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  17112   Mon Aug 29 18:25:12 2022 CiciUpdateGeneralTaking finer measurements of the actuator transfer function

Took finer measurements of the x-arm aux laser actuator tranfer function (10 kHz - 1 MHz, 1024 pts/decade) using the Moku.

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

I took finer measurements using the moku by splitting the measurement into 4 sections (10 - 32 (~10^4.5) kHz, 32 - 100 kHz, 100 - 320 kHz, 320 - 1000 kHz) and then grouping them together. I took 25 measurements of each ( + a bonus in case my counting was off), plotted them in the attached notebook, and calculated/plotted the standard deviation of the magnitude (normalized for DC offset). Could not upload to the ELOG as .pdf, but the pdf's are in the .zip file.

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

Next steps are to do the same stdev calculation for phase, which shouldn't take long, and to use the vectfit of this better data to create a PZT inversion filter.

  660   Fri Jul 11 20:16:01 2008 EricDAQCamerasTaking data from the GC 750 Camera
Mafalda has been set up with a background process to constantly take data from the GC 750 camera (at the end of the x-arm) for the weekend. This camera will otherwise be inoperable until then.

In the small chance that this slows either Mafalda or the network to a crawl, the process to kill should have PID 26265.
  3007   Fri May 28 11:35:33 2010 josephbUpdateCDSTaking a step backwards to get stuff running

I've modified the lsc.mdl and lsp.mdl files back to an older configuration, where we do not use an IO processor.  This seems to let things work for the time being on megatron while I try to figure out what the is wrong with the "correct" setup which includes the IO processor.

Basically I removed the adcSlave = 1 line in the cdsParameters block.

I've attached a screen shot of the desktop showing one filter bank in the LSP model passing its output correctly to a filter block in the LSC.  I also put in a quick test filter (an integrator) and you can see it got to 80 before I turned off the offset.

So far this is only running on megatron, not the new machine in the new Y end.

The models being use for this are located in /cvs/cds/caltech/cds/advLigoRTS/src/epics/simLink

  14049   Tue Jul 10 16:59:12 2018 Izabella PastranaHowToComputer Scripts / ProgramsTaking Remote TF Measurements with the Agilent 4395A

I copied the netgpibdata folder onto rossa (under the directory ~/Agilent/), which contains all the necessary scripts and templates you'll need to remotely set up, run, and download the results of measurements taken on the AG4395A network analyzer. The computer will communicate with the network analyzer through the GPIB device (plugged into the back of the Agilent, and whose communication protocol is found in the AG4395A.py file in the directory ~/Agilent/netgpibdata/).

The parameter template file you'll be concerned with is TFAG4395Atemplate.yml (again, under ~/Agilent/netgpibdata/), which you can edit to fit your measurement needs. (The parameters you can change are all helpfully commented, so it's pretty straightforward to use! Note: this template file should remain in the same directory as AGmeasure, which is the executable python script you'll be using). Then, to actually set up, run, and download your measurement, you'll want to navigate to the ~/Agilent/netgpibdata/ directory, where you can run on the command line the following: python AGmeasure TFAG4395Atemplate.yml

The above command will run the measurement defined in your template file and then save a .txt file of your measured data points to the directory specified in your parameters. If you set up the template file such that the data is also plotted and saved after the measurement, a .pdf of the plot will be saved along with your .txt file.

Now if you want to just download the data currently on the instrument display, you can run: python AGmeasure -i 192.168.113.105 -a 10 --getdata

Those are the big points, but you can also run python AGmeasure --help to learn about all the other functions of AGmeasure (alternatively, you can read through the actual python script).

Happy remote measuring! :)

 

 

 

 

  13077   Fri Jun 23 02:43:43 2017 KaustubhHowToComputer Scripts / ProgramsTaking Measurements From AG4395A

Summary:

I have written a code(a basic one which needs a lot of improvements, but still does the job) for taking multiple measurements from the AG4395A. I have also written a separate code for plotting the data taken from the previoius code along with the error bars upto 1 standard deviation.

 

Details on How To Operate AG4395A:

