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ID Date Authordown Type Category Subject
  2349   Mon Nov 30 19:23:50 2009 JenneUpdateMZMZ down

Came back from dinner to find the Mach Zehnder unlocked.  The poor IFO is kind of having a crappy day (computers, MZ, and I think the Mode Cleaner alignment might be bad too).

  2351   Fri Dec 4 18:54:03 2009 JenneUpdatePEMRanger moved

The Ranger was left in a place where it could be bumped during next week's activities (near the crawl-space to access the inside of the "L" of the IFO on the Yarm).  It has been moved a meter or so to a safer place.

Also, so that Steve can replace the battery in the SR560 that is used for the Ranger, I swapped it out with one of the ones which already has a new, charged battery.  All of the settings are identical.  For posterity, I took a pic of the front panel before unplugging the old SR560.

Attachment 1: RangerSeismometer_SR560settings_4Dec2009.JPG
RangerSeismometer_SR560settings_4Dec2009.JPG
  2352   Fri Dec 4 21:48:01 2009 JenneUpdateoplevsOplevs centered, IP_POS and IP_ANG centered

[Jenne Koji]

 We aligned the full IFO, and centered all of the oplevs and the IP_POS and IP_ANG QPDs.  During alignment of the oplevs, the oplev servos were disabled.

Koji updated all of the screenshots of 10 suspension screens.  I took a screenshot (attached) of the oplev screen and the QPD screen, since they don't have snapshot buttons.

We ran into some trouble while aligning the IFO.  We tried running the regular alignment scripts from the IFO_CONFIGURE screen, but the scripts kept failing, and reporting "Data Receiving Error".  We ended up aligning everything by hand, and then did some investigating of the c1lsc problem.  With our hand alignment we got TRX to a little above 1, and TRY to almost .9 . SPOB got to ~1200 in PRM mode, and REFL166Q got high while in DRM (I don't remember the number). We also saw a momentary lock of the full initerferometer:   On the camera view we saw that Yarm locked by itself momentarily, and at that same time TRX was above 0.5 - so both arms were locked simultaneously.   We accepted this alignment as "good", and aligned all of the oplevs and  QPDs.

It seems that C1LSC's front end code runs fine, and that it sees the RFM network, and the RFM sees it, but when we start running the front end code, the ethernet connection goes away.  That is, we can ping or ssh c1lsc, but once the front end code starts, those functions no longer work.  During these investigations, We once pushed the physical reset button on c1lsc, and once keyed the whole crate.  We also did a couple rounds of hitting the reset button on the DAQ_RFMnetwork screen.

Attachment 1: Oplev_IPang_screenshot_4Dec2009.png
Oplev_IPang_screenshot_4Dec2009.png
  2356   Sat Dec 5 15:20:10 2009 JenneAoGall down cond.sea of red, again

Quote:

Taking  a cue from entry 2346, I immediately went for the nuclear option and powered off fb40m.  Someone will probably need to restart the backup script.

 Backup script restarted.

  2361   Mon Dec 7 18:18:55 2009 JenneUpdateCOCETMX drag wiped

[Koji, Jenne, Alberto, Steve, Bob]

ETMX has been drag wiped. 

Around 2:45pm, after the main IFO volume had come up to atmospheric pressure, we removed both doors to the ETMX chamber.  Regular procedures (wiping of O-rings with a dry, lint-free cloth, covering them with the light O-ring covers, etc.) were followed.  Koji took several photos of the optic, and the rest of the ETMX chamber before anything was touched. These will be posted to the 40m Picasa page.  Steve and Koji then deionized the optic.

Koji removed the bottom front earthquake stop, and clamped the optic with the remaining earthquake stops.

The clean syringes were prepared: These are all glass and metal (nothing else) medical syringes.  The size used was 100microliters.  Earlier today, we had prepared our solvents in small little beakers which had been baked over the weekend.  Brand new glass bottles of Acetone and Isopropyl Alcohol were opened, and poured into the small beakers.  To make sure we have enough, we have 3 ~10ml beakers of each Acetone and Isopropyl.

We started with Acetone.  The syringe was filled completely with acetone, then squirted onto a kimwipe.  This was repeated ~twice, to ensure the syringe was well rinsed.  Then the syringe was filled a little past the 100 microliter mark.  Koji held a piece of lens cleaning paper to ETMX and used an allen wrench underneath the optic to help guide the paper, and keep it near the optic (of course, the only thing in actual contact with the optic was the lens paper).  In one smooth shot, the plunger of the syringe was pressed all the way down.   (This is a bit tricky, especially when the syringe is totally full.  You have to squeeze it so the plunger moves fairly quickly down the barrel of the syringe to get a good arc of liquid.  The goal is to shoot all of the solvent to the same place on the lens paper, so that it makes a little circle of wetness on the paper which covers the coated part of the optic.  The amount of solvent used should be balanced between having too little, so that the paper is dry by the time it has been wiped all the way down, and too much such that there is still a residue of liquid on the optic after the paper has been removed.)  The target was to hit the optic just above the center mark (the oplev was on, so I went for just above the red oplev dot).  Immediately after applying the liquid onto the paper, Koji slowly and smoothly pulled down on the lens paper until it came off of the bottom of the optic.  The acetone was repeated, for a total of 2 acetone wipes.  Because acetone evaporates very quickly, more acetone is used than isopropyl.  The optimal amount turned out to be ~115 microliters of acetone.  It is hard to say exactly how much I had on the second wipe, because the syringe is not marked past 100 microliters.  On the first wipe, with about 105 microliters, the lens paper was too dry at the bottom of the optic.

We then switched to Isopropyl.  A new syringe was used, and again we rinsed it by filling it completely with isopropyl, and emptying it onto a kimwipe.  This was repeated at least twice.  We followed the same procedure for applying liquid to the optic and wiping the optic with the lens paper.  On the first try with isopropyl, we used 100 microliters, since that was the preferred amount for acetone.  Since isopropyl evaporates much slower than acetone, this was determined to be too much liquid.  On the second isopropyl wipe, I filled the syringe to 50 microliters, which was just about perfect.  The isopropyl wiping was done a total of 2 times.

After wiping, we replaced the front bottom earthquake stop, and released the optic from the other earthquake stops' clamping.  The OSEM values were checked against the values from the screenshots taken yesterday afternoon, and were found to be consistent.  Koji took more photos, all of which will be placed on the 40m Picasa page.

We visually inspected the optic, and we couldn't see anything on the optical surface of the mirror.  Koji said that he saw a few particulates on some horizontal surfaces in the chamber.  Since the optic seemed (at least to the level of human vision without a strong, focused light) to be free of particulates on the optical surface to start with, the suspense will have to remain until we button down, pump down, and try to lock the IFO to determine our new finesse, to see if the wiping helped any substantial amount. 

We replaced the regular, heavy door on the inner side of the ETMX chamber (the side closer to the CES building), and put only a light door on the outer side of the chamber (the side closer to the regular walkway down the arm).  We will look at the spectra of the OSEMS tomorrow, to confirm that none of the magnets are stuck.

We commence at ~9am tomorrow with ETMY.

LESSONS LEARNED:

The LED lights are awesome.  It's easy to use several lights to get lots of brightness (more than we've had in the past), and the chamber doesn't get hot.

We should get larger syringes for the acetone for the large optics.  It's challenging to smoothly operate the plunger of the syringe while it's so far out.  We should get 200 microliter syringes, so that for the acetone we only fill them about half way.  It was noticeably easier to apply the isopropyl when the syringe only had 50 microliters.

* It may be helpful to have a strong, focused optical light to inspect the surface of the mirror.  Rana says that Garilynn might have such an optical fiber light that we could borrow.

  2364   Tue Dec 8 09:18:07 2009 JenneUpdateComputersA *great* way to start the day....

Opening of ETMY has been put on hold to deal with the computer situation.  Currently all front end computers are down.  The DAQ AWGs are flashing green, but everything else is red (fb40m is also green).  Anyhow, we'll deal with this, and open ETMY as soon as we can.

The computers take priority because we need them to tell us how the optics are doing while we're in the chambers, fitzing around.  We need to be sure we're not overly kicking up the suspensions. 

  2367   Tue Dec 8 16:27:13 2009 JenneUpdateCOCITMX wiped

Jenne, Kiwamu, Koji, Alberto, Steve, Bob

ITMX was wiped without having to move it. 
After 'practice' this morning on ETMY, Kiwamu and I successfully wiped ITMX by leaning into the chamber to get at the front face. 

Most notable (other than the not moving it) was that inspection with the fiber light before touching showed many very small particles on the coated part of the optic (this is versus ETMY, where we saw very few, but larger particles).  The after-wiping fiber light inspection showed many, many fewer particles on the optical surface.  I have high hopes for lower optical loss here!

  2382   Thu Dec 10 10:01:16 2009 JenneUpdateComputersFronte-ends down

All the front ends are back up.  

Quote:

Quote:

I found all the front-ends, except for C1SUSVME1 and C0DCU1 down this morning. DAQAWG shows up green on the C0DAQ_DETAIL screen but it is on a "bad" satus.

