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ID Date Author Typeup Category Subject
  8400   Wed Apr 3 14:45:34 2013 JamieUpdateComputersupdated EPICS database (channels selected for saving)

Quote:

I modified /opt/rtcds/caltech/c1/chans/daq/C0EDCU.ini to include the C1:LSC-DegreeOfFreedom_TRIG_MON channels.  These are the same channel that cause the LSC screen trigger indicators to light up. 

I vaguely followed Koji's directions in elog 5991, although I didn't add new grecords, since these channels are already included in the .db file as a result of EpicsOut blocks in the simulink model.  So really, I only did Step 2.  I still need to restart the framebuilder, but locking (attempt at locking) is happening.

The idea here is that we should be able to search through this channel, and when we get a trigger, we can go back and plot useful signals (PDs, error signals, cotrol signals,....), and try to figure out why we're losing lock. 

Rana tells me that this is similar to an old LockAcq script that would run DTT and get data.

EDIT:  I restarted the daqd on the fb, and I now see the channel in dataviewer, but I can only get live data, no past data, even though it says that it is (16,float).  Here's what Dataviewer is telling me:

Connecting to NDS Server fb (TCP port 8088)
Connecting.... done
read(); errno=0
LONG: DataRead = -1
No data found

read(); errno=9
read(); errno=9
T0=13-03-29-08-59-43; Length=432010 (s)
No data output.
 

I seem to be able to retrieve these channels ok from the past:

controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ tconvert 1049050000
Apr 03 2013 18:46:24 UTC
controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ ./general/getdata -s 1049050000 -d 10 --noplot C1:LSC-PRCL_TRIG_MON
Connecting to server fb:8088 ...
nds_logging_init: Entrynds_logging_init: Exit
fetching... 1049050000.0
Hit any key to exit: 
controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ 

Maybe DTT just needed to be reloaded/restarted?

  8403   Wed Apr 3 16:03:59 2013 ChloeUpdate QPD Voltage Regulators

The voltage regulator on the QPD breadboard seems to be having problems... yesterday Eric helped me debug my circuit and discovered that the +12V regulator was overheating, so we replaced it. Today, I found that the -12V regulator was also doing the same thing, so I replaced it. However, it's still overheating. We checked all of the setup for the power regulators yesterday, so I'm not sure what's wrong.

I've also noticed that not all the connections on the breadboard that I've been using seem to work - I may search for a new breadboard in this case. Need to check I'm not doing something stupid with that.

  8405   Wed Apr 3 18:22:00 2013 JenneUpdateElectronicsPOP110 re-implemented

I have re-implemented POP110.  The cable coming from the AS110 diode is disconnected, labeled, and sitting in the cable tray next to the LSC rack. 

Now the POP diode path is:

 

Thorlabs 10CF ----many meters of heliax cable-----> Bias Tee ------> RF amplifier ------> Splitter ------> Bandpass 21.7MHz --------> POP22 demod board

                                                                                                                   |                                                                                    |

                                                                                                                   |                                                                                    |

                                                                                                                   V                                                                                  V

                                                                                                            POP DC                                                                        High pass 100MHz

                                                                                                                                                                                                        |

                                                                                                                                                                                                        |

                                                                                                                                                                                                       V

                                                                                                                                                                                              Lowpass 150MHz

                                                                                                                                                                                                       |

                                                                                                                                                                                                       |

                                                                                                                                                                                                      V

                                                                                                                                                                                        POP110 demod board

  8406   Wed Apr 3 18:27:03 2013 KojiUpdate QPD Voltage Regulators

Breadboards may not be suitable for a reliable work. Why don't you switch to any protoboard and real soldering?

  8408   Wed Apr 3 19:01:06 2013 AlbertUpdateoptical tablesOptical Table Toolboxes Update

Quote:

Quote:

A heavy duty plastic box is the likeliest candidate for the optical table toolbox. It measures 5 9/16 in. x 11 5/8 in. x 4 5/8 in. and fits all the tools comfortably. ( http://www.mcmaster.com/#plastic-bin-boxes/=m4yh4m  ,  under Heavy Duty Plastic Bin Boxes)

The list of tools has been updated to include a pen and a wire cutter as well as everything previously stated.

In addition, Steve has recommended that boxes should be secured to the walls or surfaces near the optical tables as opposed to the optical tables themselves, as to keep the tables from wobbling when tools are being exchanged.

A diagram of tentative box placements will go out soon.

 No, the small boxes must be attached to the optical tables. They won't be heavy enough to change the table tilt.

Also, all tools must be color coded according to the optical table using the 3M Vinyl table color code:

http://www.3m.com/product/images/Vinyl-Electrical-Color-Tape-300.jpg

 Ok.

So the new tentative plan on the boxes is to bolt them (magnetic strips were proposed but overruled on the grounds that they're not strong enough to withstand being knocked down by accidents).

The boxes are going to be a mix of the Thorlabs Benchtop Organizer (http://www.thorlabs.com/thorProduct.cfm?partNumber=BT17) and the original box. The box will have a region covered in mesh, so tools can be placed and held there. The box will also have a spacer at the bottom, with another mesh right above it, lined up. However, this double-mesh will only cover half of the box. The other half of the box will be compartmentalized to hold things such as screws, connectors, etc. I will talk to Steve about building the boxes.

Also, using nail-polish to coat the Allen wrenches is not going to work. Nail polish does not stick easily enough. The tentative new plan is oil paint, but this is to be reviewed.

Finally, the diagram with the placement of the boxes relative to the optical tables has been put on paper, but needs to be computerized so it's easier to read. This will be done as soon as possible.

