MCR camera.

 + checked the MCR camera.

  => found the camera view shows a negative image (i.e. the beam spot is dark and the background is bright !!)

 + replaced the camera by a spare one.

 + modified the videoswitch script because the input channel 3 was wrongly assigned to MCR.

  MCR was correctly assigned to the input channel 18.

  5486   Tue Sep 20 17:45:30 2011 kiwamuUpdateCDSdaqd is restarting by hisself ?

[Jenne / Kiwamu]

 Fb was sick. Dataviewer and Fourier Tools didn't work for a while.

After 10 minutes later they became healthy again. No idea what exactly was going on.

One thing we found was that : during the sickness of fb, it looks like daqd was restarting by hisself. Is this normal ??

Here is the bottom sentences of restart.log. Apparently daqd was rebooting although we didn't command to do so.

  daqd_start Tue Sep 20 02:41:17 PDT 2011
  daqd_start Tue Sep 20 13:18:12 PDT 2011
  daqd_start Tue Sep 20 17:33:00 PDT 2011

  5508   Wed Sep 21 23:25:51 2011 kiwamuUpdateSUSRe:ITMY and SRM actuator response functions - fitting results

Did you take the 180 deg shift into your account ?

Since your measurement was done when the loop was closed, there must be an additional 180 deg phase shift (in other words, minus sign).

Quote from #5507

In the end I just fitted the response magnitude. I was initially fitting the complex response function, but ran into problems which I think were cased by overall phase offsets between the data and test function. Can I canvass for opinion if fitting the magnitude is OK, or should I try again fitting the phase too?

  5515   Thu Sep 22 11:49:05 2011 kiwamuUpdateLSCsome LSC scripts don't run on pianosa

Found some LSC scripts didn't run on pianosa. Particularly all the scripts on the C1:IFO_CONFIGURE screen don't run.

They need to be fixed.

  5518   Thu Sep 22 13:56:56 2011 kiwamuUpdateASCC1ASS : status update

The output matrix in the C1ASS servo were coarsely readjusted and the servos seemed working.

However it is difficult to say the servo is very good or so-so,

because the ETMY suspension moves a lot and hence the cavity eigen axis moves a lot too.

 


(to do)

 + optimization of the ETMY oplevs and OSEM damping.
 + evaluation of the performance of the C1ASS with a good damping.

(Background)

 Since we have installed the new mid-HV amplifier for the PZT1 mirror (#5450) it changed the response of the PZT1 (gains from EPICS to the actual angles).
Therefore the C1ASS output matrix needs be adapted to the new PZT1 response.
 
(What I have done)
  What I was measuring was a coupling from each PZT mirror to both beam angle and beam position by looking at the output from the LOCKINs.
So this measurement eventually gives us a nicely diagonalized output matrix by inverting the coupling.
However the measurement turned out to be difficult because the ETMY moved too much.
In fact the cavity eigen axis also moves and the fluctuation was larger than the intentionally introduced beam angle/translation offsets, which are for the coupling measurement.
 
 Instead of measuring the couplings, I put some numbers into the matrix based on a guess.
Since the PZT1 HV amp became weaker than that of PZT2, the elements in the output matrix should be amplified by some number.
Right now the PZT1 amp can drive the mirror in a range of -5 -30 V with EPICS range of +/-10 counts, and for PZT2 it is about 0 -150V with EPICS range of +/-5 counts.
So the difference of the responses in unit of V/counts is about 8.5.
The PZT1 elements in the matrix were multiplied by this number and I became able to close the servos.

Quote from #5455

  + Modification of C1ASS (Kiwamu)

  5521   Thu Sep 22 17:48:20 2011 kiwamuUpdateSUSbad oplev on ETMY

It turned out the oplev controls on ETMY were just bad.

It looks like the whitening filters have been OFF and because of that the resultant open-loop was not crossing the unity gain.

I will check the whitening filters.

 

(open-loop transfer function)

The blue dots are the measured data points and the green curve is the fit.

