40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 232 of 341  Not logged in ELOG logo
ID Date Author Type Category Subject
  5493   Wed Sep 21 00:34:29 2011 ranaUpdateSUSSUS diag stuff... just so I remember what I'm doing

ETMX was ringing up when it was mis-aligned for Y arm locking. I restored the input matrix to something more diagonal and its now damping again. Needs more work before we can use the calculated matrix.

  5492   Tue Sep 20 23:59:53 2011 KojiSummaryLSCPlan to update the LSC code for multiple lock-ins

DRMI team needs to use at least three lockins on LSC

  • Increase the number of the lockin matrix  done
  • Duplicate lockin modules in the LSC code  done
  • modify the main LSC screen done
  • modify the lockin screen done
  • modify the lockin matrix screen done
  5491   Tue Sep 20 23:01:37 2011 KeikoUpdateIOOAM modulation mistery

Keiko, Suresh

AM modulations are still there ... the mechanical design for the stages, RF cables, and connections are not good and affecting the alignment.

I write the activity in the time series this time - Because we suspect the slight EOM misalignment to the beam produces the unwanted AM sidebands, we tried to align the EOM as much as possible. First I aligned the EOM tilt aligner so that the maximum power goes through. I found that about 5% power was dumped by EOM. After adjusting the alignment, the AM modulation seemed be much better and stable, however, it came up after about 20 mins. They grew up up to about -40dBm, while the noise floor is -60 dBm (when AM is minimised, with DC power of 8V by PDA225 photodetector).

We changed the EOM stage (below the tilt aligner) from a small plate to a large plate, so that the EOM base can be more stable. The EOM stands on the pile of several black plate. There was a gap below the tilt aligner because of a small plate.  So we swapped the small plate to large plate to eliminate the springly gap. However it didn't make any difference - it is the current status and there is still AM modulations right now.

During above activities, we leaned that the main cause of the EOM misalignment may be the RF cables and the resonator box connected to the EOM. They are connected to the EOM by an SMA adaptor, not any soft cables. It is very likely applying some  torc force to the EOM box. The resonator box is almost hunging from the EOM case and just your slight touch changes EOM alinment quite a bit and AM mod becomes large. 

I will replace the SMA connector between the resonator box and EOM to be a soft cable, so that the box doesn't hung from EOM tomorrow. Also, I will measure the AM mod depth so that we compare with the PM mod depth.

 

Quote:

 Keiko, Anamaria

We started to investigate the AM modulation mistery again. Checking just after the EOM, there are AM modulation about -45dBm. Even if we adjust the HWP just before the EOM, AM components grow up in 5 mins. This is the same situation as before. Only the difference from before is that we don't have PBS and HWP between the EOM and the monitor PD. So we have a simpler setup this time.

We will try to align the pockells cell alignment tomorrow daytime, as it may be a problem when the crystal and the beam are not well parallel. This adjustment has been done before and it didn't improve AM level at that time.

 

  5490   Tue Sep 20 21:13:39 2011 SureshUpdateIOOMC aligned and PSL beam into MC readjusted

This morning after Kiwamu maximised the PSL beam coupling into the MC we noticed that the MC2 face camera showed the spot position had moved away from the center by about a diameter.  So I checked the beam spot positions with MCASS and indeed found that the spot on MC2 had moved to about 6mm away from the center in yaw and about 3mm in pitch.  I adjusted the MC2 (and only MC2) to recenter the spots on all the three mirrors.  The new spot positions are given below

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
    1.3337   -0.2660    0.6641   -1.0973    0.0468   -1.7130

The PSL beam into MC has been readjusted for maximal coupling into MC.

 

  5489   Tue Sep 20 20:58:35 2011 AnamariaConfigurationLSCNew AP Table Drawing

As promised, I have made a final AP table drawing, including the MC camera relocation changes by Kiwamu. I have posted it in the wiki on the tables list, and on the AP table page I've attached the inkscape .svg I used to make it, if someone needs to do small modifications.

Attached is a pdf version of it.

Big changes:

1) REFL beam has been split into 4, to go in equal powers and equal beam size to the now 4 REFL RFPDs, 11, 33, 55 and 165. A lens had to be added for REFL165 because it's a 1mm PD instead of 2mm like the other 3.

2) MC camera has moved.

3) I've cleaned up most of the random components on the table, put them away, and tidied up the cabling.