  1. Under 'Measurement' tab, press the 'Meas' button and select the Analyzer Type (Network Analyzer or Spectrum Analyzer).
  2. Then under the same options select which 'ratio' needs to be measured (A/R, B/R or A/B).
  3. Then press the 'Format' button to select what needs to be measured (Eg - Log|Mag|, Phase, etc.).
  4. In order to measure and see two channels at the same time (Eg - Log|Mag| and Phase), press the 'Display' button and select 'Dual Channel'.
  5. Using the 'Scale' button we can set the scale/div or use autoscale and also set the attenuator values of the different channels.
  6. The 'Bw/Avg' option gives us an averaging option which averages few sets of data to produce the result. In doing this we lose quiet a lot of data and the resulting plot isn't able to give us the information on the statistical errors.
  7. This option also allows us to set the 'Intermediate Frequency' Bandwidth. This basically dictates the sampling rate of the Analyzer. The lower the IF bw, the higher is lesser is the noise (due to less uncertainty in Frequency).
  8. The 'Cal' button helps us calibrate the Analyzer to the current connections and signals. This is done because there is usually a difference in the 'cable lengths' for the two channels which introduces an extra phase term depnding upon the rf frequency. The calibration can be simply done by removing the Device Under Test (DUT) and diectly connecting the coaxial cables to the channels. After this the 'Calibrate Menu' allows us to calibrate the response using the short, open and thru methods.
  9. Now, under the 'Sweep' tab, the 'Sweep' button allows us to select various sweep options such as 'Sweep Time' (Auto, or set a time), 'Number of Points' (b/w 201-801) and 'Sweep Type' (Linear, Log, List Freq. etc.).
  10. Using the 'Source' button we can set the source power in dBm units (Usually kept as -20 to -10 dBm).
  11. The Scan Range can be set in a few ways such as using the start and end points or using the center and span range/width.
  12. After setting up all of the above, we can take the measurement either from the analyzer itself or using one of the control PCs. The command to download the data from AG4395A is netgpibdata -i 192.168.113.105 -d AG4395A -a 10 -f [filename].

 

Brief Details on How the 'AGmeasure' command works:

AGmeasure is a python script developed by some of the people who work at 40m. It is set as a global command and can be used from within any directory. The source code is in the scripts folder on the network, or else it can also be found in Eric Quintero's git repository. This command accepts at the very least a parameter file. This is supposed to be a .yml file. A template (TFAG4395Atemplate.yml) can be found in the scripts folder or in Eric's repo. There are some other options that can be passed to this command, see the help for more details.

 

The Multi_Measurement Script:

This script calls the 'AGmeasure' command repetitively and keeps storing the data files in a folder. Right now, the script needs to be fed in th template file manually at prompt.

 

The Test_Plotting Script:

This script plots the a set of data files obtained from the above mentioned script and produces a plot along with the errors bands upto 1 standard deviation of the data. The format (names) and total number of text files need to be explicitly known, for now at least.

 

Attachments:

  1. The output test files and the two scripts.
  2. This is the 'Bode Plot' for a data set made using the above two scripts.

 

To Do:

  • Improve upon the two scripts to be as compatible as the AGmeasure function itself.
  • Try and incorporate the whole script into AGmeasure itself along with improving upon the templates.
  • The above details, with some edits perhaps, can go into the 40m wiki too(?).

 

Update: Increased the font size in the plot. Added a few comments to the two scripts

To Do: Need to consider the transfer function as a single physical quantity (both the magnitude and phase) and then take the averages and calculate the standard deviation and then plot these results. 

 

EDIT:

The attachment with the test files and the code now also contains a pdf with all the relations/equations I have used to calculate the averages and errors.

  869   Fri Aug 22 10:39:41 2008 JenneUpdateSUSTaking Free Swinging spectra of PRM, SRM, ITMX, BS
I'm taking free swinging spectra of PRM, SRM, ITMX and BS, so I've turned off their watchdogs for now. I should be done around 11:15am, so I'll turn them back on then.
  13926   Thu Jun 7 14:35:26 2018 keerthanaUpdateelogTable- useful for doing the scanning.

I think this table will help us to fix the scanning range of the Marconi frequency. This will also help in predicting the position of the resonance peak corresponding to the injected frequency.

fdiff = fm ±80 MHz ;                     fdiff = N*FSRy ;              FSRy = 3.893 MHz.

N = Integer number fdiff =injected fm = Marconi frequency
1 3.893 76.107
2 7.786 72.214
3 11.679 68.321
4 15.572 64.428
5 19.465 60.535
6 23.34 56.66
7 27.251 52.749
8 31.144 48.856
9 35.037 44.963
10 38.93 41.07
11 42.79 37.21
12 46.716 33.284
13 50.609 29.391
  2419   Tue Dec 15 17:16:22 2009 KojiUpdateGeneralTable distance measurements

During the vent we have tried to measure the distances of the optical tables for BS-ITMX and BS-ITMY.
We need to take into account the difference between the AutoCAD drawing and the reality.

X direction distance of the table center for BS and ITMX:
84.086" (= 2135.8mm)
(This is 84.0000" in AutoCAD drawing)

Y direction distance of the table center for BS and ITMX:
83.9685" (= 2132.8mm)
(This is 83.5397" in AutoCAD drawing)

We used two scales attached each other in order to measure the distance of the certain holes on the tables.

We got more numbers that were estimated from several separated measurements.
I think they were not so accurate, but just as a record, I also put the figure as an attachment 2.

  8282   Wed Mar 13 03:12:47 2013 Manasa, JenneUpdateLockingTWO arms TWO colors

[Jenne, Manasa]

2 colors 2 arms realized!

