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ID Date Author Typeup Category Subject
  8635   Thu May 23 21:45:51 2013 JenneUpdateLSCSensing matrix scripts now check for lockloss

A few more small mods to the sensing matrix script.  Now the script saves the data after each measurement, so that in case you lose lock and can't measure any more, you still have the data you already measured.  Also, the error bar measurements are last, so that the consequence of losing lock partway through the measurement is just that you get fewer error bar numbers.  Not a big deal, since the actual sensing matrix data is already saved.

Also, the old script had a lockloss checker that I had overridden since it wasn't where I wanted it.  I have now re-implemented it, so that the script will stop the oscillation and quit measuring if either the LSC enable switch is off, or the degrees of freedom you're trying to measure are not triggered.  All data saved before the lockloss is saved though (as mentioned above).

  8636   Thu May 23 22:13:12 2013 KojiUpdateLSCPRMI sensing matrix measured at 580.1Hz

Can you clarify the definition of the phase "0deg" of your plot?

Is "I" the definition of "0deg"? Or does the demod phase of "0deg" define "0deg"?

I want to know if the demod phase of REFL55 is correctly adjusted or not.

With the decent level of the separation, we should be able to keep the decent lock of PRMI with REFL55.

  8637   Fri May 24 02:12:50 2013 AnnalisaUpdate40m upgradingETMY - Mode Matching for green

 

 Mode Matching calculation for green beam - Yarm

After measuring the beam radius out from the Faraday for the green, I made the calculation to match the green beam mode with the IR mode inside the arm.

The beam waist after the Faraday is elliptical, and I found the following value for the waist:

w0x = 3.55e-5 m @ z0x = -0.042 m

w0y = 2.44e-5 m @ z0y = -0.036 m

(the origin of the z axis is the output of the Faraday, so the waist is inside the Faraday itself)

I did the calculation using a la mode, using as beam waist and its position the following values:

w0 = sqrt(w0x*w0y) = 2.943e-5 m @ z0 = (z0x+z0y)/2 = -0.039 m

The results are shown in the attached plots.

                      Focal length (m)             position (m)

lens1            0.125                                0.1416

lens2            0.100                                0.5225

L                    1.000                                1.5748 (fixed lens used to focus transmitted beam)

 

As the first plot shows, the green beam size on the ETMY is about 6mm. My concern is that it could be too big.

The third plot shows the X and Y section of the beam. It is strongly elliptical, but nevertheless the coupling factor calculated with Koji's formula  gives C=0.936 for the astigmatic beam, and C=0.985 for the non astigmatic beam, so it seems to be still ok.

 

 

Attachment 1: ModeMatchingGreen.jpg
ModeMatchingGreen.jpg
Attachment 2: ModeMatchingGreenZoom.jpg
ModeMatchingGreenZoom.jpg
Attachment 3: XYpath.jpg
XYpath.jpg
  8638   Fri May 24 11:38:00 2013 KojiUpdate40m upgradingETMY - Mode Matching for green

I got confused. Is the mode calculation in the cavity correct?
Are you sure the wavelength in the code is 532nm?

The first plot says "the waist radius at ITMY is 2.15mm". This number is already very close to
the waist size of the cavity mode (2.1mm@ITM, 3.7mm@ETM), but the spot radius at ETMY is 6mm.
They are inconsistent.

 

  8639   Fri May 24 12:50:25 2013 AnnalisaUpdate40m upgradingETMY - Mode Matching for green

Quote:

I got confused. Is the mode calculation in the cavity correct?
Are you sure the wavelength in the code is 532nm?

The first plot says "the waist radius at ITMY is 2.15mm". This number is already very close to
the waist size of the cavity mode (2.1mm@ITM, 3.7mm@ETM), but the spot radius at ETMY is 6mm.
They are inconsistent.

 

 Jenne and I just realized that a la mode has 1064e-9 m as default value. I'll change it and make the calculation again.

  8640   Fri May 24 13:41:19 2013 JenneUpdateLSCPRMI sensing matrix measured at 580.1Hz

"0 degrees" is 0 degrees of demod phase.  I have now added the PD demod phases to the plot:

SensMat_23May2013_withIQ.png

  8641   Fri May 24 14:01:59 2013 KojiUpdateLSCPRMI sensing matrix measured at 580.1Hz

It's hard to believe but is AS55Q really almost insensitive to MICH?

Well, anyway, now it is the time to use the automatic demod phase (and input matrix) adjustment.