  8410   Wed Apr 3 23:22:20 2013 ranaUpdateoptical tablesOptical Table Toolboxes Update

 There are some tips for how to appy nail polish on YouTube from MKNails and MissJenFABULOUS. Their tips on how to prepare the site for a strong bonding strength are probably helpful for our gold/nickel coated tools. For chrome tools we may need to abrade the surface with a stone or fine sandpaper for it to take the layer better. IF the YouTube videos don't do it for you, then I suggest contacting Tom Evans at LLO to find out what kind of nail polish he uses.

  8414   Thu Apr 4 13:39:12 2013 Max HortonUpdateSummary PagesGraph Limits

Graph Limits: The limits on graphs have been problematic.  They often reflect too large of a range of values, usually because of dropouts in data collection.  Thus, they do not provide useful information because the important information is washed out by the large limits on the graph.  For example, the graph below shows data over an unnecessarily large range, because of the dropout in the 300-1000Hz pressure values.

Time series data from frames

The limits on the graphs can be modified using the config file found in /40m-summary/share/c1_summary_page.ini.  At the entry for the appropriate graph, change the amplitude-lim=y1,y2 line by setting y1 to the desired lower limit and y2 to the desired upper limit.  For example, I changed the amplitude limits on the above graph to amplitude-lim=.001,1, and achieved the following graph.

Time series data from frames

The limits could be tightened further to improve clarity - this is easily done by modifying the config file.  I modified the config file for all the 2D plots to improve the bounds.  However, on some plots, I wasn't sure what bounds were appropriate or what range of values we were interested in, so I will have to ask someone to find out.

Next:  I now want to fix all the funny little problems with the site, such as scroll bars appearing where they should not appear, and graphs only plotting until 6PM.  In order to do this most effectively, I need to restructure the code and factor it into several files.  Otherwise, the code will not only be much harder to edit, but will become more and more confusing as I add on to it, compounding the problems that we currently have (i.e. that this code isn't very well documented and nobody knows how it works).  We need lots of specific documentation on what exactly is happening before too many changes are made.  Take the config files, for example.  Someone put a lot of work into them, but we need a README specifying which options are supported for which types of graphs, etc.  So we are slowed down because I have to figure out what is going on before I make small changes.

To fix this, I will divide the code into three main sectors.  The division of labor will be:
- Sector 1: Figure out what the user wants (i.e. read config files, create a ConfigParser, etc...)
- Sector 2: Process the data and generate the plots based on what the user wants
- Sector 3: Generate the HTML

  8416   Thu Apr 4 17:23:05 2013 SteveUpdate40m Upgrading ETMY optical table & enclosure is ready for optics

Quote:

 Enclosure is at the east end. It has it's bottom o-ring in place. It will be ready for optics tomorrow around 5pm

I have to shim out the enclosure, finish leveling the table and cut surgical tubing O-ring for the top.

 

 Glued surgical latex tubing with super glue into O-ring shape. The existing in place tubing K-100, OD 0.125" (actual size 0.140"), wall 0.031", ID 0.062".

I have just found out that tolerances on tubing OD are + - 0.026" by the manufacturer. I'm getting larger tubing for better fit.

The table is ready for optics.

Things left to do:

1, finalize o-ring size  2, finish cable feedthrough  3, finalize window connection 4, IR-Thermashield strips for bridge sides 5, replace bridge support post with solid one

 

  8417   Fri Apr 5 01:18:34 2013 ManasaUpdate40m UpgradingNot a fan of the new plastic box yet

Quote:

Quote:

 Enclosure is at the east end. It has it's bottom o-ring in place. It will be ready for optics tomorrow around 5pm

I have to shim out the enclosure, finish leveling the table and cut surgical tubing O-ring for the top.

 

 Glued surgical latex tubing with super glue into O-ring shape. The existing in place tubing K-100, OD 0.125" (actual size 0.140"), wall 0.031", ID 0.062".

I have just found out that tolerances on tubing OD are + - 0.026" by the manufacturer. I'm getting larger tubing for better fit.

The table is ready for optics.

Things left to do:

1, finalize o-ring size  2, finish cable feedthrough  3, finalize window connection 4, IR-Thermashield strips for bridge sides

 

While I did think that the plastic boxes were cool; I am not happy with the new enclosure on several aspects as I am setting up the TRY PDs/camera.

1. I strongly feel the o-rings should be glued/fixed to the plastic box atleast at some points. Even if we replace the current thin one with a thicker tubing, it takes forever to get the o-ring into the groove when it slips out. Also if it slips from the groove, it falls through the optical path and there are chances of burning the tubing when the NPRO is ON.

2. With the transparent tables, the cameras are sensitive to the room lights. I had to switch off the room lights/use ND filters to see a nice beam at the TRY camera.

3. The lids are heavy...might be a good way to train....but removing and putting them back will definitely increase the pain in getting the green aligned to the arms atleast until we have the PZTs set up.

  8418   Fri Apr 5 01:28:56 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : populating the table

I started populating the end table; the TRY path to start with. I found that I need to redo the cables/electronics layout around the table as we have only one cable feedthrough hole with the new box right now. I need another hand with this and will have Annalisa help me tomorrow.

P.S. I misaligned PRM and restored ETMY to get TRY flashes. I tweaked ETMY to see strong TEM00 flashes.

Old slider positions on medm screen in case we need to restore them:

        TT1    TT2     ITMY    ETMY

P   -1.3586  0.8443   0.9114   -3.7693

Y   0.3049   1.1507  -0.2823  -0.2761

 

  8419   Sat Apr 6 09:21:36 2013 ranaUpdate40m UpgradingNot a fan of the new plastic box yet

 

 1) We still need to drill and install the thumbscrew latches which secure the lids to the table. We cannot use the tables as an acoustic enclosure with loose lids.