Apparently the open-loop doesn't go above the unity gain, so the oplev had been doing nothing.

If we try to increase the overall gain it will oscillate because of the phase delay of more than 180 deg around 3 Hz.

The red curve is the expected one with the whitening filters (WFs) properly engaged.

Note that WF are supposed to have two zeros at 1 Hz and two poles at 10 Hz.

 OLETMY.png

Quote from #5518
(to do)
 + optimization of the ETMY oplevs and OSEM damping.

  5523   Thu Sep 22 20:12:54 2011 kiwamuUpdateSUSETMY oplev whitening engaged

The whitening filters for the ETMY oplevs are back.

The whitening board had been in the rack but the ADC was connected directly to the oplev interface board without going through the whitening board.

In fact the interface board and the whitening board had been already connected. So the ADC was making a shortcut.

I disconnected the ADC from the interface board and plugged it to the output of the whitening board.

Here is an example of the new open-loop transfer function with the whitening filters.

OLETMY_WF.png

 Note :

before the measurement I increased the control gain by an arbitrary number to obtain gain of more than 1 around 1 Hz.

Quote from #5521

I will check the whitening filters.

  5534   Sat Sep 24 01:21:11 2011 kiwamuUpdateSUSdamping test

As a suspension test I am leaving all of the suspensions restored and damped with OSEMS but without oplevs

  5535   Sat Sep 24 01:38:14 2011 kiwamuUpdateCDSc1scx and c1x01 restarted

[Koji / Kiwamu]

 The c1scx and c1x01 realtime processes became frozen. We restarted them around 1:30 by sshing and running the kill/start scripts.

  5537   Sat Sep 24 02:09:43 2011 kiwamuUpdateSUSRe:Oplev filter optimization for 2 poles and 2 zeros

Good work for the oplev noise simulations. Here are some comments/questions:

 (A) The noise looks suppressed but the open-loop transfer function doesn't look so good, because it doesn't have sufficient phase margins at the UGFs (0.01 and 10 Hz).

      I guess it is better to have a phase margin detector in your code so that the code automatically rejects a bad phase margin case.

      Actually since the number of data points are finite, the rms detector in the simulation can not always find a sharp loop oscillation.

 (B) The resultant poles and zeros seem canceling each other but the filter still has a structure. Is something wrong ?

Quote from #5332

 Pole 1 frequency = 0.0497181 Hz 

 Pole 2 frequency = 2.01809 Hz 

 Zero 1 frequency = 0.0497181 Hz 

 Zero 2 frequency = 2.01809 Hz

  5543   Mon Sep 26 12:41:27 2011 kiwamuUpdateASCC1ASS : status update

Quote from #5518
(to do)
 + optimization of the ETMY oplevs and OSEM damping.
 + evaluation of the performance of the C1ASS with a good damping.

The servo for aligning the Y arm is working fine with the coarse gain coefficients.

However then I found the ASS_Xarm servo was not healthy.

So the next step is to refine the X arm servo in C1ASS.

 

(some notes)

  + With the ETMY oplev the Y arm became quieter after we recovered the oplev whitening filter (#5523)

  + The Y arm alignment scripts can be run from the usual C1IFO_CONFIGURE screen.

   It will servo the spot positions on ITMY and ETMY, and align the input beam pointing. It brings the Y arm power to about 1.

 + The X arm servo is doing something funny. It doesn't bring the arm power up to 1.

   I thought the X arm didn't need any modifications because the X arm servo doesn't include PZT1 and PZT2.

   So it maybe a simple bug (for example, some switches are disable and so on)

 

  5544   Mon Sep 26 14:21:07 2011 kiwamuUpdateSUSITMX ULSEN shows jumps

Quote from #5534

As a suspension test I am leaving all of the suspensions restored and damped with OSEMS but without oplevs

According to the spectra, all of the suspensions had been damped with the OSEMs. The peaks around 1Hz are reasonably suppressed.

However the spectra from ITMX showed a noise floor at very high level. This is because of strange jumps in the signal of the UL shadow sensor.

