40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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ID Date Authorup Type Category Subject
  6793   Mon Jun 11 21:35:55 2012 JenneUpdateEnvironmentRattling in the HEPA

Quote:

There is an intermittent rattling sound coming from the HEPA in the NE corner of the PSL table (right above the PMC, all of our input optics).

Steve says it might be a bad bearing, but he'll check it out in the morning and get it fixed.

 MC was having a hard time staying locked, with no discernable reason from the control room (i.e. no big seismic, no PMC PZT railing).    The HEPA was on 100%, so I turned it down to 50% to hopefully reduce the rattling, if that was what was wrong. 

  6795   Mon Jun 11 22:51:11 2012 JenneUpdateComputerstdsavg not working

tdsavg isn't working:

controls@rossa:/opt/rtcds/caltech/c1/scripts/LSC 6$ tdsavg 10 C1:LSC-ASDC_IN1
ERROR: LDAQ - Unable to find NDS host "fb0"
ERROR: LDAQ - Unable to find NDS host "fb1"
ERROR: LDAQ - Unable to open socket to NDS.

 

When this command is executed inside a script, it doesn't return anything.  eg:

set offset = `tdsavg 10 C1:LSC_ASDC_IN1`
echo $offset

returns a blank line. 

Past elog research said lots of things about test points.  I didn't suspect that, since there aren't many test points occupied (according to the CDS status screens), but I cleared the test points anyway (elog 6319).  Didn't change anything, still broken.

LSCoffsets script, and any others depending on tdsavg will not work until this is fixed.

  6796   Tue Jun 12 00:15:51 2012 JenneUpdateComputersrtcds: command not found

We can't compile any changes to the LSC or the GCV models since Jamie's new script / program isn't found.  I don't know where it is (I can't find it either), so I can't do the compiling by hand, or point explicitly to the script.  The old way of compiling models in the wiki is obsolete, and didn't work :(

This means we can't (a) record TRY or (b) add the Q quadrature of the beat PD to the real time system tonight.

We're going to try just using Yuta's pynds script to capture data in real time, so we can keep working for tonight.

  6797   Tue Jun 12 01:03:18 2012 JenneUpdateComputersmini boot fest

As usual, we noticed the frame builder wasn't connecting happily with the rest of the computers just as we were about to lock some stuff (we never notice it being bad when we're not trying to use the frame builder....)

All the big rectangles by each computer were white.  I restarted daqd, and that brought most things back.  c1lsc and c1sus needed their mx_streams restarted manually to get everything green again.

stock-vector-wine-icon-on-computer-keyboard-original-illustration-58731781.jpg

I've had about enough whine with my computers for tonight.

  6799   Tue Jun 12 02:07:42 2012 JenneUpdateSUSPRM oplevs left off

Yuta claims he fixed the PRM oplev by centering it the other day, but no one has left it on and watched it for a long while, to make sure it's okay.  We watched it now for ~2 min, and it was good, but we're leaving the oplevs off anyway for the night.  Tomorrow we should restore PRM (it's currently restored), turn on the oplevs, and let it sit to make sure it doesn't go crazy.

 

  6800   Tue Jun 12 02:09:43 2012 JenneUpdateComputersmini boot fest

Quote:

stock-vector-wine-icon-on-computer-keyboard-original-illustration-58731781.jpg

 I'm starting to feel like a wine-o here.  Yuta wanted to glance at the PRM oplev dataviewer, and lo and behold, the fb lost connection just as he decided to do that.  We had checked the front end status screen not 1 minute beforehand, and everything was green.  Lame.

  6802   Tue Jun 12 11:54:50 2012 JenneUpdateGreen Lockingc1gcv recompiled

Yuta added channels so we can get the Q phase of all the beat PDs to the c1gcv model.  I showed him how to recompile/install/start.

During the install, it couldn't find: Unable to find the following file in CDS_MEDM_PATH: LOCKIN_FILTER.adl

On all the screens (ALS and SUS), lockin parts are white.  Someone changed something, then didn't go back to fix the screens.

Otherwise, things look to be working fine.

Attachment 1: c1gcv20120612.png
c1gcv20120612.png
  6807   Tue Jun 12 17:46:09 2012 JenneUpdateComputersrtcds: command found

Quote:

Quote:

We can't compile any changes to the LSC or the GCV models since Jamie's new script / program isn't found.  I don't know where it is (I can't find it either), so I can't do the compiling by hand, or point explicitly to the script.  The old way of compiling models in the wiki is obsolete, and didn't work :(

Sorry about that.  I had modified the path environment that pointed to the rtcds util.  The rtcds util is now in /opt/rtcds/caltech/c1/scripts/rtcds, which is in the path.  Starting a new shell should make it available again.

 Added TRX and TRY and POY11_I_ERR and POX11_I_ERR to the c1lsc.mdl using a new-style DAQ Channels block, recompiled, installed, started the model, all good.  Restarted the daqd on the framebuilder, and everything is green.  I can go back and get recorded data using dataviewer (for the last few minutes since I started fb), so it all looks good.

Note on the new DAQ Channels block:  Put the text block (from CDS_PARTS) at the same level as the channel you want to save, and name it exactly as it is in the model.  The code-generator will add the _DQ for you.  i.e. if you define a channel "TRY_OUT_DQ" in the lsc model, you'll end up with a channel "C1:LSC-TRY_OUT_DQ_DQ".

  6829   Mon Jun 18 16:23:59 2012 JenneUpdateLockingLSC trigger update

The LSC triggers for the individual filter modules in a filter bank now works.  This is handy so that boosts can come on as soon as a cavity is locked, but will turn off when the cavity unlocks.

You choose which filter modules you want to be triggered, and which ones you want to be manually controlled. 