  8642   Fri May 24 14:40:22 2013 JenneUpdateLSCPRMI sensing matrix: now what?

Quote:

It's hard to believe but is AS55Q really almost insensitive to MICH?

Well, anyway, now it is the time to use the automatic demod phase (and input matrix) adjustment.

 I am also wondering if I understand / am using the demod phase from the screen correctly.  This plot is indicating that MICH is entirely in I, and not at all in Q.

Currently, I take the demod phase, and plot that as the "I" line, then plot the "Q" line 90 degrees away from the I line.  Maybe it should be the other way around?

Re: the auto-demod phase, I was starting to wonder about that.  For each sensor, can I declare what degree of freedom I want in which quadrature to take priority (ex. MICH goes to REFL55 Q), and set the demod phase to the value that makes that true?

  8643   Fri May 24 14:44:34 2013 JenneUpdateGeneralRossa freezes all the time

I am getting tired of having to restart Rossa all the time.  She freezes almost once per day now.  Jamie has looked at it with me in the past, and we (a) don't know why exactly it's happening and (b) have determined that we can't un-freeze it by ssh-ing from another machine.

I wonder if it's because I start to have too many different windows open?  Even if that's the cause, that's stupid, and we shouldn't have to deal with it.

\end{vent}

  8644   Fri May 24 22:18:33 2013 JenneUpdateLSCPRMI sensing matrix: Got it!

Okay, I think I am finished with the sensing matrix scripts!  

I had the syntax for atan2() wrong, so I was calculating the demod phase wrong.  Do not trust the phase in any previous elogs!!

Also, the theta=0 axis of the plots are for 0 degree demod phase, but our PDs are not at 0 deg.  The measured sensing matrix phase is relative to the current demod phase, not 0 (unless the demod phase for that PD is currently 0degrees).  So, now I take that into account.  I add the current PD demod phase to the measured sensing matrix phase, so that the plot is actually true.

For interested parties, I have made all of the sensing matrix scripts, and the data folder a subdirectory of the /scripts/LSC folder, since it was starting to get crowded in there.  I have moved the 2 data sets that have been collected (21May, 23May) into the new place.

Future thoughts: 

* Save the amplitude and modulation frequency and the current demod phases in the data file.  Right now the ampl and mod freqs are included in the title of the data file, but there is no record of what the demod phase was at the time.  I need to fix this.

 

So, really, really, the Sensing Matrix:

Sensing Matrix, units = counts/meter, phase in degrees
 
            PRCL Mag   PRCL Phase    MICH Mag   MICH Phase  
AS55         5.485E+08   -43.424      2.679E+09    93.392    
REFL11       1.126E+13    -7.168      1.618E+11   135.296    
REFL33       2.658E+11   164.973      8.910E+09    -2.226    
REFL55       3.012E+11   -75.216      1.210E+10   172.764

SensMat_23May2013_withIQ_andCorrectPhases.png

  8645   Sat May 25 02:03:48 2013 AnnalisaUpdate40m upgradingETMY - Mode Matching for green - new calculation

 Mode matching calculation for green - Yarm

I did again the mode matching calculation. The previous one was using 1064nm as wavelength, so it was wrong.

The seed beam waist and its position are the same as in elog 8637. The new results are shown in the attached graphs.

I got the following values for focal lengths and positions of the two Mode Matching lenses:

 

                    Focal length (m)             Distance from the Faraday output (m)

lens1            0.125                                                  0.1829

lens2           -0.200                                                  0.4398

L                   1.000                                                  1.4986 (fixed)

The position of the lens L has changed because the path lengh has been slightly  reduced. 

The Coupling factor for he astigmatic beam is C = 0.959 (it is C = 0.9974 if we consider the beam as non astigmatic).

I put the lenses and aligned the beam up to the shutter, which has been moved from its initial position because the beam size on it was too large. 

TO DO

The green beam needs to be aligned and sent into the arm cavity. 

Polarization has to be checked.

Many beams still have to be dumped, both in IR and Green paths. 

 

 

 

 

Attachment 1: ModeMatchingGreenNEW.jpg
ModeMatchingGreenNEW.jpg
Attachment 2: ModeMatchingGreenZoomNEW.jpg
ModeMatchingGreenZoomNEW.jpg
Attachment 3: XYpathNEW.jpg
XYpathNEW.jpg
Attachment 4: photo1.JPG
photo1.JPG
Attachment 5: photo2.JPG
photo2.JPG
  8646   Mon May 27 21:38:53 2013 AnnalisaUpdate40m upgradingETMY - Beam Dumps

 

I put many razor dumps along the IR/green path. The rejected beam from the IR Faraday needs to be dumped (about 1.5 mW). I used all the new razor blade I had, so I need one more for that beam.