1. Spot centering:

We spot centered the IR in both arms.
- Use TT1 and TT2 to center in Y arm (I visually center the spots on the ITM and ETM and then use TTs iteratively)
- Use BS-ETM to center in X arm

Spot positions after centering
               X arm            Y arm
         itmx    etmx        itmy    etmy
pitch    -0.86    0.37        1.51    0.05
yaw      0.01    -0.1        0.08    0.10


2. TT1 drifting in pitch (Bistable)
During the arm alignment routine for spot centering, we observed that TRY dropped (from TRY = 0.9 until the arm lost lock) every 40minutes or so. The arm was relocked by moving TT1 in pitch. The (locking - unlocking due to drift - relocking) cycle was monitored and we observed that it was bistable i.e. if TT1 was moved up in pitch (0.2 on the slider) to relock for the first time ; the next time it lost lock, TT1 had to be moved down by nearly the same distance to relock the arm.
Moving TT2 or the testmasses did not help with relocking the arms; so TT1 seems to be the one causing all th trouble atleast for today.

3. ALS - green alignment

We then moved on to Ygreen.  We used the out of vac steering mirrors to center the beam on the 2 irises that are in place on the table, which was a good starting place.  After doing that, and tweaking a small amount to overlap the incident and reflected beams on the green steering mirrors, we saw some mode lock.  We adjusted the end table steering mirrors until the Ygreen locked on TEM00.  We then followed Rana's suggestion of locking the IR to keep the cavity rigid while we optimized the green transmission.  Yuta, while adjusting ITMY and ETMY (rather than the out of vac mirrors) had been able to achieve a green transmission for the Yarm of ~2700 counts using the GTRX DC PD that's on the table. We were only able to get ~2200, with brief flashes up to 2500.

After that, we moved on to the X arm.  Since there are no irises on the table, we used the shutter as a reference, and the ETM optic itself.  Jenne looked through the viewport at the back of the ETM, while Manasa steered mirrors such that we were on the center of the ETM and the shutter.  After some tweaking, we saw some higher order modes lock.  We had a very hard time getting TEM00 to stay locked for more than ~1 second, even if the IR beam was locked.  It looks like we need to translate the beam up in pitch.  The leakage of the locked cavity mode is not overlapped with the incident beam or the promptly reflected beam.  This indicates that we're pretty far from optimally aligned.  Manasa was able to get up to ~2000 counts using the same GTRX PD though (with the Ygreen shutter closed, to avoid confusion).  Tomorrow we will get the Xarm resonating green in the 00 mode.

We need to do a little cleanup on the PSL green setup.  Yuta installed a shutter (I forget which unused one he took, but it was already connected to the computers.), so we can use it to block the PSL green beam.  The idea here is to use the 4th port of the combining beam splitters that are just before each beat PD, and place a PD and camera for each arm.  We already have 2 PDs on the table connected to channels, and one camera, so we're almost there. Jenne will work on this tommorrow during the day, so that we can try to get some beat signals and do some handoffs in the evening.

  8283   Wed Mar 13 08:34:33 2013 yutaUpdateLockingTWO arms TWO colors

- I took the shutter from AS table to use it for the PSL green. It was sitting near MC REFL path unused (elog #8259).

- If X green lock is not tight, maybe temporarily increasing loop gain helps. This can be done by increasing the amplitude of the frequency modulation or increasing green refl PD gain. Also, if X green beam spot is too wiggly compared with Y green, it is maybe because of air flow from the air conditioner (elog #6849). I temporarily turned it off when I did X green steering last summer.

- X green transmission on PSL table reached ~270 uW last summer (elog #6849, elog #6914). Y green transmission is now ~240 uW and ~2700 counts at maximum. So, X green transmission should reach ~3000 in counts.

- Did you have to re-align TRX path? We moved the harmonic separator on X end table horizontally to avoid IR TRX clipping before beam centering on X arm (elog #8162). I wonder what is the current situation after the beam centering.

  8289   Wed Mar 13 16:29:25 2013 ManasaUpdateLockingTWO arms TWO colors

Quote:

- If X green lock is not tight, maybe temporarily increasing loop gain helps. This can be done by increasing the amplitude of the frequency modulation or increasing green refl PD gain. Also, if X green beam spot is too wiggly compared with Y green, it is maybe because of air flow from the air conditioner (elog #6849). I temporarily turned it off when I did X green steering last summer.

- Did you have to re-align TRX path? We moved the harmonic separator on X end table horizontally to avoid IR TRX clipping before beam centering on X arm (elog #8162). I wonder what is the current situation after the beam centering.

 - We tried locking with the air conditioning switched off at the X-end

- TRX path is unaltered (IR still goes through the center of the harmonic separator.

  3447   Fri Aug 20 15:22:09 2010 JenneUpdateSUSTTs done!!!

[Yoichi, Jenne]

Hooray!!! The Tip Tilts are completely done!  The only things remaining are (1) Install 4 TTs in chambers sometime in September and (2) do shake tests / take TFs of the spare.

