40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 258 of 341  Not logged in ELOG logo
ID Date Author Type Category Subjectup
  15590   Mon Sep 21 12:40:58 2020 gautamUpdateGeneralWorkable IFO recovery

See Attachment #1.

  • The original ETMY actuation matrix was the naive one so I simply retuned everything by adding the butterfly mode appropriately.
  • The cross coupling between the DOFs has not been characterized, but the local damping, Oplev loops, POX/POY locking, simpel Michelson locking, and ASS dither alignemnt all seem to work so I'm thinking this is good enough for now.
  • A copy of the ETMYaux.db file was made, and the slow bias voltage was redistributed among the three available face OSEMs - note that the magnet polarity has to be taken into account.
  • The series resistance on the slow path was reduced from 430 ohms, 1W to 100 ohms, 3W, to allow DC alignment of the cavity axis to the beam axis.
  • Vertex Oplevs were re-centered on their respective QPDs after locking POX/POY and running the ASS dither alignment.
  • The AS spot was a little low on the camera - presumably the SR2/SR3 got macroscopically misaligned. I re-centered the beam on the camera on the AS table (by moving the camera, the beam path was not disturbed).

The beam spot on ETMY looks weird (looks almost like a TEM10 mode), but the one on ITMY seems fine, see Attachment #2. Wonder what's going on there, maybe just a focusing problem?

Quote:
 

We need a vent to fix the suspension, but until then what we can do is to redistribute the POS/PIT/YAW actuations to the three coils.

Attachment 1: IFOrecovery.png
IFOrecovery.png
Attachment 2: IMG_5345.JPG
IMG_5345.JPG
  11604   Wed Sep 16 03:37:06 2015 KojiSummaryGreen LockingWorkable delay line setup prepared

[Koji Gautam]

The variable delay line has been setup for practical use. The hardware and basic software are ready.

The delay time is given by [512-1-mod(C1:LSC-BO_1_0_SET, 512)]*(1/16) ns

Giving 511 (LLLL LLLH HHHH HHHH) to C1:LSC-BO_1_0_SET makes the delayline shortest (+0ns).
Giving 0 (LLLL LLLL LLLL LLLL) to C1:LSC-BO_1_0_SET makes the delayline longest (~32ns).

The SR785 was removed from the rack for our access >> Eric


DO setup

- Three CONTEC DO-32L-PE cards are found in the Yarm digital cabinet. (I brought a card from WB, but will bring it back).
- The card was installed in the C1LSC chassis.

- The models for c1x04 and c1lsc were modified to include the card. Once they are restarted, the card was recognized without problem.
  The frame builder also needed to be restarted (Attachment 1&2). The changes were committed to the repository.

- MEDM screen "CDS_BO_STATUS.adl" has been modified to include the bit monitors for the new DO card. (Attachment 3)

Epics values "C1:LSC-BO_1_0_SET" and "C1:LSC-BO_1_1_SET" are hooked up to the DO block.

Cables

- The DO board has DB37(F). I made a I/F cable with a DB37(M) crimp connector, DB25 breakout board, and a ribbon cable.
  Pin 1 is connected to pin 14 of the DB25 (GND of the delayline circuit).
  Pin 2~10 are connected to pin 1~9 of the DB25 (Switch 1~9 of the delayline circuit)
  Pin 18 is connected to X01 (external = spare) (Attachment 4)
 

- [CONFESSION] A bench +15V power supply was prepared to power the transisters of the DO (Attachment 6). The hot side is connected to X01 (not connected to the DB25),
  and the cold side is connected to pin 14 of the DB25. Once we find this is a useful setup we need to make a dedicated interface unit to convert DB37
  into DB25 (and provide more connectivities).

- A DB25 M-F cable was installed on the cable tray above the LSC racks.

Delay line unit

- The delay line box was mounted on 34H of the LSC analog rack (Attachment 5).

- The side cross connect power supply was not available (to be described later). Therefore we decided to use the same +15V supply as the one for the DO card.

- Checked the functionarity of the local switches using a function generator @30MHz and the front panel switches. The maximum (~32ns) delay was confirmed.
  (Just not enough to have 360 deg shift).

- Now the delay line function was tested with the front panel swicth at "ext". We confirmed that the delay time changes with the number given to C1:LSC-BO_1_0_SET.


What we need further

- Implement delay time slider control (511 = 0ns, 0 = 31.94ns). The delay time is given by
  [512-1-mod(C1:LSC-BO_1_0_SET, 512)]*(1/16) ns

- Some independent RF issues I found. (Next entry)

Attachment 1: 21.png
21.png
Attachment 2: 51.png
51.png
Attachment 3: 46.png
46.png
Attachment 4: IMG_20150915_222236066.jpg
IMG_20150915_222236066.jpg
Attachment 5: IMG_20150915_234222349.jpg
IMG_20150915_234222349.jpg
Attachment 6: IMG_20150915_234323363.jpg
IMG_20150915_234323363.jpg
  15513   Mon Aug 10 16:52:04 2020 gautamUpdateBHDWorkable setup prepared

All the details are in E2000436, and documents linked from there, I think an elog would be much too verbose. In summary, a workable setup consisting of

  • 2 DCPDs interfaced with the realtime CDS system. Note that because this circuit is single-ended, while the AA and ADC are differential receiving, there is an overall gain of 0.5. Explicitly, for the 300 ohm DC transimpedance, the conversion is ~350 cts/mW.
  • A local oscillator beam delivered via fiber that is mode-matched (roughly) with the IFO AS beam.
  • A PZT mounted mirror to control the homodyne phase. The PZT (S320) is an obsolete part and it's hard to find a datasheet for it, but if its specs are comparable to the more modern S330, the full stroke is 10 um, for a max applied voltage of 100 V DC, so 100nm/V. c.f. 200V for 3um full stroke of the Noliac.

was prepared.