The IR reflection of the Harmonic separator right after the doubler needs to be dumped in a better way. At the moment there is a black screen, but we need something suitable to dump more than 300 mW.

After the second steering mirror along the green beam path there is a very small transmission (about 6 uW), which is difficult to dump because there is no space enough. Can it be dumped with a black screen?

 

The Oplev has a lot of reflection hitting the central BS (The BS for the transmitted beam). It is very difficult to dump them without intercepting the main beam path. Maybe we have to slightly change the Oplev beam angle to avoid so many reflections.

 

  8647   Tue May 28 11:11:37 2013 ManasaUpdateIOOMC aligned

[Jenne, Manasa]

Fixed crappy alignment of MC by moving MC mirrors. MC REFL PD measured 0.5 after alignment. Spot positions were measured using msassMCdecenter. Plot for the same is attached.

Attachment 1: MC_0528.png
MC_0528.png
  8648   Tue May 28 14:52:56 2013 JenneUpdateLSCPRMI sensing matrix: Got it!

Just so we have it, here is the re-analysis with the correct plot and phases for the May 21st data, taken near the violin mode:

Sensing Matrix, units = counts/meter, phase in degrees
 
            PRCL Mag   PRCL Phase    MICH Mag   MICH Phase  
AS55         9.048E+11   -22.880      2.927E+12   107.071    
REFL11       2.954E+16   -21.628      3.670E+14   123.857    
REFL33       2.757E+14  -192.608      9.186E+12    -4.037    
REFL55       2.868E+14   -82.690      1.186E+13   170.097 

SensMat_21May2013_withIQ_andCorrectPhases.png

Even though this data was taken near the violin mode (oops!), it is fairly consistent with the stuff taken a few days later at 580Hz (elog 8644). 

Neither of these is at all similar to what Kiwamu had measured a year ago (elog 6283), but we have changed many, many things since then.  He also includes an Optickle simulation, which is fairly similar to the Koji simulation in the wiki, but neither his measurements nor mine are particularly close to the simulated version.  I should think about why this is.

Also, I have fixed up the measurement scripts so that they record all of the relevant current settings / information:  Current actuator calibration, current PD demod phases, drive amplitude and drive frequency.  The "Analyze Saved Data" script has been updated to read all of this info from the files.  If you want to plot / look at any old data, open up SensMatAnalyzeSavedData in /scripts/LSC/SensingMatrix/ and put in the relevant filename that you want (which should be saved in /scripts/LSC/SensingMatrix/SensMatData/)

  8649   Tue May 28 17:00:50 2013 JenneUpdateASCProposed POP path, to be installed this evening

I have mounted 2 2" G&H high reflective mirrors, to be used in the new POP path.  Manasa and Annalisa are doing green things on their respective arms, so I will hopefully be able to install the new POP path after dinner tonight.

Here are photos of the current POP path, and my proposed POP layout.  In the proposed layout, the optical components whose labels are shaded are the ones which will change.

CurrentPOPpath.pdf

ProposedPOPpath.pdf

  8650   Tue May 28 17:06:04 2013 KojiUpdateLSCPRMI sensing matrix: Got it!

- We want to add POX11/POY11 in the collection. They may indicates some abnormal asymmetry between two arms (for PRMI).

- We also want to PRCL/MICH after the input matrix. This will be useful when we want to adjust the input matrix to give the optimul
demod phase for the two signals from a single port.

  8651   Tue May 28 19:35:17 2013 ManasaUpdateGreen LockingStill searching for the X green beat note

Procedure

1. Aligned X-arm to IR.
2. Aligned green to the X-arm.
3. PSL green and X-green aligned to the X-green beat PD.
4. Scanned X-green laser temperature (sweep X slow servo offset through the whole range)

I did not succeed in finding the beat note; but noticed something I cannot explain.
With green very stably aligned to the X-arm, GTRX reads 3000 counts. But when the laser temperature is changed and the green unlocks and locks to the X-arm, it locks with GTRX counts over 5000. GTRX stays at 5000 counts as long as the temperature is changing but settles down to 3000 (over a time lapse of tens of seconds) when let to stay at any specific temperature.

  8652   Tue May 28 22:11:23 2013 AnnalisaUpdate40m upgradingETMY - Yarm shutter cable

 

 For some strange reason the Yarm shutter cable runs up to the POY table, where it is connected to another cable going to the rack. It has to be put off from the table, at least. It would be better to have only one cable going directly to the rack.