I will check some analog circuits for the UL sensor.

 


(ITMX shadow sensors)

Here is the spectra of the ITMX shadow sensors taken during the damping test (#5534)- -

 ITMXspectra.png 

The UL sensor shows a unacceptable amount of noise.

 

Additionally I checked the time series of the ITMX shadow sensors and found ONLY the UL sensor frequently showed strange jumps in data.

Here is an example of the time series showing a jump ONLY in the UL sensor.

ITMX-sensors.png

It is possible that the jumps are coming from some circuits, since the rest of the sensors (including the oplevs) don't detect the same jump.

  5546   Mon Sep 26 15:54:46 2011 kiwamuUpdateSUSITMX ULSEN shows jumps

Currently the damping of the ITMX suspension is intentionally disabled for the noise investigation.

Quote from #5544

 

However the spectra from ITMX showed a noise floor at very high level. This is because of strange jumps in the signal of the UL shadow sensor.

I will check some analog circuits for the UL sensor.

 

  5547   Mon Sep 26 16:42:08 2011 kiwamuUpdateSUSITMX ULSEN : fixed

The issue on the ITMX UL sensor has been fixed. It was because of a loose connection in the sensor signal path.

After the fix, the sensor responses completely changed and the suspension became unable to be damped with the new matrix.

At the moment the ITMX suspension is damped by the default input matrix.

we should do the free swinging test once again.

 


(details)

 The loose connection was found on the rear side of the 1X5 rack.

There is an adapter card on the rear side, where the driver and sensor signals are combined into a single cable.

I pushed the sensor cable (bottom right in the picture) and the noise disappeared.

connection.png

Note that I changed the labels on the adapter cards from the old X/Y convention to the new one.

After fixing the loose cable the ITMX suspension became unable to be damped.

So I put the input matrix back to the default and it immediately started damping happily. It means our new matrix is not valid any more.

 

 Here is the latest noise spectra of the ITMX sensors damped with the default input matrix.

As usual all of them are limited by the ADC noise above 20 Hz. (ADC noise is plotted in purple curve)

ITMXsensors.png

 

During the work I also pushed not only ITMX ones but also the cable for the rest of the optics in the adapter cards.

Then PRM became unable to be damped, so it implies the PRM suspension also used to be the same situation.

The input matrix of PRM has been also back to the default.

 

Quote from #5546

Currently the damping of the ITMX suspension is intentionally disabled for the noise investigation.

 

  5553   Tue Sep 27 04:13:22 2011 kiwamuUpdateLSCtonight's locking activity

The lock of PRMI wasn't so robust although it could stay locked for more than 10 minutes.

There have been 2-3Hz spikes in everywhere. It needs to be investigated.

 

(to do)

 + Diagnosis on the suspensions.

 + Check the beam centering on the RFPDs.

 + Check the f2a filters on PRM and BS.

 + Health check of the suspensions by locking some cavities and measuring the noise spectra for comparison.

 + Trying to use another signal port other than AS55.

 

(Spikes)

 The attached picture below is an example of the REFLDC and POXDC signals in time series.

This was when PRCL and MICH were locked by REFL33_I and AS55_Q respectively.

PRMI.png

Note that when PRMI is unlocked, REFLDC goes to ~ 5000 counts and POXDC goes within ADC noise of ~ 1 counts.

According to the POP camera it looked like something was oscillating in the YAW direction which coincided with the spikes.

I tried finding any suspicious angular motions in the ITMs, BS and PRM olevs, but none of them showed the 2-3 Hz feature.

  5561   Wed Sep 28 02:42:04 2011 kiwamuUpdateCDSsome DAQ channel lost in c1sus : fb, c1sus and c1pem restarted

Somehow some DAQ channels for C1SUS have disappeared from the DAQ channel list.

Indeed there are only a few DAQ channels listed in the C1SUS.ini file.

I ran the activateDQ.py and restarted daqd.

Everything looks okay.  C1SUS and C1PEM were restarted because they became frozen.

