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ID Date Authorup Type Category Subject
  1734   Sun Jul 12 23:14:56 2009 JenneOmnistructureGeneralWeb screenshots aren't being updated

Before heading back to the 40m to check on the computer situation, I thought I'd check the web screenshots page that Kakeru worked on, and it looks like none of the screens have been updated since June 1st.  I don't know what the story is on that one, or how to fix it, but it'd be handy if it were fixed.

  1745   Tue Jul 14 17:48:20 2009 JenneOmnistructureEnvironmentRemoval of the cold air deflection device for the MOPA chiller



Around 2 PM today, I removed the blue flap which has been deflecting the cold air from the AC down into the laser chiller.
Let's watch the laser trends for a few days to see if there's any effect.

Alberto has moved us to stage 2 of this experiment: turning off the AC.

The situation at the control room computers with the AC on minus the blue flap is untenable--it's too cold and the air flow has an unpleasant eye-drying effect.

I turned the AC back on because the temperature of the room was going up so also that of the laser chiller.

I reinstalled the blue-flap technology on the AC, because the MOPA power was dropping like a rock. A light-ish rock since it wasn't going down too fast, but the alarms started going a little while ago because PMC trans was too low, because the power was getting a little low. The laser water chiller is reading 21.97C, which is higher than it normally does/did before the AC shenanigans (It usually reads 20.00C).

Attached is a look-back of 18 hours, during which you can see in the AMPMON the time that Rana removed the blue flap around 2pm yesterday and the AMPMON changes a little bit, but not drastically, the time around 11pm when the AC was turned off, and AMPMON goes down pretty fast, and about 12:30am, when Alberto turned the AC back on, and AMPMON starts to recover. I think that the AMPMON starts to go down again in the morning because it's been crazy hot here in Pasadena, so the room might be getting warmer, especially with the laser chiller-chiller not actively chilling the laser chiller (by not being pointed at the water chiller), so the water isn't getting as cold, and the HTEMP started to go up.

In the last few minutes of having put the blue flap back on the AC, the laser chiller is already reading a lower temperature, and the AMPMON is starting to recover.
Attachment 1: ACeffectonLASER2.png
  1752   Wed Jul 15 17:18:24 2009 JenneDAQComputersDAQAWG gone, now back

Yet again, the DAQAWG flipped out for an unknowable reason.  In order of restart activities listed on the Wiki, I keyed the crate and nothing really happened, then I hit the physical reset button and nothing happened, and then I did the 'telnet....vmeBusReset', and a couple minutes later, it was all good again.

  1765   Mon Jul 20 17:06:29 2009 JenneUpdatePEMGuralp Box Fail

That's terrible: R5 & R8 should definitely be 100 Ohm and not 100kOhm. 100k would make it a noise disaster. They should also be metal film (from the expensive box, not from the standard box). This is the same for all channels so might as well stuff them.

The circuit diagram between TP3 and TP4 appears to be designed to make the whitening not work. That's why R6 & R7 should be 100k. And R2 should be metal film too.

Basically, every time we want good low frequency performance we have to use the metal film or metal foil or wirewound resistors. Everything else produces a lot of crackling noise under the influence of DC current.

I'm also attaching the voltage and current noise spectra for the AD620 from the datasheet. These should allow us to compare our measurements to a reasonable baseline.

While we're comparing things to other things, Ben Abbott just emailed me his measurement of the AD620 from back in the day. Clara's going to use this along with the specs to make sure that (a) we're not taking crazy measurements and (b) our AD620s aren't broken and in need of replacement. In this plot, we're looking at the GOLD trace, which has the AD620 set up with a gain of 10, which is how our AD620's are set up in the Guralp breakout box.

Just picking a single point to compare, it looks like at 1Hz, Ben saw ~130dBVrms/rtHz. Converting this to regular units [ 10^(#dB/20)*1Vrms = Vrms ], this is about 3*10^-7 Vrms. That means that Clara's measurements of our AD620 noise is within a factor of 2 of Ben's. Maybe the way we're connecting them up just isn't allowing us to achieve the ~50nV/rtHz that is claimed.
Attachment 1: AD620noise_BenAbbott.pdf
  1768   Tue Jul 21 15:32:47 2009 JenneUpdateIOOMC_L flatlined

[Clara, Jenne]

While Clara was working on her Wiener filtering and optimizing the locations of the accelerometers, she discovered that MC_L and MC_L_256 are totally flatlined.  I looked at them, and it looks like they've been dead since ~9:30pm-ish on Sunday night.  Bootfest-type activities shall commence shortly.

  1770   Tue Jul 21 17:52:12 2009 JenneUpdateIOOMC_L flatlined


[Clara, Jenne]

While Clara was working on her Wiener filtering and optimizing the locations of the accelerometers, she discovered that MC_L and MC_L_256 are totally flatlined.  I looked at them, and it looks like they've been dead since ~9:30pm-ish on Sunday night.  Bootfest-type activities shall commence shortly.

 Under Alberto's tutalage, I rebooted the whole vme set (iovme, sosvme, susvme1, susvme2), and after that MC_L was all good again.

  1786   Fri Jul 24 17:20:48 2009 JenneUpdateoplevsETMY oplev is iffy

ETMY oplev is currently a work in progress.  The HeNe beam is hitting the photodiode, but the spot size there is pretty much the size of the entire QPD.  Thus, the ETMY oplev isn't really useful right now.  I'm re-figuring things out (note to self: close to the laser, you have to use Gaussian optics...regular ray tracing doesn't really work), and hopefully will have the oplev back under control by the time Alberto is finished realigning the IFO, so this doesn't keep anyone from doing any exciting locking work.

  1798   Mon Jul 27 17:48:44 2009 JenneUpdateoplevsETMY oplev is still down for the count

ETMY oplev is still out of order.  Hopefully I'll get it under control by tomorrow. 

  1808   Wed Jul 29 14:56:44 2009 JenneUpdatePEMMiniEarthquakes due to construction

The construction people next door seem to be getting pretty excited about pounding things lately.  At my desk the floor was shaking like a mini-earthquake, and all of the accelerometers were pretty much railed. Clara has the Guralp box out right now, so the Guralp is unplugged, but the Ranger didn't seem to be railed.