I roughly aligned the green into the Yarm and I've seen the green beam flashing on the PSL table, but the mode matching is not so good and I get an higher order mode, so I'm going to fix the mode matching tomorrow.

  8653   Thu May 30 01:02:41 2013 ManasaUpdateGreen LockingFound it!

X green beat note found!

Key points
1. Near-field and far-field alignment on the PSL table. The near-field alignment checked by looking at the camera and the far-field alignment checked by allowing the beams to propagate by removing the DC PD.
2. Check laser temperature and get a sense of how the offset translates to the actual laser temperature.
3. Get an idea of the expected temperature of laser using the plot in elog.

Data
PSL laser temperature = 31.45 deg C

X end laser temperature = 39.24 deg C
C1-ALS-X_SLOW_SEERVO2_OFFSET = 4810
Amplitude of beat note = -40dBm

I do not understand why
1. The amplitude of beatnote falls linearly with frequency (peak traced using 'hold' option of the spectrum analyzer).
2. I found the beat note at the RF output of the PD. Earlier, while I was trying to search for the beatnote from the RFmon output of the betabox, there was a strong peak at 29.6MHz that existed even when the green shutters were closed. It's source has to be traced.

Next
Solve beatbox puzzle and lock arm using ALS.

IMG_0598.JPGIMG_0599.JPG

  8655   Thu May 30 11:10:00 2013 SteveUpdateendtable upgradeETMY - oplev

Quote:

 Temporary oplev in place. The spot on the qpd is still big. My two lens solution did not work.

I will finalize optical component position of the oplev after the the arm transmitted and green beam optics in place. They have priority.

 

 Oplev spot size on qpd ~ 1 mm 

PS: I realized it later that the returning beam is going through a lens for TRY. This is a nono.

      This beam path will be relayed again as the TRY, green beam and IP-ang get there place.

Attachment 1: ETMYoplev.jpg
ETMYoplev.jpg
  8658   Thu May 30 17:18:58 2013 JenneUpdateASCNew POP path

I have placed the G&H mirrors and the Y1 as pictured in my proposed layout in elog 8649.  The distance between the 2" lens and the PDs has increased, so the focus point is all wrong.  I have measured the distances between optics on the table, and will pick new lenses and finish the POP layout later today or tomorrow.

For now, here are the powers measured using the Ophir power meter:

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

PRM-ITMY lock, POPDC was ~190 counts

5.29 uW after Y1 weird angle.  Can't see beam before then to measure

5.27 uW before BS50
3.5 uW before razor PD
3.00 uW before 110PD

 ------------------------

After installing G&H mirrors, replacing BS-98 with Y1:

4.94 uW before y1 (after G&H's)
4.92 uW after y1
2.66 uW before razor PD
1.61 uW before 110PD

  8659   Thu May 30 18:29:21 2013 ManasaUpdateGeneralALS medm screens edited

Renaming of the c1gcv model earlier (elog 7011) had left white boxes in most of the ALS medm screens.

Channels names were corrected. No more white boxes.

  8660   Thu May 30 20:45:53 2013 AnnalisaUpdateendtable upgradeETMY - oplev

Quote:

Quote:

 Temporary oplev in place. The spot on the qpd is still big. My two lens solution did not work.

I will finalize optical component position of the oplev after the the arm transmitted and green beam optics in place. They have priority.

 

 Oplev spot size on qpd ~ 1 mm 

PS: I realized it later that the returning beam is going through a lens for TRY. This is a nono.

      This beam path will be relayed again as the TRY, green beam and IP-ang get there place.

 Oplev is disabled. I removed one of the steering mirrors because it was on the green beam  path.

  8661   Fri May 31 10:25:17 2013 steveUpdatesafetyfirst aid kits refilled

Quote:

 

                                                 Recommended correction list:

1,  refill- upgrade first aid boxes

2,  maintain 18" ceiling to bookshelf clearance so the ceiling fire sprinklers are not blocked: room 101

3,  label chilled water supply & return valves in IFO room

4,  calibrate bake room hoods annually

5,  update safety sign at fenced storage

 

              40m still to do list:

1,   clean and measure all safety glasses

2,   annual crane inspection is scheduled for 8am March 19, 1013

3,   make PSL encloser shelf earthquake proof

 

Do you see something that is not safe? Add it to this list please.