 

Attachment 1: APtableSep20th.pdf
APtableSep20th.pdf
  5488   Tue Sep 20 19:00:49 2011 PaulUpdateSUSITMY and SRM oplev calibrations - measured and estimated

 

Kiwamu noticed that the 1/L in the counts per radian should have just been L, which accounts for most of the discrepancy. We checked the input filters on the OSEMs, and they have 10dB of gain at DC. Accounting for this, estimates on the order of 20urad/count, which is much more reasonable!

  5487   Tue Sep 20 18:03:45 2011 PaulUpdateSUSITMY and SRM oplev calibrations - measured and estimated

The measured calibration factors for the oplevs are as follows:

 
SRM pitch: 666urad per count on channel C1-SUS-SRM-OLPIT-INMON
SRM yaw: 557urad per count on channel C1-SUS-SRM-OLYAW-INMON
 
ITMY pitch: 470urad per count on channel C1-SUS-ITMY-OLPIT-INMON
ITMY yaw: 491urad per count on channel C1-SUS-ITMY-OLYAW-INMON
 
Since I'm going to calibrate all the other oplevs with the rougher technique of estimating the angle from the OSEM signals directly, I thought I would check the result of such an estimation for the oplevs I have calibrated already. My method was as follows:
 
dA = change in angle
dx = change in OSEM flag position
dV = change in OSEM PD voltage
dC = change in OSEM counts
D = optic diameter
L = distance between OSEMs = D/sqrt(2)-0.002m = 0.052m
dV/dx = OSEMs volts per meter flag position change = 1700 V/m
dC/dV = OSEM counts per volt = 2^16/40 = 65536/40 counts/V
 
counts per radian = dC/dA = dV/dx  x   dC/dV   x  1/L = 1700*65536/40/0.052 = 5.3564x10^7 counts/rad
 
radians per count = dA/dC = 1.867x10^-8, or 0.019 urad/count
 
This is around a factor of 1000 smaller than what I measured earlier, reported in entry 5468. I guess this might be an issue with the whitening filter on the OSEMs, but my initial feeling was that this was only a factor of a few. If anyone can see a big obvious mistake in my above calculations please let me know!
 
 
  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

  5485   Tue Sep 20 16:45:09 2011 JenneUpdateSUSSUS diag stuff... just so I remember what I'm doing

Has the Q been checked?  Still in progress...

Optic POS PIT YAW SIDE
ITMX  done  done done done
ITMY  done  done  fine??  done
ETMX  done  done  done  done
ETMY  done  done  done  done
BS  done  done  done  done
PRM done done done done
SRM done done done done
MC1        
MC2        
MC3        

 So, update as of 6:17pm:  I have tuned the damping gains for all IFO optics.  Everything is good, except for ITMY Yaw.  It's probably fine, the optic damps okay, but it doesn't look like a nice clean ringdown.  I haven't taken the time to go back and look at it again.

I have to go to a dinner, but later (probably in the morning, so I don't disturb evening locking) I'll check the MC Qs.

  5484   Tue Sep 20 16:38:25 2011 KeikoUpdateIOOSmall modulation depth

Resonator box and the modulations are back now. But the modulation depth seems to be a bit smaller than yesterday, looking at the optical spectrum analyser.

 

Quote:

 Modulation resonator box is removed and the modulation depth is small right now.

I have broke the BNC connector on the modulation resonator box. The connector was attached by the screw inside very loosely and when we connect and disconnect the BNC cables from outside, extra force was applied to the cable inside and it was broke. It is being fix by Kiwamu and will be back in a bit

 

  5483   Tue Sep 20 16:31:24 2011 KeikoUpdateIOOSmall modulation depth

 Modulation resonator box is removed and the modulation depth is small right now.

I have broke the BNC connector on the modulation resonator box. The connector was attached by the screw inside very loosely and when we connect and disconnect the BNC cables from outside, extra force was applied to the cable inside and it was broke. It is being fix by Kiwamu and will be back in a bit.

 

 

 

 

  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.

  5481   Tue Sep 20 15:39:57 2011 KojiUpdateSUSfree swinging test in vacuum condition

Can't we use Yuta's auto-Q adjust script?

 http://nodus.ligo.caltech.edu:8080/40m/3723

Edit by KI :

Of course we can use it but first we have to fix some pynds sentences since his script was written for the OLD pynds.