I'll go for a big boot fest.

Since I wanted to understand once for all what's the faulting system when these situations occur, I tried to reboot the computers one by one.

1) I reset the RFM Network by pushing the reset button on the bypass switch on the 1Y7 rack. Then I tried to bring C1SOSVME up by power-cycling and restarting it as in the procedure in the wiki. I repeated a second time but it didn't work. At some point of the restarting process I get the error message "No response from EPICS".
2) I also tried rebooting only C1DCUEPICS but it didn't work: I kept having the same response when restarting C1SOSVME
3) I tried to reboot C0DAQCTRL and C1DCU1 by power cycling their crate; power-cycled and restarted C1SOSVME. Nada. Same response from C1SOSVME.
4) I restarted the framebuilder;  power-cycled and restarted C1SOSVME. Nothing. Same response from C1SOSVME.
5) I restarted the framebuilder, then rebooted C0DAQCTRL and C1DCU, then power-cycled and restarted C1SOSVME. Niente. Same response from C1SOSVME.
 
The following is the so called "Nuclear Option", the only solution that so far has proven to work in these circumstances. Execute the following steps in the order they are listed, waiting for each step to be completed before passing to the next one.
0) Switch off: the frame builder, the C0DAQCTRL and C1DCU crate, C1DCUEPICS
1) turn on the frame builder
2) reset of the RFM Network switch on 1Y7 (although, it's not sure whether this step is really necessary; but it's costless)
3) turn on C1DCUEPICS
4) turn on the C0DAQCTRL and C1DCU crate
 
One other possibility remains to be explored to avoid the Nuclear Option. And that is to just try to reset both RFM Network switches: the one in 1Y7 and the one in 1Y6.

 

  2383   Thu Dec 10 10:31:18 2009 JenneUpdateComputersFronte-ends down

Quote:

All the front ends are back up.  

Quote:

Quote:

I found all the front-ends, except for C1SUSVME1 and C0DCU1 down this morning. DAQAWG shows up green on the C0DAQ_DETAIL screen but it is on a "bad" satus.

I'll go for a big boot fest.

Since I wanted to understand once for all what's the faulting system when these situations occur, I tried to reboot the computers one by one.

1) I reset the RFM Network by pushing the reset button on the bypass switch on the 1Y7 rack. Then I tried to bring C1SOSVME up by power-cycling and restarting it as in the procedure in the wiki. I repeated a second time but it didn't work. At some point of the restarting process I get the error message "No response from EPICS".
2) I also tried rebooting only C1DCUEPICS but it didn't work: I kept having the same response when restarting C1SOSVME
3) I tried to reboot C0DAQCTRL and C1DCU1 by power cycling their crate; power-cycled and restarted C1SOSVME. Nada. Same response from C1SOSVME.
4) I restarted the framebuilder;  power-cycled and restarted C1SOSVME. Nothing. Same response from C1SOSVME.
5) I restarted the framebuilder, then rebooted C0DAQCTRL and C1DCU, then power-cycled and restarted C1SOSVME. Niente. Same response from C1SOSVME.
 
The following is the so called "Nuclear Option", the only solution that so far has proven to work in these circumstances. Execute the following steps in the order they are listed, waiting for each step to be completed before passing to the next one.
0) Switch off: the frame builder, the C0DAQCTRL and C1DCU crate, C1DCUEPICS
1) turn on the frame builder
2) reset of the RFM Network switch on 1Y7 (although, it's not sure whether this step is really necessary; but it's costless)
3) turn on C1DCUEPICS
4) turn on the C0DAQCTRL and C1DCU crate
 
One other possibility remains to be explored to avoid the Nuclear Option. And that is to just try to reset both RFM Network switches: the one in 1Y7 and the one in 1Y6.

 

 I burtrestored all the snapshots to Dec 9 2009 at 18:00.

  2385   Thu Dec 10 13:13:08 2009 JenneUpdateComputersfb40m backup restarted

The frame builder was power cycled during the morning bootfest.  I have restarted the backup script once more.

  2386   Thu Dec 10 13:50:02 2009 JenneUpdateVACAll doors on, ready to pump

[Everybody:  Alberto, Kiwamu, Joe, Koji, Steve, Bob, Jenne]

The last heavy door was put on after lunch.  We're now ready to pump.

  2387   Thu Dec 10 15:18:55 2009 JenneUpdateVACseisBLRMS

last 20 days - including the pounding from next door

Attachment 1: Untitled.png
Untitled.png
  2410   Mon Dec 14 12:13:52 2009 JenneUpdateTreasureWe are *ROCKSTARS* ! IFO is back up

[Jenne, Kiwamu, Koji]

We got the IFO back up and running!  After all of our aligning, we even managed to get both arms locked simultaneously.  Basically, we are awesome. 

 This morning, we did the following:

*  Turned on the PZT High voltages for both the steering mirrors and the OMC.  (For the steering mirrors, turn on the power, then hit "close loop" on each.  For the OMC, hit Output ON/OFF).

*  Looked at the PZT strain gauges, to confirm that the PZTs came back to where they had been.  (Look at the snapshot of C1ASC_PZT_Al)

*  Locked all components of the PSL (This had already been done.)

*  Removed beam dump which was blocking the PSL, and opened the PSL mechanical shutter.  Light into the IFO!

*  Locked the Mode Cleaner.  The auto-locker handled this with no problem.

*  Confirm that light is going through the Faraday.  (Look at the TV sitting on top of MC13 tank...it shows the Faraday, and we're hitting the input of the Faraday pretty much dead-on).

*  Look at IP_ANG and IP_POS.  Adjust the steering mirrors slightly to zero the X&Y readings on IP_ANG.  This did not change the PZTs by very much, so that's good.

*  Align all of the Core Optics to their OpLev positions.

*  On the IFO_Align screen, save these positions.

*  Run the IFO_Configure scripts, in the usual order.  (Xarm, Yarm, PRM, DRM).  Save the appropriate optics' positions after running the alignment scripts.  We ended up running each alignment script twice, because there was some residual misalignment after the first iteration, which we could see in the signal as viewed on DataViewer (Either TRX, TRY, or SPOB, for those respective DoFs).

*  Restore Full IFO.

*  Watch the beauty of both arms and the central cavity snapping together all by themselves!  In the attached screenshot, notice that TRX and TRY are both ~0.5, and SPOB and AS166Q are high.  Yay!

Conclusions: 

*  The wiping may have helped.  While aligning X and Y separately, TRX got as high as ~1.08, and TRY got as high as 0.98  This seems to be a little bit higher than it was previously.

*  Since everything locked up in pretty short order, and the free swinging spectra (as measured by Kiwamu in elog 2405) looks good, we didn't break anything while we were in the chambers last week.  Excellent.

*  We are now ready for a finesse measurement to tell us more quantitatively how we did with the wiping last week.

 

Attachment 1: Jenne14Dec09_IFOlocked.png
Jenne14Dec09_IFOlocked.png
  2414   Mon Dec 14 15:18:18 2009 JenneUpdatelorearmLoss script ran....results confidential

I ran the armLoss script for both Xarm and Yarm.  The results are confidential, pending the completion of Alberto's cavity pole/finesse measurement due to the 'bet' as to what the new losses are after the drag wiping.

If you're the kind of person who likes to look at their Chrismas presents, the log files with the results are in the usual place for this script: /scripts/LSC/loss-ARM-GPStime.log  (loss-Y-944865071.log and loss-X-944865946.log)

  2425   Thu Dec 17 02:57:08 2009 JenneUpdateWienerFilteringL1 DARM Static Wiener Filtered data

This is perhaps best put in the LLO elog, but I'm not yet a 'person' there, so I can't write to their elog (yet another thing for the eternal to-do list).  So for now, we're putting things here...

This isn't totally finalized, but I do want to get what I have posted before I hop on a plane in the morning.  Mostly it just needs more time to run, to make the plot longer.  Hopefully I'll be able to edit this in the morning and have a longer-duration plot. 

What's plotted:

This spectrogram shows the amplitude spectra of L1:LSC-DARM_CTRL, after being subtracted via a Static Wiener Filter.  Each spectra is normalized by the very first one, which was created from the same data that was used to determine the Wiener Filter.  The X-axis is time.  The Y-axis is frequency, and the Color/Z-axis is amplitude in dB.  I'm only looking at Science Mode time, so other times when the IFO isn't in science mode, I plot a black stripe to fill in the plot.  The start time of the plot is 83675598, which is Jul 08 2006 06:33:04 UTC. 

Why?

The idea is to see that the filter does equally well a long time after it was created, as when it was initially made.  This will help tell us how often it is useful to recompute the Wiener filters.  Less often is nice, because redoing the Wiener filters may also include remeasuring the high precision transfer functions...if the filter isn't working as well anymore it may be because the transfer function has changed ever so slightly. 