 

 

 

Restocked First Aid Kits Location:

Main entrance, room 100

Drill press - above N2 cylinders, room 103

Control room, next to fire extinguisher, room  102

Vertex-north wall, IFO room 104

ETMY - right on ends light switches, IFO room 104_ east end

ETMX - on vertical I-beam of crane, IFO room 104_south end

Behind 1X3 Rack, on south wall - under instrument breakers panel PC-1, IFO room 104

 

Last thing remaining to be fixed from 2013 Safety Audit:

replace book shelf with 83" height

 

 

Attachment 1: refilledFAidK.jpg
refilledFAidK.jpg
  8662   Fri May 31 11:15:01 2013 AnnalisaUpdateendtable upgradeETMY - Mode Matching for green - new calculation

 Since the beam waist after the Faraday had changed since the last time I measured it (maybe alignment changed a bit), I made a new mode matching calculation for green. I attached the results.

I'm going to align the beam into the Yarm.

RXA: JPG images deleted - replace with PDF please.

  8663   Sat Jun 1 14:14:56 2013 JenneUpdateASCNew POP path

I have a lens solution for the new POP QPD, plotted below.  To get the beam size, I started with the waist at the ITM, so the out of vacuum table starts around 6 meters on this plot.  Also, "PD" is the QPD, but the position marked on the plot is the maximum distance from the 2nd lens.  In reality, I will place it a few cm after the lens.  Once I've got that laid out, I'll move the 110PD (and its lens) and the camera around so that they are in good spots relative to the beam size.

 POP_QPD_lensSolution.png

Here is a photo of the way I left the table last Thursday.  The notations in orange indicate what I need to do to make the actual table match my lens solution.

 POX_table_30May2013progress.pdf

 

  8664   Mon Jun 3 09:46:40 2013 SteveUpdateVACRGA scan at day 100

 Vacuum normal condition at pumdown day 100

 

Attachment 1: d100Mpd75.png
d100Mpd75.png
Attachment 2: d100Mpd75p.png
d100Mpd75p.png
Attachment 3: badguys.png
badguys.png
  8665   Mon Jun 3 18:49:44 2013 GautamUpdateGeneralITMx Oplev Fixed

 (Manasa)

The ITMx Oplev was misaligned. Switched the ITMx Oplev back on and fixed the alignment.

EDIT, JCD:  This is totally my fault, sorry.  I turned it off the other day when I was working on the POP layout, and forgot to turn the laser back on.  Also, I moved the fork on the lens directly in front of the laser (in order to accommodate one of the G&H mirrors), and I nudged that lens a bit, in both X and Y directions (although very minimally along the beam path).  Anyhow, bad Jenne for forgetting to elog this part of my work.

  8666   Mon Jun 3 21:09:55 2013 ManasaUpdateGreen LockingX green beatnote through beatbox

I connected the X green beat PD output back to the beatbox, did the usual PSL alignment for green and searched for the beat note from the RFmon of the beatbox.

Yuta had used a power splitter which took Xbeat-RFmon and Ybeat-RFmon and used the SUM port to monitor the beat signals. I have removed this splitter and just used the X beat RFmon.

I found the beat note with:

Beat@58.7MHz : Amplitude -30dBm
C1:ALS-TRX_OUT16 = 3000 counts
C1:PSL-FSS_SLOWDC = 0.2250
PSL temperature = 31.52 degC
X- green temperature = 39.34 degC (OFFSET = 5140)

Next
Beatbox calibration

IMG_0608.JPG

  8667   Mon Jun 3 22:36:07 2013 ranaUpdateLSCALS-TRY_OUT needs anti-whitening

 After working some more on the EY table, we are getting some TEM00 flashes for the Y arm green. We have had to raise the height of one of the MM lenses to prevent clipping.

We used a function generator to apply a ~300 mV 10 Hz triangle wave to scan the laser frequency while aligning.

We tried to use the C1:ALS-TRY_OUT channel to help us in our alignment but there are a couple problems:

1) It seems that there is an uncompensated whitening filter before the ADC - Annalisa is making a compensation filter now.

2) The data delay is too much to use this for fast alignment. We might need to get a coax cable down there or mount a wired ethernet computer on the wall.

3) We need to make DQ channels for the TRY and TRX OUT. We need long term data of these, not just test points.

Attachment 1: try.pdf
try.pdf
  8668   Tue Jun 4 10:33:09 2013 ranaUpdateSUSETMY oplev path redone

 We also redid the oplev path.