2) For the camera issue, the idea is to put the longpass filters on the front of the cameras: then they are only sensitive to light with wavelength > 800 nm.

3) Whenever any interferometer work is happening the light switches must be in the positions which have been marked on them (and which most everyone ignores foolishly). We have never been insensitive to the room lights; the black table enclosures just give us a false sense of security. Room lights impact the interferometer noise.

  8420   Sun Apr 7 20:49:19 2013 ZachUpdateGeneralRestarted elog

with the script, as it was down.

  8421   Mon Apr 8 08:05:41 2013 SteveUpdatePSLPMC locked

The PMC locked manually. MC  grabbed lock instantaniously

  8422   Mon Apr 8 10:19:46 2013 JenneUpdatePSLLSC left enabled

 

 Note: The TRY PD isn't installed and normalized properly yet, so the IFO OVERVIEW screen indicates lock for the Yarm constantly, which is not true.  Hopefully in the next day or so the screen will be back to telling the truth.

Also, the LSC Locking was left ENABLED (presumably over the weekend).   This is not so good.  It can kick optics around, so we should all take a look when we walk through the control room, and if no one is locking, please disable the LSC master switch. 

  8423   Mon Apr 8 16:37:26 2013 SteveUpdate40m UpgradingETMY enclosure wall transmission

 

 Enclosure cover #1 transmission measured  in 1064 nm,  156 mW,  P polarization and beam size ~ 1 mm

As condition:  fully assembled, protective layer removed, tinted- adhesive activated on yellow acrylic on top of each other.

T = 1.2 % in 20 minutes exposure test. This agrees with the test measurement of 6-18-2012

There is a reflected  2-3 cm circular glare that is barely visible on sensor card. It is well below 1 mW level

As we are installing the NPRO with ~350 mW of power we have to address what additional shield should be installed.

The June 2012 test with 1W power burned through of the 3 layer  IR coated films in 3-4 hours.

We 'll use Aluminum shields in the high power path till we come up with better solution.

  8424   Mon Apr 8 22:43:44 2013 ranaUpdatePSLMC locking troubles: MC/FSS servo unstable

The MC seemed to be losing lock recently quite a bit. I noticed that the PC Drive RMS signal was red.

This means that the high frequency drive to the Pockels cell was too high by a factor of 2-3 and sometimes saturating and breaking the lock.

I fiddled with the gains on the FSS screen until this value went down. It looks like there is some kind of high Q oscillation; it takes a couple minutes for the PC Drive RMS to settle to its new position after changing the gains.

The attached trend plot show the last 2 hours. The mean is now back to ~1 V and seems OK. We should really examine the FSS or MC error point spectra with the RF analyzer while exploring this gain space.

Attachment 1: Untitled.png
Untitled.png
  8425   Tue Apr 9 00:15:18 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : populating the table

[Den, Annalisa, Manasa]

The Alberto laser was moved from the PSL table. The height of the heat sink rendered a beam height of only 3 inches. I did not want to deal with changing beam height at the table. So, we went ahead and used the old heat sink. I used the beam scan to make measurements of the beam width to match my mode-matching calculations and found some mismatch with the measurements done earlier. So I will measure the beam width again before alignment.

I will also have to change the layout because of the supporting posts that have come up with the new box. Annalisa is doing a COMSOL model to check what the thickness of these supporting posts should be so that the box stays stiff.

  8427   Tue Apr 9 00:32:57 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : TRY temporarily in place

The TRY path on the end table is temporarily in place to help IFO locking.
The Y arm transmission was steered to get TRY back on the PD and the camera. I found that TRY is a couple of inches off in yaw at the end table (comparing to the CAD layout and the earlier layout) and I believe it is because of the changes in input pointing.
I've used a Y1 mirror to steer the Y transmission to an R98% BS. The reflected beam falls on PDA520 and the transmitted beam is steered to the camera. The earlier normalization of TRY is no more valid as the power distribution at the PD has changed.

  8428   Tue Apr 9 01:46:40 2013 ZachUpdateGeneralRestarted elog

Again.

Quote:

with the script, as it was down.

 

  8429   Tue Apr 9 07:48:10 2013 SteveUpdatePSLPMC locked

Quote:

The PMC locked manually. MC  grabbed lock instantaniously

 PMC locked

Attachment 1: pmc10d.png
pmc10d.png
  8430   Tue Apr 9 08:37:54 2013 SteveUpdate40m UpgradingEndtable upgrade for auxiliary green laser : TRY temporarily in place

Quote:

The TRY path on the end table is temporarily in place to help IFO locking.
The Y arm transmission was steered to get TRY back on the PD and the camera. I found that TRY is a couple of inches off in yaw at the end table (comparing to the CAD layout and the earlier layout) and I believe it is because of the changes in input pointing.
I've used a Y1 mirror to steer the Y transmission to an R98% BS. The reflected beam falls on PDA520 and the transmitted beam is steered to the camera. The earlier normalization of TRY is no more valid as the power distribution at the PD has changed.

Temporary  acrylic wind guard added between enclosure and ETMY transmission window to help IFO locking

  8431   Tue Apr 9 14:55:13 2013 JamieUpdateCDSoverbooked test points cause of DAQ problems

Folks were complaining that they were getting zeros whenever they tried to open fast channels in DTT or Dataviewer.  It turned out that the problem was that all available test points were in use in the c1lsc model:

lsc-gds.png

There is a limit to how many test points can be open to a single model (in point of fact I think the limit is on the data rate from the model to the frame builder, not the actual number of open test points).  In any event, they was all used up.  The grid at the bottom right of the C1LSC GDS screen was all full of non-zeros, and the FE TRATE number was red, indicating that the data rate from this model had surpassed threshold.