This either (a) is part of the reason the MC is being wonky lately, or (b) has nothing whatsoever to do with it.  The MC watchdogs haven't been tripping all the time, so maybe this isn't a primary cause of the wonky-ness.

In looking at a many-days/months trend to see how far back this has been going, it looks like the accelerometers are hitting their rails pretty much all day every day.  This may be significantly hindering Clara's Wiener filtering work.  I think the gain on the accelerometer's controler panel is already set to 1, but if it's set to 10, we may want to reduce that.  Alternatively, we may want to put in attenuators just as the signal is entering the PEM ADCU, to help reduce the amount of rail-hitting that's going on. I don't remember this from a couple of months ago, so this may be a problem that will go away once the construction / landscaping is done next door.

  1820   Mon Aug 3 14:15:50 2009 JenneUpdateIOOWFS recentered

I am (was) able to get the mode cleaner mostly locked, but because WFS2 wasn't centered, the MC would drift, then lose lock.  I recentered both the WFS (after unlocking the MC and the MZ), and am now about to commence relocking both of those.


/end{quick update}


Note to self:  WFS get centered based on the direct reflection from MC1.  Once the MC is close enough, the WFS are enabled, and they twiddle all 3 MC mirrors to minimize their error signal.  Moral of the story: make sure the WFS are centered.

  1821   Mon Aug 3 14:47:53 2009 JenneUpdateIOOMC locks again

The mode cleaner seems to be locking again.  I've manually unlocked it a few times in the past 20min, and most of the time it catches lock again (maybe about 80% of the time).  Other times, it starts to lock in a bad mode, and can't fix itself, so I unlock it, and let it restart and it usually does fine the second time around. 


I'd like it to be a little more robust, but I'm having a bit of trouble zeroing in on the optimal alignment for quickest, most durable lock aquisition of the MC.  Right now I'm going to leave it for a little while to make sure it doesn't fall apart.

  1825   Tue Aug 4 11:54:20 2009 JenneUpdateIOOMC_trans readout on LOCK_MC screen now normalized

The MC_trans QPD Pitch and Yaw readout on the Lock_MC screen are now normalized by the trans_sum. I used the method described in my entry elog 1488

/caltech/target/c1iool0/ioo.db now includes:

grecord(calc, "C1:IOO-MC_TRANS_P")
        field(INPA, "C1:IOO-MC_TRANS_VERT")
        field(INPB, "C1:IOO-MC_TRANS_SUM")
        field(SCAN, ".1 second")
        field(PREC, "3")
        field(CALC, "A/B")

grecord(calc, "C1:IOO-MC_TRANS_Y")
        field(INPA, "C1:IOO-MC_TRANS_HOR")
        field(INPB, "C1:IOO-MC_TRANS_SUM")
        field(SCAN, ".1 second")
        field(PREC, "3")
        field(CALC, "A/B")


The Lock_MC screen was changed to show these new P and Y channels. 

  1827   Tue Aug 4 15:48:25 2009 JenneUpdateComputersmini boot fest

Last night Rana noticed that the overflows on the ITM and ETM coils were a crazy huge number.  Today I rebooted c1dcuepics, c1iovme, c1sosvme, c1susvme1 and c1susvme2 (in that order).  Rob helped me burt restore losepics and iscepics, which needs to be done whenever you reboot the epics computer.

Unfortunately this didn't help the overflow problem at all.  I don't know what to do about that.

  1844   Thu Aug 6 17:45:37 2009 JenneUpdatePSLHEPAs on high

Stephanie has needed the doors to the PSL open all day, and still has them open, so I just turned the HEPAs on high. 

  1847   Thu Aug 6 18:26:26 2009 JenneUpdatePSLRef Cav and PMC aligned

[Alberto, Jenne]

We aligned both the reference cavity and the PMC, each by looking at their Trans PD on Davaviewer, and adjusting the two steering mirrors to maximize the transmission power.  We got a pretty good amount of improvement for the ref cav, but since the PMC hasn't decayed a whole lot, we got a much smaller amount of improvement.

  1850   Thu Aug 6 23:29:47 2009 JenneUpdatePSLRef cav reflection PD is funky

After Alberto and I worked on aligning the reference cavity, Rob asked the important and useful question: what is the visibility of the reference cavity.  This helps tell us if we're optimally aligned or not even close.

I did a scan of the ref cav temperature, using /scripts/PSL/FSS/SLOWscan, but there seems to be no real signal is C1:PSL-FSS_RFPDDC.  As shown in Alberto's 200-day plot, it does change sometimes, but if you zoom in on the flat parts, it seems like it's not really reading anything meaningful.  I did a cursory check-out of it, but I'm not 100% sure where to go from here:  There are (as with all of these gold-box PDs) 3 outputs:  a ribbon cable (for ADC purposes I think), an SMA for the RF signal, and a BNC for the DC signal.  The photodiode is clearly working, since if you stick the Lollypop in front of the PD, the cavity unlocks.  I plugged a 'scope into the DC BNC, and it also behaves as expected: block the beam and the signal goes down; unblock the beam and the signal goes up.  Something of note is that this readout gives a positive voltage, which decreases when the beam is blocked.  However, looking at the dataviewer channel, nothing at all seems to happen when the beam is blocked/unblocked.  So the problem lies somewhere in the get-signal-to-DAQ path.  I unplugged and replugged in the ribbon cable, and the value at which the channel has been stuck changed.  Many days ago, the value was -0.5, for the last few days it's been -1.5, and after my unplug/replug, it's now back to ~ -0.5 . The other day Alberto mentioned, and made the point again today that it's a little weird that the PD reads out a negative voltage.  Hmm.


Do we have a tester-cable, so that instead of the ribbon cable, I can plug that connector (or pins thereof) into a 'scope?