  5574   Thu Sep 29 03:43:20 2011 kiwamuUpdateASCwrong channel assignment on IPPOS

The channels for IPPOS had been assigned in a wrong way.

Because of this, C1:ASC-IP_POS_X_Calc corresponds to the actual vertical motion and C1:ASC-IP_POS_Y_Calc is for the horizontal motion.

We should fix the database file to get the correct vertical/horizontal corrdinate.

  5578   Fri Sep 30 01:18:39 2011 kiwamuUpdateASCC1ASS : status update

Now the C1ASS servos are working fine.

However at the end of the scripts sometimes it changes the DC force (e.g. C1:SUS-ITMX_PIT_COMM and so on) by a wrong amount.

So for this bug, it misaligns the suspensions a lot. I will take a look at the script tomorrow.

Quote from #5543

However then I found the ASS_Xarm servo was not healthy.

  5579   Fri Sep 30 02:56:56 2011 kiwamuUpdateCDSC1IOO.ini and C1LSC.ini files reverted

[Suresh/Kiwamu]

We found that the C1LSC.ini and C1IOO.ini file had been refreshed and there were a few recorded channels in the files.

So we manually recovered C1LSC.ini file using the daqconfig GUI screen.

For the C1IOO.ini file we simply replaced it by the archived one which had been saved in 22nd of September.

Then we restarted daqd.

  5580   Fri Sep 30 03:14:18 2011 kiwamuUpdateCDSsuspension became crazy : c1sus rebooted

Quote from #5579

Then we restarted daqd.

[Suresh / Kiwamu]

The c1lsc and c1sus machine were rebooted.

 

- - (CDS troubles)

 After we restarted daqd and pressed some DAQ RELOAD buttons the c1lsc machine crashed.

The machine didn't respond to ssh, so the machine was physically rebooted by pressing the reset button.

Then we found all the realtime processes on the c1sus machine became frozen, so we restarted them by sshing and typing the start scripts.

However after that, the vertex suspensions became undamped, even though we did the burt restore correctly.

This symptom was exactly the same as Jenne reported (#5571).

We tried the same technique as Jenne did ; hardware reboot of the c1sus machine. Then everything became okay.

The burt restore was done for c1lsc, c1asc, c1sus and c1mcs.

 

- - (ITMX trouble)

During the trial of damping recovery, the ITMX mirror seemed stacked to an OSEM. The UL readout became zero and the rest of them became full range.

Eventually introducing a small offset in C1:SUS-ITMX_YAW_COMM released the mirror. The amount of the offset we introduced was about +1.

  5582   Fri Sep 30 05:35:42 2011 kiwamuUpdateLSClength fluctuations in MICH and PRCL

The MICH and PRCL motions have been measured in some different configurations.

According to the measurements :

      + PRCL is always noisier than MICH.

      + MICH motion becomes noisier when the configuration is Power-Recycled Michelson (PRMI).

The next actions are :

      + check the ASPD

      + check the demodulation phases

      + try different RFPDs to lock MICH

 


(Motivation)
 The lock of PRMI have been unstable for some reason.
One thing we wanted to check was the length fluctuations in MICH and PRCL.


(Measurement)
Four kinds of configuration were applied.
     (1) Power-recycled ITMX (PR-ITMX) locked with REFL33_I, acting on PRM.
     (2) Power-recycled ITMY (PR-ITMY) locked with REFL33_I, acting on PRM.
     (3) Michelson locked with AS55_Q, acting on BS.
     (4) Power-recycled Michelson locked with REFL33_I and AS55_Q, acting on PRM and BS.

In each configuration the spectrum of the length control signal was measured.
With the measured spectra the length motions were estimated by simply multiplying the actuator transfer function.
Therefore the resultant spectra are valid below the UGFs which were at about 200 Hz.
The BS and PRM actuator responses had been well-measured at AC (50 - 1000 Hz)
For the low frequency responses they were assumed to have the resonances at 1 Hz with Q of 5.
 