Last night, I locked the PRMI with the carrier resonant, and convinced myself that the DCPD null stream was sensing the MICH degree of freedom (while it was locked on AS55_Q) with good SNR below ~60 Hz. Above ~60 Hz, in this configuration, the ADC noise was dominating, but by next week, I'll have a whitening board installed that will solve this particular issue. With the optical gain of MICH in this configuration, the ADC noise level was equivalent to ~500 nrad/rtHz of phase noise above ~60 Hz (plots later).

Now, I can think about how to commission this setup interferometrically.

  4144   Wed Jan 12 17:50:21 2011 josephbUpdateCDSWorked on c1lsc, MC2 screens

[josephb, osamu, kiwamu]

We worked over by the 1Y2 rack today, trying to debug why we didn't get any signal to the c1lsc ADC.

We turned off the power to the rack several times while examining cards, including the whitening filter board, AA board, and the REFL 33 demod board.  I will note, I incorrectly turned off power in the 1Y1 rack briefly. 

We noticed a small wire on the whitening filter board on the channel 5 path.  Rana suggested this was to part of a fix for the channels 4 and 5 having too much cross talk.  A trace was cut and this jumper added to fix that particular problem.

We confirmed would could pass signals through each individual channel on the AA and whitening filter boards.  When we put them back in, we did noticed a large offset when the inputs were not terminated.  After terminating all inputs, values at the ADC were reasonable, measuring on from 0 to about -20 counts.  We applied a 1 Hz, 0.1 Vpp signal and confirmed we saw the digital controls respond back with the correct sine wave.

We examined the REFL 33 demod board and confirmed it would work for demodulating 11 MHZ, although without tuning, the I and Q phases will not be exactly 90 degrees apart.

The REFL 33  I and Q outputs have been connected to the whitening board's 1 and 2 inputs, respectively.  Once Kiwamu  adds approriate LO and PD signals to the REFL 33 demod board he should be able to see the resulting I and Q signals digitally on the PD1 I and Q channels.

 

In an unrelated fix, we examined the suspensions screens, specifically the Dewhitening lights.  Turns out the lights were still looking at SW2 bit 7 instead of SW2 bit 5.  The actual front end models were using the correct bit (21 which corresponds to the 9th filter bank), so this was purely a display issue.  Tomorrow I'll take a look at the binary outputs and see why the analog filters aren't actually changing.

 

 

 

  12244   Tue Jul 5 18:44:39 2016 PrafulUpdateComputer Scripts / ProgramsWorking 40m Summary Pages

After hardware errors prevented me from using optimus, I switched my generation of summary pages back to the clusters. A day's worth of data is still too much to process using one computer, but I have successfully made summary pages for a timescales of a couple of hours on this site: https://ldas-jobs.ligo.caltech.edu/~praful.vasireddy/

 

Currently, I'm working on learning the current plot-generation code so that it can eventually be modified to include an interactive component (e.g., hovering over a point on a timeseries would display the GPS time). Also, the 40m summary pages have been down for the past 3 weeks but should be up and working soon as the clusters are now alive.

  3319   Thu Jul 29 12:31:24 2010 josephbUpdateCDSWorking DAC, working IOP - next up SUS

Ok, after a few minutes of talking to Alex, I got the correct "GUI syntax" through my head, and we now have a simple working green end control which in fact puts signals out through the DAC.

Note to self, do not put any additional filters or controls in the IOP module.  Basically just change the master block with GDS numbers, DCU_ID numbers, etc.  When using a control model, copy the approriate ADC and ADC selector or DAC to the control model.  It will magically be connected to the IOP.

A correct example of a simple control model is attached.

Next in line is to get the adapter boxes for SUS into the new 1X5 rack and get started on SUS filter conversion and figuring out which ADC/DAC channels correspond to which inputs.

 

Attachment 1: Simple_Green_Control.png
Simple_Green_Control.png
  266   Fri Jan 25 11:38:16 2008 josephbConfigurationCamerasWorking GiGE video on Linux - sort of
1)I have been able to compile the SampleViewer program which can stream the video from the Prosilica 750C camera. This was accomplished on my 64-bit laptop running Ubuntu, after about 3 hours of explicitly converting strings to wxStrings and back again within the C++ code. (There was probably an easier way to simply overload the functions that were being called, but I wasn't sure how to go about doing so). By connecting it to the CDS network, I was able to immediately detect the camera and display the images.

Unfortunately, I have not yet been able to get it to compile on Mafalda with the x86 architecture. This may be do the fact that it has wxWidgets version 2.8.7 while my laptop has 2.8.4. Certainly the failure at compile time looks different from the errors earlier, and seem to be within the wxWidget code rather than the SampleViewer code. I may simply need to uninstall 2.8.7 and install 2.8.4 of wxWidgets.

The modified code that will compile on my machine has been copied to /cvs/cds/caltech/target/Prosilica/examples/SampleViewer2b.