Example:  LSC-YARM    FM4 and FM5 should always be on, but FM2 and FM3 are controlled by the trigger.  You can set the trigger thresholds for the filter modules independently of the main DoF enable trigger thresholds.

  6831   Mon Jun 18 23:38:39 2012 JenneUpdateLSCAdded LSC channels to frames

Since the .ini files get overwritten every time a model is compiled now, we need to put all channels we want saved to frames in the DAQ Channels list inside the model.

I added the _ERR channels for all RFPDs (I and Q for each), as well as the _OUT channels for the DCPDs.  I also added the _OUT channels for the DoF servos (ex. C1:LSC-DARM_OUT).  I don't remember off the top of my head what else we used to save from the LSC model, but those all seemed like ones we'll possibly want access to later. 

We need to go through and do this to all the models we use regularly.

Since SUS hasn't been recompiled in a while, all those channels are saved (until such time as someone does a recompile).  Den has gone through and edited the PEM and OAF .ini files by hand each time he recompiles, so we have that data, although we need to put it into the model (which is the new proper way to acquire channels).

  6833   Tue Jun 19 20:26:50 2012 JenneHowToLockingSummer Plan

Jenne and Yuta's Summer Plan

These are the things that we'd like to accomplish, hopefully before Yuta leaves in mid-July

* Yarm mode scan

  ~ Measure residual motion of Yarm cavity when ALS is engaged

* Xarm mode scan

  ~ Align Xarm IR

  ~ Align Xarm green to cavity

  ~ Do mode scan (similar to Yarm)

  ~ Measure residual motion of Xarm cavity when ALS is engaged

* Hold both arms on IR resonance simultaneously (quick proof that we can)

  ~ Modify beatbox so we can use both X and Y at the same time (Jamie will do this Wednesday morning - we've already discussed)

* PRMI + Arms

  ~ Lock the PRMI (which we already know we can do) holding arms off resonance, bring both arms into resonance using ALS

* PRC mode matching - figure out what the deal is

  ~ Look at POP camera with video capture - use software that Eric the Tall wrote with JoeB to measure spot size

* DRMI glitches

  ~ Why can't we keep the DRMI locked stably?

* DRMI + Arms

  ~ Full lock!!

  ~ Make lots of useful diagnostics for aLIGO, measure sensing matricies, etc.

  6835   Wed Jun 20 00:01:04 2012 JenneUpdateLSCcalibrated POY error signal

[Yuta, Jenne]

We have measured the out of loop residual motion of the Yarm while locked with the ALS.  We see ~70pm RMS, as compared to Kiwamu's best of ~24pm RMS.  So we're not yet meeting Kiwamu's best measurement, but we're certainly not in crazy-land.

The Yarm ALS was locked, I took a spectrum of POY11_I_ERR, and used the calibration that we determined earlier this evening.  For reference, I attach a screenshot of our ALS loop filters - we had on all the boosts, and both resonant gain filters (~3Hz and ~16Hz).

A large part of the RMS is coming from the 60Hz power line and the 180Hz harmonic....if we could get rid of these (how were they eliminated from the measurement that Kiwamu used in the paper?? - plotted elog 6780) we would be closer. 

Also, it looks like the hump (in our measurementf ~100Hz, in Kiwamu's ~200Hz) is not quite an order of magnitude higher in amplitude in our measurement vs. Kiwamu's.  We have ~5e-11 m/rtHz, Kiwamu had ~7e-12 m/rtHz.  This increase in noise could be coming from the fact that Yuta and Koji decreased the gain in the Ygreen PDH loop to prevent the PDH box from oscillating. 

While we should still think about why we can't use the same gain that Kiwamu was able to ~6 months ago, we think that we're good enough that we can move on to doing mode scans and residual motion measurements of the Xarm.

 

Attachment 1: LSC_POY_11_I_ERR_calib_19June2012.pdf
LSC_POY_11_I_ERR_calib_19June2012.pdf
Attachment 2: POY_calib_19June2012_FiltBankSettings.png
POY_calib_19June2012_FiltBankSettings.png
  6842   Thu Jun 21 01:58:29 2012 JenneUpdateGreen LockingXgreen preparations

[Yuta, Koji, Jenne]

Lots of small things happened tonight, in preparation for having both arms' ALS working simultaneously.

1. Xarm aligned in IR

     1.1 ETMX oplev centered

2. Xgreen coarsely aligned to Xarm

3. X beat setup on PSL table resurrected. 

     3.1 Steering optics for both X and Y green (before PBS) were touched to fix clipping Xgreen on some of the first mirrors after the light exits the chambers.

     3.2 Xgreen aligned to beat PD

     3.3 PSL green waveplate rotated so ~half of the light goes to X beat, other ~half goes to Y beat (recall we had rotated the polarization so we had max light on the Y beat PD a few weeks ago).

          3.3.1 Now we have ~80uW of PSL green going to each beat PD.

     3.4 PSL green aligned to X beat PD

          3.4.1 Replaced mount for mirror between PBS (which splits PSL green light) and BS (which combines PSL green and X green) so that I could get the alignment correct without having to use the full range of the knobs on the mount.

     3.5 Realigned (coarsely) Ygreen to Y beat PD - the mirrors just after the chambers had been touched, so Y green was no longer directly on the PD.  This will need to be done more finely when we're ready to lock the Yarm again.

     3.6 Dedicated cables for the DC of each beat PD were put in place, so we have those in addition to the DC transmission PDs which we are putting in temporarily each time we align the green to the cavities.  Some mystery unused cables that were running under the PSL table were removed.  The power for the X beat PD was rerouted so that it's much closer to the actual diode, and out of the way. 

4. Better alignment of X green to X arm.

     4.1 Put Green Transmission camera into place

     4.2 Noticed that the X green spot on the transmission camera is not nearly as steady as the Y green.  Increased the gain of the X green refl PD on the end table to see if it helped the spot be more steady, but it's still very wiggly.  We reverted the gain to what it was.  We need to fix this!!!!