  5480   Tue Sep 20 15:23:16 2011 JenneUpdateSUSfree swinging test in vacuum condition

This is using data for the SRM from: 20 Sept 2011 03:20:00 PDT = 1000549215

You can see that there are still some funny peaks between Pit and Yaw, but I finnessed the peak-finding, and I was able to fit all of the correct peaks, and invert the matrix:

 SRM now has its new matrix, and is damping happily.

Optic The Plot Matrix Badness
SRM SRM.png                pit     yaw     pos     side    butt
UL    0.877   0.983   1.105  -0.288   1.092 
UR    1.010  -1.017   1.123  -0.145  -1.055 
LR   -0.990  -1.002   0.895  -0.091   0.848 
LL   -1.123   0.998   0.877  -0.234  -1.006 
SD    0.089   0.064   3.752   1.000  -0.009
 4.4076

 

 

  5479   Tue Sep 20 14:53:13 2011 JenneUpdateSUSJenne's Scripts started

Quote:

Quote:

Quote:

I followed Jenne's instructions, ran the matrix filler script and then set the optics to freeswing. Someone has to burt resture and damp them in the morning.

 Thanks!  I'll give them a little more time, then restore things.

 I began restoring the optics at ~9:30am, so I have a full 6 hours of data, in case I need that much to separate the Pos/Side modes on some of the optics.  They are all damping again with their original matricies.

 So, clearly this was a kind of dumb idea.  There is nothing mechanical going on between our sensor inputs and our Pit/Pos/Yaw/Side DoF filter banks.  It's just math.  On the other hand, we now have a 3rd set of in-vac free swinging data, so I can (after all the suspensions are working) have a look at the drift in matrix elements over time.

In other news, after some meditation, and fitzing with DoF gain values, all of the IFO optics except for SRM now have their new input matricies, and are damping pretty nicely.  I need to go through and do an "eyeball" check to make sure that everything has a Q of ~5ish.  So far, I've kicked the optics, and watched that they damped fairly quickly, but I don't have a guesstimate of the Q's for each optic, for each DoF.

So, still to do:

Use another set of data and invert the SRM matrix DONE

Plug in the MC matricies, make sure they're okay. DONE

Check the Q's for all optics, all DoFs. 

  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.

  5477   Tue Sep 20 09:44:44 2011 JenneUpdateSUSJenne's Scripts started

Quote:

Quote:

I followed Jenne's instructions, ran the matrix filler script and then set the optics to freeswing. Someone has to burt resture and damp them in the morning.

 Thanks!  I'll give them a little more time, then restore things.

 I began restoring the optics at ~9:30am, so I have a full 6 hours of data, in case I need that much to separate the Pos/Side modes on some of the optics.  They are all damping again with their original matricies.

  5476   Tue Sep 20 04:12:26 2011 JenneUpdateSUSJenne's Scripts started

Quote:

I followed Jenne's instructions, ran the matrix filler script and then set the optics to freeswing. Someone has to burt resture and damp them in the morning.

 Thanks!  I'll give them a little more time, then restore things.

  5475   Tue Sep 20 03:12:14 2011 AnamariaUpdateSUSJenne's Scripts started

I followed Jenne's instructions, ran the matrix filler script and then set the optics to freeswing. Someone has to burt resture and damp them in the morning.

  5474   Tue Sep 20 03:02:23 2011 KeikoUpdateLSClocking activity tonight

 Keiko, Anamaria, Koji

We were not able to establish the stable DRMI tonight. We could lock MICH and PRCL quite OK, and lock the three degrees of freedom at somewhere strange for several seconds quite easily, but the proper DRMI lock was not obtained.

When MICH and PRC are locked to the carrier, REFL DC PD reading dropps from ~3000 counts to 2600~2700 counts as REFL beam is absorbed to PRC. We'll try to lock PRC to sidebands - but flipping gain sign didn't work today, although it worked a few days ago. 

POP beam (monitor) is useful to align PRM.

  5473   Tue Sep 20 02:21:10 2011 KojiUpdateLSCLSC MEDM screen cleaning up

I have made some cleaning up of the LSC-related MEDM screens.

- LSC overview screen: ADC OVFL and WFAA indicators are now correctly matched to it associated PD signals.

- Whitening screens now have the correct indication of the associated PD signals.