2)The Snap program (under /cvs/cds/caltech/target/Prosilica/examples/Snap) also will now take full resolution images even on Mafalda. This was achieved by reducing the packet size to 1000 and also increasing the wait until timeout time up to 400 ms, which originally was at 100. Apparently, it takes on the order of 1 ms per packet as far as I can tell. So full resolution at 752x480 required something of order 360 packets.

To Do:
1) Get sample viewer to compile on Mafalda, and then statically compile it so it can be run from any Linux based machine.
2) Get a user friendly version of Snap up and running, statically compiled, with options for a continuous loop every X seconds and also to set desired parameters (such as height, width, file name to save to, save format, etc).
3) Figure out data analysis with the images in Matlab and an after the fact image viewer.

Attached is an example .tiff image from the Snap program.
Attachment 1: snap.tiff
  267   Fri Jan 25 13:36:13 2008 josephbConfigurationCamerasWorking GiGE video on Mafalda
Finally got the GiGE camera sample viewer video running on Mafalda by updating to the latest API (version 1.16 from Dec 16, 2007) from Prosilica and then using the modified Sample Viewer code I had written. The API version previously in cvs was 1.14.

It can currently be run by ssh -X into Mafalda and going to /cvs/cds/caltech/target/Prosilica/bin-pc/x86 and running the SampleViewer executable found there.
  17070   Wed Aug 10 15:33:59 2022 CiciUpdateGeneralWorking Red Pitaya VNA

TL;DR: I am now able to inject a swept sine and measure a transfer function with python on my Red Pitaya! Attached is a Bode plot for a swept sine from 1 - 30 MHz, going through a band pass filter of 9.5 - 11.5 MHz.

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

  • Spent too long trying to get pyRPL to work, do not recommend. The code on their website has a lot of problems (like syntax-error level problems), and is ultimately designed to open up and start a GUI, which is not what I want even if it did work.
  • Found some code on the git repository of someone at Delft University of Technology, worked better but still not great (oscilloscope/spectrum analyzer functions were alright, but couldn't successfully run a VNA with it, and overcomplicated). Helped me figure out appropriate decimation factors. Realized it was not using the FPGA to get TF data but instead just collecting a lot of time trace data and then taking an FFT in the code to get the TF, which wasn't ideal.
  • Eventually switched to using the Red Pitaya SCPI server to talk to the Red Pitaya myself, successful! I inject a swept sine with a for loop that just cycles through frequencies and takes the transfer function at each one.
    • Was originally getting the transfer function by using scipy.signal.csd() and scipy.signal.welch() to get Pxy and Pxx and dividing, and then just finding the closest point in the frequency spectrum to the frequency I was inserting.
    • Switched to doing IQ demodulation myself: where x(t) is the measurement before the band pass filter and y(t) is the measurement after, taking the mean of (x(t) * cos(2pi*freq)) = a1, mean(x*sin()) = a2, mean(y*cos()) = b1, mean(y*sin()) = b2, and then TF(freq) = (b1 + i b2)/(a1 + i a2).
    • Unfortunately still taking time trace data and then calculating the TF instead of using the FPGA, but I have not found anything online indicating that people are able to get VNA capabilities on the Red Pitaya without collecting and sending all the time trace data... I'm still not sure if that's actually a Red Pitaya capability yet.

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

To do:

  • Will go take measurements of the AUX laser loop with the RPi! Have a good diagram of when I did it with the SR785 so it shouldn't be too hard hopefully.
  • Figure out how to get coherence data!!
  • Figure out how to get the RPi on the wifi. Right now I'm just plugging the RPi into my computer. Paco and I were working on this before and had trouble finding old passwords... Hopefully will not be too much of a roadblock.
Attachment 1: rpi_vna_test.pdf
rpi_vna_test.pdf
  17071   Wed Aug 10 19:24:19 2022 ranaUpdateGeneralWorking Red Pitaya VNA

                 Boom!

 

  2753   Thu Apr 1 17:35:24 2010 KojiUpdateSUSWorking on ITMX/Y

Steve and Koji

- We removed old ITMX/Y from the chambers. Now they are temporarily placed on the flow table at the end. Steve is looking for nice storages for the 5inch optics.

- We wiped new ITMX/Y by isopropanol as they were dusty.

- We put them into the corresponding towers. Checked the balancing and magnet arrangements with the OSEMs. They were totally fine.

- We clamped the mirrors by the EQ stops. Wrapped the towers by Al foils.

Tomorrow we will put them into the chambers.

 

Attachment 1: IMG_2353.jpg
IMG_2353.jpg
  245   Thu Jan 17 15:11:13 2008 josephbUpdateCamerasWorking on Malfalda
1) I can statically compile the ListCamera code (which basically just goes out and finds what cameras are connected to the network) on Malfalda and use that compiled code to run on Linux2 without a problem. Simply needed to add explicit links to libpthread.a and librt.a.
(i.e. -Bstatic -L /usr/lib/ -lpthread -Bstatic -L /usr/lib -lrt)

With appropriate static libraries, it should be possible to port this code to other linux machines even if we can't get it to compile on the target machine itself.

2)I've modified the Snap.cpp file so that it uses a packet size of 1000 or less. This simply involves setting the "PacketSize" attribute with the built in functions they provide in their library. After un-commenting some lines in that code, I was able to save tiff type images from the camera of up to 400x240 pixels on Malfalda. The claimed maximum resolution for the camera is 752x480, but it doesn't seem to work with the current setup. The max number of pixels seems to about 100 times the packet size. I.e. packet size of 1000 will allow up to 400x240 (96000) but not 500x240 (120,000). Not sure if this is an issue just with snap code or the general libraries used.