Someone had used the illegal tactic of using aluminum dogs to hold down mounts which already have screw holes in the bases. This is too flimsy to use.

We then adjusted the position of the second lens to get a ~1 mm spot on the QPD. There is a lot of stray red light from extra reflections, but so be it.

Its possible that we are now clipping the IPANG path, but we will need to lock the Y arm and verify the input pointing to be sure. At this point we are ready to measure the ETMY OL loop gain and tune, etc.

  8669   Tue Jun 4 10:44:13 2013 SteveUpdateendtable upgradePI pzt holders are ready

The PI pzt holders are back from the shop. They are numbered 1, 2 & 3 and machined to match.

Tapered black delrin opener is to gauge the gap if it is too small to fit pzt. This is to prevent holder to be opened too much.

Attachment 1: PIpztholders.jpg
PIpztholders.jpg
  8670   Tue Jun 4 10:47:57 2013 SteveUpdatesafetysafety training

Our early bird surf student Gautem has received 40m specific basic safety training today.

  8671   Tue Jun 4 16:04:34 2013 AnnalisaUpdateLSCALS-TRY_OUT needs anti-whitening

Quote:

 After working some more on the EY table, we are getting some TEM00 flashes for the Y arm green. We have had to raise the height of one of the MM lenses to prevent clipping.

We used a function generator to apply a ~300 mV 10 Hz triangle wave to scan the laser frequency while aligning.

We tried to use the C1:ALS-TRY_OUT channel to help us in our alignment but there are a couple problems:

1) It seems that there is an uncompensated whitening filter before the ADC - Annalisa is making a compensation filter now.

2) The data delay is too much to use this for fast alignment. We might need to get a coax cable down there or mount a wired ethernet computer on the wall.

3) We need to make DQ channels for the TRY and TRX OUT. We need long term data of these, not just test points.

 I made the anti-whitening filter for the C1:ALS-TRY_OUT channel. But then I forgot to make an ELOG because I am bad.

  8672   Tue Jun 4 17:28:09 2013 AnnalisaUpdateLSCC1:ALS-TRY_OUT filter and green progress

 [Annalisa, Gautam, Rana]

I made the anti-whitening filter for the C1:ALS-TRY_OUT channel.

zpk [[150],[15],1] Hz

Now we can look at the picks of this signal to align the green into the cavity.

We already had some 00 flash, but a better alignment has to be done.

TO DO:

- put the shutter along the beam path

- check the polarization (we have a new PBS for visible)

 

Attachment 1: green.JPG
green.JPG
Attachment 2: QUAD1_1054358327.mp4
  8674   Tue Jun 4 21:50:23 2013 AnnalisaUpdateLSCC1:ALS-TRY_OUT filter and green progress

 

 [Annalisa, Gautam]

 The green beam alignment has been improved, so we see much more 00 bright flashing. We checked the polarization and the Ygreen shutter is back in place.

A mirror is already in place to steer the rejected beam from the green Faraday into a PD, tomorrow morning we'll put a lens and the PD to take the signal for PDH locking.

 

  8675   Wed Jun 5 10:22:12 2013 ManasaUpdateGeneralProjector - viewsonic

Update: We don't have our BIG screen 

There was no light from the projector when I came in this morning. I suspected it might have to do with the lifetime of the bulb. But turning the projector OFF and ON got the projector working....but only for about 10-15 seconds. The display would go OFF after that. I will wait for some additional help to dismount it and check what the problem really is.

 

  8676   Wed Jun 5 10:46:43 2013 GautamUpdateGeneralCable re-routing at 1Y4

 There were 4 cables running over the front side of rack 1Y4 such that the front door could not be closed. I re-routed them (one at a time) through the opening on the top of the rack. The concerned channels were

  • Green refl mon
  • Err mon
  • Pzt out (temp) (has been marked "Door Damaged BNC")
  • Laser temp ctrl

Before and after pics attached.

Before

.before.JPG

After

after.JPG

 

 

 

  8677   Wed Jun 5 14:01:37 2013 ranaUpdateLSCC1:ALS-TRY_OUT filter and green progress

The rejected beam from this Faraday comes out at a tiny, tiny angle and so its tough to pick it off without clipping the main beam.

Some care must be taken in setting this up - Steve may have some good ideas on what kind of mount can be placed so close to the beam.

Why did we ever order this terrible Faraday? Let's never get a Faraday with a tiny angle between the beams again.

  8678   Wed Jun 5 14:39:41 2013 Max HortonUpdate Importing New Code

Most dependencies are met.  The next issue is that matplotlib.basemap is not installed, because it is not available for our version of python.  We need to update python on megatron to fix this.