  1860   Fri Aug 7 17:05:34 2009 JenneUpdatePSLRef cav reflection PD is funky


we have a tester cable, but you don't want it. Instead the problem is probably at the cross-connect. The D-cable goes to a cross-connect and you can probe there with a voltmeter. If the signal is good there, trace it to the ADC. Also trend for several years to see when this happened - Yoichi may know the history better.

Also, we still need to complete the FSS RFPD task list from last year.


 [Jenne, Ben]

I called in the reinforcements today.  Ben came over and we looked all around at all of the cross-connects and cables relating to the FSS.  Everything looks pretty much okey-dokey, except that we still weren't getting signal in the DataViewer channels.  Finally we looked at the psl.db file, which indicates that the C1:PSL-FSS_RFPDDC channel looks at channel 21 of the ADC cross connect thing.  We followed the cable which was plugged into this, and it led to a cable which was disconnected, but laying right next to the Ref Cav refl PD.  We plugged this into the DC out SMA connection of the photodiode (which had not been connected to anything), and suddenly everything was mostly golden again in dataviewer land.  RFPDDC_F now has a signal, but RFPDDC is still flat. 


Even though this seems to be working now, it's still not perfect.  Rob suggested that instead of having this SMA cable going from the photodiode's DC out, we should take the signal from the ribbon cable.  So I'm going to figure out which pin of the D-connector is the DC out, and take that from the cross connect to the ADC cross connect.  This will help avoid some persnickity ground loops. 

  1871   Mon Aug 10 11:33:58 2009 JenneUpdatePSLNon-Elogged Beam dump on the PSL table - BadBadBad

Big thumbs down to whoever put a beam dump on the PSL table in front of the PMC yesterday afternoon without noting it in the elog

The offending beam dump has been removed, and the PMC relocked.

Attachment 1: commodusthumbsdown.jpg
  1872   Mon Aug 10 14:58:01 2009 JenneUpdatePEM2nd set of Guralp channels plugged into ADCU

The second set of Guralp channels is now plugged into the PEM ADCU, into channels which are confirmed to be working.  (Method: 1Vpp sine wave into channel, check with DataViewer).


Direction, Channel Name, .ini chnum, BNC plug # on ADCU

Vertical: C1:PEM-SEIS_GUR_VERT, 15023, #24

N/S (should be Y when the seismometer is put in place): C1:PEM-TEMP_2, 15001, #2

E/W (should be X when the seismometer is put in place): C1:PEM-TEMP_3, 15002, #3


There is IFO work going on, so I don't want to rename the channels / restart fb40m until a little later, so I'll just use the old TEMP channel names for now. 


There is something totally wrong with the E/W channel.  I can look at all 3 channels on a 'scope (while it's on battery, so the op-amps in the breakout box aren't grounded), and VERT and NS look fine, and when I jump around ("seismic testing"), they show spikes.  But the EW channel's signal on the 'scope is way smaller, and it doesn't show anything when I jump. 


I might use the handheld Guralp tester breakout box to check the seismometer.  Also, a suspicion I have is that whoever put the box back in on Friday night after our final noise measurements left the inputs shorted for this one channel.  It's the 3rd channel in the set, so it would be most likely to be stuck shorted...  Investigations will ensue.

  1873   Mon Aug 10 15:21:15 2009 JenneUpdatePSLNon-Elogged Beam dump on the PSL table - BadBadBad


Big thumbs down to whoever put a beam dump on the PSL table in front of the PMC yesterday afternoon without noting it in the elog

The offending beam dump has been removed, and the PMC relocked.

 Maybe it was Russell Crowe

  1882   Mon Aug 10 18:12:25 2009 JenneUpdatePEM2nd set of Guralp channels plugged into ADCU


The second set of Guralp channels is now plugged into the PEM ADCU, into channels which are confirmed to be working.  (Method: 1Vpp sine wave into channel, check with DataViewer).


Direction, Channel Name, .ini chnum, BNC plug # on ADCU

Vertical: C1:PEM-SEIS_GUR_VERT, 15023, #24

N/S (should be Y when the seismometer is put in place): C1:PEM-TEMP_2, 15001, #2

E/W (should be X when the seismometer is put in place): C1:PEM-TEMP_3, 15002, #3


There is IFO work going on, so I don't want to rename the channels / restart fb40m until a little later, so I'll just use the old TEMP channel names for now. 


There is something totally wrong with the E/W channel.  I can look at all 3 channels on a 'scope (while it's on battery, so the op-amps in the breakout box aren't grounded), and VERT and NS look fine, and when I jump around ("seismic testing"), they show spikes.  But the EW channel's signal on the 'scope is way smaller, and it doesn't show anything when I jump. 


I might use the handheld Guralp tester breakout box to check the seismometer.  Also, a suspicion I have is that whoever put the box back in on Friday night after our final noise measurements left the inputs shorted for this one channel.  It's the 3rd channel in the set, so it would be most likely to be stuck shorted...  Investigations will ensue.

 All the channels are now good, and all the names are back to making sense. 

The problem with EW2 was in fact that the alligator clip used to short the inputs during the noise test Friday night was left in the box.  Not great, but now it's taken care of, and we have recorded data of the noise of the breakout box, so we can include that in our plots to see if we're at the limit of how good we can do at subtracting noise.


The channels are now named thusly:

C1:PEM-SEIS_GUR_VERT  (BNC input #24, .ini channel #15023)

C1:PEM-SEIS_GUR_EW     (BNC input #3, .ini channel #15002)

C1:PEM-SEIS_GUR_NS      (BNC input #2, .ini channel #15001)

C1:PEM-SEIS_MC1_X         (BNC input #11, .ini channel #15010)

C1:PEM-SEIS_MC1_Y        (BNC input #12, .ini channel #15011)

C1:PEM-SEIS_MC1_Z       (BNC input #10, .ini channel #15009)

C1:PEM-SEIS_MC2_Y (Ranger, which for the Huddle Test is oriented VERTICALLY)   (BNC input #4, .ini channel #15003)


Now we wait.....and tomorrow extract the noise of each of the seismometers from this!