3)Will be working towards getting video running over the next day or so.
  2895   Fri May 7 14:51:04 2010 josephbUpdateCDSWorking on meta .mdl file scripts

I'm currently working on a set of scripts which will be able to parse a "template" mdl file, replacing certain key words, with other key words, and save it to a new .mdl file.

For example  you pass it the "template" file of scx.mdl file (suspension controller ETMX), and the keyword ETMX, followed by an output list of scy.mdl ETMY,  bs.mdl BS, itmx.mdl  ITMX, itmy.mdl ITMY, prm.mdl PRM, srm.mdl SRM.  It produces these new files, with the keyword replaced, and a few other minor tweaks to get the new file to work (gds_node, specific_cpu, etc).  You can then do a couple of copy paste actions to produce a combined sus.mdl file with all the BS, ITM, PRM, SRM controls (there might be a way to handle this better so it automatically merges into a single file, but I'd have to do something fancy with the positioning of the modules - something to look into).

I also have plans for a script which gets passed a mdl file, and updates the C1.ipc file, by adding any new channels and incrementing the ipcNum appropriately.  So when you make a change you want to propagate to all the suspensions, you run the two scripts, and have an already up to date copy of memory locations - no additional typing required.

Similar scripts could be written for the DAQ screens as well, so as to have all the suspension screens look the same after changing one set.

  2238   Wed Nov 11 15:04:52 2009 AlbertoUpdateABSLWorking on the AP table

I've opened the AP table and I'm working on it.

  2239   Wed Nov 11 16:18:57 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

I've opened the AP table and I'm working on it.

I re-aligned the Faraday on the AP table. I also aligned the beam to the periscope on the PSL and all the other optics along the beam path.  Now I have a nice NPRO beam at the PLL which overlaps with the PSL beam. The alignment has to be further improved because I see no beat yet.

I wonder if the all the tinkering on the PSL laser done recently to revive the power has changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat. So maybe the misalignment is the casue.

Not feeling very well right now. I need to go home for a while.

AP table closed at the moment.

NPRO shutter closed

  2240   Wed Nov 11 17:10:51 2009 JenneUpdateABSLWorking on the AP table

Quote:

Quote:

I've opened the AP table and I'm working on it.

I re-aligned the Faraday on the AP table. I also aligned the beam to the periscope on the PSL and all the other optics along the beam path.  Now I have a nice NPRO beam at the PLL which overlaps with the PSL beam. The alignment has to be further improved becasue I see no beat yet.

I wonder if the all the tinkering on the PSL laser done recently to revive the power have changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat. So maybe the misalignment is the casue.

Not feeling very well right now. I need to go home for a while.

AP table closed at the moment.

NPRO shutter closed

 We definitely changed the PSL NPRO temp while fiddling around, trying to increase the laser power.  I think it's noted in the elog both times that it's happened in the last few months (once when Rana, Koji and I worked on it, and then again when it was just Koji), but we opened up the side of the MOPA box so that we could get at (and change) the potentiometer which adjusts the NPRO temp.  So you may have to search around for a while.

  2241   Wed Nov 11 17:33:54 2009 KojiUpdateABSLWorking on the AP table

Yes it did.

For long time, the crystal temperature C1:PSL-126MOPA_LTMP was 43~46deg. Now it is 34deg. Try ~10deg lower temperature.

Quote:

I wonder if the all the tinkering on the PSL laser done recently to revive the power have changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat.

 

  2250   Thu Nov 12 10:45:36 2009 AlbertoUpdateABSLWorking on the AP table

I've opened the AP table and I'm working on it.

Also auxiliary NPRO turned on and mechanical shutter opened.

  2252   Thu Nov 12 11:34:38 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

Yes it did.

For long time, the crystal temperature C1:PSL-126MOPA_LTMP was 43~46deg. Now it is 34deg. Try ~10deg lower temperature.

Quote:

I wonder if the all the tinkering on the PSL laser done recently to revive the power have changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat.

 

 Beat found at 30MHz with auxiliary NPRO temperature of 37.19 degrees, vs. ~48 deg as it used to be.

The beat is small (-70dBm). PLL alignment has to be improved.

  2254   Thu Nov 12 12:51:45 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

I've opened the AP table and I'm working on it.

Also auxiliary NPRO turned on and mechanical shutter opened.

AP table and aux NPRO shutter just closed.

  2257   Thu Nov 12 16:53:59 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

Quote:

Yes it did.

For long time, the crystal temperature C1:PSL-126MOPA_LTMP was 43~46deg. Now it is 34deg. Try ~10deg lower temperature.

Quote:

I wonder if the all the tinkering on the PSL laser done recently to revive the power have changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat.

 

 Beat found at 30MHz with auxiliary NPRO temperature of 37.19 degrees, vs. ~48 deg as it used to be.

The beat is small (-70dBm). PLL alignment has to be improved.

 PLL alignment improved. Beat amplitude = -10dBm. Good enough.

DC readouts at the PLL photodiode:

V_NPRO = -4.44V

V_PSL = -3.76V

The NPRO beam is attenuated by a N.D.=1 attenuator just before going to the photodiode.