Today we balanced and characterized #'s 1 and 5.  All 5 TTs are waiting happily on the flow bench in the cleanroom for installation.

  7783   Tue Dec 4 18:06:35 2012 DenUpdateSUSTTs are ready

 Using instructions from Bram and Suresh, I was able to plug in connectors to BOSEMs. Today I've tested electronics, everything works good. Jamie made an medm screen and channels for TTs. Sliders for pitch and yaw go from -100 to 100 counts. Calibration to angle is 1e-5 rad / count.

TTs are in the clean room waiting for installation.

IMG_0105.JPG    IMG_0108.JPG

  7785   Tue Dec 4 20:13:55 2012 KojiUpdateSUSTTs are ready

Please leave here what was the instruction by Bran and Suresh so that the other people can redo it sometime later!

  7787   Tue Dec 4 21:57:04 2012 DenUpdateSUSTTs are ready

Quote:

Please leave here what was the instruction by Bran and Suresh so that the other people can redo it sometime later!

 The connectors can be plugged into the BOSEMs if we loosen the two screws which hold down the mini-D connector and the flex circuit.  Tighten the screws after the connector is pluged in.

  3812   Thu Oct 28 19:10:26 2010 taraUpdateElectronicsTTFSS for 40m

I keep a set of new TTFSS for 40m in electronic cabinet along the North arm.

The set number is #6. It is working and has not been modified by me.

Other two sets,# 5 and #7, are kept at PSL lab.

  4512   Mon Apr 11 20:03:05 2011 taraUpdateElectronicsTTFSS for 40m

I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.

note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.

Q3 is now pzt3904, not PZT2222A.

 

  7492   Fri Oct 5 14:53:29 2012 JenneUpdatePSLTTFSS board not fully seated!

[Den, Jenne]

Den noticed that the -15V LED on the TTFSS board was not illuminated.  A further symptom of the FSS being funny was that the PC RMS Drive was constantly high (3.6 ish) and the FAST Monitor was very high, often saturated. 

We took the TTFSS board out, and put an extender card in, and it looked like all of the correct power is being supplied to the board (the +\- 24V LEDs on the extender card were illuminated).  Just to check, we put the board back in, and this time both +\- 15V LEDs came on.  So it looks like the board is fine, it just wasn't seated in there all the way.

Now the readbacks on the FSS screen look good (PC RMS Drive is less than 1, FAST Mon is 5ish), the MC is locked, and I think we're back in business. 

 

  4777   Wed Jun 1 13:33:22 2011 koji, taraUpdateElectronicsTTFSS #7

We replaced GE81 by PZT2907A (PNP transistor) in TTFSS #7, it's working fine.

  Last time I broke Q4 transistor, which is used in the low noise power module for TTFSS, (see the schematic) and could not find another PZT2907A, so GE81 was used temporarily. Now we changed it back to PZT2907A as designed.  I tested it by checking the voltage outputs of the board. It works fine, all voltage outputs are correct. I labeled one of the slot on the blue cabinet tower and kept the rest of the transistors there.

q4.png

Quote:

I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.

note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.

Q3 is now pzt3904, not PZT2222A.

 

 

  7890   Thu Jan 10 15:30:33 2013 JenneUpdateAlignmentTT2 pins swapped, ITMX door open

 

[Bob, Manasa, Jenne]

We opened the ITMX heavy door.  Before getting too far, we realized that we had to do the fancy pin swapping before we can activate TT2.  So....

[Nic, Jenne]

We followed the instructions in elog 7869, and the associated Picasa album, and swapped the pins for the in-vac connector that will go to TT2.  Pretty easy, since the procedure was already well documented.

We then looked at the beam location on PR2, and the beam is ~2 inches up and to the left (as viewed from the front) from the center of the optic.  This is very easily correctable with the actuators, so we're leaving TT2 as it is.

  7886   Wed Jan 9 18:59:01 2013 JenneUpdateAlignmentTT2 installed, PRM oplev layout changed

[Jenne, Manasa]

PZT2 was removed from the BS table, and packed away in a foil-lined plastic box.

PRM oplev path has been altered, including installation of a 3rd mirror, to accommodate TT2, which is larger than PZT2.

      * Unfortunately, PR3 is a few mm more north than is indicated in the CAD drawing, so I wasn't able to place the oplev mirrors exactly as Manasa indicated in elog 7815

      * We came up with a different layout. Photos were taken.  We will need to confirm that the IPPOS, AS, and GreenX beams all clear past the oplev mirrors, but by imagining straight lines between mirrors for those beams, I think we should be okay.  but we must confirm when we have real beams.