The result of this overbooking is that any new test points just get zeros.  This is a pretty dumb failure mode (ideally one would not be able to request the TP at all with an appropriate error message), but it is what it is.  This usually means that there are too many dtt/dataviewers left with open connections.

We tried killing all the open processes that we could find that might be holding open test points, but that didn't seem to clear them up.  Stuck open test points is another known problem.  Referencing the solution in #6968 I opened the diag shell and killed all test points everywhere:

controls@pianosa:~ 0$ diag -l -z
Set new test FFT
NDS version = 12
supported capabilities: testing  testpoints  awg  
diag> tp clear * *
test point cleared
diag> quit
EXIT KERNEL
controls@pianosa:~ 0$
  8432   Tue Apr 9 21:27:48 2013 JenneUpdate40m Upgrading TRY temporarily in place

Quote:

I've used a Y1 mirror to steer the Y transmission to an R98% BS. The reflected beam falls on PDA520 and the transmitted beam is steered to the camera. The earlier normalization of TRY is no more valid as the power distribution at the PD has changed.

 To take this into account, last night, I reduced the TRY gain by a factor of 2.  This is not exactly correct - when the layout is finalized we need to figure out what the pickoff situation used to be (we think, based on the Xend, that it could have been 0.5*0.9), and do the correct normalization.

  8433   Wed Apr 10 01:10:22 2013 JenneUpdateLockingConfigure screen and scripts updated

I have gone through the different individual degrees of freedom on the IFO_CONFIGURE screen (I haven't done anything to the full IFO yet), and updated the burt snapshot request files to include all of the trigger thresholds (the DoF triggers were there, but the FM triggers and the FM mask - which filter modules to trigger - were not).  I also made all of the restore scripts (which does the burt restore for all those settings) the same.  They were widely different, rather than just different optics chosen for misaligning and restoring.

Before doing any of this work, I moved the whole folder ..../caltech/c1/burt/c1ifoconfigure to ..../caltech/c1/burt/c1ifoconfigure_OLD_but_SAVE , so we can go back and look at the past settings, if we need to.

I also changed the "C1save{DoF}" scripts to ask for keyboard input, and then added them as options to the CONFIGURE screen.  The keyboard input is so that people randomly pushing the buttons don't overwrite our saved burt files.  Here's the secret:  It asks if you are REALLY sure you want to save the configuration.  If you are, type the word "really", then hit enter (as in yes, I am really sure).  Any other answer, and the script will tell you that it is quitting without saving.

I have also removed the "PRM" option, since we really only want the "PRMsb" for almost all purposes.

Also, I removed access to the very, very old text file about how to lock from the screen.  That information is now on the wiki:  https://wiki-40m.ligo.caltech.edu/How_To/Lock_the_Interferometer

I have noted in the drop-down menus that the "align" functions are not yet working.  I know that Den has gotten at least one of the arms' ASSes working today, so once those scripts are ready, we can call them from the configure screen.

Anyhow, the IFO_CONFIGURE screen should be back to being useful!

  8435   Wed Apr 10 07:37:33 2013 SteveUpdatePSLPMC locked

Quote:

Quote:

The PMC locked manually. MC  grabbed lock instantaniously

 PMC locked

 PMC locked.

Attachment 1: pmc4d.png
pmc4d.png
  8436   Wed Apr 10 14:25:04 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : LWE Alberto laser beam profile

I measured the beam profile of the Alberto laser (that will be the ETMY end laser) as I found the data inconsistent with the measurements done earlier.

Method

The laser was set to nominal current (ADJ =0) and the output measured 330mW. I used a 99% BS and measured the beam profile of the transmitted light at several points along propagation using Beamscan. I am attaching the data and matlab script for the fit for future reference.

LWE_Alberto_BP.png

Attachment 2: beam_waist.zip
  8438   Thu Apr 11 02:00:21 2013 JenneUpdateLockingTRY gone???

TRY signals are all gone!  Both the PD and the camera show no signal.  I went down there to turn off the lights, and look to see what was up, and I don't see any obvious things blocking the beam path on the table.  However, Steve has experimentally bungeed the lids down, so I didn't open the box to really look to see what the story is.

Absent TRY, I redid the IFO alignment.  Yarm locked, so I assumed it was close enough.  I redid Xarm alignment pretty significantly.  Transmission was ~0.5, which I got up to ~0.85 (which isn't too bad, since the PMC transmission is 0.74 instead of the usual 0.83).  I then aligned MICH, and PRM.  After fixing up the BS alignment, the POP beam wasn't hitting the POP PD in the center any more.  I centered the beam on the PD, although as Gabriele pointed out to me a week or two ago, we really need to put a lens in front of POP, since the beam is so big.  We're never getting the full beam when the cavity flashes, which is not so good.

Den is still working on locking, so I'll let him write the main locking report for the night.

We see that the PRC carrier lock seems to be more stable when we lock MICH with +1 for ITMY and -1 for ITMX, and PRCL with -1 for both ITMs.  This indicates that we need to revisit the systematic problem with using the PRM oplev to balance the coils, since that oplev has a relatively wide opening angle.  I am working on how to do this.