- LSC Ctrl screen, which is invoked from the overview screen by clicking the servo filters, now has the switches of the servo filters.

- LSC tab of the sitemap was cleaned up by removing the broken links.

  5472   Mon Sep 19 23:19:40 2011 KeikoUpdateIOOAM modulation mistery

 Keiko, Anamaria

We started to investigate the AM modulation mistery again. Checking just after the EOM, there are AM modulation about -45dBm. Even if we adjust the HWP just before the EOM, AM components grow up in 5 mins. This is the same situation as before. Only the difference from before is that we don't have PBS and HWP between the EOM and the monitor PD. So we have a simpler setup this time.

We will try to align the pockells cell alignment tomorrow daytime, as it may be a problem when the crystal and the beam are not well parallel. This adjustment has been done before and it didn't improve AM level at that time.

  5471   Mon Sep 19 22:47:44 2011 JenneUpdateSUSSUS diag stuff... just so I remember what I'm doing

 The last person out tonight should run the following scripts:

In Matlab: 

/opt/rtcds/caltech/c1/scripts/SUS/peakFit/writeMultiSUSinmat.m

In command line:

/opt/rtcds/caltech/c1/scripts/SUS/freeswing all

 

Then in the morning, someone should do a BURT restore to early today (to get the default matricies back), and also restore the watchdogs.

Thanks!
 

  5470   Mon Sep 19 21:19:25 2011 KatrinUpdateGreen LockingBroadband photodiode characterization

Another Hamasutu S3399 photodiode was tested with the electronic circuit as described in LIGO-D-1002969-v.

RF transimpedance is 1k although the DC transimpedance is 2k.

The noise level is 25pA/sqrt(Hz) which corresponds to a dark current of 1.9mA or 1.7mA in the independent measurement.

At all frequencies the noise is larger compared to Koji's measurement (see labbook page 4778).

 


In file idet_S3399.pdf the first point is not within its error bars on the fitted curved. This point corresponds to the dark noise measurement

I made this measurement again. Now it is on the fitted curve. In the previous measurement I pushed the save button a bit too early. The

averaging process has not been ready while I pushed the 'save'  button.

Dark current is 1.05mA and noise is lower than in the previous measurement.

New file are the XXX_v2.pdf files

current_noise_S3399_v2.pdf

 idet_S3399_v2.pdf

 


 idet_S3399.pdf

 current_noise_S3399.pdf

S3399_response.pdf

  5468   Mon Sep 19 20:56:36 2011 PaulSummarySUSRemaining SRM and ITMY OSEMs calibrations

 

I've now taken data for the pitch and yaw calibrations for the OSEMs of SRM and ITMY. Until such time as I know what the calibrated oplev noise spectra are like, I'm leaving the servo gains at zero.

I estimate the length of the lever arm from SRM to measurement position to be 3.06m, and the length of the lever arm from the ITMY to the measurement position to be 3.13m.

From the fits shown on the attached plots, this gives the following calibration factors for the SRM and ITMY OSEMs pitch and yaw counts (i.e. counts from channels such as SUS-ITMY_ULSEN_SW2 multiplied by a matrix of 1s and -1s) to pitch and yaw angle:

 

SRM PITCH: 1 OSEMs pitch count = 11.74 microradians

SRM YAW: 1 OSEMs yaw count = 12.73 microradians

 

ITMY PITCH: 1 OSEMs pitch count = 13.18 microradians

ITMY YAW: 1 OSEMs yaw count = 13.52 microradians

 

Next step is to do some DC offsets with the oplev paths back in place to get the final calibration between OSEMs counts and oplev counts, thus finally getting a conversion factor from oplev counts to radians.

I noticed while taking these measurements that the DC offsets I put on ITMY caused around 5 times larger change in angle than those on the SRM. The different path length is not enough to account for this, so I propose that the actuation is working differently for the two. I guess this should be taken into account when designing the output matrices (unless the control is passed through a different output matrix than the DC offsets?). I'll quantify the difference shortly, and write a conversion factor between output alignment count (e.g. SUS-ITMY_PIT_COMM) and angle.