TT2 was installed, according to the placement in the diagram.   Dogged down just as TT1 - one dog for the riser, 3 dogs for the TT base which also squish the riser.  You should be able to see this in the photos. Without having installed the PRM target, it looks like the input beam is hitting pretty close to the PRM's center.  Tomorrow Jamie The Tall can install the PRM target for us so we can confirm.

 

Photos - I'm posting them on Picasa here.  The new camera, and the fact that you can rotate the viewfinder, is amazing for overhead in-chamber photos.  Seriously, it's much easier to take useful photos.  It's great.

 

Tomorrow:

We remove the ITMX door first thing.  If Steve isn't here, we'll ask Koji or Bob to help us with the crane. 

First thing on the alignment list is to finalize TT2's pointing.  Put a target in front of PR2, put on the PRM target, etc, etc.  We're basically back to the same alignment procedure as we've been doing the last few vents.

 

Item for meditation:

Do we trust ourselves, or do we want to think about installing a 'bathroom mirror' so we can see the face of PR3 while we are pumped down?

  7893   Fri Jan 11 17:32:10 2013 ManasaUpdateAlignmentTT2 connections

 

 Manasa, Jenne

We started off to try and get TT2 working. We used the cables Jamie had already prepared while working on TT1 and used them to connect TT to the channels in 1Y3.

There were sma cable connectors already running between the channels 5-8 on the board to the UL,LL,UR and LR. Triggering the UL LL UR LR matrix on epics did not show any analog voltage at the output analog channels on the board. Talking to Jamie over phone, we inferred  that the  SMA cables that were already left connected corresponded to channels assigned for TT4 in epics.  So we set the connections right and could see analog voltage outputs corresponding to epics triggers.

We connected the ribbon cables running from the board to the TT. But changing pitch and yaw did not do anything to the TT2 mirror. We opened the BS door and checked if  the tt cables were connected to the post. We beeped the cable running from the board to TT (we also traced the cable's trail through the cable rack pile from 1Y3 to BSC). Using a function generator at the board end of the cable, we could not observe anything at the TT end of the cable.

We ran out of options on what can be done next and closed the doors. We hope Jamie can fix the problem once he returns next week.

  7894   Fri Jan 11 19:12:20 2013 KojiUpdateAlignmentTT2 connections

Was the connection between the feedthrough (atmosphere side) and the connector on the optical table confirmed to be OK?

We had a similar situation for the TT1. We found that we were using the wrong feedthrough connector (see TT1 elog).

  7896   Mon Jan 14 10:12:09 2013 JenneUpdateAlignmentTT2 connections

Quote:

Was the connection between the feedthrough (atmosphere side) and the connector on the optical table confirmed to be OK?

We had a similar situation for the TT1. We found that we were using the wrong feedthrough connector (see TT1 elog).

 The major problem that Manasa and I found was that we weren't getting voltage along the cable between the rack and the chamber (all out-of-vac stuff).  We used a function generator to put voltage across 2 pins, then a DMM to try to measure that voltage on the other end of the cable.  No go.  Jamie and I will look at it again today.

  7897   Mon Jan 14 12:08:39 2013 jamieUpdateAlignmentTT2 connections

Quote:

Quote:

Was the connection between the feedthrough (atmosphere side) and the connector on the optical table confirmed to be OK?

We had a similar situation for the TT1. We found that we were using the wrong feedthrough connector (see TT1 elog).

 The major problem that Manasa and I found was that we weren't getting voltage along the cable between the rack and the chamber (all out-of-vac stuff).  We used a function generator to put voltage across 2 pins, then a DMM to try to measure that voltage on the other end of the cable.  No go.  Jamie and I will look at it again today.

Everything was fine.  Apparently these guys just forgot that the cable from the rack to the chamber flips it's pins.  There was also a small problem with the patch cable from the coil driver that had flipped pins.  This was fixed.  The coil driver signals are now getting to the TTs.

Investigating why the pitch/yaw seems to be flipped...

  14362   Sat Dec 15 20:04:03 2018 gautamUpdateIOOTT1/TT2 stepping

I'm running a script that moves TT1 and TT2 randomly in some restricted P/Y space to try and find an alignment that gets some light onto the TRY PD. Test started at gpstime 1228967990, should be done in a few hours. The IMC has to remain locked for the duration of this test. I will close the PSL shutter once the test is done. Not sure if the light level transmitted through the ITM, which I estimate to be ~30uW, will be enough to show up on the TRY PD, but worth a shot I figure.

Test was completed and PSL shutter was closed at 1228977122.

  14368   Wed Dec 19 15:15:56 2018 gautamUpdateIOOTT1/TT2 stepping

I removed the ND filter from the ETMYT camera to facilitate searching for a TRY beam. This should be replaced before we go back to high power.