  8439   Thu Apr 11 02:49:18 2013 DenUpdateLockingPRCL on carrier

Jenne, Den

We suspect PRM shows significant length to angle coupling due to large oplev beam angle in yaw.  Tonight we locked PRCL with ITMs.

We could lock PRCL on carrier to power recycling gain of 15. Lock continued for a few hours but power rin RMS was 0.15.

We triggered and normalized on POP_DC. MICH gain was -1 (filters FM3-5), PRCL gain was -8 (filters FM2,4,5,6,9).

MC_L was OFF during locking.

 

Attachment 1: pop_rin.pdf
pop_rin.pdf
Attachment 2: power.png
power.png
  8440   Thu Apr 11 03:23:12 2013 DenUpdateGeneralMCL threshold

MC down script is too slow to block MC_L when the cavity goes out of lock. As a result the loop strongly kicks MC2. We decided to make a threshold inside MCS model on MC TRANS that will block MC_L during lock loss. This is a lower threshold. Upper threshold can be slow and is implemented inside MC up script.

Fast threshold can be set inside MC2 POS. I did not correct MC2 top level medm screen as it is the same for all core optics.

Note: Fast trigger will also block ALS signal if MC loose lock.

  8442   Thu Apr 11 03:38:40 2013 DenUpdateLockingangular motion

Spectra of BS, PRM, ITMX, ITMY are attached with oplevs ON and OFF (in units of urad). Loops reduce RMS from ~2urad to ~0.3urad but phase margin should be increased. REF traces show loop OFF. <-- really?

Note how PRM pitch and yaw spectra are different in the frequency range 0.5 - 7 Hz; yaw is factor of 50 larger then pitch at 2 Hz.

Attachment 1: oplevs.pdf
oplevs.pdf oplevs.pdf oplevs.pdf oplevs.pdf
  8443   Thu Apr 11 10:15:55 2013 SteveUpdateLockingPRM yaw oplev transferfunction

See   Feb 2012 PRM yaw transferfunctions, also check Valera's modified  side sensor may effect yaw motion

 

  8444   Thu Apr 11 11:58:21 2013 JenneUpdateComputersLSC whitening c-code ready

The big hold-up with getting the LSC whitening triggering ready has been a problem with running the c-code on the front end models.  That problem has now been solved (Thanks Alex!), so I can move forward.

The background:

We want the RFPD whitening filters to be OFF while in acquisition mode, but after we lock, we want to turn the analog whitening (and the digital compensation) ON.  The difference between this and the other DoF and filter module triggers is that we must parse the input matrix to see which PD is being used for locking at that time.  It is the c-code that parses this matrix that has been causing trouble.  I have been testing this code on the c1tst.mdl, which runs on the Y-end computer.  Every time I tried to compile and run the c1tst model, the entire Y-end computer would crash.

The solution:

Alex came over to look at things with Jamie and me.  In the 2.5 version of the RCG (which we are still using), there is an optimization flag "-O3" in the make file.  This optimization, while it can make models run a little faster, has been known in the past to cause problems.  Here at the 40m, our make files had an if-statement, so that the c1pem model would compile using the "-O" optimization flag instead, so clearly we had seen the problem here before, probably when Masha was here and running the neural network code on the pem model.  In the RCG 2.6 release, all models are compiled using the "-O" flag.  We tried compiling the c1tst model with this "-O" optimization, and the model started and the computer is just fine.  This solved the problem.

Since we are going to upgrade to RCG 2.6 in the near-ish future anyway, Alex changed our make files so that all models will now compile with the "-O" flagWe should monitor other models when we recompile them, to make sure none of them start running long with the different optimization. 

The future:

Implement LSC whitening triggering!

  8445   Thu Apr 11 16:29:23 2013 AlbertUpdateoptical tablesOptical Table Toolboxes Update

Quote:

 There are some tips for how to appy nail polish on YouTube from MKNails and MissJenFABULOUS. Their tips on how to prepare the site for a strong bonding strength are probably helpful for our gold/nickel coated tools. For chrome tools we may need to abrade the surface with a stone or fine sandpaper for it to take the layer better. IF the YouTube videos don't do it for you, then I suggest contacting Tom Evans at LLO to find out what kind of nail polish he uses.

 This is the tentative box placement per optical table. The toolboxes are going to be color-coded by a combination of two colors (the order won't matter). The side of each toolbox will have a little panel to let you know which box corresponds to which set of colors.

On the diagram, the set of colors is simply the color of the box border and the color of the text.

If anyone has a problem with any of the colors or the box placement let me know before they are installed and become an annoyance:

Diagram.png

Box Placements:

ETMY: Box will be attached to the underside of the table by magnets. The box will be on the north side of the optical table.

POY: Box will be attached to the side of the optical table by magnets. The box will be on the west side of the optical table.

BSPRM: Box will be attached to the side of the optical table by magnets. The box will be on the west side of the optical table.

AS: Box will be attached to the side of the optical table by magnets. The box will be on the north side of the optical table.

PSL1: Box will be inside the optical table, in the northeast corner.

PSL2: Box will be inside the optical table, in the southwest corner.

POX: Box will be attached to the side of the optical table by magnets. The box will be on the south side of the optical table.

MC2: Box will be attached to the side of the optical table by magnets. The box will be on the south side of the optical table.

ETMX: Box will be attached to the side of the optical table by magnets. The box will be on the east side of the optical table.

  8446   Fri Apr 12 02:56:34 2013 DenUpdateLockingprcl angular motion

I compared PCRL and XARM angular motions by misaligning the cavities and measuring power RIN. Divergence angles for both cavities I calculated to be 100 urad.

XARM pointing noise sums from input steering TTs, PR2 and PR3 TTs, BS, ITMX, ETMY.