How the plot is created / the background story:

I use one hour of DARM_CTRL data and the following seismometer channels to create an optimal Wiener Filter (pem indicates L0:PEM- , sei indicates L1:SEI- , and lsc indicates L1:LSC- ) :

chans = {[pem 'EX_SEISX'],...
         [pem 'EX_SEISY'],...
         [pem 'EX_SEISZ'],...
         [pem 'EY_SEISX'],...
         [pem 'EY_SEISY'],...
         [pem 'EY_SEISZ'],...
         [pem 'LVEA_SEISX'],...
         [pem 'LVEA_SEISY'],...
         [pem 'LVEA_SEISZ'],...
         [sei 'LVEA_STS2_X'],...
         [sei 'LVEA_STS2_Y'],...
         [sei 'LVEA_STS2_Z'],...
         [sei 'ETMX_STS2_X'],...
         [sei 'ETMX_STS2_Y'],...
         [sei 'ETMX_STS2_Z'],...
         [sei 'ETMY_STS2_X'],...
         [sei 'ETMY_STS2_Y'],...
         [sei 'ETMY_STS2_Z'],...
         [lsc 'DARM_CTRL']};

I then apply this one filter to ten minute chunks of science mode data, for some long period of time.  The game plan is to have a month long plot, but it takes a while to fetch all of the data in separate 10min intervals (~45sec per iteration, times ~3000 iterations), so this plot isn't a full month.  Even if I don't get a chance to plot a full month by Thursday morning, it'll go up here within the next few days. The particular times chosen have the most science mode data within a 30 day period.  I can easily run the code for some other time, if there is a known time (or season) which might be more interesting.  For the spectrogram plot, I then normalize each amplitude spectra by the first one, which comes from the first ten minutes in the hour which was used to make the filter.  This makes it easier to see how the filter's efficacy changes over time.

The analogous analysis for Hanford is in the 40m elog: 1606.  The Hanford stuff in the elog has some cool BLRMS plots also, but I'm not sure that they're so helpful when I only have a few days of L1 data so far.  I'll do those and add them later.

Conclusions:

I can't really say anything yet about the long-term efficacy of a Wiener Filter for LLO yet, since my code hasn't finished filtering my one month of S5 L1 data.  It definitely looks like (so far) that there was a big seismic event around the (arbitrarily defined) 'Day 4'. 

Attachment 1: L1darmCompPlot_17Dec2009_4daysLong.png
L1darmCompPlot_17Dec2009_4daysLong.png
  2426   Thu Dec 17 07:47:29 2009 JenneUpdateWienerFilteringL1 DARM Static Wiener Filtered data

This surface plot is the same as the previous one, with a little more data than I had previously. 

This time around, I also include the "BLRMS" plots for this data.  The first one takes each residual and normalizes it by the DARM_CTRL signal at that time, separates the spectra into bands, and integrates underneath the spectra within that band.  The second one is the raw DARM_CTRL signal's spectra at each time, and integrates under the spectra for each band, and the third BLRMS plot does the same thing for the residuals.  Unfortunately, these plots don't have the same handy black stripe during time which I don't analyze that the spectrogram utilizes.

From the second BLRMS plot we can see that the large red splotch in the spectrogram is due to higher noise in the DARM spectrum, and that (by looking at the Ratio BLRMS plot) the Wiener filter still does a pretty good job during this time.  I expect that for later times when the seismic (or something) event is gone, the Wiener filter will continue performing almost as well as it had been initially.

Again, once the script finishes applying the filter to the many ten minute chunks (the huge time drain is the data fetching, so this shouldn't be a limiting factor for using Wiener filters online), I'll post a final plot.

Attachment 1: L1darmComp_17Dec2009_6day_residualsNormSurfacePlot.png
L1darmComp_17Dec2009_6day_residualsNormSurfacePlot.png
Attachment 2: L1darmComp_17Dec2009_6day_ratioBLRMS.png
L1darmComp_17Dec2009_6day_ratioBLRMS.png
Attachment 3: L1darmComp_17Dec2009_6day_rawBLRMS.png
L1darmComp_17Dec2009_6day_rawBLRMS.png
Attachment 4: L1darmComp_17Dec2009_6day_residualsBLRMS.png
L1darmComp_17Dec2009_6day_residualsBLRMS.png
  2435   Sun Dec 20 23:42:44 2009 JenneUpdateIOONew Input Mode Matching Telescope

I've got most of the new Mode Matching Telescope figured out.  The scripts and an example result are at: MMT09 wiki  (Rather, the scripts are in the svn: MMT svn)

Issues still to be resolved: 

* We're getting pretty iffy 'angles' between tilt and translation when using the mode matching mirrors for steering.

* I haven't taken into account the astigmatism which occurs when you tilt the mode matching mirrors. 

The nifty thing about these scripts is that they take a look at the mode matching overlap:  For each possible mode matching solution it adds noise to all of the distances and radii of curvature during ~10,000 iterations and plots a histogram of the overlap so that we can see which solutions have a better chance of giving us the optimal overlap, even if we place the optics in slightly the wrong place.

 

I'd like to update the overlap part of the script with the astigmatism business:  do we lose goodness of overlap if we tilt the mirrors by a bit?  I think this will require redoing the overlap part with the X and Y directions separate.  Koji has done this in the past.  My current code assumes that the beam is always symmetric in X and Y. 

  2456   Mon Dec 28 10:29:31 2009 JenneUpdateComputersMonday Morning Bootfest

Nothing like a good ol' Bootfest to get back into the swing of things after vacation....

It was a regular bootfest, keying crates and running everyone's startup.cmd .  There wasn't any RFM funny business which we had been dealing with a lot earlier in December (maybe Kiwamu took care of that part of things last night).

After finishing the bootfest, I tried to re-enable the watchdogs.  I noticed that the optics weren't damping at all (not that any of them were swinging crazily, they just weren't damped like regular).  This was traced to the OSEM sensor inputs and outputs being disabled on all of the suspensions' screens.  I suspect that no burt-restoring happened after c1dcuepics was powercycled yesterday. 

All of the optics are now happy as clams.

  2457   Mon Dec 28 12:35:57 2009 JenneUpdateSUSMC2 is having a bad day

MC2 is having a bad day, and I'm not yet sure why.  It's to do with the damping though.  When the damping is off, after a little while it will settle to ~30mV or so on the Watchdog screen.  When I enable all of the outputs and then turn on the damping, the optic gets kicked up.  It's like there's a minus sign error somewhere, maybe in a bad burtrestore?  This has been going on since I did my morning bootfest.

It's started to sit down and play nicely now.  Is someone doing magic remotely that is fixing things that I hadn't figured out yet?

  2473   Mon Jan 4 17:21:30 2010 JenneConfigurationIOOElusive Mode Matching Solution found!

I think I have finally found a Mode Matching solution for our new Input Mode Matching Telescope!  And after looking at the layout diagram with Koji and Raffaele, it seems like all of the optics will fit into the chambers / onto the tables (not true as of last week). 

3. RoCMMT1 is -5m
   RoCMMT2 is 8m,
   with the MMTs 1.89m apart.
   This is a 1.6x telescope.
   MMT2 is 2.2641m from the PRM
   MMT1 is 2m from MC3.
   The Condition Number for this optical chain is 89219047.5781.

This layout is very similar to the one that Koji posted on the wiki yesterday:  Upgrade09/Optical Layout.  The difference is that I want to move MMT1 ~20cm closer to the MC13 table, so just on the other side of the main red beam that goes directly to PRM.  There is plenty of space there, so it should be all good.  The tricky bit is that the flat steering mirrors fit into things now while they are piezos, but they will be trickier to fit if we make them into Tip Tilts.  But I have full faith in Koji's amazing optical table layout skills, that he can make it happen. 

Unless there are major objections, I think this is the MMT that we're going to go with. (So speak now or forever hold your peace.)  The angle between tilt and translation isn't quite what we'd like it to be (at ~18deg), but it's not too terrible.  And we still have 99.5% overlap which is very important.

Attachment 1: Awesome_MM_Solution.png
Awesome_MM_Solution.png
  2475   Tue Jan 5 01:31:09 2010 JenneUpdateWienerFilteringNew Wiener Filters installed in PEM IIR matrix on OAF screen

Using the techniques employed at LLO, and then by Rana here at the 40m a few weeks ago, Wiener filters have been installed on the inputs of all of the PEM IIR channels which are hooked up to the 110B PEM ADCU.  Some slight modifications have taken place to the code, and it's all been checked in to the 40m svn. 

I have installed the filters into:  All 6 Wilcoxon accelerometers, the Ranger seismometer, and one of the Guralps (GUR1).  The other Guralp is currently connected through the ASS/OAF machine's ADC, so it's not used in this test. The filters are all labeled "Wiener", and are FM1 in the C1:ASS-TOP_PEMIIR_## filter banks.

The first figure below is the output of the Wiener Filter calculation program.  It shows the uncorrected MC_L (black) and the corrected MC_L (red), using the optimal wiener filter.  This is as good as we should be able to do with these sensors in these positions.

The second figure is a DTT shot of me trying out the nifty new filters.  They seem to maybe do a teensy bit on the microseism, but otherwise it's a bit unremarkable.  Hopefully I'll get better subtraction during the day, when the base level for MC_L is higher.  Here, Black is uncorrected MC_L, Red is the corrected MC_L, Blue is the actuation channel, and green is an example seismometer channel to illustrate the ground motion at the time.