  8336   Mon Mar 25 15:01:33 2013 ManasaUpdateLockingTT1 drift

Quote:

2. TT1 drifting in pitch (Bistable)
During the arm alignment routine for spot centering, we observed that TRY dropped (from TRY = 0.9 until the arm lost lock) every 40minutes or so. The arm was relocked by moving TT1 in pitch. The (locking - unlocking due to drift - relocking) cycle was monitored and we observed that it was bistable i.e. if TT1 was moved up in pitch (0.2 on the slider) to relock for the first time ; the next time it lost lock, TT1 had to be moved down by nearly the same distance to relock the arm.
Moving TT2 or the testmasses did not help with relocking the arms; so TT1 seems to be the one causing all th trouble atleast for today.

Update

TT1 was moved in pitch to restore flashing in the arms on Wednesday (Mar 20) so that it doesn't drift too far off making it difficult to lock again. Since then, the arms have been flashing without any drifting and TTs have remained untouched. The hysteresis has disappeared.

  8337   Mon Mar 25 15:24:41 2013 ranaUpdateLockingTT1 drift

 

 I doubt that it has truly disappeared. Can you please make a measurement of it and quantify the hysteresis using some angle sensor?

  7861   Thu Dec 20 10:11:12 2012 ManasaUpdateIOOTT1 connections

[Jamie,Manasa]

We've been trying to figure out the connector for the TTs. Since, we found the cables were plugged in wrong in TT1; when triggered in pitch, the mirror moves in yaw and viceversa.

Referring to the cabling diagram, D1000234-v10, we infer that connectors go as J2 - LR, J3 - UR, J4 - LL, J5 - UL and the connections are made looking at the mirror from behind.

  7862   Thu Dec 20 10:35:27 2012 SteveUpdateIOOTT1 connections

Quote:

[Jamie,Manasa]

We've been trying to figure out the connector for the TTs. Since, we found the cables were plugged in wrong in TT1; when triggered in pitch, the mirror moves in yaw and viceversa.

Referring to the cabling diagram, D1000234-v10, we infer that connectors go as J2 - LR, J3 - UR, J4 - LL, J5 - UL and the connections are made looking at the mirror from behind.

 The view looking at the optic from the back:  

UL    UR

LL    LR

 

 

  14753   Thu Jul 11 17:58:38 2019 gautamUpdateEquipment loanTT suspension --> Downs

Arnaud has taken 1 TT suspension from the 40m clean lab to Downs for modal testing. Estimated time of return is tomorrow evening.

  7528   Thu Oct 11 11:36:52 2012 SteveUpdateSUSTT pitch adjustment

Tip Tilt pitch adjustment on existing-in vacuum suspension. This can be added by a simple installation of a 1.25" long 2-56 threaded rod with nuts.

  7888   Thu Jan 10 12:22:36 2013 JenneUpdateAlignmentTT matrix is funny

Quote:

* TT1 is in place, aligned so beam hits center of TT1, hits center of MMT1 (used pitch biases to finish pitch).

 I had asked Q to write this down on a piece of paper, but then I forgot to transcribe it into the elog....

The TT screen matrix, at least for TT1, is flipped or something.  When Eric moved the pit slider, the optic moved in yaw, and vice versa. 

We need to fix this, but for now, here's the situation when TT1 was pointed correctly at MMT1:

                       PIT    YAW

TT1 Pit slider     |  1000   1000  | --->   700 UL

     0             | -1000   1000  | --->   700 LL

TT1 Yaw slider     |  1000  -1000  | --->  -700 UR

    0.7            | -1000  -1000  | --->  -700 LR

 

The confusing thing is that Koji and I confirmed (by plugging in the correct cable to the correct sensor) that "UL" on the screen goes to the UL coil, and the same for the other 3 coils.  This needs investigation / fixing.

  7869   Fri Dec 21 16:50:30 2012 RanaUpdateSUSTT in vac DB25 pin swapping

[Koji, Rana, Nic, Steve]

We went to the 25-pin D cable which connects to the TT1 quadropus and succeeded eventually in swapping pins 12/24 into the 13/25 positions.

  1. The D-sub connector is a custom made LIGO part and so it doesn't at all work to use the standard pin extractor tools to move the pins out; we should have investigated this before spending all this time poking at and possibly damaging the existing connector.
  2. To move the pins, we have to partially dis-assemble the connector and fish the pins/wires through the appropriate holes. Unfortunately, the design is such that we nearly lose all of the pins when trying to do this. Pictures describe the story better than words.
  3. After the swap we tried to test the TT, but again wasted some time because the vac feedthrough was incorrectly labeled. The 25-pin feedthrough labeled as "PZT1" does not, in fact, connect to the TT. Instead, its the one slightly above it that is labeled "Pico". I have moved the PZT1 sticker up to match the actual connector. In order to discover this, we beeped through several stages of the coil driver, cable system. WE need to order some in-line D-sub breakouts for 25pin, 37pin, and 9pin which are similar to the ones we have now for 15pin. These are better than the green terminal block breakouts.
  4. After this, we were able to see the TT move, but elected to leave the final piece of the work (determining which microD goes with which coil) to when Jamie gets back.
  5. The TT screen is not good: it needs to be just like the usual sus screen so that we can put in offsets, excitations, etc. Perhaps also the ASC-TT screen can link to the TT:SUS screens. We can just copy the eLIGO TT screens to get going.
  7871   Wed Jan 2 06:52:50 2013 KojiUpdateSUSTT in vac DB25 pin swapping

[Koji, Rana, Nic, Steve]

I recalled that we used an optical lever to check if the TT is moving or not.
We used a laser pointer on a tripod, which was prepared by Steve.