(Results)
The below plot shows the length noise spectra of four different configurations.
There are two things which we can easily notice from the plot.
    + PRCL (including the usual PRCL and PR-ITMs) is always noisier than MICH.
    + MICH became noisier when the power recycling was applied.
In addition to them, the MICH noise spectrum tended to have higher 3 Hz bump as the alignment gets improved.
In fact everytime when we tried to perfectly align PRMI it eventually unlocked.
I am suspecting that something funny (or stupid) is going on with the MICH control rather than the PRCL control.

noise.png

(Notes)
   BS actuator = 2.190150e-08 / f2
   PRM actuator = 2.022459e-08 /  f2
  5583   Fri Sep 30 06:25:20 2011 kiwamuUpdateLSCCalbiration of BS, ITMs and PRM actuators
The AC responses of the BS, ITMs and PRM actuators have been calibrated.
 
(Background)
 To perform some interferometric works such as #5582, the actuator responses must be measured.
 
(Results)
     BS = 2.190e-08 / f2     [m/counts]
     ITMX  = 4.913e-09 / f2   [m/counts]
     ITMY  = 4.832e-09 / f2   [m/counts]
     PRM   = 2.022e-08 / f2  [m/counts]
 
actuators.png
 
(Measurement)
The same technique as I reported some times ago (#4721) were used for measuring the BS and ITMs actuators.
In order to measure the PRM actuator, power-recycled ITMY (PR-ITMY) was locked and the same measurement was applied.
The sensor response of PR-ITMY was calibrated by exciting the ITMY actuator since the response of the ITMY had been already measured.
  5586   Fri Sep 30 16:17:10 2011 kiwamuUpdateGreen Lockingthings to be done for the Yarm green lock

Thank you for the summary.

I think now you are getting into a phase where you should start doing some quantitative and careful checks.

    1. Calculate how much light will be reflected from the cavity if the alignment is perfect.

    2. Investigate where those kHz oscillations are coming from.

    3. Estimate how much the 1.1 kHz corner frequency in LPF will reduce the phase margin around 10 kHz.

    4. Calculate the estimated amplitude of the PDH signal.

    5. Compute how big the gain of the PDH box should be.

Quote from #5585

 This is a kind of summary of what I have worked on this week. 

  • DC level of green PD when light resonates 75%
                    --> Not sure if this alignment is good enough
  • The PDH error signal was covered with oscillations of 3.3 kHz, 7.1 kHz and 35 kHz.
  • Designed and build a new LPF: second order, cut of frequency of 1.1 kHz (this is just the design value, haven't measured that so far)
  • Signal-to-noise ratio (SNR) could be improved to values between 7.8 and 11.1 (old SNR was 5 to 7)

  5588   Fri Sep 30 17:40:03 2011 kiwamuUpdateIOOAM / PM ratio

[Mirko / Kiwamu]

 We have reviewed the AM issue and confirmed the ratio of AM vs. PM had been about 6 x103.

The ratio sounds reasonably big, but in reality we still have some amount of offsets in the LSC demod signals.

Next week, Mirko will estimate the effect from a mismatch in the MC absolute length and the modulation frequency.

 


(Details)

 Please correct us if something is wrong in the calculations.

 According to the measurement done by Keiko (#5502):

        DC = 5.2 V

        AM @ 11 and 55 MHz = - 56 dBm = 0.35 mV (in 50 Ohm system)

Therefore the intensity modulation is 0.35 mV / 5.2 V = 6.7 x 10-5

Since the AM index is half of the intensity modulation index, our AM index is now about 3.4 x 10-5

According to Mirko's OSA measurement, the PM index have been about 0.2.

As a result,  PM/AM = 6 x 103

Quote from #5502

Measured values;

* DC power = 5.2V which is assumed to be 0.74mW according to the PDA255 manual.

*AM_f1 and AM_f2 power = -55.9 dBm = 2.5 * 10^(-9) W.