Something strange happened at the last. Right before -10dBm, the amplitude of the beat was about -33dBm. Then I was checking the two interfering beams with the IR card and saw that they overlapped quite well. I then turned my head back to the spectrum analyzer and suddenly the beat was at -10dBm. Not only, but a bunch of new peaks had appeared on the spectrum. Either I inadvertently hit the PD moving it to a better position or something else happened.

Like if someone was making some other modulation on the beam or the modulation depth of the PSL's sidebands had gone up.

  2326   Wed Nov 25 08:43:08 2009 AlbertoUpdateABSLWorking on the AP table

I'm working on the AP table. I also opened the auxiliary NPRO shutter. The auxiliary beam is on its path on the AP table and PSL table.

  2334   Wed Nov 25 15:42:27 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

I'm working on the AP table. I also opened the auxiliary NPRO shutter. The auxiliary beam is on its path on the AP table and PSL table.

 NPRO shutter closed

  2460   Mon Dec 28 15:34:14 2009 AlbertoUpdateABSLWorking on the AP table

I opened the auxiliary laser's shutter.

I'm currently working on the AP table.

  2461   Mon Dec 28 18:35:27 2009 AlbertoUpdateABSLWorking on the AP table

Quote:

I opened the auxiliary laser's shutter.

I'm currently working on the AP table.

 I finished working on the table.

I closed the AUX NPRO's shutter.

  3321   Thu Jul 29 15:35:21 2010 josephb, kiwamuUpdateCDSWorking out ADC/DAC/BO wiring

We are currently using the SUS wiring diagram found on Ben Abbott's page (link here) to determine the ADC/DAC/BO channel numbers for each individual optics inputs and outputs.  Basically it involves tracking the paths back from the Pentek's, XY220, and IC110Bs to a point where we can identify it as a Coil UL or a PD whitening filter control or whatever it might be.

Once done we will have a nice wiki page describing what the final wiring is going to be, along with which ADC effectively plugs into which analog board and so forth.

  11503   Thu Aug 13 20:32:07 2015 IgnacioUpdateLSCWorking towards YARM FF

The mode cleaner FF static filtering is by no means done. More work has to be done in order to succefuly implement it, by the means of fine tuning the IIR fit and finding better MISO Wiener filters. 

I have begun to look at implementing FF to the YARM cavity for several reasons.

1) Even if the mode cleaner FF is set up as best as we can, there will still be seismic noise coupling into the arm cavities.

2) YARM is in the way of the beam path. When locking the IFO, one locks YARM first, then XARM. This means that it makes sense to look at YARM FF first rather than XARM.

3) XARM FF can't be done now since GUR2 is sketchy.

I'm planning on using this eLOG entry to document my Journey and Adventures (Chapter 2: YARM) to the OPTIMAL land of zero-seismic-noise (ZSN) at the 40m telescope.

 

  14382   Thu Jan 3 21:17:49 2019 ranaConfigurationComputersWorkstation Upgrade: Donatella -> Scientific Linux 7.2

donatella was one of our last workstations running ubuntu12. we installed SL7 on there today

  1. had to use a DVD; wouldn't boot from USB stick
  2. made sure to use userID=1001 and groupID=1001 at the initial install part
  3. went to the Keith Thorne LLO wiki on SL7
  4. The 'yum update' command failed due to a gstreamer conflict. I did "yum remove gstreamer1-plugins-ugly-free-1.10.4-3.el7.x86_64" and then it continued a bit more.
  5. Then there are ~20 errors related to gds-crtools that look like this:Error: Package: gds-crtools-2.18.12-1.el7.x86_64 (lscsoft-production) Requires: libMatrix.so.6.14()(64bit)

  6. I re-ran the yum install .... command using the --skip-broken command and that seemed to complete, although I guess the GDS stuff will not work.
  7. Installed: terminator, inconsolata-fonts, 
  8. Installed XFCE desktop as per K Thorne:  yum groupinstall "Xfce" -y
  9.  
Attachment 1: IMG_20190103_205158.jpg
IMG_20190103_205158.jpg
  14972   Tue Oct 15 17:22:26 2019 gautamUpdateGeneralWorkstation computers back on UPS

Batteries + power cables replaced, and computers back on UPS from today ~3pm.

Quote:

The UPS is now incessantly beeping. I cannot handle this constant sound so I shut down all the control room workstations and moved the power strip hosting the 4 CPUs to a wall socket for tonight. Chub and I will replace the UPS batteries tomorrow.

  14969   Mon Oct 14 17:24:28 2019 gautamUpdateGeneralWorkstation computers taken off UPS (temporarily)

The UPS is now incessantly beeping. I cannot handle this constant sound so I shut down all the control room workstations and moved the power strip hosting the 4 CPUs to a wall socket for tonight. Chub and I will replace the UPS batteries tomorrow.

  9259   Tue Oct 22 18:55:55 2013 ranaUpdateCDSWorkstation swap: Rosalba to ???

We got a new computer from Xi computer corp. I am currently installing Ubuntu 10.04 LTS on to it to start with and then will move on to 12 if we can figure out a way to test it besides "I guess it should work?"

Rosalba has been removed and put onto the old Jamie desk. Old Jamie desk also has a Mac Mini running on there.

At the meeting tomorrow we need to decide on a new Italian baby girl name for this new machine.