    4.3 Removed camera, looked at X transmission DC (PD is temporarily in front of the beat PD), tried to increase the transmission.

     4.4 Aligning the green to the X arm has been really tough - there were a few more iterations of camera then DC PD.

     4.5 Measured X green power on the PSL table - 02 mode was ~150uW.  The 00 mode is still not very stable, which is frustrating, although we have a reasonable amount of power transmitted.   

     4.6 The X end green shutter was moved out of the beam path since the green beam was clipping while going through the shutter.  We need to put it back now that the beam is pretty much aligned.  The beam size and the aperture are roughly the same, so we should look to see if there is a different place on the table where the beam is a little smaller, where we can put the shutter.

5. Whitening filters (Pomona box-style) made for the Xarm I and Q channels - these are the same as the whitening for the Y arm.

6. 30m SMA cable made to be used for 2nd delay line.

     6.1 Steve reminded me this morning that we returned one of the fancy spools of cable that was purchased for the delay lines, since it was defective.  We didn't get it replaced because there was debate as to what is the best kind of cable to use.  We need to come to a conclusion, but for now we have a regular RG-405 cable.

7.  Jamie has started work on modifying the beatbox so that we can have 2-arm ALS.  Hopefully that will be done soon-ish, because we're otherwise pretty close to being ready.

  6843   Thu Jun 21 02:57:16 2012 JenneBureaucracyGeneral40m Action Items

PRIORITY ITEMS:

ASS doesn't run on Ubuntu!
Put beatbox back, simultaneous arm ALS
Input matricies, output filters to tune SUS.  check after upgrade.
POX11 whitening is not toggling the analog whitening???
Look into PMC PZT drift - PZT failing? Real MC length change?
Vent planning / organization

THE FULL LIST:

General

     Audio system for the signals!!!! Even a crappy one!

SUS

     Input matricies, output filters to tune SUS.  Check after upgrade.

IFO

     Fix occasional common-mode power transient in the arm transmissions. Probably an alignment thing. Would ISS help?

     Drift of the green incident axis -> Assess the amount of the drift / replace the mount

     Calibration of POP22 / AS110

     PMC/IMC/ARM characterization (loss, finesse, reflectivity, etc)

     Arm cavity sweeps, mode scan

     Align AS OSA (others?)

     Investigate PRMI glitches, instability

     PZT or Picomotor mounts for PSL/ALS beams

     ALS on the both arm simultaneously / common / diff ALS scripts

     Measure green locking (Aux laser to arm) transfer functions, residual spectra

     Measure oplev spectra while locking Xgreen - see if the optics are particularly noisy

     Measure Xarm residual motion using POX while ALS is engaged.

     Fix Vio2 filter modules on SUS 

     Switch power supply for amplifiers of beatnote signal to rack power

     Add temp sensors for end lasers to CDS slow channels

     Put windows / pickoffs on PSL table for (a) green trans camera, (b) GTRY, (c) GTRX

CDS

     Capture OSA signals in CDS (the 'scope TDS1001B has a USB port in the back for connecting to the computer)

     Transmon (arms) for high and low power

     POX11 whitening is not toggling the analog whitening???

     Install guardians to monitor EPICS values

Electronics

     Actuator noise level characterization (coil driver response in V/m & coil driver noise level V/rtHz)

     Improvement of POP22/110/AS110 RF circuits?

MEDM

     Complete 40m overview screen - everything should be clickable with pseudo 3D icons

     Script to generate a MEDM tree

     Resurrect MEDM snapshots

     New ! buttons on every screen, include wiki page

     Add all screens to svn

SCRIPT

     Daily diagnosis of the MC spot positions (there must be something already...)

     Daily/occasional adjustment of the incident axis on the MC

     Panic button on Watchdog screen isn't working on Ubuntu

     OPLEV/OSEM trending script before the IFO work for diagnosis. Put into 40m summary screen.

     Auto-locker for arms

     Auto-locker for PSL things

     Diagnostic script for CDS - mx_stream, other stuff.

     Make sure scripts are all svn-ed

Video

     If each video screen has a caption, that would be great

     GUI interface of "videoswitch"

Ubuntu vs. CentOS

     Upgrade Ottavia to Ubuntu, make sure connect to DTT, Dataviewer, AWG.

MM

     IPPOS beam measurement

     AS beam measurement (if beam is bright enough)

     Mode matching calculations, sensitivity to MC waist measurement errors, PRM position

     Think up diagnostic measurement to determine mode matching to PRC while chambers are open, while we tweak MMT

     Use sensoray to capture, measure beam mode at AS, POP

Stray Light

     Scattered light measurement at the end stations: design / confirmation of the mechanical parts/optics/cameras

     Align AUX laser into dark port

     Assemble in-vac beam dumps - how many do we need?

OAF

     OAF comparison plot, both online and offline, comparing static, adaptive and static+adaptive

     Static-only OAF noise budget (Adaptive noise budget as next step)

     Script for daily / weekly re-calculation of Wiener, post to elog if need changing

Tip Tilts

     Prepare electronics for TTs (coil drivers)

      In-air TT testing to confirm we can control / move TTs before we vent

     Connect TTs to digital system and controls, lay cables if needed

     Determine whether we need to add a new flange to OMC chamber

RF Photodiodes

     Opto Energy diode laser - purchase

     Set everything up

     Demod board for AS110 - so we can also have POP110?

  6846   Thu Jun 21 12:13:35 2012 JenneUpdatePEMflow bench must be running all times

Quote:

The south end flow bench HEPA filter should be run all times. You can turn it off for a measurement or two but remember we are storing clean optics there.