 

For posterity, since it's not all in one elog that I can find, the order of operations to install a Wiener Feed Forward filter is as follows:

1.  (When you can borrow the IFO) Take a very careful TF of the plant, between your actuation point and your error signal readout.  At the 40m, this means between C1:ASS-TOP_SUS_MC1_EXC and C1:IOO-MC_L, since we actuate by pushing on the MC1 coils.  At the sites / future 40m, this would be between the HEPI (or STACIS) and the error signal.  The limit of how good your Feed Forward can do will depend heavily on how good this TF is.  Coherence should be above ~0.95 for all points.  Export this data from DTT as a .txt file, using units "Complex (abs/rad)". 

2. Run fitMC12MCL.m (or equivalent wrapper file) to fit the transfer function you just took with some Poles and Zeros.  Make sure to edit the wrapper file with your new .txt file's name so you're getting a fresh TF (if you've just taken one).

3. (Again, when you can borrow the IFO) Run getMCdata.m (or equivalent) to fetch witness channel data and error signal data.  At the 40m, this usually means C1:IOO-MC_L, and witness sensors which are around the MC chambers.  This data should be taken at a time when the cavity is locked, but pretty much on it's own. (i.e. probably shouldn't have Common Mode feedback on the MC - so the MC should be locked, but not the full IFO, for example.)

4.  Run c1winoiir.m (the main program here, which contains some of these notes). This will take in the TF data you've fit, and the witness channel data you have, and calculate the optimal combination of Wiener filters for your witness channels.  It pre-filters your witness data by your TF, then calculates the Wiener filter.  The resulting FIR filters are saved in a file.

5.  Run firfit.m  This will take the FIR Wiener filters you've just created, and convert them conveniently to IIR filters, in a format to be copied directly into Foton.  For each witness channel, you'll get the IIR filter in 2 formats:  the first is for copying into the Foton .txt file (ex ASS.txt), and the second is for copying into the Foton gui, in the "Command" box on the filter design screen.  The "o" at the end of the copy-able filter indicates to Foton that it is a Z-Plane Online filter.  Copy filters appropriately (there should be a line preceding each set of SOS filter formats to indicate which channel this Wiener filter is for...these channel names are extracted from your getMCdata.m)

6. Save your Foton file, and update your Coefficients in MEDM.  Enable your outputs to actuators, and watch magic happen!

 

On the To-Do list:

Check the transfer of signal btwn PEMIIR matrix and the 9x1 'matrix' that sends the signals to the SUS inputs.  In the SimuLink, the input to the 9x1 matrix is a bundle of 8 numbers (the 8 outputs of the PEMIIR matrix), but it looks like it only pays attention to the first one.  Need to figure out how to make it realize that it's a bundle, not a single number. 

Also, the OAF up / down scripts don't seem to be working on any of the control room computers.  This needs to be checked in to / fixed (but not tonight....)

Attachment 1: MCwino-FFtest_4Jan10_sameFiltersAsinEPICS.png
MCwino-FFtest_4Jan10_sameFiltersAsinEPICS.png
Attachment 2: OAF-FF_test_4Jan10.png
OAF-FF_test_4Jan10.png
  2480   Tue Jan 5 17:32:59 2010 JenneUpdateWienerFilteringNew Wiener Filters installed in PEM IIR matrix on OAF screen

EDIT 6 Jan 2010:  Shouldn't have done this.  My bad.  The AA32 is on the other PEM matrix because the Adaptive code runs at 64Hz, so there's downsampling, calculating, and upsampling which goes on.  The Feed Forward path all runs at 2kHz, the regular rate of the ASS/OAF machine.  All of these filters are turned off (although I haven't deleted them from Foton).  Since we're focusing on low frequency stuff and trying to get that to do some subtraction, we're not worrying about the junk at higher frequencies just yet.

 

I have put AA32 filters into the PEMIIR matrix's input filter banks (ie, C1:ASS-TOP_PEMIIR_##), to match the ones that are in the same places in the regular PEM matrix on the OAF screen. 

I redid the uncorrected vs. corrected MC_L DTT printout, shown below. You can see that there's less junk at higher frequencies in the Blue (actuation channel) trace, which is good.

Attachment 1: OAF-FF_test_5Jan10.png
OAF-FF_test_5Jan10.png
  2483   Thu Jan 7 14:08:46 2010 JenneUpdateComputersWe haven't had a bootfest yet this week.....so today's the day

All the DAQ screens are bright red.  Thumbs down to that.

  2484   Thu Jan 7 14:55:36 2010 JenneUpdateComputersWe haven't had a bootfest yet this week.....so today's the day

Quote:

All the DAQ screens are bright red.  Thumbs down to that.

 All better now. 

  2499   Sun Jan 10 23:22:56 2010 JenneSummaryGeneralScattering Measurements of 35W Beam Dumps

On Friday, Rana and I measured the scatter coming from the 35W beam dumps.

(These are the ones with big aluminum heat sinks on the back that kind of look like little robots with 2 legs...inside the horn is a piece of polished silicon at Brewster's Angle.)

 

SETUP:

For the measurement, we used the Scatterometer setup at the 40m on the small optical table near MC2. 

We used a frequency of 1743 Hz for the Chopper, and this was also used as the reference frequency for the SR830 Lock-In Amplifier. 

The settings on the Lock-In were as follows:

Input A

24dB/octave

AC coupled

Floating input

"Low Noise"

Time Constant = 1sec

'Scope reading Output A, Output A set to 'Display', and A's display set to "R" (as in magnitude).

Sensitivity changed throughout the experiment, so that's quoted for each measurement.

 

MEASUREMENTS:

White Paper Calibration - white paper placed just in front of Beam Dump.  Sensitivity = 500microVolts.  Reading on 'scope = 7V

Laser Shuttered.  Sensitivity = 500microVolts. 'scope reading = 9mV.

Black Glass at Beam Dump location.  Sensitivity = 500microVolts.  Reading on 'scope = 142mV.   (DON'T touch the glass....measure the same setup with different sensitivity)

Black Glass at Beam Dump location (Not Touched since prev. measurement). Sensitivity = 10microVolts. Reading on 'scope = 6.8V

Laser Shuttered. Sensitivity = 10microVolts. 'scope Reading = 14mV +/- 10mV (lots of fluctuation).

Black Glass Wedge Dump at Beam Dump location. Sensitivity = 10microVolts. 'scope = 100mV.

Beam Dump with original shiny front plate. Sensitivity = 10microVolts.  'scope railing at 11V

Beam Dump with front plate removed. Sensitivity = 10microVolts. 'scope reading = 770mV

Beam Dump, no front plate, but horn's opening surrounded by 2 pieces of Black Glass (one per side ~1cm opening), BG is NOT flush with the opening...it's at an angle relative to where the front plate was.  Sensitivity = 10microV. 'scope = 160mV +/- 20mV.

Beam Dump, no front plate, only 1 piece of Black Glass. Sensitivity = 10microV. 'scope reading = 260mV.

Beam Dump, no front plate, 2 pieces of Black Glass, normal incidence (the BG is flush with where the front plate would have been). Sensitivity = 10microV. 'Scope reading = ~600mV

 

CALIBRATION:

Using our calibration numbers (Black Glass measured at 2 different sensitivities, not touching the setup between the measurements), we can find the calibration between our 2 different sets of measurements (at 500microV and 10microV), to compare our Beam Dump with regular white paper. 

BG at 500uV was 142mV.  BG at 10uV was 6.8V.    6.8V/0.142V = 47.9 

So the white paper, which was measured at 500uV sensitivity, would have been (7V * 47.9) = 335 V in 10uV sensitivity units. 

This is compared to the BG wedge dump at 10uV sensitivity of 100mV, and the Beam Dump reading of 770mV, and the Beam Dump with-black-glass-at-the-opening reading of 160mV.

So our Silicon/Steel horn dump is ~8x worse than a Black Glass wedge and (335 / 0.77) = 435x better than white paper.

We used regular white paper as a calibration because it has a Lambertian reflectance. For some general idea of how to do these kinds of scatter measurements, you can look at this MZ doc.

Assuming that our white paper had a BRDF of (1/pi)/steradian, we can estimate some numbers for our setup:

Sensitivity (signal with the laser shuttered) = (0.02 / 335 / pi) = 2 x 10^-5 / sr.   This is ~3x worse than the best black glass surfaces.

Our wedge = (0.1 / 335 / pi) = 1 x 10^-4 / sr.  Needs a wipe.

Our Silicon-Steel Horn = (0.75 / 335 / pi) = 7 x 10^-4 / steradian.

Our measurements were all made at a small angle since we are interested in scatter back along the incoming beam. We were using a 1" lens to collect the scatter onto a PDA55. The distance from the beam to the center of the lens was ~2" and the detector's lens was ~20" from the front of the horn. So that's an incident angle of ~3 deg.

CONCLUSIONS:

* It seems that any front plate other than Black Glass is probably worse than just having no front plate at all.