  9271   Wed Oct 23 22:11:20 2013 ranaUpdateCDSWorkstation swap: Rosalba to ???

  I've finished setting up the fstab on Chiara and the upgrade to Ubuntu 12 seems to have gone well enough. She's fast:

24.png

but I forgot to make sure to order a dual head graphics card for it. So we'll order some dual DVI gaming card that the company recommends. Until then, its only one monitor.

Still, its ready for testing control room tools on. If everything works OK for a couple weeks, we can go to 12 on all the other ones.

  10031   Thu Jun 12 11:03:11 2014 KojiFrogsGeneralWorld Cup Soccer 2014

world_cup.jpg

  10032   Thu Jun 12 12:30:50 2014 denFrogsGeneralWorld Cup Soccer 2014

Quote:

 

 world-cup-2014-mascots.jpg

  10346   Thu Aug 7 13:39:41 2014 NichinUpdateComputer Scripts / ProgramsWrapping up PDFR

1)The PDFR scripts have all been migrated into /scripts/PDFR/

2) The MEDM screen to run PDFR is /medm/MISC/PDFR.adl

3) A new button has been added on sitemap to open the above medm window.

4) All data and plots generated will sit in /scripts/PDFR/"PD Name"/

5) All features are working after the migration and absolute file paths are being used.

Work Remaining : Manual for others to make changes and keep using my system.

 

  13157   Tue Aug 1 19:23:06 2017 ranaUpdateALSX - arm alignment

Rana, Naomi

We dither locked the X arm and then aligned the green beam to it using the PZTs. Everything looks ready for us to do a mode scan tomorrow.

We got buildup for Red and Green, but saw no beat in the control room. Quick glance at the PSL seems OK, but needs more investigation. We did not try moving around the X-NPRO temperature.

Tomorrow: get the beat, scan the PhaseTracker, and get data using pyNDS.

  9963   Fri May 16 10:54:42 2014 ericqUpdateLSCX Arm ALS Noise coming in and out

Den and I spent some time with the interferometer last night with hopes of bringing in the AO path, but were stymied by the (re)occurrence of the anomalously high low frequency motion of the Xarm, as seen by fluctuations of TRX from .9 to .2 while "held" on resonance.

Jenne reported that they weren't seeing it earlier in the evening, and then it started again when I showed up. Holding the arms on IR, we could see a fair amount of excess low frequency noise in the BEATX_FINE_PHASE_OUT_HZ channel, as compared to BEATY, bringing its RMS to 5 times that of the Y arm. From the shape of the excess noise (broad slope from DC to tens of Hz), Rana suspected air currents and/or scattering effects being the culprit.

Den poked around a bit on the PSL table, which didn't really change much. He then went down to the X end table to inspect the table, and while he was there, I noticed the noise go down to being in line with the Yarm. I joined him at the end, and we found the beat phase noise in the frequency region of concern to be hugely sensitive to tapping on the enclosure, air current, etc. There is also a ton of green light everywhere, and multiple spots of green light around the green refl PD.

At that point however, the quiescent noise was acceptable (TRX fluctuations of <.2), so we went back to the control room to try to lock. Unfortunately, after a few attempts, the noise was back. At this point, we went home. The layout of the end table likely needs some attention to try and minimize our susceptibility to excess scatter effects. 

  9964   Fri May 16 11:22:23 2014 SteveUpdateLSCX Arm ALS Noise coming in and out

Quote:

Den and I spent some time with the interferometer last night with hopes of bringing in the AO path, but were stymied by the (re)occurrence of the anomalously high low frequency motion of the Xarm, as seen by fluctuations of TRX from .9 to .2 while "held" on resonance.

Jenne reported that they weren't seeing it earlier in the evening, and then it started again when I showed up. Holding the arms on IR, we could see a fair amount of excess low frequency noise in the BEATX_FINE_PHASE_OUT_HZ channel, as compared to BEATY, bringing its RMS to 5 times that of the Y arm. From the shape of the excess noise (broad slope from DC to tens of Hz), Rana suspected air currents and/or scattering effects being the culprit.

Den poked around a bit on the PSL table, which didn't really change much. He then went down to the X end table to inspect the table, and while he was there, I noticed the noise go down to being in line with the Yarm. I joined him at the end, and we found the beat phase noise in the frequency region of concern to be hugely sensitive to tapping on the enclosure, air current, etc. There is also a ton of green light everywhere, and multiple spots of green light around the green refl PD.

At that point however, the quiescent noise was acceptable (TRX fluctuations of <.2), so we went back to the control room to try to lock. Unfortunately, after a few attempts, the noise was back. At this point, we went home. The layout of the end table likely needs some attention to try and minimize our susceptibility to excess scatter effects. 

 Turn off the AC and flow bench please.

  13229   Fri Aug 18 23:59:53 2017 gautamUpdateALSX Arm ALS lock

[ericq, gautam]

  • I was just getting the IFO aligned, and single arm lock going, when EricQ came in and asked if we could get some ALS data.
  • ALS beats seemed fine, in particular the X-Arm. The broad hump around ~70Hz that was present in my previous ALS update was nowhere to be seen - reasons unknown.
  • Copied over /opt/rtcds/caltech/c1/scripts/YARM/Lock_ALS_YARM.py to /opt/rtcds/caltech/c1/scripts/XARM/Lock_ALS_XARM.py. Could be useful when we want to do arm cavity scans.
  • Made appropriate changes to allow ALS locking of Xarm - the testpoint inaccessibility makes things a little annoying but for tonight we just used DQ channels in place (or slow channels when DQ chans were not available)
  • Calibration of X arm error signal seemed off - so we fixed it by driving a line in ETMX and matching up the peaks in the ALS error signal and POX11. We then updated the gain of the filter in the CINV filter bank accordingly.
  • Got some decent data - X arm stayed locked on ALS for >60mins, during which time the Y arm stayed locked on POY11, and the Y green also reained locked yes. There was no evidence of the X arm 00 mode randomly dropping out of lock tonight.
  • EQ will update with a sick comparison plot - today we looked at the ALS noise from the perspective of the Green Locking Izumi et. al. paper.
  • Y arm ALS noise didn't look so hot tonight - to be investigated...