The zero count bench will reach  room particle count  ~ 10,000 in one minute.

 My bad.  I turned it off last night to see if it would help make the Xgreen more stable, and then when I woke up this morning I realized that I had forgotten to turn it back on.  Bad Jenne.

  6851   Fri Jun 22 02:21:57 2012 JenneUpdateGreen Locking2 arm ALS - Success!!!!

[Yuta, Jenne]

We locked both arms using the ALS system simultaneously!  Hooray!

Video of spectrum analyzer during lock acquisition of both beats is attached.

Jamie is super awesome, since he fixed us up a beatbox speedy-quick.  Thanks Jamie!!  speedy_gonzales-5257.jpg

 Details:

1:  Aligned PSL green optics

     1.1:  We added an amplifier of ~20dB after the X beat PD (more Xgreen power on the PSL table so the signal was ~3dB higher than Y, so required less amplification).  The ~24dB amplifier is still in place after the Y beat PD.  Both beat signals go to a splitter after their amplifiers.  One side of each splitter goes to one of the channels on the beatbox.  The other side of each splitter goes to a 3rd splitter, which we're using backwards to combine the 2 signals so we can see both peaks on the spectrum analyzer at the same time.

2:  Found both beat notes

     2.1:  Y beat was easy since we knew the temps that have been working for the past several days

     2.2:  X beat was more tricky - the last time it was locked was the end of February (elog 6342)

         2.2.1:  We found it by adjusting the PSL laser temp nearly the full range - DC Adjust slider was at 8.8V or so (Y beat was found with the slider at ~1.1V tonight)

          2.2.2:  We then walked the beat around to get the PSL temp back to "normal" by moving the PSL temp, then compensating with the Xend laser temp, keeping the beatnote within the range of the spectrum analyzer.

          2.2.3:  Fine tuned the temps of all 3 lasers until we had 2 peaks on the analyzer at the same time!!

               2.2.3.1:  Yend - measured Temp=34.14 C, thermal Out of Slow servo=29820

               2.2.3.2:  Xend - displayed temp=39.33 C, thermal Out of Slow servo=5070

               2.2.3.3: PSL - displayed temp=31.49 C, Slow actuator Adjust=1.100V

3:  Locked both arms using ALS!!

     3.1:  We were a little concerned that the Xarm wasn't locking.  We tried switching the cables on the beatbox so that we used the old channels for the Xarm, since the old channels had been working for Y.  Eventually we discovered that the input of the filter module for ETMX's POS-ALS input was OFF, so we weren't really sending any signals to ETMX.  We reverted the cabling to how it was this evening when Jamie reinstalled the beatbox.

          3.1.1:  We need to sort out our SUS screens - Not all buttons in medm-land link to the same versions of the SUS screens!  It looks like the ALS screen was modified to point the ETMY button to a custom ETMY SUS screen which has the ALS path in the POS screen, along with LSC and SUSPOS.  There is no such screen (that I have found) for ETMX.  The regular IFO_ALIGN screen points to the generic SUS screens for both ETMY and ETMX, so we didn't know until Yuta searched around for the filter bank that the ALS input for ETMX was off.  We just need to make sure that all of the screens reflect what's going on in the models.

     3.2:  See the video attached - it shows the beat peaks during locking!!! (how do I embed it? right now you have to download it)

          3.2.1:  First you will see both peaks moving around freely

          3.2.2:  Then X arm is locked briefly, then unlocked

          3.2.3: Y arm is locked, steadily increasing gain

          3.2.4:  X arm is locked, so both arms locked simultaneously

          3.2.5:  Yuta clicked a button, accidentally unlocking the Xarm

4:  The transmission of the X arm was not so great, and both of our green beams (although X green especially) were no longer nicely aligned with the cavities.  Yuta tried to align the X arm to the X green, but it's bad enough that we really need to start over with the whole IFO alignment - we leave this until tomorrow.  Since we didn't have any good IR transmission, we didn't bother to try to find and hold the Xarm on IR resonance using ALS, so we didn't measure a POX out of loop residual cavity motion spectrum.  Again, tomorrow. 

Attachment 1: P6210140.AVI
  6854   Fri Jun 22 13:37:17 2012 JenneUpdateComputersfb lost connection

...Perhaps related to the fact that Jamie is copying a lot of stuff over the network to back up Ottavia before converting her to Ubuntu, perhaps totally independent. 

After restarting the daqd, c1lsc was the only computer whose mx_stream came up on its own.  I restarted c1sus. c1ioo, c1iscey, c1iscex by hand.

  6855   Fri Jun 22 17:51:04 2012 JenneUpdateCamerasGreen Trans camera repositioning attempt

[Yuta, Jenne]

We tried to find a different place, not in the main green transmitted beam path, to place the trans camera for the green beams.  There is a little bit of leakage through the 3 high reflector mirrors which steer the beams from the direction when they first come out of the chamber over to the main green beat setup.  2 of these mirrors have virtually no space behind them for a camera (the first one the green beams encounters is right next to the EOM mount, and the 2nd one is pretty close to the Input Pointing QPDs.  We can potentially use the beam leaking through the 3rd steering mirror, if the camera is very close to the edge of the table (so that the camera isn't blocking the IR input pointing beams), but the X beam is so dim as to be nearly impossible to see, even when TEM00.  This precludes the point of the camera, which is to see the modes when we're aligning the beams.  (X power on the PSL table is pretty high - 330uW measured today, but those mirrors must transmit the Y beam's polarization more than the X beam's.)

Our other thought was to use one of the secondary beams coming out of the chambers.  This is kind of Mickey Mouse, but we thought that since this is just a camera to see the modes, as opposed to a PD, maybe it's okay.  This is a moot point however, since the secondary and tertiary beams (due to the wedge of the window) are clipped for the Y green.  We closed the PSL shutter then removed the beam pipe between the PSL table and the chamber so I could look inside. 