  1895   Thu Aug 13 00:11:43 2009 JenneUpdateIOOMode Cleaner Unlock

So that I can collect a bit of free-swinging Mode Cleaner data, I started a script to wait 14400 seconds (4 hours), then unlock the mode cleaner.  It should unlock the MC around 4am.  As soon as someone gets in in the morning, you can relock it.  I should have plenty of data by then.

  1896   Thu Aug 13 02:17:56 2009 JenneUpdateIOOMode Cleaner Alignment

When Rob and I were getting started on locking for the evening, Mode Cleaner lost lock a few times, but every time it lost lock, it took forever to reaquire, and was pretty insistent on locking in the TEM10 mode.  I proposed that the alignment might be sketchy.  I've been fiddling with the MC alignment sliders for the last hour and a half or so, but I think I'm not 100% in tune with the 3 mirror parameter space.  The mode cleaner now locks, but I'm not in love with its' alignment.  The WFS are definitely catywhompus.  Before doing hardware things like recentering the WFS, I'm going to wait until tomorrow to consult with an alignment expert.

In case this is helpful for tomorrow, before I touched any of the sliders:

Optic, Pitch, Yaw

MC1, 3.1459, -0.7200

MC3, -0.8168, -3.0700

MC2, 3.6360, -1.0576


Now that mode cleaner locks, although not in a great alignment:

MC1, 3.1089, -0.7320

MC3, -0.7508, -3.0770

MC2, 3.6610, -1.0786


If I knew how to kill my script to unlock the mode cleaner, I would.  But I sourced it, and Rob didn't know earlier this evening how to kill something which is started with 'source' since it doesn't seem to get a process number like when you './'  to run a script. So the Mode Cleaner will probably be unlocked in the morning, and it may be persnickity to get it relocked, especially if the tree people are doing tree things with giant trucks again in the morning.

  1903   Fri Aug 14 14:33:51 2009 JenneSummaryComputersnodus rebooted


nodus was rebooted by Alex at Fri Aug 14 13:53. I launched elogd.

cd /export/elog/elog-2.7.5/
./elogd -p 8080 -c /export/elog/elog-2.7.5/elogd.cfg -D

 It looks like Alex also rebooted all of the control room computers.  Or something.  The alarm handler and strip tool aren't running.....after I fix susvme2 (which was down when I got in earlier today), I'll figure out how to restart those.

  1905   Fri Aug 14 15:29:43 2009 JenneUpdateComputersc1susvme2 was unmounted from /cvs/cds

When I came in earlier today, I noticed that c1susvme2 was red on the DAQ screens.  Since the vme computers always seem to be happier as a set, I hit the physical reset buttons on sosvme, susvme1 and susvme2.  I then did the telnet or ssh in as appropriate for each computer in turn.  sosvme and susvme1 came back just fine. However, I couldn't cd to /cvs/cds/caltech/target/c1susvme2 while ssh-ed in to susvme2.  I could cd to /cvs/cds, and then did an ls, and it came back totally blank.  There was nothing at all in the folder. 

Yoichi showed me how to do 'df' to figure out what filesystems are mounted, and it looked as though the filesystem was mounted.  But then Yoichi tried to unmount the filesystem, and it claimed that it wasn't mounted at all.  We then remounted the filesystem, and things were good again.  I was able to continue the regular restart procedure, and the computer is back up again.

Recap: c1susvme2 mysteriously got unmounted from /cvs/cds!  But it's back, and the computers are all good again.

  1922   Tue Aug 18 01:16:01 2009 JenneUpdatePSLMach Zehnder is realigned

The Mach Zehnder and I got to know each other today.  The reason for redoing the alignment was to improve pointing from the PSL table into the MC/IFO in hopes that this would solve the MC unlocking problems that we've been having lately.  Since Rana had aligned the IOO QPDs a few weeks ago when all of the alignments and things were good, I used them as a reference for my Mach Zehnder alignment activities. 

The order of operations were approximately as follows:

1. Block the secondary (west) arm of the Mach Zehnder using either an aluminum or razor dump.

2. Use SM1 in the MZ to align the beam to the IOO_QPDs (Pos and Ang).  I unfortunately also touched BS2 at this juncture, which made the refl path no longer a reference.

3.  Make sure that the QPD Sum on both Pos and Ang was sensible.  Since there are 2 beamsplitters in a Mach Zehnder, the power on the QPDs should be a quarter when only one beam is on them.  Be careful not to allow the beam no clip on anything.  The biggest problem was the bottom periscope mirror - if you hit it too high or too low, since it is a very thick optic, you end up coming out its side!  This is the frosty part on the edges, totally inappropriate for beams to go through!  Since the side of the periscope mirror isn't HR coated, when going through it like this, I was able to saturate the QPDs.  Not so good. 

4. Also, make sure that this first beam is on the MZ Refl PD.  Do this using the steering optics after the beam has left the MZ.  Use a viewer to look at the PD, and see the small spot of the beam on the diode.  We closed the iris which is present and was standing fully open to remove a spurious beam which was a parallel split-off of the main beam.  Since it was very weak, it is fine.

5.  Unblock the west arm, and block the east arm of the MZ.

6. Align this arm to both the IOO QPDs and the MZ refl diode using the adjustments on BS1, the PZT mirror and if necessary, BS2.  Note that the adjust knobs on the PZT mirror have lock screws.  Make sure to unlock them before adjusting, and relock afterward, to avoid slipping while the PZT is moving.

7.  Unblock all the beams, and make sure there is only one spot both on the transmission side and the reflection side, i.e. the 2 spots from the 2 arms are completely overlapping.  For the Trans side, make sure to look both in the near field and the far field (even after the periscope) to ensure that you really have one spot, instead of just the 2 spots crossing at a single location.

8.  Look at the MZ refl DC out and the PD out from the ISS box (which is essentially MZ trans, looking at Morag and Siobhan) on a 'scope.

9.  Touch / gently wiggle BS1 or another optic, and watch the 'scope.  At the same time, adjust BS1, the PZT mirror and BS2 to maximize the contrast between light and dark fringes.  Ideally, the refl PD should go almost to zero at the dark fringes.