  8679   Wed Jun 5 14:43:42 2013 AnnalisaUpdateLSCALS-TRY_OUT DQ channels

Quote:

 After working some more on the EY table, we are getting some TEM00 flashes for the Y arm green. We have had to raise the height of one of the MM lenses to prevent clipping.

We used a function generator to apply a ~300 mV 10 Hz triangle wave to scan the laser frequency while aligning.

We tried to use the C1:ALS-TRY_OUT channel to help us in our alignment but there are a couple problems:

1) It seems that there is an uncompensated whitening filter before the ADC - Annalisa is making a compensation filter now.

2) The data delay is too much to use this for fast alignment. We might need to get a coax cable down there or mount a wired ethernet computer on the wall.

3) We need to make DQ channels for the TRY and TRX OUT. We need long term data of these, not just test points.

 [Jenne, Annalisa]

DQ channels have been created in the C1ALS model for TRX and TRY. They are called TRX_OUT and TRY_OUT and the sampling rate is 2048 Hz.

  8680   Wed Jun 5 15:03:42 2013 AnnalisaUpdateLSCC1:ALS-TRY_OUT filter and green progress

Quote:

The rejected beam from this Faraday comes out at a tiny, tiny angle and so its tough to pick it off without clipping the main beam.

Some care must be taken in setting this up - Steve may have some good ideas on what kind of mount can be placed so close to the beam.

Why did we ever order this terrible Faraday? Let's never get a Faraday with a tiny angle between the beams again.

The rejected beam from the Faraday is steered with a mirror into the PDA32A PD  and a 75mm fl lens is used to focus the beam into it.

The main beam is a few millimeters away from the mirror mount (maybe 2mm), and I think it should be fine as long as the main beam is not supposed to move.

 

Attachment 1: faraday_rejected_beam.JPG
faraday_rejected_beam.JPG
  8681   Wed Jun 5 15:48:02 2013 SteveUpdateGeneralfast 2004 qpd

Thank you Ben Abbott forwarding this information:

 QPD Amplifier D990272 https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D990272&version= at the X-end.  It plugs into a Generic QPD Interface, D990692, https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D990692&version= according to my drawings, that should be in 1x4-2-2A.

Attachment 1: D990272qpd.jpg
D990272qpd.jpg
Attachment 2: interfaceD990692.jpg
interfaceD990692.jpg
  8682   Wed Jun 5 15:55:16 2013 SteveUpdateGeneralProjector - lightbulb ordered

Quote:

Update: We don't have our BIG screen 

There was no light from the projector when I came in this morning. I suspected it might have to do with the lifetime of the bulb. But turning the projector OFF and ON got the projector working....but only for about 10-15 seconds. The display would go OFF after that. I will wait for some additional help to dismount it and check what the problem really is.

 

 

  • Shipping Estimate Friday June 7, 2013 - Monday June 10, 2013
    Delivery Estimate: Wednesday June 12, 2013 - Monday June 17, 2013 by 8:00pm
  • Lampedia Projector Lamp for VIEWSONIC PRO8200 / PRO8300
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  8683   Wed Jun 5 17:37:10 2013 ranaUpdateGeneralfast 2004 qpd

Quote:

Thank you Ben Abbott forwarding this information:

 QPD Amplifier D990272 https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D990272&version= at the X-end.  It plugs into a Generic QPD Interface, D990692, https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=D990692&version= according to my drawings, that should be in 1x4-2-2A.

 Wrong: this is not an interface.

  8684   Wed Jun 5 20:45:19 2013 gautamUpdateGeneralITMx Oplev Fixed

Quote:

 (Manasa)

The ITMx Oplev was misaligned. Switched the ITMx Oplev back on and fixed the alignment.

EDIT, JCD:  This is totally my fault, sorry.  I turned it off the other day when I was working on the POP layout, and forgot to turn the laser back on.  Also, I moved the fork on the lens directly in front of the laser (in order to accommodate one of the G&H mirrors), and I nudged that lens a bit, in both X and Y directions (although very minimally along the beam path).  Anyhow, bad Jenne for forgetting to elog this part of my work.

 [Jenne, Gautam]

It turned out that the earlier fix was not really a fix, because there was some confusion as to which of the two lenses Jenne moved while working, and while Manasa and I were re-aligning the beam, we may have moved the other lens.