It looks to me like the main green transmitted beams are exiting through the window several inches from any edge, so they're definitely not clipping.  But the reflection from the window back into the chamber is hitting some optic.  The X green is hitting the face of the optic, while the Y green is hitting the edge of the optic and part of the mount.  The reflections from this mount then go back toward the chamber window and out toward the PSL table.  This isn't a big deal for the camera situation - we'll just use the leakage from one of the steering mirrors somehow, but it does mean that there is some green light reflected back onto an IR mirror, and potentially causing grief.  I didn't look to see if the mirror it's hitting is the 1st in-vac IR steering mirror (I don't think so) or something in the OMC / AS path (I think it's something here), but either way, we could be making trouble for ourselves.  We should try to dump the reflection from the window when we vent.  Jamie has put it on the List.

We replaced the beam pipe between the PSL table and the chamber before opening the shutter on the laser.  We are currently sticking with the plan of putting the camera in the main green trans path for initial alignment, then removing it for the rest of the work.

  6858   Fri Jun 22 20:58:15 2012 JenneUpdateGreen LockingCalibrated POX spectra - Xarm stabilized by ALS

[Yuta, Jenne, Koji]

We stabilized the Xarm using the ALS and took a spectrum of POX as our out of loop sensor.  We used the calibration from elog 6841 to go from counts to meters.

We find (see attached pdf) that the RMS is around 60pm, dominated by 1Hz motion.

 

In other, related, news, I took out the beam pipe connecting the AP and PSL tables and covered the holes with foil.  This makes it much easier and faster to get to the X beat setup for alignment.  Eventually we'll have to put it back, but while the AUX laser on the AP table is not being used for beating against the PSL it'll be nice to have it out of the way.

Attachment 1: POX11_I_ERR_calib_residualCavityMotion_better.pdf
POX11_I_ERR_calib_residualCavityMotion_better.pdf
  6865   Mon Jun 25 10:35:59 2012 JenneSummaryComputersc1ioo is down

Quote:

I tried to restart c1ioo becuase I can't live without him.

I couldn't ssh or ping c1ioo, so I did hardware reboot.
c1ioo came back, but now ADC/DAC stats are all red.

c1ioo was OK until 3am when I left the control room last night. I don't know what happened, but StripTool from zita tells me that MC lock went off at around 4pm.

 c1ioo was still all red on the CDS status screen, so I tried a couple of things.

mxstreamrestart (which aliases on the front ends to sudo /etc/init.d/mx_stream restart) didn't help

sudo shutdown -r now didn't change anything either....c1ioo came back with red everywhere and 0x2bad on the IOP

eventually doing as Jamie did for c1sus in elog 6742, rtcds stop all, then rtcds start all fixed everything.  Interestingly, when I tried rtcds start iop, I got the error
Cannot start/stop model 'iop' on host c1ioo, so I just tried rtcds start all, and that worked fine....started with c1x03, then c1ioo, then c1gcv.

  6866   Mon Jun 25 11:23:14 2012 JenneUpdateComputerstdsavg not working

Quote:

LSCoffsets script, and any others depending on tdsavg will not work until this is fixed.

 LSCoffsets is working again. 

tdsavg (now, but didn't used to) needs "LIGONDSIP=fb" to be specified.  Jamie just put this in the global environment, so tdsavg should just work like normal again.

Also, the rest of the LSCoffsets script (really the subcommand offset2) was tsch syntax, so I created offset3 which is bash syntax.

Now we can use LSCoffsets again.

  6890   Thu Jun 28 22:08:57 2012 JenneBureaucracyLockingvent for PRC check, TOMORROW!

Quote:

Check List:
 We will just open the BS chamber.
  - PRM flipping
  - PR2, PR3 flipping
  - PRC suspensions
  - Cipping check in PRC

 What do you mean by PR2, PR3 flipping?  They are (supposed to be) flat mirrors, so obviously they should be installed correctly, but they won't change the mode matching in a huge way if they're backwards, right?

For the PRM, I recommend checking (a) the arrow inscribed on the thinner side of the optic and (b) that the arrow *actually* points to the HR side.  I'm pretty sure I installed all the optics with the arrow pointing away from the OSEMs, but I never did a thorough check that the arrow always actually pointed to the HR coated side.  I don't remember any optics where I said "hmmm, that's funny, the arrow is pointing backwards", but nor did I write down that I had checked.

Also, hopefully the PRM is correct.  If however it's not, that means that all of the magnets are glued onto the HR side, and we'll have to redo all of the magnet gluing.  The guiderods should be fine, but all 6 magnets would need redoing.  If we were very, very careful and didn't break any of the magnets off of the dumbbells, it's a 24 hour turnaround due to drying time.  Since inevitably we break magnets away from dumbbells, conservatively we should think about a 48 hour turnaround. 

  6902   Mon Jul 2 10:45:25 2012 JenneSummaryGeneralclipping at BS

Quote

No significant change was found inside the vacuum. We still see clipping at the Faraday, and also, we saw clipping by BS coil holder. Using PZT1, we could make it better, but this might be causing PRC problem -- BS is inside the PRC, too.

 Yuta just told Jamie and I that when he and Koji were looking at things yesterday, they saw that the beam spot was roughly at the center of the PRM, but was clipping on the lower OSEM holder plate on the BS.  This indicates that the beam spot on the BS is much too low.  The easiest way I can see this happening is poor pitch pointing with the tip tilts, which we unfortunately don't have active control over.

Recall elog 3425, where I mentioned some pretty bad pitch pointing after a TT was moved from the cleanroom, to the chamber, back to the cleanroom.  I think that we may need to check the pitch pointing at the chamber before installing tip tilts in the future.