I should also note that we stepped back the eddy current dampers from the magnets
in order to enhance the motion of the suspension. They should be restored in the end.

The mini-D connectors on the OSEMs are loosened so that we can plug the cables in.
This requires a specific metric allen key
that is stored in a clean tool box with an aluminum foil.

  7446   Thu Sep 27 15:21:04 2012 SteveUpdateSUSTT height adaptor & PTICH damping

Quote:

  [Koji, Steve, Den]

TT alignment is fine, yaw damping is satisfactory, pitch damping is slow. We might want to add magnets to the mirror and attach blades to the frame for pitch edge current damping.

We are moving towards electronics testing.

Atm1,  TT 1.5" high adaptor base will be back from the shop in 10 days.

Atm2,  There is no PITCH damping, YAW edie current damping works well at 0.5 mm gap

Atm3,  Adjustable Al -disc that contains a small magnet is purely designed.

We have to come up with a solution to have damping in PITCH

  14469   Fri Feb 22 12:19:46 2019 gautamUpdateIOOTT coil driver Vmon

To debug the issue of the suspected drifting TTs further, I temporarily hijacked CH0-CH8 of ADC1 in the c1lsc expansion chassis, and connected the "MON" outputs of the coil drivers (D010001) to them via some DB9 breakouts. The idea is to see if the problem is electrical. We should see some  slow drift in the voltage to the TTs correlated with the spot walking off the IPPOS QPD. From the wiring diagram, it doesn't look like there is any monitoring (slow or fast) of the control voltages to the TT coils, this should be factored into the Acromag upgrade of c1iscaux/c1iscaux2. EPICS monitoring should be sufficient for this purpose so I didn't setup any new DQ channels, I'll just look at the EPICS from the IOP model.

Quote:
Already, in the last ~1 hour, there has been considerable drift - see Attachment #2. The spot, which started at the center of the CCD monitor, has now nearly drifted off the top end. The ITMX and BS Oplev spots have been pretty constant over the same timescale, so it has to be the TTs?
  14897   Wed Sep 18 15:27:45 2019 gautamUpdateIOOTT cables need to be remade

Summary:

The custom ribbon cables piping the coil driver board outputs to the eLIGO (?) TTs (a.k.a. TT1 and TT2) are damaged. They need to be re-made. I can't find any pin-mapping for them.

Details:

While waiting for the LSC photodiode whitening switching cross-connect work to be done, I thought I'd re-align the IFO a bit. However, I was unable to find any beam making it to the REFL/AS ports despite some TT steering. I remembered that Chub had undone the TT connections at 1Y2 as well, and thought I'd check the cabling to make sure all was in order. On going to the rack, however, I found that these connections were damaged at the coil-driver end (see Attachment #1), presumably during the cable extraction. These need to be re-made...😔 

  14898   Thu Sep 19 09:39:30 2019 gautamUpdateIOOTT cables need to be remade

While debugging this problem, c1lsc models crashed. I ran the reboot script this morning to bring the models back. There was a 0x4000 error on the DC indicators for the c1lsc models (mx_stream error which couldn't be fixed by restarting the mx service) the first time I ran the script so I did it again, now the indicator lights are in their nominal state.

  14899   Thu Sep 19 11:26:18 2019 gautamUpdateIOOTT cables DON'T need to be remade

False alarm - the mistake was mine. Looking at the schematic diagram, the AI/Dewhite board, D000316, accepts the inputs from the DAC on the P2 connector. While restoring the connections at 1Y2, I had plugged the outputs of the DAC interface board into the P1 connectors of the AI boards. Having rectified this problem, I am now able to move the beam on the AS camera in both PIT and YAW using TT1 or TT2. So to zero-th order, this subsystem appears to work. A more in-depth analysis of the angular stability of the TTs can only be done once we re-align the arms and lock some cavities.

  7775   Sun Dec 2 00:37:49 2012 DenUpdateSUSTT cable problem

 This week I've got all TT stuff baked and today was testing eddy current damping and electronics.

In the beginning everything was good: ring magnets fit mirror holder holes and their interaction with actuation magnets is strong enough to keep damping magnets in the wholes. I've put the frame horizontally and kicked it, magnets were still in the whole. Brackets also fit to the TT frame.  

DSC_4945.JPG     DSC_4946.JPG

I've tested eddy current dumping during ring down measurements, it was strong enough.