10.  Check that you still have only one overlapping beam everywhere, and that you're actually hitting the MZ refl PD.

11. Because I was concerned about clipping while still figuring out the status of the lower periscope mirror, I removed the beam pipe holders between the last optic before the periscope, and the lower periscope mirror.  The beam pipe had already been removed, this was just the pedestals and the snap-in clamps.

All done for now!  Still to be done:  Optimize the position of the EOMs.  There is a waveplate out front and the EOMs are mounted in such a way that they can be moved in several directions, so that we can optimize the alignment into them.  They ideally only should see a single polarization, in order to apply solely a phase modulation on the beam.  If the input polarization isn't correct, then we'll get a bit of amplitude modulation as well, which on PDs looks like a cavity length change.  Also, the little blue pomona-type box which has the RF signals for the EOMs needs to be clamped to the table with a dog clamp, or better yet needs to be moved underneath the PSL table, with just the cables coming up to the EOMs.  The SMA connections and the SMA cable kept interfering with the MZ refl beam...it's a wonder anyone ever made the beam snake around those cables the way they were in the first place. Right now, the box is sitting just off the side of the table, just inside the doors.

Something else that Rana and I did while on the table:  We moved the PMC trans optics just a teensy bit toward the PSL door (to the east) to avoid coming so unbelievably close to the MZ refl optics.  The PMC trans beam shown in the lowest part of my sketch was very nearly clipping on the MZ refl steering optic just near it.  This situation isn't totally ideal, since (as it has been in the past), the first optic which is dedicated to the PMC trans isn't fully sitting on the PSL table.  The pedestal needs to hang off the edge of the table a bit to keep this beam from clipping.  Unfortunately there really isn't space to make a better beam path.  Since we're planning on getting rid of the MZ when the upgrade happens, and this isn't causing us noticeable trouble right now, we're going to let it stay the way it is.

Also, we dumped the reflection from the PMC RFPD onto a razor blade dump. And we noticed that the PZT mirror and BS2 in the MZ are badly vibrationally sensitive. BS2 has a ~400 Hz resonance (which is OK) but a ~150 ms ringdown time!! PZT mirror is similar.

Q = pi * f * tau = 200!  Needs some damping.

Attachment 1: MachZehnderOptics2.pdf
  1925   Tue Aug 18 15:52:27 2009 JenneUpdatePSLMZ
I tweaked up the MZ alignment.  The reflection had been around 0.550, which kept the MEDM indicator green, but was still too high.  I fiddled with BS1, and a little bit with BS2.  When I had the doors of the PSL table open, I got as low as 0.320.  When I closed up and came back to the control room, the MZ refl had drifted up to 0.354.  But it's good again now.

In the future, mirrors shouldn't be so close together that you can't get at their knobs to adjust them No good.  I ended up blocking the beam coming out of the PMC to prevent sticking my hand in some beam, making the adjustment, then removing the dump.  It worked in a safe way, but it was obnoxious. 

  1928   Wed Aug 19 17:11:33 2009 JenneUpdateIOOQPDs aligned



If Rob/Yoichi say the alignment is now good, the we absolutely must center the IOO QPDs and IP POS and IP ANG and MC TRANS  today so that we have good references.


 IOO_QPD_POS,    IOO_QPD_ANG,    MC_TRANS,    IP_POS, IP_ANG    have all been centered.

Also, the MCWFS have been centered.

I'm now working on making sure beam is hitting all of the RF PDs around.

  1929   Wed Aug 19 18:02:22 2009 JenneUpdateLSCRF PDs aligned

All of the LSC RF PDs have been aligned.  I didn't really change much of anything, since for all of them, the beam was already pretty close to center.  But they all got the treatment of attaching a Voltmeter to the DC out, and adjusting the steering mirror in both pitch and yaw, finding where you fall off the PD in each direction, and then leave the optic in the middle of the two 'edges'.

Before aligning each set (PO, Refl, AS), I followed the procedure in Rob's new RF photodiode Wiki Page

Also, for superstitious reasons, and in case I actually bumped them, I squished all of the ribbon cable connectors into the PDs, just in case.

  1932   Fri Aug 21 17:05:04 2009 JenneUpdateGeneralrestarted the elog

[Kevin, Jenne]

Kevin's awesome final report/elog entry was so awesome that it crashed the elog.  It has been restarted.  We're going to put his pictures and documentation in the wiki, with a link from the elog to prevent re-crashing.

  1935   Fri Aug 21 18:37:16 2009 JenneUpdateGeneralTransfer function of Mode Cleaner Stacks

Using free-swinging Mode Cleaner OSEM data and Guralp seismometers, I have taken transfer functions of the Mode Cleaner stacks.

During this experiment, the MC was unlocked overnight, and one Guralp seismometer was underneath each chamber (MC1/MC3, and MC2).  Clara will let me know what the orientation of the seismometers were (including which seismometer was underneath which chamber and what direction the seismometer axes were pointing), but for now I have included TFs for every combination of suspension motion and seismometer channels.

I combined the 4 OSEM channels for each optic in POS and PIT, and then calibrated each of my sus channels using the method described in Kakeru's elog entry 1413. Units are meters for POS, and radians for PIT.  I also calibrated the guralp channels into meters.

The traces on each plot are: MC_{POS or PIT} / Guralp_{1 or 2}_{direction}.  So each plot shows the coupling between every seismometer direction and a single mirror direction.  The colors are the same for all the plots, ie the gold trace is always Gur1Z.

Attachment 1: TF_osems_guralps.png
  1975   Tue Sep 8 17:57:30 2009 JenneUpdatePEMAll the Acc/Seis working again

All of the accelerometers and seismometers are plugged in and functional again.  The cables to the back of the accelerometer preamp board (sitting under the BS oplev table) had been unplugged, which was unexpected.  I finally figured out that that's what the problem was with half of the accelerometers, plugged them back in, and now all of the sensors are up and running.

TheSEIS_GUR seismometer is under MC1, and all the others (the other Guralp, the Ranger which is oriented vertically, and all 6 accelerometers) are under MC2.