  6904   Mon Jul 2 18:28:09 2012 JenneUpdatePhotosMany photos taken

Many photos were taken by many different people....most of the fuzzy ones are by yours truely (doing a reach-around to get to hard-to-reach places), so sorry about that.

I put all the photos from yesterday and today into 6 new albums on Picasa:  https://picasaweb.google.com/foteee

The album titles are generally descriptive, and I threw in a few comments where it seemed prudent.

Big note:  The tip tilt on the ITMX table does, in fact, have the arrow pointing in the correct direction.  Photo is in the TT album from today.

  6918   Thu Jul 5 11:12:53 2012 JenneUpdateCDSfront-end/fb communication lost, likely again due to timing offsets

Quote:

All the front-ends are showing 0x4000 status and have lost communication with the frame builder.  It looks like the timing skew is back again.  The fb is ahead of real time by one second, and strangely nodus is ahead of real time by something like 5 seconds!  I'm looking into it now.

 I was bad and didn't read the elog before touching things, so I did a daqd restart, and mxstream restart on all the front ends, but neither of those things helped.  Then I saw the elog that Jamie's working on figuring it out.

  6923   Thu Jul 5 16:49:35 2012 JenneUpdateComputersc1sus is funny

I was trying to use a new BLRMs c-code block that the seismic people developed, instead of Mirko's more clunky version, but putting this in crashed c1sus.

I reverted to a known good c1pem.mdl, and Jamie and I did a reboot, but c1sus is still funny - none of the models are actually running. 

rtcds restart all - all the models are happy again, c1sus is fine.

But, we still need to figure out what was wrong with the c-code block.

Also, the BLRMS channels are listed in a Daq Channels block inside of the (new) library part, so they're all saved with the new CDS system which became effective as of the upgrade.  (I made the Mirko copy-paste BLRMS into a library part, including a DAQ channels block before trying the c-code.  This is the known-working version to which I reverted, and we are currently running.)

  6924   Fri Jul 6 01:12:02 2012 JenneUpdateComputersc1sus is fine

Quote:

I was trying to use a new BLRMs c-code block that the seismic people developed, instead of Mirko's more clunky version, but putting this in crashed c1sus.

I reverted to a known good c1pem.mdl, and Jamie and I did a reboot, but c1sus is still funny - none of the models are actually running. 

rtcds restart all - all the models are happy again, c1sus is fine.

But, we still need to figure out what was wrong with the c-code block.

Also, the BLRMS channels are listed in a Daq Channels block inside of the (new) library part, so they're all saved with the new CDS system which became effective as of the upgrade.  (I made the Mirko copy-paste BLRMS into a library part, including a DAQ channels block before trying the c-code.  This is the known-working version to which I reverted, and we are currently running.)

 The reason I started looking at BLRMS and c1sus today was that the BLRMS striptool was totally wacky.  I finally figured out that the pemepics hadn't been burt restored, so none of the channels were being filtered.  It's all better now, and will be even better soon when Masha finishes updating the filters (she'll make her own elog later)

  6944   Mon Jul 9 11:27:27 2012 JenneUpdateComputersc1oaf has been down for several days - BURT restore wasn't done correctly on startup

The c1oaf model hasn't been running for a few days (since the leap second problems we were having last week).  I had looked into it, but finally figured it out (with Jamie's help) today. 

The BURT restore has to be given to the model during startup, but for whatever reason it wasn't BURT restoring until *after* the model had already failed to start.  The symptoms were:  no 'heartbeat' for the oaf model, no connection to the fb, NO SYNC on the GDS screen, 0x4000.  the BURT restore button was green, which threw me off the scent, but that's just because it did, in fact, get set, just way too late.

I ended up looking in the dmesg of the lsc computer, and the last set of stuff was several lines of "[3354303.626446] c1oaf: Epics burt restore is 0".  Nothing else was written after that.  Jamie pointed out that this meant the BURT restore wasn't getting sent before the model unloaded itself and decided not to run.

The solution:  restart the model, and manually click the BURT restore button as soon as you're able (after everything comes back from being white).  We used to have to do this, but then there was a "fix", which apparently isn't super robust and failed for the oaf (even though it used to work just fine).  Bugzilla report submitted.

  6945   Mon Jul 9 15:05:00 2012 JenneUpdatePEMSeismometers being moved, new safety shower

[Masha, Jenne]

Masha is moving the seismometers, so they are all off right now.  Were they on, they would see a bunch of noise from the guy outside the 40m front door who is installing a safety shower.

  6961   Wed Jul 11 13:45:01 2012 JenneUpdatePEMmore seismic noise next week

Quote:
 
   The fabricators of the big flume in the CES lab have begun testing the sediment feed system which is the noisiest component and plan to test off and on during the day for the next week.
   Please let me know if you detect the noise or have any issues.
 
 
Brian Fuller

phone: 626-395-2465

 Masha and Yaakov - this is an excellent opportunity for you guys to test out your triangulation stuff!  Also, it might give a lot of good data times for the learning algorithms.

Maybe you should also put out the 3 accelerometers that Yaakov isn't using (take them off their cube, so they can be placed separately), then you'll have 6 sensors for vertical motion.  Or you can leave the accelerometers as a cube, and have 4 3-axis sensors (3 seismometers + accelerometer set).

  6966   Thu Jul 12 11:55:00 2012 JenneUpdateGreen LockingNew BS mounts for PSL beats - Y is finished

Yuta and I bought some new BS mounts so that we could use the 4th port of the beamsplitters which are combining the PSL green and the arm transmitted beam, just before the Beat PD for each arm.  I just placed the Yarm one, and have aligned the light onto both the Beat PD and the Trans DC PD. 

I'll do the Xarm after lunch.