PRCL noise - from input TT, PRM, PR2 and PR3 TT, BS, ITMX, ITMY.

I would expect these noises to be the same as angular motion of different optics measured by oplves is simular. We do not have oplves on TT but they are present in both passes.

I measured RIN and converted to angle. Sharp 1 Hz resonance at XARM pointing spectrum is due to EMTX, it is not seen by PRCL. Other then that XARM is much quiter, especially at 3 - 30 Hz.

As PRM  is the main difference in two passes, I checked its spectrum. When PRCL was locked I excited PRM in pitch and yaw. I could see this excitation at RIN only when the peak was 100 times higher then background seismic noise measured by oplev.

pointing.png

Attachment 2: oplev_exc.pdf
oplev_exc.pdf
  8447   Fri Apr 12 09:20:32 2013 ranaUpdateLockingprcl angular motion

 How is the cavity g-factor accounted for in this calculation?

  8449   Fri Apr 12 13:21:34 2013 DenUpdateLockingprcl angular motion

Quote:

 How is the cavity g-factor accounted for in this calculation?

 I assume that pointing noise and dc misalignment couples 00 to 01 by a factor theta / theta_cavity

Inside the cavity 01 is suppressed by 2/pi*F*sin(arccos(sqrt(g_cav))).

For the XARM this number is 116 taking g-factor to be 0.32. So all pointing noise couples to power RIN.

Suppression factor inside PRC is 6.5 for g-factor 0.97. This means that 85% of jitter couples to RIN, I accounted for this factor while converting RIN to angle.

I did not consider translational motion of the beam. But still PRC RIN can not be explained by oples readings as we can see exciting optics in pitch and yaw. I suspect this RIN is due to PR3, as it can create stronger motion in yaw than in pitch due to incident angle and translational motion of the mirror. I do not have a number yet.

  8450   Sat Apr 13 03:45:51 2013 ranaUpdateLockingprcl angular motion

 

 Maybe its equivalent, but I would have assumed that the input beam is fixed and then calculate the cavity axis rotation and translation. If its small, then the modal expansion is OK. Otherwise, the overlap integral can be used.

For the ETM motion, its a purely translation effect, whereas its tilt for the ITM. For the PRM, it is also a mostly translation effect as calculated at the PRC waist position (ITM face).

  8451   Sat Apr 13 23:11:04 2013 DenUpdateLockingprcl angular motion

Quote:

For the PRM, it is also a mostly translation effect as calculated at the PRC waist position (ITM face).

I made another estimation assuming that PRCL RIN is caused by translation of the cavity axis:

  • calibrated RIN to translation, beam waist = 4mm
  • measured PRM yaw motion using oplev
  • estimated PR3 TT yaw motion: measured BS yaw spectrum with oplev OFF, divided it by pendulum TF with f0=0.9 Hz, Q=100 (BS TF), multiplied it by pendulum TF with f0 = 1.5 Hz, Q = 2 (TT TF with eddy current damping), accounted for BS local damping that reduces Q down to 10.

PRM and TT angular motion to cavity axis translation I estimated as 0.11 mm/urad and 0.22 mm/urad assuming that TTs are flat. We can make a more detailed analysis to account for curvature.

I think beam motion is caused by PR3 and PR2 TT angular motion. I guess yaw motion is larger because horizontal g-factor is closer to unity then vertical.

Attachment 1: pointing.pdf
pointing.pdf
  8452   Sun Apr 14 15:03:17 2013 ManasaUpdateLockingFixing - progress

Quote:

TRY signals are all gone!  Both the PD and the camera show no signal.  I went down there to turn off the lights, and look to see what was up, and I don't see any obvious things blocking the beam path on the table.  However, Steve has experimentally bungeed the lids down, so I didn't open the box to really look to see what the story is.

Absent TRY, I redid the IFO alignment.  Yarm locked, so I assumed it was close enough.  I redid Xarm alignment pretty significantly.  Transmission was ~0.5, which I got up to ~0.85 (which isn't too bad, since the PMC transmission is 0.74 instead of the usual 0.83).  I then aligned MICH, and PRM.  After fixing up the BS alignment, the POP beam wasn't hitting the POP PD in the center any more.  I centered the beam on the PD, although as Gabriele pointed out to me a week or two ago, we really need to put a lens in front of POP, since the beam is so big.  We're never getting the full beam when the cavity flashes, which is not so good.

Den is still working on locking, so I'll let him write the main locking report for the night.

We see that the PRC carrier lock seems to be more stable when we lock MICH with +1 for ITMY and -1 for ITMX, and PRCL with -1 for both ITMs.  This indicates that we need to revisit the systematic problem with using the PRM oplev to balance the coils, since that oplev has a relatively wide opening angle.  I am working on how to do this.

I'm fixing the TRY path.

I misaligned PRM and restored ETMY; but did not see the Y arm flashing. I am going ahead and moving the optics to get Y arm flashing again.

The slider values on the medm screen before touching any of them (for the record):

       tt1        tt2      itmy        etmy
p    -1.3886    0.8443     0.9320    -3.2583
y     0.3249    1.1407    -0.2849    -0.2751
  8453   Sun Apr 14 17:30:14 2013 ManasaUpdateLockingFixed

TRY path fixed and ready for normalization.

I used 2" BS at R=50 and R=98 to reflect the Y arm transmission at QPD-Y and TRY PD respectively. The residual beam transmitted by the BS is now steered by a Y1mirror to the camera. With Y arm locked, transmission currently measures 40mW against the expected 70mW. TRY shows 0.45 counts in dataviewer.