 

 

Attachment 1: SRM_PITCH_calib_curve.png
SRM_PITCH_calib_curve.png
Attachment 2: SRM_YAW_calib_curve.png
SRM_YAW_calib_curve.png
Attachment 3: ITMY_PITCH_calib_curve.png
ITMY_PITCH_calib_curve.png
Attachment 4: ITMY_YAW_calib_curve.png
ITMY_YAW_calib_curve.png
  5467   Mon Sep 19 18:05:27 2011 ranaUpdateSUSSummary screen

Quote:

I changed some colors on the Summary of Suspension Sensor  using my italian creativity.

I wrote a script in Python to change the thresholds for the "alarm mode" of the screen.

I've started to fix up the script somewhat (as a way to teach myself some more python):

* moved all of the SUS Summary screen scripts into SUS/SUS_SUMMARY/

* removed the hardcoded channel names (a list of 190 hand-typed names !!!!!!!)

* fixed it to use NDS2 instead of try to use the NDS2 protocol on fb:8088 (which is an NDS1 only machine)

* it was trying to set alarms for the SUS gains, WDs, Vmons, etc. using the same logic as the OSEM PD values. This is non-sensical. We'll need to make a different logic for each type of channel.

New script is called setSensors.py. There are also different scripts for each of the different kinds of fields (gains, sensors, vmons, etc.)

Some Examples:

pianosa:SUS_SUMMARY 0> ./setDogs.py 3 5
Done writing new values.

sussum.png

  5466   Mon Sep 19 17:45:39 2011 ranaUpdateSUSSome screens fixed

Quote:

Kiwamu:       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.

 

 Really? I found this one with ~15 seconds of clicking around.

Untitled.png

  5465   Mon Sep 19 16:56:29 2011 PaulUpdateSUSSRM oplev pitch calibration

 Same measurements for SRM pitch (as previously done for yaw in entry 5460) are complete. The QPD is back in the path and aligned. I will be doing the same measurements for ITMY now though, so please ask before activating the SRM or ITMY oplev servos, as I may be blocking the beam.

  5464   Mon Sep 19 16:44:16 2011 KeikoHowToLSCProcedure for the demodulation board check

 Here I note the procedure for the demodulation board orthogonality check for the future reference.

1. prepare two function generators and make sure I an Q demodulation signals go to the data acquisition system.

2. sync the two generators

3. drive the function generator at the modulation frequency and connect to the LO input on the demod board

4. drive the other function generator at the modulation frequency + 50Hz  the RF in

5. run "orthogonality.py"  from a control computer scripts/demphase directory. It returns the amplitude and phase information for I and Q signals. If necessary, compensate the amplitude and phase by the command that  "orthogonality.py" returns.

 

If you want to check in the frequency domain (optional):

1. 2. 3 are the same as above.

4. drive the function generator at the LO frequency + sweep the frequency, for example from 1Hz to 1kHz, 50ms sweep time. You can do it by the function generator carrier frequency sweep option.

5. While sweeping the LO frequency, run "orthogonality.py"

6. The resulting plot from "orthogonality.py" will show the transfer function from the RF to demodulated signal. The data is saved in "dataout.txt" in the same directory.

  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.

  5462   Mon Sep 19 15:44:32 2011 MirkoUpdateLSCRF modulation depth measurement

Earlier measurements of the modulation index were less than optimal because we had too low transmission through the cavity. Contrary to what was believed you actually need to modematch onto the cavity.

Earlier transmitted power was about 8.5uW.

With a 250mm lens we archived 41uW.

Impinging power on the cavity is 1.7mW.

PD TF approx 0.1V / uW.

Carrier power: 4.1V => 41uW

41uW/1.7mW = 2.4 % transmission. Manufacturer clain for peak transmission: 20-30%.

11MHz SB: 28.8mV => m=0.17

55MHz SB:36mV => m=0.19


As you can see on the pic the SNR of the SBs is not too good.

P9190138.JPG

  5461   Mon Sep 19 15:41:48 2011 JenneUpdateSUSSUS diag stuff... just so I remember what I'm doing

The following optics were kicked:
ETMX
Mon Sep 19 15:39:44 PDT 2011
1000507199

  5460   Mon Sep 19 15:30:22 2011 PaulUpdateSUSSRM oplev OSEM yaw calibration curve

 I made the first measurements towards oplev calibration measurements: calibrating the oplevs in SRM YAW. The measurements seemed fine, I had a range of between -1.5 and 1.5 in SRM DC alignment before clipping on mirrors on the oplev bench became a problem. This seemed to be plenty to get a decent fit for the spot position against DC alignment value - see attached plot. The fitted gradient was -420um oplev yaw count. I calculated oplev yaw values as UL+LL-UR-LR. Pitch next.