  6968   Thu Jul 12 15:25:24 2012 JenneUpdateSUSClearing test points

Somehow we got an excitation going on BS OpLevs, and even though Yuta thought he might have accidentally started it, he couldn't find where, so we couldn't stop it.

Since we don't have anything written on the wiki, I ended up calling Joe to remind me how to clear test points:

controls@allegra:~ 0$ diag -l -z
diag> tp clear * *
test point cleared
diag> awg clear 21.*
reset succeeded

The tp clear clears all test points everywhere.  The awg clear wouldn't let me do a universal clear, so I just did #21, which is the SUS model.  So if you want to kill excitations on a specific model, you must find it's DCU ID (it's in the top right corner of the GDS status screens for each model). 

  6975   Fri Jul 13 19:48:56 2012 JenneUpdateEnvironmentRocks - very loud

I assume it's the rock tumbler, although it could be something else, but the MC has had trouble staying locked yesterday and today (yesterday Yaakov and I went over there and they were doing stuff almost constantly - it's super loud over there), and today even the PMC has fallen out of lock twice.  I just relocked it again, since it went out of lock just after Journal club started.

Anyhow, I think this will be good data for Masha, and then also for the Masha+Yaakov triangulation project.

  6978   Mon Jul 16 16:41:49 2012 JenneUpdatePSLPMC locked in funny place - PSL laser temp changed

The PMC was unlocked earlier this morning, for ~20min, presumably from the rocks next door.  I relocked it.

Then, a few min ago, the PMC suddenly decided that it wouldn't lock with a transmission greater than ~0.7 .  I found that the laser temp adjust on the FSS screen was at -1.9ish.  I put it back to zero, and now the PMC locks happily again.  I think we got into a PSL mode-hopping temperature region on accident.

  6979   Tue Jul 17 02:17:50 2012 JenneUpdateASCASS gains wrong?
I was checking on the ASS system, and I think that the gains on some of the loops may not be correct. An old symptom was that the commands in the script were not being executed when we changed over to Ubuntu. Now it seems that each command is working fine, but the loops are pushing the optics more out of alignment than anything. I flipped the sign on some of the loops and it helped, others it didn't. I need to measure some transfer functions and meditate on what they should look like. It will be really nice to have the alignment system working again.
  6980   Tue Jul 17 11:28:29 2012 JenneUpdateASSNames of DoF filters in ASS wrong

The names of the DoF filters in the ASS loop were wrong.  The filters themselves were correct (low pass filters at super low freq, for the Lock-in), but the names were backward.

Our convention is to name filters "poles:zeros", but they had been "z:p".  The names of FM1 in all the DoF filter banks are now fixed.

  6982   Wed Jul 18 00:36:22 2012 JenneUpdateIOOWFS oscillating

I was trying to lock and look at the ASS for the Yarm, but the transmitted power was oscillating very near 1Hz.  Eventually I looked at the mode cleaner, and it was also moving around at a similar frequency.  I took spectra of the ETMY SUS damping feedback signals, and they (POS, PIT, YAW) saw this 1Hz motion too (see attached plots...same data, one is a zoom around 1Hz).

As a first place to start, I turned off the WFS, which immediately stopped the MC oscillation.  Turning the WFS back on, the oscillation didn't come back.  I'm not sure what happened to make the WFS bad, but I perhaps had the ASS dither lines on (I've had them on and off, so I'm not sure), although turning off the dither lines didn't make the WFS any better.

As an aside, the MC refl with the WFS off was ~1.5, rather than the ~0.5 with the WFS on, which means that the PSL beam and the MC axis are not well matched.

Attachment 1: Yarm_oscillating_1Hz_while_WFS_crazy_full_17July2012.pdf
Yarm_oscillating_1Hz_while_WFS_crazy_full_17July2012.pdf
Attachment 2: Yarm_oscillating_1Hz_while_WFS_crazy_17July2012.pdf
Yarm_oscillating_1Hz_while_WFS_crazy_17July2012.pdf
  6989   Wed Jul 18 14:25:44 2012 JenneUpdateIOOMC spot position measurements

The script ....../scripts/ASS/MC/mcassMCdecenter  takes ~17 minutes to run.  The biggest time sink is measuring a no-offset-added-to-coil-gains set, in between each measurement set with the coil gain offsets.  This is useful to confirm that the nominal place hasn't changed over the time of the measurement, but maybe we don't need it.  I'm leaving it for now, but if we want to make this faster, that's one of the first things to look at.

Today's measurement:

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
[3.5716862287669224, 3.937869278443594, 2.9038058599576595, -6.511822708584913, -0.90364583591421999, 4.8221820002404279]

There doesn't seem to be any spot measurement stuff for any other optics, so I'm going to try to replicate the MC spot measuring script for the Michelson to start.

  6991   Thu Jul 19 02:14:37 2012 JenneUpdateVIDEOMade a video gui

I learned a little bit of python scripting while looking at the videoswitch script, and I made a video medm screen. 

Each monitor has a dropdown menu for all the common cameras we use (medm only lets you put a limited # of lines on a dropdown menu...when we want to add things like OMCR or RCT, we'll need to add another dropdown set)

Each monitor also has a readback to tell you what is on the TV.  So far, the quads only say "QUAD#", not what the 4 components are. 

I put a set of epics inputs in the PEM model, under a subsystem with top-names VID to represent the different monitors.  The readbacks on the video screen look at these, with the names corresponding to the numbers listed in the videoswitch script.  The videoswitch script now does an ezcawrite to these epics inputs so that even if you change the monitors via command line, the screen stays updated.

For example, since MC2F's camera is plugged in to Input #1 of the video matrix, if you type "./videoswitch MON1 MC2F", the script will write a "1" to the channel "C1:VID-MON1", and the screen will show "MC2F" in the Mon1 cartoon.

This required a quick recompile of the PEM model, but not the framebuilder since these were just epics channels.