  8454   Sun Apr 14 17:56:03 2013 ranaUpdateLockingprcl angular motion

Quote:

Quote:

For the PRM, it is also a mostly translation effect as calculated at the PRC waist position (ITM face).

I made another estimation assuming that PRCL RIN is caused by translation of the cavity axis:

  • calibrated RIN to translation, beam waist = 4mm

 In order to get translation to RIN, we need to know the offset of the input beam from the cavity axis...

This should be possible to calibrate by putting a pitch and yaw excitation lines into the PRM and measuring the RIN.

See secret document from Koji.

  8455   Sun Apr 14 23:20:42 2013 DenUpdateLockingFixed

Quote:

TRY path fixed and ready for normalization.

I used 2" BS at R=50 and R=98 to reflect the Y arm transmission at QPD-Y and TRY PD respectively. The residual beam transmitted by the BS is now steered by a Y1mirror to the camera. With Y arm locked, transmission currently measures 40mW against the expected 70mW. TRY shows 0.45 counts in dataviewer.

 I think it is too much. Incident power to IFO is 1.3 W. Even if we assume no losses and pick-offs on the path to the arms, we should get ~100 uW out of the cavity. I measured X and Y arms transmission to be 60 uW. Did you disable triggering during your measurement?

  8456   Mon Apr 15 16:10:52 2013 DenUpdatePEMseismometer isolation kit

 We got granite bases today from the manufacturer. We plan to set them up on Wednesday, 8 am. Please note, there will be an installation mess at Xend, Yend and corner during ~4 hours. Let us know if you have any objections to do this at this particular time.

Installation locations are specified in elog 8270, scheme attached is valid except for Xend. Instrument will be installed on the place of nitrogen containers.

(  next to the wall at corner sout-east of the south end )

  8457   Mon Apr 15 17:44:28 2013 AlbertUpdateoptical tablesOptical Table Toolboxes Update

I decided to go see what the electrical tape looks like on the other tools.

These are the tools I felt were necessary to label with tape: (the others don't seem to be terribly important in terms of not interchanging between boxes)

photo.JPG

On another note I'm not sure why electrical tape can't be used on the Allen Wrenches too.

I also plan on ordering smaller flash lights for each table (this one is bulky and unwieldy), and filling in the gaps of the Allen Wrench sets as soon as I get the go-ahead.

  8458   Wed Apr 17 02:20:13 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : progress

 

Assembly progress:

1. ETMY oplev setup has been put together. Because of the shift in the TRY path, I had to modify the oplev path on the table as well.

TRY_OPL.jpg

2. Green laser setup coming together:
    (i) Used a HWP after the NPRO to convert s-polarization to p-polarization. (Verified by introducing a PBS after the HWP and then removed later).
    (ii) Lens focuses the beam into the Faraday.
    (iii) Used steering mirrors to align the beam to the faraday. With 320mW before the Faraday, I was able to get 240mW after the output aperture. The spec sheet for the faraday specifies a 93% transmission; but what I measure is only 75%.

GRY.jpg

 

  8459   Thu Apr 18 02:24:58 2013 DenUpdateASCdither alignment of yarm

I modified our existing c1ass model to include alignment of input steering TT1 and TT2 for YARM and BS for XARM. Corresponding medm screens are also created.

Dithering:

ETM_PIT: frequency = 6 Hz, amplitude = 100 cnts
ETM_YAW: 8 Hz, 400 cnts
ITM_PIT: 11 Hz, 800 cnts
ITM_YAW: 14 Hz, 1200 cnts

These values were chosen by looking at cavity transmission and length signals - excitation peaks should be high enough but do not shake the optics too much.

Demodulation:

LO for each degree of freedom is mixed with cavity length and transmission signals that are first bandpassed at LO frequency. After mixing low-pass filter is applied. Phase rotation is chosen to minimize Q component

ETM_PIT_LENGTH 0
ETM_YAW_LENGTH 20
ITM_PIT_LENGTH 0
ITM_YAW_LENGTH -25
ETM_PIT_TRANS -5
ETM_YAW_TRANS 10
ITM_PIT_TRANS 10
ITM_YAW_TRANS -30

Sensing matrix:

8 * 8 matrix was measured by providing excitation at 0.03 Hz to optics and measuring the response in the demodulated signals. Excitation amplitude was different for each optics to create cavity transmission fluctuations of 25%

-0.0373333 -0.010202 -0.018368 0.0042552 0 0 0 0
0.0432509 -0.209207 0.0139471 0.0780632 0 0 0 0
0.0483903 -0.0077304 0.00917147 0.000860323 0 0 0 0
-0.0751211 0.699778 -0.0115889 -0.09944 0 0 0 0
0.356164 0.121226 0.0690162 -0.0183074 -59.52 -21.9863 -30.9437 13.5582
-0.141744 1.15369 -0.0100607 -0.12914 -18.8434 -105.828 -48.213 14.8612
-0.0446516 0.00682156 -0.0204571 -0.00207764 21.3057 -1.66971 22.1538 3.93419
0.0278091 -0.205367 0.0114271 0.0648548 -4.66919 97.9043 -6.26847 -95.9963

Though coherence was > 0.95 during the measurement for each element (except for TT -> Length signals), after inverting and putting it to control servo, loops started to fight each other. So I decided to try a simple diagonal matrix:

TT1_PIT -> ETM_PIT_TRANS, TT1_YAW -> ETM_YAW_TRANS, TT2_PIT -> ITM_PIT_TRANS, TT2_YAW -> ITM_YAW_TRANS,

ITM_PIT -> ETM_PIT_LENGTH, ITM_YAW -> ETM_YAW_LENGTH, ETM_PIT -> ITM_PIT_LENGTH, ETM_YAW -> ITM_YAW_LENGTH

And this matrix worked much better.