* If we put in a front plate, it shouldn't be normal to the incident beam.  Black Glass at normal incidence was almost at the same level as having no front plate. So if we're going to bother with a front plate, it should be about 30deg or 40deg from where the original front plate was.

* No front plate on the Dump is about 7x a Black Glass wedge dump.

* The silicon looks like it might have some dust on it (as well as the rest of the inside of the horn).  We should clean everything.  (Maybe with deionized nitrogen?)

* We should remeasure the Beam Dump using polished steel at a small (30-40deg) angle as the front plate. 

 

ATTACHMENTS:

 * Photos taken with the Olympus camera, which has its IR blocker removed.

* In the photo you can see that we have a lot of reflection off of the horn on the side opposite from the silicon.

* The 2nd picture is of the scatterometer setup.

Attachment 1: P1090014_copy.JPG
P1090014_copy.JPG
Attachment 2: ScatterometerSetup.png
ScatterometerSetup.png
  2503   Mon Jan 11 14:16:59 2010 JenneUpdatePEMGur2 cables reconnected to the PEM ADCU

So that we can use both Guralps for Adaptive stuff, and so that I can look at the differential ground motion spectra, I've reconnected the Guralp Seismometers to the PEM ADCU, instead of where they've been sitting for a while connected to the ASS ADC.  I redid the ASS.mdl file, so that the PEM and PEMIIR matricies know where to look for the Gur2 data.  I followed the 'make ass' procedure in the wiki.  The spectra of the Gur1 and Gur2 seismometers look pretty much the same, so everything should be all good.

There's a problem with DataViewer though:  After selecting signals to plot, whenever I hit the "Start" button for the realtime plots, DataViewer closes abruptly. 

When I open dataviewer in terminal, I get the following output:

allegra:~>dataviewer
Warning: communication protocol revision mismatch: expected 11.3, received 11.4
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: Not all children have same parent in XtManageChildren
Warning: communication protocol revision mismatch: expected 11.3, received 11.4
msgget: No space left on device
allegra:~>framer4 msgget:msqid: No space left on device

Does anyone have any inspiration for why this is, or what the story is?  I have GR class, but I'll try to follow up later this afternoon.

  2506   Mon Jan 11 21:49:17 2010 JenneUpdateABSLMeasurement running

Quote:

Leaving for dinner. Back in ~1hr.

I left a measurement running. Please don't interfere with it till I'm back. Thanks.

 Per Alberto's instructions, I have closed the shutter on his laser so that the Adaptive Team can play with the Mode Cleaner.

  2563   Tue Feb 2 22:39:12 2010 JenneUpdatePSLIFO isn't playing nice tonight

[Jenne, Kiwamu]

It's been an iffy last few hours here at the 40m.  Kiwamu, Koji and I were all sitting at our desks, and the computers / RFM network decided to crash.  We brought all of the computers back, but now the RefCav and PMC don't want to lock.  I'm a wee bit confused by this.  Both Kiwamu and I have given it a shot, and we can each get the ref cav to sit and flash, but we can't catch it.  Also, when I bring the PMC slider rail to rail, we see no change in the PMC refl camera.  Since c1psl had been finicky coming back the first time, I tried soft rebooting, and then keying the crate again, but the symptoms remained the same.  Also, I tried burt restoring to several different times in the last few days, to see if that helped.  It didn't.  I did notice that MC2 was unhappy, which was a result of the burtrestores setting the MCL filters as if the cavity were locked, so I manually ran mcdown.  Also, the MC autolocker script had died, so Kiwamu brought it back to life.

Since we've spent an hour on trying to relock the PSL cavities (the descriptive word I'm going to suggest for us is persistent, not losers), we're giving up in favor of waiting for expert advice in the morning.  I suppose there's something obvious that we're missing, but we haven't found it yet......

  2574   Fri Feb 5 14:31:46 2010 JenneUpdateSUS2 SOS towers assembled

[Jenne, Kiwamu]

The 2 SOS towers for the ITMs have been assembled, and are on the flow bench in the cleanroom.  Next up is to glue magnets, dumbells, guiderods and wire standoffs to the optics, then actually hang the mirrors.

DSC_1156.JPG

  2584   Tue Feb 9 17:51:48 2010 JenneSummaryIOOInput Mode Matching Telescope design is complete

The upgrade's input mode matching telescope design is complete.  A summary document is on the MMT wiki page, as are the final distances between the optics in the chain from the mode cleaner to the ITMs.  Unless we all failed kindergarden and can't use rulers, we should be able to get very good mode matching overlap.  We seem to be able (in Matlab simulation land) to achieve better than 99.9% overlap even if we are wrong on the optics' placement by ~5mm.  Everything is checked in to the svn, and is ready for output mode matching when we get there.

  2614   Fri Feb 19 00:31:17 2010 JenneUpdateCOCNew ITMX guiderods glued

[Jenne, Kiwamu, with moral support from Koji, and loads of advice from Steve and Bob]

New upgrade ITMX (ITMU03) has it's guiderod & standoff glued on, as step 1 toward hanging the ITMs.

Procedure:

1. Make sure you have everything ready.  This is long and complicated, but not really worth detail here.  Follow instructions in E970037 (SOS Assembly Spec), and get all the stuff in there.

2. Set optic in a 'ring stand', of which Bob has many, of many different sizes. They are cleaned and baked, and in the cleanroom cupboard on the bottom just behind the door. We used the one for 3" optics.  This lets you sit the optic down, and it only rests on the bevel on the outside, so no coated surface touches anything.

3. Drag wipe the first surface of the optic, using Isopropyl Alcohol.  We used the little syringes that had been cleaned for the Drag Wipe Event which happened in December, and got fresh Iso out of the bottle which was opened in Dec, and put it into a baked glass jar.  The drag wipe procedure was the same as for the December event, except the optic was flat on the bench, in the ring holder.

4. Turn the optic over.

5. Drag wipe the other surface.

6. Align the optic in the guiderod gluing fixture (Step 3 in Section 3.2.1: Applying Guide Rod and Wire Standoff of E970037).

7. Set guiderod and standoff (1 guiderod on one side, 1 standoff on the other, per instructions) against the side of the optic.

8.a.  Use a microscope mounted on a 3-axis micrometer base to help align the guiderod and standoff to the correct places on the optic (Steps 4-5 of Section 3.2.1).  This will be much easier now that we've done it once, but it took a looooooong time. 

8.b.  We put the optic in 180deg from the way we should, based on the direction of the wedge angle in the upgrade table layout (wedge angle stuff used a "Call a Friend" lifeline.  We talked to Koji.) The instructions say to put the guiderod and standoff "above" the scribe lines in the picture on Page 5 of E970037 - the picture has the arms of the fixture crossing over the scribe lines.  However, to make the optic hang correctly, we needed to put the guiderod and standoff below the scribe lines.  This will be true as long as the arrow scribe line (which marks the skinniest part of the optic, and points to the HR side) is closest to you when the optic is in the fixture, the fixture is laying on the table (not standing up on end) with the micrometer parts to your right.  We should put the other ITM into the fixture the other way, so that the arrow is on the far side, and then we'll glue the guiderod and standoff "above" the scribe lines.  Mostly this will be helpful so that we can glue in exactly the places the instructions want us to.

8.c.  The biggest help was getting a flashlight to help illuminate the scribe lines in the optic while trying to site them in the microscope.  If you don't do this, you're pretty much destined to failure, since the lights in the cleanroom aren't all that bright. 

8.d.  The micrometer mount we were able to find for the microscope has a max travel of 0.5", but the optic is ~1" thick.  To find the center of the optic for Step 5 in the guiderod and standoff alignment we had to measure smaller steps, such as bevel-to-end-of-scribe-line, and length-of-scribe-line then end-of-scribe-line-to-other-bevel.  Thankfully once we found the total thickness and calculated the center, we were able to measure once bevel-to-center. 

9. Apply glue to the guiderod and standoff.  We made sure to put this on the "down" side, which once the optic is hung, will be the top of the little rods.  This matches the instructions as to which side of the rods to apply the glue on.  The instructions do want the glue in the center of the rod though, but since we put the optic in the fixture the wrong way, we couldn't reach the center, so we glued the ends of the rods.  We will probably apply another tiny dab of glue on the center of the rod once it's out of the fixture, perhaps while the magnet assemblies are being glued.

10.  We didn't know if the airbake oven which Bob showed us to speed up the curing of our practice epoxy last night was clean enough for the ITM (he was gone by the time we got to that part), so for safety, we're leaving the optic on the flow bench with a foil tent (the foil is secured so there's no way it can blow and touch the optic).  This means that we'll need the full curing time of the epoxy, not half the time.  Maybe tomorrow he'll let us know that the oven is in fact okay, and we can warm it up for the morning.

  2616   Fri Feb 19 10:18:19 2010 JenneUpdateVACThe P1 vac pressure is almost to 3mTorr

The Vac pressure measured at P1 is at 2.5mTorr.  I expect we'll hit 3mTorr sometime this afternoon, at which point (according to Steve) the interlock will shut the shutter, and we won't have light in the IFO.  Anything which needs to happen with light in the IFO before Monday needs to happen fairly soon.