Leaving LSC mode OFF for now while CDS is still under investigation


Not really related to this work: We saw that the safe.snap file for c1oaf seems to have gotten overwritten at some point. I restored the EPICS values from a known good time, and over-wrote the safe.snap file.

  13230   Sat Aug 19 01:35:08 2017 ericqUpdateALSX Arm ALS lock

My motivation tonight was to get an up-to-date spectrum of a calibrated measurement of the out-of-loop displacement of an arm locked on ALS (using the PDH signal as the out-of-loop sensor) to compare the performance of ALS control noise with the Izumi et al green locking paper. 

I was able to fish out the PSD from the paper from the 40m svn, but the comparison as plotted looks kind of fishy. I don't see why the noise from 10-60Hz should be so different/worse. We updated the POX counts to meters conversion by looking at the Hz-calibrated ALSX signal and a ~800Hz line injected on ETMX.

Attachment 1: ALS_comparison.pdf
ALS_comparison.pdf
  1145   Tue Nov 18 19:44:53 2008 AlbertoUpdateGeneralX Arm Cavity "Negative" FSRs Measured
Previous measurements on the X arm cavity revealed a shift of the frequencies of the cavity resonances from where one would expect these to be by just looking at integer multiples of the cavity FSR. In particular, plotting the resonant frequencies versus the order of their occurrences while sweeping the laser frequency (in our case that of the beat between the two lasers), the linear fit of the data contained an unwanted offset:

resonant_frequency = n x FSR + offset

In part, we attributed this offset to the local oscillator of the PLL, the Marconi, which was not referred to an absolute frequency clock.
For that reason, I connected the Marconi to the RS FS275 which uses the 1PPS from the GPS to generate a 10 MHZ reference signal, and then scanned the cavity again. This time I started from negative beat frequencies, that happen when the frequency of the secondary laser is smaller than the main laser's, to positive frequencies. The way I made sure of the sign of the frequency was looking at the effect of changing the temperature of the NPRO. I decided that negative frequencies where those for which an increase in temperature lowered the beat frequency and positive frequencies those for which increasing the temperature made the beat frequency go up.
I then plotted the data and obtained the attached plot.

The offset was reduced to about 80 Hz (from more than 200 in the previous measurements). I think the residual offset has to do with something that happens in the cavity, something, as Koji found out, related to the alignment of the mirrors.

Thanks to the more data points, the measurement of the FSR improved to (3897627 +/- 5) Hz, which would let us know the measure of the cavity length with an error of 50um, if it weren't for the offset. I have to understand whether and how to take this into account to determine the precision in the cavity length. I guess it depends on whether it is real or it is still a systematic error due to the measurements.
Attachment 1: 2008-11-17_Linear_Fit.pdf
2008-11-17_Linear_Fit.pdf
  2185   Thu Nov 5 22:30:09 2009 AlbertoUpdateLSCX Arm Cavity Transfer Function

It seems that just repeating the measurement was enough to get a good transfer function of the x arm cavity. Here's what I got.

XarmTF01.png

I'm going to fit the data on matlab, but at first sight, the pole seems to be at about 1.7KHz (that is where the phase is 45deg): as expected.

Probably it was useful to realign the beam on the Transmission PD. (btw, I'm using the PDA255 that was still on the X end table since the AbsL experiemtn that measured the arm length)

  2177   Wed Nov 4 23:17:51 2009 AlbertoUpdateLSCX Arm Cavity transfer Function

I measured the transfer function between MC_TRANS and TRX and I'm attaching the result.

ArmCavityTF02.png

That looks quite strange. Something's wrong. I'll repeat it tomorrow.

for the night I'm putting everything back. I'm also reconnecting the OMC_ISS_EXC and opening again the test switch on the ISS screen.

The RFAM monitor remains disable

  2178   Thu Nov 5 05:07:22 2009 ranaUpdateLSCX Arm Cavity transfer Function

I would have guessed that you have to calibrate the detectors relative to each other before trying this. Its also going to be tricky if you use 2 different kinds of ADC for this (c.f. today's delay discussion in the group meeting).

I think Osamu used to look at fast transmission signals by making sure the PD at the end had a 50 Ohm output impedance and just drive the 40m long cable and terminate the receiving end with 50 Ohms. Then both PDs go into the SR785.

 

  2184   Thu Nov 5 19:25:11 2009 AlbertoUpdateLSCX Arm Cavity transfer Function

Quote:

I would have guessed that you have to calibrate the detectors relative to each other before trying this. Its also going to be tricky if you use 2 different kinds of ADC for this (c.f. today's delay discussion in the group meeting).

I think Osamu used to look at fast transmission signals by making sure the PD at the end had a 50 Ohm output impedance and just drive the 40m long cable and terminate the receiving end with 50 Ohms. Then both PDs go into the SR785.