Control loops:

8 loops are running at the same time. UGF for input steering loops is 20 mHz, for cavity axis loops - 80 mHz. Slower loop is stronger at low frequencies so that cavity axis servo follows input steering alignment.

OL.png

Results:

When I started experiment the cavity was misaligned, transmission was ~0.4. Servo was able to align the cavity in ~30 seconds. This time depends on mirrors misalignment as well as input optics and cavity axis misalignment relative to each other.

When servo converged I disturbed ETMY, ITMY, TT1 and TT2. Servo was able to compensate for this.

dither_yarm.png

Excitation lines seen by transmission and length of the cavity are suppressed as shown on the attached as pdf figures.

Note:

Though the servo is able to align the cavity during my tests, this does not mean it will work perfectly any time. So please, if you lock, try to use the servo for alignment. If something goes wrong we'll fix it. This is better then to align IFO by hands every time.

Attachment 3: YARM_CTRL_DITHER.pdf
YARM_CTRL_DITHER.pdf
Attachment 4: TRY_DITHER.pdf
TRY_DITHER.pdf
  8460   Thu Apr 18 02:51:52 2013 DenUpdatePSLFSS slow servo

Today Rana pointed out that our FSS slow servo is malfunctioning. It has been for a while that our laser temperature control voltage drifted from 0 to 10.

I looked at FSSSlowServo script that runs at op340m and controls the servo. Script disables the servo when MC transmission is less then FSS_LOCKEDLEVEL. But his value was set to 0.2 probably till reference cavity time.

This means that slow servo was not disabled when MC was unlocked. I changed this value to 7000.

Also I increased integral gain from 0.0350 to 0.215 such that fast control is always in the range 4.5 - 5.5

  8461   Thu Apr 18 15:08:14 2013 SteveUpdatePEMseismometer isolation kit in place

Quote:

 We got granite bases today from the manufacturer. We plan to set them up on Wednesday, 8 am. Please note, there will be an installation mess at Xend, Yend and corner during ~4 hours. Let us know if you have any objections to do this at this particular time.

Installation locations are specified in elog 8270, scheme attached is valid except for Xend. Instrument will be installed on the place of nitrogen containers.

(  next to the wall at corner sout-east of the south end )

 The carpenter shop finished the installation of the 3 granite bases.Rapid Set Cement All high strength non-shrink grout was used.

 Compressive strength  3000 PSI at 1 hour and 9000 PSI at day 28 The janitor is still cleaning up after them at the south end.

The  soft silicon gas kits are working well with the SS can.  Den is making  the adaptor plate drawing for the feedthrough.

Attachment 1: grouting1.jpg
grouting1.jpg
Attachment 2: grouting2.jpg
grouting2.jpg
Attachment 3: grouting3.jpg
grouting3.jpg
Attachment 4: grouting4.png
grouting4.png
  8462   Thu Apr 18 19:54:11 2013 JenneUpdateLSCLSC whitening triggering working

I have implemented automatic triggered switching of the analog whitening (and digital dewhitening). 

The trigger is the same as the degree of freedom trigger.  On the LSC RFPD screen there is a space to enter the amount of time (in seconds) you would like to wait between receiving a trigger and actually having the whitening filter switch. 

The trigger logic is as follows: 

* For each column of the LSC input matrix (e.g. AS11 I), check if there is a non-zero element.  If there is a non-zero element (indicating that we are using that PD as the error signal for a degree of freedom), check if the corresponding DoF has been triggered.  Repeat for all columns of the matrix. 

* If either the I or the Q signal from a single PD is being used, send a trigger in the direction of the PD signal conditioning / phase rotation blocks.  (Since the whitening happens before the phase rotation, we want to have the whitening state be the same for both the I and Q signals coming from the demod boards.

* Before actually changing the whitening state, wait for the amount of time indicated on the RFPD overview screen.

* Switch the digital dewhitening.  If the digital dewhitening is on, send a bit over to the binary I/O to switch the analog whitening on.

LSC_triggers.png

LSC_SigCond.png

 

This required changing the LSC RF_PD library part so that you can send the trigger to the filter bank from outside that part..  This part is in use by all LSC models, so I'll make sure the LLO people are aware of this change before I commit it to the svn.

RF_PD_block.png

 

While I was working on the LSC model, I also put in a wait between the time that the filter module trigger is received, and when it actually switches the filter modules.  So far, this time is defined for a whole filter bank (so all filters for a given DoF still switch at the same time).  If I need to go back and make the timing individual for each filter module, I can do that.  This new EPICS variable (the WAIT) defaults to zero seconds, so the functionality will not change for anyone who uses this part.

LSC_FM_Trig.png

These changes also require 2 pieces of c-code:  {userapps}/cds/common/src/wait.c and {userapps}/isc/c1/src/inmtrxparse.c

  8463   Thu Apr 18 21:12:56 2013 ManasaUpdateLockingFixed

[Den, Manasa]

TRY & TRX power measurement was redone.

TRY measures 66uW and 0.8counts on dataviewer.
TRX measures 70.4uW and 0.84counts on dataviewer.

___________________________
Detector       Power
-------------------------------------------------
QPD-Y          33uW (50%)
TRY-PD         29.8uW (49%)
Y-Camera         1%
QPD-X         35.2uW (50%)
TRX-PD        25.1uW (90%)
X-Camera    10%
____________________________

ELOG V3.1.3-