Attachment 1: VacPressureAlmostShutoffLaser_19Feb2010.png
VacPressureAlmostShutoffLaser_19Feb2010.png
  2623   Mon Feb 22 10:25:37 2010 JenneUpdateCOCITMY standoff and guiderod epoxied

This work happened on Friday, after Nodus and the elog went down....

[Jenne, Kiwamu]

The guiderod and standoff for ITMY were epoxied, and left drying over the weekend on the flow bench under a foil tent.  The flow bench was off for the weekend, so we made tents which hopefully didn't have any place for dust to get in and settle on the mirrors.

There is a small chance that there will be a problem with glue on the arm of the fixture holding the guiderod to the optic.  Kiwamu and I examined it, and hopefully it won't stick.  We'll check it out this afternoon when we start getting ready for gluing magnets onto optics this afternoon.

  2629   Mon Feb 22 21:07:26 2010 JenneUpdateCOCMagnets glued to ITMX

[Kiwamu, Jenne]

The magnets + dumbbell standoffs have been glued to ITMX.  We're waiting overnight for them to dry. 

Since I broke one of the magnet + dumbbells on the ITMY set, we've glued another dumbbell to the 6th magnet, and it should be ready for us to glue to ITMY tomorrow, once ITMX is dry and out of the fixture.  This doesn't put us behind schedule at all, so that's good.

We had been concerned that there might be a problem with the arm of the guiderod fixture being glued to ITMY, but it was fine after all.  Everything is going smoothly so far.

 

[Zach, Mott]

Zach and Mott are almost prepared to start cutting the viton for the earthquake stops.  We need 2 full sets by Wednesday morning, when we expect to begin hanging the ITMs.

  2638   Wed Feb 24 16:11:15 2010 JenneUpdatePEMSeismic witnesses near MC1 tank moved

Since we're going to open the MC1 tank tomorrow, I've moved the MC1 accelerometers and the Guralp over to underneath MC2 for the vent.  I'll reconnect them later.

  2642   Fri Feb 26 01:00:07 2010 JenneUpdateCOCSuspension Progress

This is going to be a laundry list of the mile markers achieved so far:

* Guiderod and wire standoff glued to each ITMX and ITMY

* Magnets glued to dumbbells (4 sets done now).  ITMX has 244 +- 3 Gauss, ITMY has 255 +- 3 Gauss.  The 2 sets for SRM and PRM are 255 +- 3 G and 264 +- 3 G.  I don't know which set will go with which optic yet.

* Magnets glued to ITMX.  There were some complications removing the optic from the magnet gluing fixture.  The way the optic is left with the glue to dry overnight is with "pickle picker" type grippers holding the magnets to the optic.  After the epoxy had cured, Kiwamu and I took the grippers off, in preparation to remove the optic from the fixture.  The side magnet (thankfully the side where we won't have an OSEM) and dumbbell assembly snapped off.  Also, on the UL magnet, the magnet came off of the dumbbell (the dumbbell was still glued to the glass).  We left the optic in the fixture (to maintain the original alignment), and used one of the grippers to glue the magnet back to the UL dumbbell.  The gripper in the fixture has very little slop in where it places the magnet/dumbbell, so the magnet was reglued with very good axial alignment.  Since after the side magnet+dumbbell came off the glass, the 2 broke apart, we did not glue them back on to the optic.  They were reattached, so that we can in the future put the extra side magnet on, but I don't think that will be necessary, since we already know which side the OSEM will be on.

* Magnets glued to ITMY.  This happened today, so it's drying overnight.  Hopefully the grippers won't be sticky and jerky like last time when we were removing them from the fixture, so hopefully we won't lose any magnets when I take the optic out of the fixture.

* ITMX has been placed in its suspension cage.  The first step, before getting out the wire, is to set the optic on the bottom EQ stops, and get the correct height and get the optic leveled, to make things easier once the wire is in place.  Koji and I did this step, and then we clamped all of the EQ stops in place to leave it for the night.

* The HeNe laser has been leveled, to a beam height of 5.5inches, in preparation for the final leveling of the optics, beginning tomorrow.  The QPD with the XY decoder is also in place at the 5.5 inch height for the op lev readout.  The game plan is to leave this set up for the entire time that we're hanging optics.  This is kind of a pain to set up, but now that it's there, it can stay out of the way huddled on the side of the flow bench table, ready for whenever we get the ETMs in, and the recoated PRM. 

* Koji and Steve got the ITMX OSEMs from in the vacuum, and they're ready for the hanging and balancing of the optic tomorrow.  Also, they got out the satellite box, and ran the crazy-long cable to control the OSEMs while they're on the flow bench in the clean room.

 

Koji and I discovered a problem with the small EQ stops, which will be used in all of the SOS suspensions for the bottom EQ stops.  They're too big.  :(  The original document (D970312-A-D) describing the size for these screws was drawn in 1997, and it calls for 4-40 screws.  The updated drawing, from 2000 (D970312-B-D) calls for 6-32 screws.  I naively trusted that updated meant updated, and ordered and prepared 6-32 screws for the bottom EQ stops for all of the SOSes.  Unfortunately, the suspension towers that we have are tapped for 4-40.  Thumbs down to that.  We have a bunch of vented 4-40 screws in the clean room cabinets, which I can drill, and have Bob rebake, so that Zach and Mott can make viton inserts for them, but that will be a future enhancement.  For tonight, Koji and I put in bare vented 4-40 screws from the clean room supply of pre-baked screws.  This is consistent with the optics in our chambers having bare screws for the bottom EQ stops, although it might be nicer to have cushy viton for emergencies when the wire might snap.  The real moral of this story is: don't trust the drawings.  They're good for guidelines, but I should have confirmed that everything fit and was the correct size.

  2652   Wed Mar 3 02:57:29 2010 JenneUpdateSUSITMX hung

Quote:

Jenne and Koji

We successfully hung ITMX on the SOS. Side magnet is ~2mm off from the center of the OSEM.

Reguled ITMY side magnet.

Cleaned up the lab for the safety inspection.

 Some details on the side magnet situation from today: 

To glue the magnets+dumbbells to the optics, we use the magnet-dumbbell gluing fixture.  This fixture is supposed to have teflon 'pads' for the optic to sit on while you align it in the fixture, however the fixture which we received from MIT (it's Betsy's....but it came via MIT) only had one of the 4 teflon pads. 

Kiwamu and I decided (last week, when we first glued ITMX's magnets) that it would be bad news to let the AR face of the optic sit on bare metal, so we fashioned up some teflon pads using stock in a cabinet down the Yarm.  We were focused on thinking about the face magnets, and didn't think about how the thickness of the teflon affected the placement of the side magnet.  We chose some teflon that was too thin by ~1mm, so the optic sat too low in the fixture, resulting in the side magnet being glued too close to the HR side of the optic (this is all along the Z - axis, where Z is the direction of beam propagation). 

Why it ended up being 2mm off instead of only 1mm I don't really have an explanation for, other than perhaps tightening the set screws to hold the optic (by the barrel) in the fixture pushes the optic up.  I observed this happening when I didn't put any effort into keeping the optic flat on the teflon pads, but I thought that I made sure the optic was seated nicely in the fixture before starting to glue.  When I glued the new ITMY side magnet tonight I tried to make sure that the optic was seated nicely in the fixture.  We'll see what happens.

Before gluing the new ITMY side magnet (and now it's set for all future magnet gluings....), I found 4 teflon pads of all the correct thickness.  It turns out that we have a magnet gluing fixture of our own, which I found in the cabinets in the clean room.  This fixture had all 4 teflon pads, so I stole them and put them into the one that we're using for this round of upgrade / suspension hangings.  The height of all future side magnets should be correct. The thickness of the pads in the 'spare' fixture matched the one which came with the fixture from MIT as closely as I could feel by putting them on the same flat surface next to each other and feeling if there was a step. 

A side note about this magnet gluing fixture that I found:  It has the word "TOP" etched into it, to prevent exactly my problem with the ITMY side magnets in the first place.  Unfortunately the threads for the set screws which hold the optic are shot (or something is funny with them), so we can't just use this fixture. 

Gluing notes regarding the standoffs and guiderods:

There's more glue than I'd like on the guiderods / standoff for ITMX.  The glue was starting to get a little tacky when I glued the standoff in place after we balanced the optic, so it was hard to get it in the right place.  I'm confident we have a good epoxy contact, and we don't have much glue that I think it'll be a big problem.  Certainly I'll be a lot better at manuvering my glue-stick a.k.a skinny piece of wire around the suspension tower to get to the standoff for the rest of the optics that we're hanging, and I won't have glued something like ITMY side magnet immediately beforehand, which took enough time that the glue started to get tacky (not very tacky, just barely noticeably tacky).

I'd say that most gluing activities should be completed within ~10-15min of mixing the glue, after spending ~2min stirring to make sure it's nice and uniform.  It doesn't dry fast enough to be a huge rush, but you should get right on the gluing once the epoxy has been mixed. 