  1977   Tue Sep 8 19:36:52 2009 JenneOmnistructureDMFDMF restarted

I (think I) restarted DMF.  It's on Mafalda, running in matlab (not the complied version which Rana was having trouble with back in the day).  To start Matlab, I did "nohup matlab", ran mdv_config, then started seisBLRMS.m running.  Since I used nohup, I then closed the terminal window, and am crossing my fingers in hopes that it continues to work.  I would have used Screen, but that doesn't seem to work on Mafalda.

  1979   Tue Sep 8 20:25:03 2009 JenneOmnistructureDMFDMF restarted


I (think I) restarted DMF.  It's on Mafalda, running in matlab (not the complied version which Rana was having trouble with back in the day).  To start Matlab, I did "nohup matlab", ran mdv_config, then started seisBLRMS.m running.  Since I used nohup, I then closed the terminal window, and am crossing my fingers in hopes that it continues to work.  I would have used Screen, but that doesn't seem to work on Mafalda.

 Just kidding. That plan didn't work.  The new plan: I started a terminal window on Op540, which is ssh-ed into Mafalda, and started up matlab to run seisBLRMS.  That window is still open. 

Because Unix was being finicky, I had to open an xterm window (xterm -bg green -fg black), and then ssh to mafalda and run matlab there.  The symptoms which led to this were that even though in a regular terminal window on Op540, ssh-ed to mafalda, I could access tconvert, I could not make gps.m work in matlab.  When Rana ssh-ed from Allegra to Op540 to Mafalda and ran matlab, he could get gps.m to work.  So it seems like it was  a Unix terminal crazy thing. Anyhow, starting an xterm window on Op540m and ssh-ing to mafalda from there seemed to work.

Hopefully this having a terminal window open and running DMF will be a temporary solution, and we can get the compiled version to work again soon.

  1981   Thu Sep 10 15:55:44 2009 JenneUpdateComputersc1ass rebooted

c1ass had not been rebooted since before the filesystem change, so when I was sshed into c1ass I got an error saying that the NFS was stale.  Sanjit and I went out into the cleanroom and powercycled the computer.  It came back just fine.  We followed the instructions on the wiki, restarting the front end code, the tpman, and did a burt restore of c1assepics. 

  1982   Thu Sep 10 17:47:25 2009 JenneUpdateComputerschanges to the startass scripts

[Rana, Jenne]

While I was mostly able to restart the c1ass computer earlier today, the filter banks were acting totally weird.  They were showing input excitations when we weren't putting any, and they were showing that the outputs were all zero, even though the inputs were non-zero and the input and the output were both enabled. The solution to this ended up being to use the 2nd to last assfe.rtl backup file.  Rana made a symbolic link from assfe.rtl to the 2nd to last backup, so that the startup.cmd script does not need to be changed whenever we alter the front end code.

The startup_ass script, in /caltech/target/gds/ which, among other things, starts the awgtpman was changed to match the instructions on the wiki Computer Restart page.  We now start up the /opt/gds/awgtpman .  This may or may not be a good idea though, since we are currently not able to get channels on DTT and Dataviewer for the C1:ASS-TOP_PEM channels.  When we try to run the awgtpman that the script used to try to start ( /caltech/target/gds/bin/ ) we get a "Floating Exception". We should figure this out though, because the /opt/gds/awgtpman does not let us choose 2kHz as an option, which is the rate that the ASS_TOP stuff seems to run at.

The last fix made was to the screen snapshot buttons on the C1:ASS_TOP screen.  When the screen was made, the buttons were copied from one of the other ASS screens, so the snapshots saved on the ASS_TOP screen were of the ASS_PIT screen.  Not so helpful.  Now the update snapshot button will actually update the ASS_TOP snapshot, and we can view past ASS_TOP shots.

  1984   Fri Sep 11 17:07:45 2009 JenneUpdateAdaptive FilteringMinor changes to ASS_TOP_PEM screen.

There was some uncertainty as to which channels were being input into the Adaptive Filtering screen, so I checked it out to confirm.  As expected, the rows on the ASS_TOP_PEM screen directly correspond to the BNC inputs on the PEM_ADCU board in the 1Y6 (I think it's 6...) rack.  So C1:ASS-TOP_PEM_1_INMON corresponds to the first BNC (#1) on the ADCU, etc. 

After checking this out, I put text tags next to all the inputs on the ASS_TOP_PEM screen for all of the seismometers (which had not been there previously).  Now it's nice and easy to select which witness channels you want to use for the adaptation.

  1988   Wed Sep 16 11:58:11 2009 JenneUpdateAdaptive FilteringNew Filters for Adaptive Filtering

When Sanjit and I were looking at the adaptive filtering system on Monday and Friday, we noticed that turning on the Accelerometers (which had been used in the past) seemed to do good things, but that turning on the seismometers (which I just put into the system last week) made the OAF output integrate up.  Rana pointed out that this is an indication of a missing high pass filter.  And indeed, when I put the seismometers in, I neglected to copy the high pass filter at low frequencies, and the low pass at 64Hz from the accelerometer path to the seismometer path.  The accelerometers had a HP at 1Hz, which is okay since they don't really do useful things down to the mHz level.  I gave all of the seismometers HP at 1mHz.  These are now in the filter banks in the ASS_TOP_PEM screen.  The accelerometers are on channels 15, 16, 17, 18, 19, 20 and the seismometers are on channels 2, 3, 4, 10, 11, 12, 24.

I now need to modify the upass script to turn these filters on before doing adaptive filtering.

  1992   Fri Sep 18 16:05:08 2009 JenneOmnistructurePSLwater under the laser chiller


rob, koji, steve

We noticed some water (about a cup) on the floor under the NESLAB chiller today.  We put the chiller up on blocks and took off the side panel for a cursory inspection, but found no obvious leaks.  We'll keep an eye on it.

 The culprit has been found:  One of the bottles of chiller water had a tiny leak in it, and apparently the floor is sloped just right to make it look like the water had been coming from under the chiller.  All is well again in the world of chilled water.