Attachment 1: SRM_YAW_calib_curve.png
SRM_YAW_calib_curve.png
  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) 

  5458   Mon Sep 19 13:13:10 2011 PaulUpdateSUSITMY oplev available for use: SRM not for the moment

 I've got the bench set up for the measurement of the beam spot change with DC SRM alignment offsets. The ITMY oplev is aligned and fine to use, but the SRM one isn't until further notice (probably a couple of hours).

  5457   Mon Sep 19 12:23:30 2011 PaulUpdateSUSITMY and SRM oplev beam size reduced + next steps

I replaced the lenses that were there with a -150mm lens followed by a +250mm lens. This gave a significantly reduced beam size at the QPDs. With the beam analyzer up and running it should be possible to optimize this later this afternoon. Next I will remove the SRM QPD from the path and make measurements of the beam spot position movement and corresponding OSEM values for different DC mirror offsets. I will then repeat the process for ITMY.

  5456   Mon Sep 19 11:49:32 2011 JenneHowToGeneralPlan for this week: SUS inversion

Quote:

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

 It turns out that this is complicated, since there are so many people working with the IFO this week.  What I would like to do is put in the new input matricies, and then do a free swinging test, to see if the suspensions are really diagonalized in the way that we want them to be.  I can't do this during the day, since it will interfere with Paul's OpLev work.  And at "night", I can't, since we'll be doing locking.  So, this may be a late-night task.  I'll write a script this afternoon that will put in all of the new input matricies, and then run the freeswing and the restore watchdogs scripts.  Whomever is the last one to leave for the night can run the combo script.

EDIT:  As of this time (~11:45am), ITMY has its new input matrix.

  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

  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.

 

  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.

  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.

Attachment 1: f2a_ITMX.png
f2a_ITMX.png
Attachment 2: f2aITMY.png
f2aITMY.png
Attachment 3: f2a_ETMX.png
f2a_ETMX.png
  5451   Sun Sep 18 16:42:00 2011 KojiBureaucracyEnvironmentClean up your mess

Mess in the lab is increasing. Kiwamu and I had to clean up some stuffs to continue our work.
(i.e. some components were disturbing to open the lid of the tables.)

Basically the tools/equipments/component/cables/digital cameras/lens caps/IR viewers
you have used for the day should be cleaned up at the end of the day.

If one likes to leave a temporary stuff, leave a note to indicate by whom, for what, how long
it will be kept like that, and when one is going to back there with contact info like the cell phone #.

  5450   Sun Sep 18 15:57:00 2011 KojiUpdateIOOThe PZT driver engaged to PZT1

[Koji Kiwamu]

The pzt driver for PZT1 has been installed.
As there was unknown resistive connection in the vacuum chamber as described below,
the PZT out cable at the PJ driver module should always be disconnected.
The sensor cables have no problem to be connected to the controller.
In fact, they are a good monitor for the state of the PZTs.

In this configuration, Pitch and Yaw direction of PZT1 is under the control of the EPICS value as we expected.


Details:

- At the beginning, we tested the PZT driver output with low voltage level (~10V). We did not see any oscillation of the opamps.
  The pitch output was observed to be OK, while the YAW output exhibited a half of the expected output voltage.
  The opamp was holding correct voltage, however the voltage after the 1K output resister was about a half.
  This indicated there was a voltage division happening.

- The cause of the voltage division was tracked. We found that the yaw red (=hot) line is connected to pitch black
  in the vacuum chamber with a resistance of 1.4kOhm. The black cables are shorted to the ground level in the PJ driver.

- We decided to unplug the PJ's cable so that we can isolate the black cables while hoping the PZTs were drived only
  by the red and white cables. And they did.

- This means that we should not connect the PZT driving cable to the PJ's driver. The sensors have no problem to be connected.

- Pinouts:

DSUB25
|. .|
|. .|
|. o|  5
|o  | 17
|  o|  4 
|o  | 16   Yaw Black
|  o|  3   Pitch Black
|o  | 15   Yaw White
|  o|  2   Yaw Red
|o  | 14   Pitch White
 \ o|  1   Pitch Red
  \-+

* Pitch White and Yaw White are connected to the ground at the amplifier side.
* Yaw Red and Pitch Black is connected with 1.4kOhm and isolated from the others.