  2654   Thu Mar 4 02:25:14 2010 JenneUpdateCOCFurther details on the magnet story, and SRM guiderod glued

[Koji, Jenne]

First, the easy story:  SRM got it's guiderod & standoff glued on this evening.  It will be ready for magnets (assuming everything is sorted out....see below) as early as tomorrow.  We can also begin to glue PRM guiderods as early as tomorrow.

The magnet story is not as short.....

Problem: ITMX and ITMY's side magnets are not glued in the correct places along the z-axis of the optic (z-axis as in beam propagation direction). 

ITMX (as reported the other day) has the side magnet placement off by ~2mm.  ITMX side was glued using the magnet fixture from MIT and the teflon pads that Kiwamu and I improvised.

It was determined that the improvised teflon pads were too thin (maybe about 1m thick), so I took those out, and replaced them with the teflon pads stolen from the 40m's magnet gluing fixture.   (The teflon pad from the MIT fixture and the ones from the MIT fixture are the same within my measuring ability using a flat surface and feeling for a step between them.  I haven't yet measured with calipers the MIT pad thickness).  The pads from the 40m fixture, which were used in the MIT fixture to glue ITMY side last night were measured to be ~1.7mm thick.

Today when Koji hung ITMY, he discovered that the side magnet is off by ~1mm.  This improvement is consistent with the switching of the teflon pads to the ones from the 40m fixture.

We compared the 40m fixture with the one from MIT, and it looks like the distance from the edge of where the optic should sit to the center of the hole for the side magnet is different by ~1.1mm.  This explains the remaining ~1mm that ITMY is off by. 

We should put the teflon pads back into the 40m fixture, and only use that one from now on, unless we find an easy way to make thicker teflon pads for the fixture we received from MIT.  (The pads that are in there are about the maximum thickness that will fit).  I'm going to use my thickness measurements of SRM (taken in the process of gluing the guiderods) to see what thickness of pads / what fixture we want to actually use, but I'm sure that the fixture we found in the 40m is correct.  We can't use this fixture however, until we get some clean 1/4-28 screws.  I've emailed Steve and Bob, so hopefully they'll have something for us by ~lunchtime tomorrow. 

The ITMX side magnet is so far off in the Z-direction that we'll have to remove it and reglue it in the correct position in order for the shadow sensor to do anything.  For ITMY, we'll check it out tomorrow, whether the magnet is in the LED beam at all or not.  If it's not blocking the LED beam enough, we'll have to remove and reglue it too. 

Why someone made 2 almost identical fixtures, with a 1mm height difference and different threads for the set screws, I don't know.  But I don't think whoever that person was can be my friend this week. 

  2675   Tue Mar 16 04:22:02 2010 JenneUpdateEnvironmentEarthquake, Mag 4.4

Earthquake Details

Magnitude 4.4
Date-Time
  • Tuesday, March 16, 2010 at 11:04:00 UTC
  • Tuesday, March 16, 2010 at 04:04:00 AM at epicenter
Location 33.998°N, 118.072°W
Depth 18 km (11.2 miles)
Region GREATER LOS ANGELES AREA, CALIFORNIA
Distances
  • 2 km (1 miles) ENE (58°) from Pico Rivera, CA
  • 4 km (3 miles) ESE (115°) from Montebello, CA
  • 4 km (3 miles) SSW (207°) from Whittier Narrows Rec. Area, CA
  • 9 km (5 miles) NE (39°) from Downey, CA
  • 9 km (6 miles) SSW (206°) from El Monte, CA
  • 17 km (11 miles) ESE (112°) from Los Angeles Civic Center, CA
Location Uncertainty horizontal +/- 0.4 km (0.2 miles); depth +/- 0.9 km (0.6 miles)
Parameters Nph=122, Dmin=5 km, Rmss=0.37 sec, Gp= 25°,
M-type=local magnitude (ML), Version=2
Source
Event ID

ci14601172

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

MC1 and MC3 seem to have kept themselves together, but all the other optics' watchdogs tripped.

Attachment 1: EQ_16Mar2010.png
EQ_16Mar2010.png
  2770   Mon Apr 5 13:07:36 2010 JenneOmnistructureElectronicssoldering iron broken

Quote:

This morning the pencil soldering iron of our Weller WD2000M Soldering Station suddenly stopped working and got cold after I turned the station on. The unit's display is showing a message that says "TIP". i checked out the manual, but it doesn't say anything about that. I don't know what it means. Perhaps burned tip?

Before asking Steve to buy a new one, I emailed Weller about the problem.

 There should be a supply of extra tips in the Blue Spinny Cabiney (I can never remember it's French name....)  The drawer is something like the top row of one of the bottom sets of drawers.  You can pick the shape of tip you want, and stick it in.

  2802   Fri Apr 16 17:26:23 2010 JenneUpdatePEMGuralp Breakout Box pulled

I pulled the Guralp breakout box from the rack, and it's sitting on the EE bench here.  The game plan is to check out the Gur2X channel.  

Rana and Steve have been investigating, and found that the X channel has been funky (which has been known for ~a month or two) when the seismometer has been plugged in, and also when the seismometers have been unplugged, but the box is left on.  The funkyness goes away when the box is turned off.  Since it's not there when the box is off, it seems that it's not a problem with the cable from the box to the ADC, or in the ADC channel.  Since it is there when the box is on, but the seismometer is unplugged, it's clear that it's probably in the box itself.  

Preliminarily, I've connected a set of BNC clipdoodles to the input testpoints, and another set to the output.  They're both connected to a 'scope (which is on it's battery so it's not connected to any Ground), and when I tap on the circuit board the input trace is totally unchanged, but the output trace goes kind of crazy, and gets more fuzzy, and picks up a DC offset.  Koji is concerned that some of the big capacitors may have an iffy connection to the board. 

Investigations will continue Monday morning. 

  2811   Tue Apr 20 00:32:30 2010 JenneUpdatePEMGuralp Breakout Box put back

Quote:

I pulled the Guralp breakout box from the rack, and it's sitting on the EE bench here.  The game plan is to check out the Gur2X channel.  

Rana and Steve have been investigating, and found that the X channel has been funky (which has been known for ~a month or two) when the seismometer has been plugged in, and also when the seismometers have been unplugged, but the box is left on.  The funkyness goes away when the box is turned off.  Since it's not there when the box is off, it seems that it's not a problem with the cable from the box to the ADC, or in the ADC channel.  Since it is there when the box is on, but the seismometer is unplugged, it's clear that it's probably in the box itself.  

Preliminarily, I've connected a set of BNC clipdoodles to the input testpoints, and another set to the output.  They're both connected to a 'scope (which is on it's battery so it's not connected to any Ground), and when I tap on the circuit board the input trace is totally unchanged, but the output trace goes kind of crazy, and gets more fuzzy, and picks up a DC offset.  Koji is concerned that some of the big capacitors may have an iffy connection to the board. 

Investigations will continue Monday morning. 

 The Guralp Box appears to be back in working order.  It's reinstalled with the 2 seismometers plugged in.

In order:

* Koji suggested retouching the through-board solder joints on the broken channel (EW2 = Gur2X) with a bit of solder to ensure the connections were good.  Check.

* "C7", one of the giant 1uF capacitors on each channel is totally bypassed, and since that was one of the original suspects, Rana removed the (possibly) offending capacitor from EW2.

* Rana and I isolated the craziness to the final differential output stage.  We tried each of the testpoints after the individual gain / filter stages, and found that the signals were all fine, until after the output stage.

* I started to remove the resistors in the output stage (with the plan to go through the resistors, capacitors, and even the amplifier chip if neccessary), and noticed that 2 of the 1k resistors came off too easily, as if they were just barely connected in the first place.  After replacing only the 4 1k resistors, the craziness seemed to be gone.  I poked and gently bent the board, but the output wouldn't go crazy.  I declared victory.

* I reinstalled the box in its normal spot, and put Gur2 (which had been out by the bench for use as a test signal) back next to the other seismometers.  We are in nominal condition, and should be able to do a huddle test this week.

 

I looked at the time traces of all the seismometer channels, and they all looked good.  I'll put a spectra in in the morning....I'm too impatient to wait around for the low frequency FFTs.

 

Attached are the before and after pictures of the output stage of EW2 / Gur2X.  The "before" is the one with the OUT+ and OUT- words upsidedown.  The "after" picture has them right side up.

Attachment 1: Gur2X_before_20Apr2010.jpg
Gur2X_before_20Apr2010.jpg
Attachment 2: Gur2X_after_replace_100k_resistors_20Apr2010.jpg
Gur2X_after_replace_100k_resistors_20Apr2010.jpg
  2819   Tue Apr 20 13:37:36 2010 JenneUpdateGreen Locking1W NPRO output profile

Quote:

I have redone the beam fit, this time omitting the M2, which I believe was superfluous. I have made the requested changes to the plot, save for the error analysis, which I am still trying to work out (the function I used for the least squares fit does not work out standard error in fit parameters). I will figure out a way to do this and amend the plot to have error bars.

 
profile_fit_4_19_10.png

 Are you sure about your x-axis label? 