 

On Rana's suggestion I measured the trasfer function between the two photodiodes PDA255 that I'm using.

I took the one that I had on the end table and put it on the PSL table. I split the MC transmitted beam with a 50% beam splitter and sent the beams on the two diodes. (Rana's idea of picking off the beam and interposing the PDs before the ISS PDs was not doable: ISS PDs would be too close and there would be no room to install the PDA255 before them). See picture with the final setup.

DSC_0958.JPG


The transfer function also includes the 40m long cable that I was using for the Arm Cavity measurement.

Here's what I got. It looks rather flat. Yesterday the calibration was probably not the problem in that measurement.

PDA255CalibrationTF03.png
 I'm now going to install the PD back on the end table and measure the TFs between the excitation and several points of the loop.

(Trivia. At first, the PDs were saturating so Koji attached attenuation filters on to them. Suddenly the measurement got much nicer)

  11328   Wed May 27 17:14:08 2015 ericqUpdateLSCX Aux Laser crystal temperature changed

Rana suspects that the lack of X beatnote is related to the PSL laser temperature change (ELOG 11294). 

I used the information on the wiki and old elogs (wiki-40mELOG 6732), to deduce that the new end laser temperatures should be:

  • X end-> 38.98 C
  • Y end-> 35.80 C

I went out to the X end and found the laser crystal temperature set to 40.87, which is not what the measurements I linked to suggest would be the ideal temperature for the previous NPRO laser temperature of 30.89, which would be 37.02. I could not find any elog describing the choice of this setpoint.  

I've changed the X end laser crystal temperature to the value above. I've hooked up the X IR and green beatnotes to go the control room analzyer, and have been looking for the beatnote as I adjust the digital temperature offset, but haven't found it yet...

If this proves totally fruitless, we can just put the lasers back to their original temperatures, since it's unclear if it helped the PC drive noise levels. 

  6326   Mon Feb 27 18:35:45 2012 JenneUpdateGreen LockingX Beat Search

Meh.  I've searched in steps of 20 counts in C1:GCX-SLOW_SERVO2_OFFSET units (16 bit +\- 10V DAC, and 1GHz/V coeffecient for the Xgreen aux laser means this is ~0.6MHz per 20 count step).  I went from -400cts to +800 cts and haven't found the beatnote yet.  Meh. 

Both PSL green and Xgreen beams are going to the Xgreen BBPD.  Both beams are easily visible, so while I didn't actually measure the power, it should be sufficient.  The arm is being re-locked in green for each step, but it's not locked in IR, but that doesn't matter for just finding the beatnote.

I've got the output of the BBPD directly connected to the 50 ohm input of the HP8591E spectrum analyzer, with the freq span from 10MHz to 120MHz.  The BBPD is supposed to be good up to ~100MHz, so I should catch any beatnote that's there.  I have to head out, so I guess I'll continue the search tomorrow. 

One of Kiwamu's suggestions was that, since no one is using the Ygreen concurrent with my fiddling, I rotate the waveplate after the PSL doubling oven so that max power goes to the Xgreen path, thus giving myself a bigger signal.  I'll try that tomorrow.  Today, I didn't ever touch the waveplate.

  13366   Fri Oct 6 17:08:09 2017 SteveUpdateALSX End table beam traps corrected

There are no more double sided tape on this table.

 

Attachment 1: c1.jpg
c1.jpg
Attachment 2: c2.jpg
c2.jpg
Attachment 3: c3.jpg
c3.jpg
Attachment 4: c4.jpg
c4.jpg
  13326   Thu Sep 21 01:55:16 2017 ranaUpdateALSX End table of Shame

Image #1: No - we do not use magnetic mounts for beam dumps. Use a real clamp. It has to be rigid. "its not going anywhere" is a nonsense statement; this is about vibration amplitude of nanometers.

Image #2: No - we do not use sticky tape to put black glass beam dumps in place ever, anywhere. Rigid dumps only.

Image #3: Please do not ruin our nice black glass with double sticky tape. We want to keep the surfaces clean. This one and a few of the other Mickey Mouse black glass dumps on this table were dirty with fingerprints and so very useless.

Image #4: This one was worst of all: a piece of black glass was sticky taped to the wall. Shameful.

Please do not do any work on this table without elogging. Please never again do any of these type of beam dumping - they are all illegal. Better to not dump beams than to do this kind of thing.

All dumps have to be rigidly mounted. There is no finger contacting black glass or razor dumps - if you do, you might as well throw it in the garbage.

Attachment 1: 20170921_003143.jpg
20170921_003143.jpg
Attachment 2: 20170921_002430.jpg
20170921_002430.jpg
Attachment 3: 20170921_002243.jpg
20170921_002243.jpg
Attachment 4: 20170921_001906.jpg
20170921_001906.jpg
  14125   Thu Aug 2 20:47:29 2018 gautamSummaryElectronicsX Green "Mystery" solved

I walked down to the X end and found that the entire AUX laser electronics rack isn't getting any power. There was no elog about this.

I couldn't find any free points in the power strip where I think all this stuff was plugged in so I'm going to hold off on resurrecting this until tomorrow when I'll work with Steve.

Quote:

The X arm green does not stay locked to the cavity - the alignment looks fine, and the green flashes are strong, but the lock does not hold. This shouldn't be directly connected to anything we did today since the Green PDH servo is entirely analog.

ELOG V3.1.3-