  1996   Wed Sep 23 20:02:11 2009 JenneAoGComputersGremlins in the RFM


A cosmic ray struck the RFM in the framebuilder this afternoon, causing hours of consternation.  The whole FE system is just now coming back up, and it appears the mode cleaner is not coming back to the same place (alignment).


rob, jenne

 Jenne, Rana, Koji

The mode cleaner has been realigned, using a combination of techniques.  First, we used ezcaservo to look at C1:SUS-MC(1,3)_SUS(DOF)_INMON and drive C1:SUS-MC(1,3)_(DOF)_COMM, to put the MC1 and MC3 mirrors back to their DriftMon values.  Then we looked at the MC_TRANS_SUM on dataviewer and adjusted the MC alignment sliders by hand to maximize the transmission.  Once the transmission was reasonably good, we saw that the spot was still a little high, and the WFS QPDs weren't centered.  So Koji and I went out and centered the WFS, and now the MC is back to where it used to be.  The MC_TRANS QPD looks nice and centered, so the pointing is back to where it used to be.

  2000   Thu Sep 24 21:04:15 2009 JenneUpdateMOPAIncreasing the power from the MOPA

[Jenne, Rana, Koji]

Since the MOPA has been having a bad few weeks (and got even more significantly worse in the last day or so), we opened up the MOPA box to increase the power.  This involved some adjusting of the NPRO, and some adjusting of the alignment between the NPRO and the Amplifier.  Afterward, the power out of the MOPA box was increased.  Hooray! 

Steps taken:

0.  Before we touched anything, the AMPMON was 2.26, PMC_Trans was 2.23, PSL-126MOPA_126MON was 152 (and when the photodiode was blocked, it's dark reading was 23).

1.  We took off the side panel of the MOPA box nearest the NPRO, to gain access to the potentiometers that control the NPRO settings.  We selectively changed some of the pots while watching PSL-126MOPA_126MON on Striptool.

2.  We adjusted the pot labeled "DTEMP" first. (You have to use a dental mirror to see the labels on the PCB, but they're there). We went 3.25 turns clockwise, and got the 126MON to 158. 

3. To give us some elbow room, we changed the PSL-126MOPA_126CURADJ from +10.000 to 0.000 so that we have some space to move around on the slider.  This changed 126MON to 142. The 126MOPA_CURMON was at 2.308.

4.  We tried adjusting the "USR_CUR" pot, which is labeled "POWER" on the back panel of the NPRO (you reach this pot through a hole in the back of the NPRO, not through the side which we took off, like all the other pots today).  This pot did nothing at all, so we left it in its original position.  This may have been disabled since we use the slider.

5.  We adjusted the CUR_SET pot, and got the 126MON up to 185.  This changed the 126MOPA_CURMON to 2. 772 and the AMPMON to 2.45

We decided that that was enough fiddling with the NPRO, and moved on to adjusting the alignment into the Amplifier.

6.  We teed off of the AMPMON photodiode so that we could see the DC values on a DMM.  When we used a T to connect both the DMM and the regular DAQ cable, the DMM read a value a factor of 2 smaller than when the DMM was connected directly to the PD.  This shouldn't happen.....it's something on the to-fix-someday list.

7.  Rana adjusted the 2 steering mirrors immediately in front of the amplifier, inside the MOPA box.  This changed the DMM reading from its original 0.204 to 0.210, and the AMPMON reading from 2.45 to 2.55. While this did help increase the power, the mirrors weren't really moved very much.

8.  We then noticed that the beam wasn't really well aligned onto the AMPMON PD.  When Rana leaned on the MOPA box, the PD's reading changed.  So we moved the PD a little bit to maximize its readings.  After this, the AMPMON read 2.68, and the DMM read 0.220.

9.  Then Rana adjusted the 2 waveplates in the path from the NPRO to the Amplifier.  The first waveplate in the path didn't really change anything.  Adjusting the 2nd waveplate gave us an AMPMON of 2.72, and a DMM reading of 0.222.

10.  We closed up the MOPA box, and locked the PMC.  Unfortunately, the PMC_Trans was only 1.78, down from the 2.26 when we began our activities.  Not so great, considering that in the end, the MOPA power went up from 2.26 to 2.72.

11.  Koji and I adjusted the steering mirrors in front of the PMC, but we could not get a transmission higher than 1.78.

12.  We came back to the control room, and changed the 126MOPA_126CURADJ slider to -2.263 which gives a 126MOPA_CURMON to 2.503.  This increased PMC_TRANS up to 2.1. 

13.  Koji did a bit more steering mirror adjustment, but didn't get any more improvement.

14.  Koji then did a scan of the FSS SLOW actuator, and found a better temperature place (~ -5.0)for the laser to sit in.  This place (presumably with less mode hopping) lets the PMC_TRANS get up to 2.3, almost 2.4.  We leave things at this place, with the 126MOPA_126CURADJ slider at -2.263. 

Now that the MOPA is putting out more power, we can adjust the waveplate before the PBS to determine how much power we dump, so that we have ~constant power all the time.


Also, the PMCR view on the Quad TVs in the Control Room has been changed so it actually is PMCR, not PMCT like it has been for a long time.

  2001   Fri Sep 25 16:10:17 2009 JenneUpdateAdaptive FilteringSome progress on OAF, but more still to be done

[Jenne, Sanjit]

It seems now that we are able to get the OAF system to do a pretty good job of approximating the MC_L signal, but we can't get it to actually do any subtracting.  I think that we're not correctly setting the phase delay between the witness and the MC_L channels or something (I'm not sure though why we get a good filter match if the delay is set incorrectly, but we do get a good filter match for very different delay settings: 1, 5, 100, 1000 all seem to do equally well at adjusting the filter to match MC_L). 

The Matt Evans document in elog 395 suggests measuring the phase at the Nyquist frequency, and calculating the appropriate delay from that.  The sticking point with this is that we can't get test points for any channel which starts with C1:ASS.  I've emailed Alex to see what he can do about this.  Elog 1982 has a few words about how we're perhaps using a different awgtpman on the ass machine than we used to, which may be part of the problem. 