Subsequently, when we checked the quadrant sum, it was low (in the region of 20), even though OPLEV_PERROR and OPLEV_YERROR were reasonably low. We called up a 30 day trend of the quadrant sum and found that it was typically closer to 4000. This warranted a visit to the table once again. Before going to the table, we did a preliminary check from the control room so as to make sure that the beam on the QPD was indeed the right one by exciting ITMx in pitch (we tried offsets of 500 and -500 counts, and the spot responded as it should). ITMx oplev servo was then switched off.

At the table, we traced the beam path from the laser and found, first, that the iris (I have marked it in one of the photos attached) was practically shut. Having rectified this, we found that the beam was getting clipped on the first steering mirror after the laser (also marked in the same photo, and a second photo showing the clipping is attached). The beam isn't very well centred on the first lens after the laser, which was the one disturbed in the first place. Nevertheless, the path of the entering beam seems alright. The proposed fix, then, is as follows;

  1. Use the existing iris and a second one to mark the path of the entering beam.
  2. Make the necessary adjustments (i.e. move the lens immediately after the laser and the first steering mirror after the laser) such that the direction of the entering beam is unchanged, and the clipping and centering problems are resolved. 

Back in the control room we noticed that the quadrant sum had gone up to ~3500 after opening out the iris. The OPLEV_PERROR and OPLEV_YERROR counts however were rather high (~200 counts in pitch and ~100 counts in yaw). Jenne went back to the table and fixed the alignment such that these counts were sub-10, and the quadrant sum went up to ~3800, close to the trend value. 

At the time of writing, the beam is still not centred on the lens immediately after the laser and is still getting clipped at the first steering mirror. Oplev servo back on.

Photos

 An overview

ITMx_overview.JPG

 

The clipping

ITMx_clipping_.JPG

  8685   Thu Jun 6 09:58:13 2013 SteveUpdateendtable upgradeenclosure to chamber connection

 

 Thin wall connector from McMCarr#55275K25 was tested in 150 mW, 1 mm beam size of 1064 nm  overnight. It did not show any degradation.

Super-Compressible Duct for Air

Hose is made from 0.005" thick, double-ply metalized polyester with a fabric-enclosed steel wire support. 

Atm2, Enclosure viewport adaptor is shown in place of the viewport.

Soft gaskit -   durumeter hardness 10A - McMCarr#9010K51 was added on the 10" od sufaces of conflat and viewport adaptor to insure being air tight.

The duct connector clamped with soft braided elastic " Velstrech" brand loop.

 

Attachment 1: thinwallconnector.jpg
thinwallconnector.jpg
Attachment 2: 06061301.PDF
06061301.PDF 06061301.PDF
  8687   Thu Jun 6 16:33:19 2013 steveUpdatesafetyupdated laser inventory

 Updated laser inventory and operator list. They are posted in the 40m wiki and entry doors of the 40m IFO room.

Let me know if this list needs correction.

Lightwave  M126N-1064-700 NPRO sn 337 in the PSL enclosure got connected to local emergency shut off switch. This is a LIGO operational safety requirement.

 

Attachment 1: ELSOconnected.jpg
ELSOconnected.jpg
  8688   Fri Jun 7 17:12:46 2013 gautamUpdateGeneralProjector - lightbulb replaced

Quote:

Quote:

Update: We don't have our BIG screen 

There was no light from the projector when I came in this morning. I suspected it might have to do with the lifetime of the bulb. But turning the projector OFF and ON got the projector working....but only for about 10-15 seconds. The display would go OFF after that. I will wait for some additional help to dismount it and check what the problem really is.

 

 

  • Shipping Estimate Friday June 7, 2013 - Monday June 10, 2013
    Delivery Estimate: Wednesday June 12, 2013 - Monday June 17, 2013 by 8:00pm
  • Lampedia Projector Lamp for VIEWSONIC PRO8200 / PRO8300
    Sold by: Lampedia

 [manasa, gautam]

-the replacement lamp arrived a while back.

-the old lamp has been switched out, it had 3392 lamp hours on it.

-new lamp installed, projector mounted back up, and lamp hours reset to zero. there is a lingering odour of something burning, not sure what it is or if it is in any way connected to the new lamp. old lamp disposed in the hazardous waste bin. the big screen is back online.

  8689   Fri Jun 7 21:33:39 2013 ManasaUpdatePSLPSL green to Y- BEAT PD blocked

To allow Annalisa to work on the Y-green alignment as I work with the X-green, the part of the PSL green beam that goes to the Y-green beat PD has been blocked with an iris.

ELOG V3.1.3-