  2820   Tue Apr 20 18:02:22 2010 JenneUpdateCOCNew SRM and PRM Hung

[Jenne, Steve]

We removed the old SRM and PRM from their cages, and are temporarily storing them in the rings which we use to hold the optics while baking.  Steve will work on a way to store them more permanently.

We then hung the new SRM (SRMU03) and new PRM (SRMU04) in the cages.  We were careful not to break the wires, so the heights will not have changed from the old heights.

The optics have not been balanced yet.  That will hopefully happen later this week.

  2825   Wed Apr 21 15:53:57 2010 JenneUpdatePEMSeismometers now on the granite slab

The 3 seismometers are now on the granite slab.  The Ranger is now aligned with the Xarm (perpendicular to the Mode Cleaner) since that's the only way all 3 would fit on the slab.

Attachment 1: P4210048.JPG
P4210048.JPG
  2833   Thu Apr 22 20:28:40 2010 JenneUpdatePEMSeismometer Noise Characteristics

Quote from elog 2237, 11 Nov 2009:

The attached plot shows the spectra of the 3 Z axes of the 3 seismometers we have (this data is from ~20Aug2009, when the Ranger was in the Z orientation) in Magenta, Cyan and Green, and the noise of each of the sensors in Red, Blue and Black.  The noise curves were extracted from the spectra using the Huddle Test / 3 Corner Hat method.  The Blue and Black traces which are just a few points are estimates of the noise from other spectra.  The Blue points come from the Guralp Spec Sheet, and the Black comes from the noise test that Rana and I did the other day with the Ranger (elog 2223).  

I'm not really happy with the black spectra - it looks way too high.  I'm still investigating to see if this is a problem with my calibration/method....

 So, as it turns out (surprise), I'm a spaz and forgot a 2*pi when calibrating the Guralp noise spectra from the spec sheet.  I noticed this when redoing the Huddle Test, and comparing my Spec Sheet Guralp noise with Rana's, which he shows in elog 2689.  When going from m/s^2, the units in the spec sheet, I just tilted the line by a factor of frequency.  Koji pointed out that I needed a factor of 2*pi*f.  That moves the Guralp spec line in the plot in elog 2237 (to which this entry is a reply) down by ~6, so that my measured noise is not, in fact, below the spec.  This makes things much more right with the world.

In other news, I redid the Huddle analysis of the 2 Guralp seismometers, ala Rana's elog 2689. The difference is now we are on the granite slab, with soft rubber feet between the floor and the granite.  We have not yet cut holes in the linoleum (which we'll do so that we're sitting directly on the 40m's slab).

Rana> this seems horrible. Its like there's a monster in there at 6-7 Hz! Either the seismos are not centered or the rubber balls are bad or Steve is dancing on the granite slab again.

 

Attachment 1: Gur1_Gur2_noise.png
Gur1_Gur2_noise.png
  2889   Thu May 6 18:25:20 2010 JenneUpdatePEMAcc power supply turned on

The accelerometer power supply / preamp board has been OFF because of exciting new accelerometer measurements.  It's now on, so watch out and make sure to turn it back off before plugging / unplugging accelerometers.

  2892   Thu May 6 19:51:22 2010 JenneUpdatePEMNew 'Seismic Spectrum of the 40m'

For reasons unknown, the seismic spectra posted above Rosalba has been wrong since ~January when it was first posted.  The noise that we were claiming was waaaay lower than is really possible.

Rana and I checked the calibrations, and the numbers in DTT for the Ranger and the Guralp are correct (it's unknown what was being used at the time of the bad plot) - Cal for the Guralp is 3.8e-9 m/s, and for the Ranger is 1.77e-9 m/s.

Something is funny with the accelerometer calibration.  Hopefully Kevin's investigation will sort it out.  Their calibration used to be 1.2e-7 m/s^2 , but it was changed to be 7e-7 m/s^2 to match the noise level of the accelerometers with the seismometers at ~10Hz. We need to go through the calibration carefully and figure out why this is!

Posted above Rosalba for easy reference, and attached below, is the new seismic spectra.  The black trace is when the Ranger's mass is locked down, and the teal circle markers indicate the Guralp Spec-Sheet Noise Floor.

** Rana says> the y-axis in Jenne's plot is (m/s)/sqrt(Hz). The Guralp has a velocity readout bandwidth of 0.03-40 Hz, so we would have to modify the calibration to make it right in those frequencies. I believe the Ranger cal has the correct poles in it. The huge rise at low frequencies is because of the 1/f noise of the SR560.

Attachment 1: SeisRef_6May2010_AccelCalFudged.png
SeisRef_6May2010_AccelCalFudged.png
  2934   Fri May 14 16:19:22 2010 JenneUpdatePEMGuts of a Guralp

[Jenne, Rana]

We took apart and examined one of the Guralp seismometers this afternoon.  For the most part we think we understand how it works. The horizontal sensors are a little more confusing, since we didn't end up finding the moving masses.  The vertical sensor is a flat rectangle, hinged at one edge.  There are capacitive sensors above and below the rectangle.  The hinged end is connected to a leaf spring. 

The PCBs are packed full of old-school 80's components.  We probably need an actual schematic to figure out where the preamp circuit is, which is what we'd want to think about fitzing with, if we were to try to improve the noise of the seismometer.  For now, we put it all back together, and back out on the granite slab. 

There was a wee bit of confusion when putting the N/S marker-spikes back on as to where they should go.  The solution is that the handle of the seismometer is aligned with the North/South axis, so the spikes should be aligned with the handle.  The lid of the seismometer is uniquely aligned to the stuff inside by the ribbon cable connector, as well as the holes in the lid for accessing the centering potentiometers.  So, align the lid to the pots, and then align the spikes to the handle.

Photos are on Picasa.

  2941   Mon May 17 19:42:11 2010 JenneUpdateIOOFirst steps toward MC mode measuring

[Jenne, Kevin, Steve]

We made some progress toward getting the MC's beam profile measured.  In the end, no changes were made to anything today, but we're more prepared to go for tomorrow.

What we did:

* Grabbed the scanning slit beam scan from the PSL lab.  It's the same kind as we had here at the 40m, so Kevin was able to hook it up to the computer, and confirmed that it works.

* Opened the IOO and OMC chamber doors, and locked the MC.  Unfortunately the MC mode was awful in Yaw.  Awful like TEM(0,10+). But it still locked.  

* Confirmed that the beam went through the Faraday.  I looked at the beam before and after the Faraday on a card, and it was the same nasty beam both before and after.  So it looks like Zach did a good job aligning the Faraday and everything else.  I was going to clamp the Faraday, but I didn't yet, since I wanted to see the nice happy TEM00 mode go through without clipping before risking moving the Faraday during clamping (I don't know how heavy it is, so I'm not sure how much it might potentially move during clamping.)

* Noticed that there is a whole lot of crap on both the OMC and BS tables that's going to have to move.  In particular, one of the weights leveling the OMC table is right where I need to put MMT2.  Steve suggested putting the optic there, in its approximate place, before doing too much other stuff, since it could potentially affect the leveling of the table, and thus the input pointing to the MC.  Unfortunately, to do that I'll need to move the weight, which is definitely going to change things.  Sad face.  Moving the weight will likely be one of the first things I do tomorrow, so that all 3 profile measurements have the same configuration. 

* Before closing up, I tried to align the MC, to get back to TEM00, to no avail.  I got as far as achieving TEM11 flashing, along with a bunch of other crappy modes, but didn't get 00.  That's also on the to-do list.

What we're going to do:

* Open the chambers, and align the MC to TEM00 (using the sliders on the MC align screen).

* Check with an IR card that the beam goes through the Faraday.

* Clamp the Faraday, reconfirm.

* Remove the weight on the OMC table.

* Place MMT2 on the OMC table in it's approximate final location.

* Realign the MC, and make sure the beam goes through the Faraday.  If this doesn't happen smoothly, I may need more instruction since I've never dealt with aligning the Faraday before.  What are the appropriate mirrors to adjust? 

* Move the PZT flat steering mirror from the BS table to the IOO table.  (Thoughts on this?  This will change the table leveling, and also includes the trickiness of needing to move the connectors for the PZT.)

* Place a flat mirror on the BS table to route the MC beam out to the BS/PRM/SRM oplev table. 

* Measure the mode using the beam scan: on the BS oplev table, on the POX table, and then perhaps by shooting the beam through the beamtube on the ETMY (new convention) table.

* Place MMT1 on the BS table, use flat mirrors to get it out of the chambers, repeat measurements.

* Place MMT2 in the correct position, use flat mirrors to get it out of the chambers, repeat measurements.

All of this may require some serious cleaning-up of the BS table, which is going to be ugly, but it has to happen sometime. Hopefully I can get away with only moving a minimal number of things, in order to get these measurements done.

 

Another note: Don't trust the PSL shutter and the switch on the MEDM screens! Always use a manual block in addition!!! We discovered upon closeup that hitting the "Closed" button, while it reads back as if the shutter is closed (with the red box around the buttons), does not in fact close the shutter.  The shutter is still wide open.  This must be fixed.

ELOG V3.1.3-