 

  5589   Fri Sep 30 18:06:24 2011 kiwamuSummaryIOOPZTs straing guage

beforeOutage110930.png

  5593   Sat Oct 1 22:53:49 2011 kiwamuSummaryGeneralRecovery from the power shutdown : lockable

Found the Marconi for the 11 MHz source had been reset to its default.

 => reset the parameters. f = 11.065910 MHz (see #5530) amp = 13 dBm.

Interferometer became lockable. I checked the X/Y arm lock, and MICH lock, they all are fine.

  5594   Sun Oct 2 02:21:27 2011 kiwamuUpdateSUSfree swinging test once more

The following optics were kicked:
MC1 MC2 MC3 ETMX ETMY ITMX ITMY PRM SRM BS
Sun Oct  2 02:13:40 PDT 2011
1001582036

They will automatically get back after 5 hours.

  5595   Sun Oct 2 02:33:32 2011 kiwamuUpdateLSCsomething funny with AS55

Just a quick report.

The AS55 signal contains more noise than the REFL signals.

Why ? Is this the reason of the instability in PRMI ?

outofloop.png

 I locked the Power-Precycled ITMY with REFL33.

As shown in the plot above, I compared the in-loop signal (REFL33) and out-of-loop signals (REFL11 and AS55).

All the signals are calibrated into the displacements of the PR-ITMY cavity by injecting a calibration peak at 283 Hz through the actuator of PRM.

AS55 (blue curve) showed a structure around 3 Hz and higher flat noise below 1 Hz.

Quote from #5582
I am suspecting that something funny (or stupid) is going on with the MICH control rather than the PRCL control.

 

  5597   Sun Oct 2 18:33:36 2011 kiwamuUpdateSUSinversion of the input matrix on ETMX, ITMX and PRM

The input matrices of ETMX, ITMX and PRM have been newly inverted.

Those were the ones having some troubles (see #5444, #5547).

After a coarse adjustment of the damping Q factors, they look damping happily.

 

    optic                    spectra    inverted matrix   BADNESS
ETMX ETMX.png       pit     yaw     pos     side    butt
UL    0.848   0.108   1.578   0.431   1.025 
UR    0.182  -1.892   1.841  -0.128  -1.172 
LR   -1.818  -1.948   0.422  -0.122   0.939 
LL   -1.152   0.052   0.159   0.438  -0.864 
SD    1.756  -3.794  -0.787   1.000  -0.132 
  5.37028
ITMX ITMX.png     pit     yaw     pos     side    butt
UL    0.510   0.584   1.228   0.458   0.203 
UR    0.783  -1.350   0.348  -0.050   0.555 
LR   -1.217   0.065   0.772   0.264   0.312 
LL   -1.490   2.000   1.652   0.772  -2.930 
SD   -0.635   0.853  -1.799   1.000  -1.597  
 7.5125
PRM PRM.png       pit     yaw     pos     side    butt
UL    0.695   1.422   1.774  -0.333   0.954 
UR    1.291  -0.578   0.674  -0.068  -0.939 
LR   -0.709  -1.022   0.226   0.014   0.867 
LL   -1.305   0.978   1.326  -0.251  -1.240 
SD    0.392  -0.437  -0.500   1.000   0.420
 5.09674

 

(some notes)

 Before running the peakFit scripts, I woke up the nds2 sever process on Mafalda because it hasn't been recovered from the power outage.

To start the nds2 process I followed the instruction by Jamie (#5094).

Then I started requesting the data of the last night's free swinging test (#5594)

However the NDS2_GetData command failed everytime when data with long duration were requested.

It maybe because some of the data are missing in sometimes, but I haven't seriously checked the data stored in fb.

So for the reason, I had to use a short duration of 1200 sec (default is 3600 sec). That's why spectra look noisier than usual.

  5598   Mon Oct 3 04:43:03 2011 kiwamuUpdateLSCsideband-resonance PRMI locked

My goal of today was to lock PRMI without using AS55 and it is 50% successful.

The sideband-resonance PRMI (SB-PRMI) was locked with REFL33_I and REFL55_Q for the PRCL and MICH control respectively.