  5449   Sun Sep 18 15:34:09 2011 KojiUpdateAdaptive FilteringModifications to LSC, RFM models, added OAF model

[Koji Kiwamu]

This modification of the LSC model made the rows of the LSC output matrix shifted. This caused the ASS scripts nonfunctional.

Kiwamu fixed the channel names in the ASS script.

Quote:

[Jenne, Mirko, with supervision from Jamie]

I modified the c1lsc model to have shmem outputs that go from the degrees of freedom to the OAF, and shmem inputs from the OAF's output to sum into the DoFs, just like Yoichi's FF stuff.  I also removed the old OAF_OUT, because it would only allow me to select one DoF at a time, and I will eventually want the ability to do multiple amounts of OAFing at the same time.  Hopefully.

 

  5448   Sun Sep 18 14:08:52 2011 ranaUpdateSUSCalibration plan for the oplevs

We don't need a high quality calibration for the optical levers. ~50% accuracy is fine.

For that you can use the OSEM calibration of ~1.7 V/mm (its less than 2 since the OSEMs have been degrading) or you can use the cavity power method that Kakeru used; it worked just fine. There's no benefit in trying for a 1% number for optical levers.

  5447   Sat Sep 17 14:04:45 2011 KojiUpdateIOOPZT1 driver in place

The PZT driver is now in place. The actual PZTs are not connected yet!

It is accommodated on Ben's connector adapter board.

The panel has additional connectors now: two inputs and a power supply connector.

The supply voltage is +/-30V (actual maximum +/-40V), and the input range is +/-10V
which yields the output range of -5V to 30V. The gain of the amplifier is +2.

It is confirmed that the HV outputs react to the epics sliders although the PZT connector is not connected yet
so as not to disturb the locking activity.

When we engage the PZT connector, we should check the HV outputs with an oscilloscope to confirm they
have no oscillation with the capacitances of the PZTs together with the long cable.

Attachment 1: P9171579.JPG
P9171579.JPG
Attachment 2: P9171580.JPG
P9171580.JPG
  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.

 

  5445   Sat Sep 17 01:53:41 2011 KeikoUpdateLSCPOY and POP beams clipped

 Keiko, Paul, Kiwamu

We found that POP beam is clipped by the steering mirrors inside the tank. POY beam is also likely to be clipped inside. Also the hight of POY beam is too high (about 5 cm higher than the normal paths) at the first lens. These imply the input pointing is bad.

  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. 

 

  5443   Fri Sep 16 22:51:52 2011 PaulUpdateSUSCalibration plan for the oplevs

 In order to estimate the amount of noise that the oplevs are injecting into the GW channel, we first need to calibrate oplev signals in terms of angular change in the optic. I said in my previous post that there wasn't a calibration factor for OSEM values to radians, but I found that Kakeru had estimated this in 2009 - see entry 1413. However, Kakeru found that this was quite a rough estimate, and that it didn't agree with his calibrated oplev values well. He does quote the 2V/mm calibration factor for the OSEM readings though - does anyone know the provenance of this factor? I searched for OSEM calibration and found nothing.

 
Kiwamu and Suresh suggested a way to calibrate the oplevs without needing to calibrate the OSEMs in the way that Kakeru describes in entry 1413. This should give a calibration for the OSEMs _and_ the oplevs in fact. The method should be as follows:
 
1) Change the coil driver values in DC to give tip or tilt the optic. Measure the resulting change in spot position at a known distance from the optic, perhaps just using a ruler. Record the spot position and OSEM values for each coil driver value. This will definitely require a smaller spot size, so I'll implement the new telescopes first.
 
2) Knowing the length of the lever arm from the optic to the spot measurement position, we can calibrate the OSEM values to radians.
 
3) We can now put the beam onto the oplev QPD, and either change the coil driver values again in the same way (but over a smaller range), or excite the test mass in pitch or yaw, this time measuring both the OSEM values and the oplev QPD values. Since we can already convert from OSEM values to radians, we can now convert from oplev values to radians too.
 
4) I should be careful to consider the input sensing matrix for both the OSEMs and the oplevs in these measurements. Should I divide those out of the calibration to avoid that if they change the calibration factor changes too?
ELOG V3.1.3-