DSC_4947.JPG    DSC_4948.JPG

Then I started to test electronics. I've provided signal to TT1 channels and could see it in the clean room. But then things went terrible. I just could not connect TT cables to OSEMS, there is not enough space in the OSEM for the connector to plug in.

DSC_4949.JPG     DSC_4952.JPG

Connector should be machines to be more narrow. There is actually no reason for a connector to have this shape. I think it was designed to fit perfectly the OSEM frame but turned out to be ~0.5 mm wider then it should be.

  7821   Thu Dec 13 04:29:34 2012 DenUpdateSUSTT angle of incidence

I think the angle of incidence on TT inside BSC will be too large because of eddy current damping brackets. I've measured max possible angle of incidence

  Max angle of incidence, degrees
No bracket 72
Original bracket 45
New bracket (with no screws for tiny yaw magnets) 52

This means that we do not have too much range and there is a probability that 45 degree incident beam will start clipping. I think we should just cut off the central part of the bracket. We do not need it anyway, our eddy current damping due to corner magnets is good enough.

I've left the brackets near the laptop in the clean room.

  7826   Fri Dec 14 01:42:53 2012 DenUpdateSUSTT angle of incidence

I've estimated max possible angle of incidence on TT if we allow 20mm tolerance for the beam size and 5 mm tolerance for spot location on the mirror. It turns out to be

alpha = 43 degrees

So we need to cut the central part of the bracket. Then the max possible angle of incidence will be

alpha = 63 degrees

 

DSC_4791.jpeg

We can start the vent on Monday and use TT with an old bracket for yaw damping and later during the week we can install the brackets after they will be baked.

  7827   Fri Dec 14 02:52:32 2012 KojiUpdateSUSTT angle of incidence

At least, we don't want to use Al-coated mirrors. We should use multilayer dielectric mirrors.

  7828   Fri Dec 14 03:15:49 2012 JenneUpdateSUSTT angle of incidence

But have you looked yet at what angle we need? The first input string mirror has a quite small incidence angle. The other input steering mirror maybe borderline, based on your estimates. Also, have we considered just having new brackets made and cleaned? Is there a reason we would prefer to modify the ones we have?

  7850   Tue Dec 18 15:32:29 2012 JenneUpdateSUSTT angle of incidence

Quote:

At least, we don't want to use Al-coated mirrors. We should use multilayer dielectric mirrors.

 I popped into the cleanroom earlier today, and all 4 active TTs have dielectric coatings.  I'm not sure why the mirror in this photo looks funny, but the actual mirrors installed are correct, at least in type of coating. 

I'm not sure if Den wrote down what mirrors are actually in there, and I didn't look carefully - I don't know if they are G&H, CVI, other mystery company?

  7428   Fri Sep 21 22:43:51 2012 DenUpdateSUSTT alignment

I did TT alignment using red laser and QPD.

P9210079.JPG       P9210092.JPG

 I had a problem aligning TT with frame number SN-035 as some screws are damaged so all what I could move were 2 blades on the sides of the mirrors. But this was not enough to align pitch and yaw simultaneously.  It is possible to align pitch only, but then I got a huge yaw angle (~0.05-0.1 rad). The only option I had was to make a reasonable alignment in yaw and then suspend several washes on the screw on the bottom of the mirror to align pitch.

Attached are flag positions inside coils. 1 - SN034, 2 - SN012, 3 - SN006, 4 - SN035. For each TT there are 4 pictures with flag 1-4: UL, LL, UR, LR

  7831   Fri Dec 14 09:05:04 2012 steveUpdatePEMTT after eq 6.1

 

 SRM, ITMY and MC3 moved some what, but how are the TT? It may worth looking at them before we vent.

  5222   Sat Aug 13 15:40:38 2011 NicoleSummarySUSTT Shaking Today and Hopefully More?

As reported in my  previous entry of TT supsension bode plots, I found that my experimental data had what appears to be very noise peaks above 20 Hz (as mentioned earlier, the peak at 22 Hz is likely due to vertical coupling, as 22 Hz is the resonant frequency of the cantilever blades). This is very unusual and needs to be explored further. I would like to vertically-shake the TTs to obtain more data on possible coupling. However, I am leaving on Monday and will not return until Thursday (day of SURF talks). I am leaving campus Friday afternoon or so. I would may need some help coming up with an assembly plan/assembling set-up for vertical shaking (if it is possible to do so in such a limited time frame).

 

Today I wanted to see if the "noisy peaks" above 30 Hz were due to EM noise coupling. I tested this hypothesis today, seeing if EM fields generated by the coil at higher frequencies were injecting noise into my transfer function measurements. I found that the "noisy peaks" above 30 Hz are NOT DUE TO EM NOISE COUPLING. I am very curious as to what is causing the high peaks (possibly coupling from other degrees of freedom)?

 

 emnoise_and_flex.jpg

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