The carrier-resonance PRMI wasn't able to be locked without AS55.

     (it looked no clean MICH signals at the REFL ports.)

 


(Motivation)

 The motivation of not to use AS55 came from the suspicion that AS55 was injecting some noise into MICH (#5595).

So I wanted to try another RFPD to see if it helps the stability or not. 

 

(locking activity)

  The lock of SB-PRMI was quite stable so that it stayed locked more than 30 minutes (it ended because I turned off the servos.)

Then I briefly tried DRMI while PRCL and MICH kept locked by the same control loops, namely REFL33_I and REFL55_Q.

The lock of MICH and PRCL looked reasonably robust against the SRCL fringes, but wasn't able to find a good signal for SRCL.

I think I am going to try locking DRMI tomorrow.

 - - settings

    Demod phase for REFL55 = -45.3 deg

    Demod phase for REFL33 = -14.5 deg

    Whitening gain for REFL55 = 4 (12 dB)

    Whitening gain for REFL33 = 10 (30 dB)

    MICH gain = 100

    PRCL gain = 8

 

(misc.)

 + I removed an iris on the ITMY table because it was in the way of POY. See the picture below.

ITMYtable.png

 

  + I found that burtrestore for the ETMX DC coil forces were not functional.

  => currently ETMX's "restore" and "mislalign" buttons on the C1IFO_ALIGN screen are not working.

  => According to the error messages, something seemed wrong on c1auxex, which is a slow machine controlling the DC force.

  5605   Mon Oct 3 17:57:12 2011 kiwamuUpdateASCIPPOS fixed

The input matrix of IPPOS were fixed so that the horizaontal motion correctly shows up in X and the vertial is Y.

 

(what I did)

 + The data base file, QPD.db, were edited.

  QPD.db is a part of the c1isxaux slow machine and it determines the input matrix for deriving the X/Y signals from each quadrant element.

 + The previous input matrix was :

      X = (SEG1 + SEG4) - (SEG2 + SEG3)

      Y = (SEG1 + SEG2) - (SEG3 + SEG4)

 + The new matrix which I set is :

     X = (SEG1 + SEG2) - (SEG3 + SEG4)

     Y = (SEG1 + SEG4) - (SEG2 + SEG3)

    The new matrix is a just swap of the previous X and Y.

 + Then c1isxaux was rebooted by :

     telnet  c1iscaux

     reboot          

 + The I did the burt restore it to this morning.

Quote from #5574

The channels for IPPOS had been assigned in a wrong way.

 

  5607   Mon Oct 3 20:47:51 2011 kiwamuUpdateCDSc1lsc and c1sus didn't run

[Mirko / Jenne / Kiwamu]

Just a quick update. All the realtime processes on the c1lsc and c1sus machine didn't run at all.

Somehow the c1xxxfe.ko kernel module, where xxx is x04, x02, lsc, ass, sus, mcs, pem and rfm failed to be insmod.

The timing indicators on the c1lsc and c1sus machine are saying NO SYNC.

 

- According to log files (target/c1lsc/logs/log.txt)

insmod: error inserting '/opt/rtcds/caltech/c1/target/c1lsc/bin/c1lscfe.ko': -1 Unknown symbol in module

- dmesg on c1lsc (c1sus also dumps the same error message):

[   45.831507] DXH Adapter 0 : sci_map_segment - Failed to map segment - error=0x40000d01
[   45.833006] c1x04: DIS segment mapping status 1073745153

DXH dapter is a part of the Dolphine connections.

When a realtime codes is waking up, the code checks the Dolphin connections.

The checking procedure is defined by dolphin.c (/src/fe/doplhin.c).

According to a printk sentence in dolphin.c the second error message listed above will return status "0" if everything is fine.

The first error above is an error vector from a special dolphin's function called sci_map_segment, which is called in dolphin.c.

So something failed in this sci_map_segment function and is preventing the realtime code from waking up.

Note that sci_map_segment is defined in genif.h and genif.c which reside in /opt/srcdis/src/IRM_DSX/drv/src.

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