The golden plan, which in my head will work perfectly, is as follows: Alex will fix the testpoint problem, then Sanjit and I will be able to measure the phase between our OAF signal and the incoming MC_L signal, we will be able to match them as prescribed in the Matt Evans document, and then suddenly the Adaptive Filtering system will do some actual subtracting!

The plot below shows the Reference MC_L without any OAF system (black), the output of the OAF (green), and the 'reduced' MC_L (red).  As you can see, the green trace is doing a pretty good job of matching the black one, but the red trace isn't getting reduced at all.

Attachment 1: OAF_Running_25Sept2009.jpg
  2002   Fri Sep 25 16:45:29 2009 JenneUpdateMOPATotal MOPA power is constant, but the NPRO's power has decreased after last night's activities?

[Koji, Jenne]

Steve pointed this out to me today, and Koji and I just took a look at it together:  The total power coming out of the MOPA box is constant, about 2.7W.  However, the NPRO power (as measured by 126MOPA_126MON) has decreased from where we left it last night.  It's an exponential decay, and Koji and I aren't sure what is causing it.  This may be some misalignment on the PD which actually measures 126MON or something though, because 126MOPA_LMON, which measures the NPRO power inside the NPRO box (that's how it looks on the MEDM screen at least...) has stayed constant.  I'm hesitant to be sure that it's a misalignment issue since the decay is gradual, rather than a jump. 

Koji and I are going to keep an eye on the 126MON value.  Perhaps on Monday we'll take a look at maybe aligning the beam onto this PD, and look at the impedance of both this PD, and the AMPMON PD to see why the reading on the DMM changed last night when we had the DAQ cable T-ed in, and not T-ed in. 

Attachment 1: AMPMONconstant_126MONdown.jpg
  2004   Fri Sep 25 19:55:59 2009 JenneUpdateAdaptive FilteringSubtraction of the microseism using Adaptive Filtering!

[Rana, Jenne]

The OAF system did something useful today!  Attached is a plot.  Black is the reference (13 averages) with the OAF off.  Blue is the output of the OAF, and red is the reduced MC_L signal (13 averages).  If you turn tau and mu both to 0, it "pauses" the filter, but keeps the feedforward system working, so that you can take a long average to get a better idea of how well things are working. If you ramp down the output of the CORR filter bank, that lets you take a long average with the OAF "off", but doesn't mess up your nicely adapted filter.  The cyan and gold traces in the upper plot are 2 of the Guralp channels, so you can see the real seismic motion.

In the lower plot, you can see that the cyan and light green seismic channels have good coherence with IOO-MC_L (the names don't really mean anything right now...these 2 seismometer channels are the 2 Guralps' channels, one per end of the MC, which are aligned with the MC.)  The dark blue trace is the coherence between IOO-MC_L and the output of the OAF.

500 taps, delay=5, 2 Guralp channels (the ones aligned with the MC), tau~0.00001 (probably), and mu~0.01 or 0.005

Attachment 1: OAF_running_WORKING_25Sept2009.png
  2006   Sat Sep 26 13:55:20 2009 JenneUpdateMZMZ was locked in a bad place

I found the MZ locked in a bad place earlier today.  It was locked in a similarly bad spot yesterday after we fixed the cable situation for 126MOPA_126MON, with reflection of ~0.8, rather than the nominal 0.305.  It's good now though. 

  2012   Mon Sep 28 11:52:23 2009 JenneUpdateTreasureOAF screen added to the screenshots webpage

I used Kakeru's instructions in elog 1221 to add the C1OAF screen (still called C1ASS_TOP) to the medm screenshots webpage.  The tricky part of this is figuring out that the file that needs editing is in fact in /cvs/cds/projects/statScreen, not /cvs/cds/caltech/statScreen, as claimed in the entry. 

  2014   Mon Sep 28 23:13:14 2009 JenneConfigurationElectronicsRob is breaking stuff....

Koji and I were looking for an extender card to aid with MZ board testing.  Rob went off on a quest to find one.  He found 2 (in addition to the one in the drawer near the electronics bench which says "15V shorted"), and put them in some empty slots in 1X1 to test them out.  Somehow, this burned a few pins on each board (1 pin on one of them, and 3 pins on the other). We now have 0 functioning extender cards: unfortunately, both extender cards now need fixing.  The 2 slots that were used in 1X1 now have yellow electrical tape covering the connectors so that they do not get used, because the ends of the burnt-off pins may still be in there. 

In other, not-Rob's-fault news, the Martian network is down...we're going to try to reset it so that we have use of the laptops again.

  2028   Wed Sep 30 12:21:08 2009 JenneUpdateComputersrestarted the elog

I'm blaming Zach on this one, for trying to upload a pic into the ATF elog (even though he claims it was small....)  Blame assigned: check.  Elog restarted: check.

  2029   Wed Sep 30 17:49:21 2009 JenneUpdateAdaptive FilteringNew UP/DOWN scripts for OAF

[Sanjit, Jenne]

The up and down scripts accessible from the OAF (still C1:ASS-TOP) screen are now totally functional and awesome.  They are under the blue ! button.  The up script can either be for the Seismometers, or the Accelerometers at this time.  The only difference between these 2 is which burt restore file they look at:  the seismometer version puts all 7 seismometer channels in the PEM selecting matrix, while the accelerometer version puts the 6 accelerometer channels in that matrix.  Both scripts also turn on HP_1mHz filters in the ERR_EMPH filter bank and all of the witness filter banks, and the AA32 and AI32 filters in ERR_EMPH, CORR and PEM filter banks.  This makes all of the starting filters the same between the witness paths and the error path.

If you want to use a different combination of sensors, run one of the up scripts, then change the PEM matrix by hand. 

The down script disables the output to the optics, and resets the adapted filter coefficients.  DO NOT use this script if you're trying to "pause" the filter to take some nice long averages.

  2034   Thu Oct 1 11:39:47 2009 JenneUpdateSUSMC2 damping restored again


 The EQ did not change the input beam pointing. All back to normal, except MC2 wachdogs tripped again.

 Round 3 for the day of MC2 watchdogs tripping.

ELOG V3.1.3-