There is also a dropdown menu for "Presets", which right now only include my 2 arm locking settings.

All of the dropdowns just call an iteration of the videoswitch script.

  6992   Thu Jul 19 02:32:45 2012 JenneUpdateIOOWFS don't come on automatically??

The MC unlocked ~20 min ago, correlated with 2 consecutive earthquakes in Mexico.  The MC came back fine after a few minutes, but the WFS never engaged.  I turned them on by hand.  I think that Yuta mentioned once that he also had to turn the WFS on by hand.  There may be a problem in the unlock/relock catching that needs to be looked at, to make sure the WFS come back on automatically.

Also, someone (Masha and I) should look at the seismic BLRMS.  I have suspected for a few days that they're not telling us everything that we want to know.  Usually, if there's an earthquake close enough / big enough that it pops the MC out of lock, it is clear from the BLRMS that that's what happened, but right now it doesn't look like much of anything....just kind of flat for hours.

  7002   Mon Jul 23 13:30:06 2012 JenneUpdateGreen LockingYarm ALS laser is funny / dying

Jamie and I were doing some locking, and we found that the Yarm green wasn't locking.  It would flash, but not really stay locked for more than a few seconds, and sometimes the green light would totally disappear.  If the end shutter is open, you can always see some green light on the arm transmission cameras.  So if the shutter is open but there is nothing on the camera, that means something is wrong.

I went down to the end, and indeed, sometimes the green light completely disappears from the end table.  At those times, the LED on the front of the laser goes off, then it comes back on, and the green light is back.  This also corresponds to the POWER display on the lcd on the laser driver going to ~0 (usually it reads ~680mW, but then it goes to ~40mW).  The laser stays off for 1-2 seconds, then comes back and stays on for 1-2 minutes, before turning off for a few seconds again.

Koji suggested turning the laser off for an hour or so to see if letting it cool down helps (I just turned it off ~10min ago), otherwise we may have to ship it somewhere for repairs :( 

  7003   Mon Jul 23 17:39:34 2012 JenneUpdateIOOMC_F vs. MC_L

[Rana, Jenne]

We looked at the different outputs of the MC servo board to make sure they make some kind of sense.  As per my elog 6625, the names of the channels were wrong, but we wanted to confirm that we have something sensible.

Currently, OUT1 of the servo board is called "MC_F" and the SERVO out is called "MC_SERVO".  We looked at the spectrum of each, and the transfer function between them.

You can see that in addition to a 2kHz pole, MC_L also seems to have a 10-100 zero-pole pair.

 

Also, while cleaning things up in the models, I fixed the names of these MCL/MCF channels.  OUT1 is now called MC_L, and is connected to ADC0_0, and SERVO is called MC_F and is connected to ADC0_6.  Both MC_L and MC_F go to the RFM, and thence on to the OAF.  MC_L (which used to be mis-named MC_F) still goes both to the MCS model for actuation on MC2, and to the OAF for MC-OAF-ing.  Right now MC_F is unused in the OAF model, but we can change that later if we want.

 

Attachment 1: MCF_vs_MCL_23July2012.pdf
MCF_vs_MCL_23July2012.pdf
  7004   Mon Jul 23 18:01:30 2012 JenneUpdateGreen LockingYarm ALS laser is funny / dying

 I turned the Yend laser back on....it hasn't turned itself off yet, but I'm watching it.  As long as we leave the shutter open, we can watch the C1:ALS-Y_REFL_DC value to see if there's light on the diode.

  7006   Mon Jul 23 18:38:58 2012 JenneUpdatePSLPSL channels added to IOO model

I added a subblock to the IOO model, and gave it a top_names of PSL, so the channels show up as C1:PSL-......

So far, there are just 2 channels acquired, C1:PSL-FSS_MIXER and C1:PSL-FSS_FAST, since those were already connected to the ADC.  Those signals are both on the DAQ OUT of the FSS board in the rack.  They are DQ channels now too.

 

  7010   Mon Jul 23 19:13:12 2012 JenneUpdatePSLPSL channels added to IOO model

Quote:

I added a subblock to the IOO model, and gave it a top_names of PSL, so the channels show up as C1:PSL-......

So far, there are just 2 channels acquired, C1:PSL-FSS_MIXER and C1:PSL-FSS_FAST, since those were already connected to the ADC.  Those signals are both on the DAQ OUT of the FSS board in the rack.  They are DQ channels now too. 

 So there was a problem with the channel name C1:PSL-FSS_FAST, which conflicts with an existing slow channel.  This was causing daqd to fail to start (shockingly, with an appropriate error message!).  I renamed the channel to be C1:PSL-FSS_NPRO until we come up with something better.

After the change everthing worked and fb came back.

  7017   Tue Jul 24 03:14:13 2012 JenneUpdateASSCalibration of MC ASS lockins

I wanted to check that the calibration of the MC ASS lockins was sensible, before trusting them forevermore.

To measure the calibration, I took a 30sec average of C1:IOO-MC_ASS_LOCKIN(1-6)_I_OUT with no misalignment. 

Then step MC1 pitch by 10% (add 0.1 to the coil output gains).  Remeasure the lockin outputs.

2.63 / (Lockin1noStep - Lockin1withStep) = calibration.

Repeat, with Lockin2 = MC2 pit, lockin3 = MC3 pit, and lockins 4-6 are MC1-3 yaw.

 

The number 2.63 comes from: half the side of the square between all 4 magnets.  Since our offsets are in pitch and yaw, we want the distance between the line connecting the lower magnets and the center line of the optic, and similar for yaw.  Presumably if all of the magnets are in the correct place, this number is the same for all magnets.  The optics are 3 inches in diameter.  I assume that the center of each magnet is 0.9mm from the edge of the optic, since the magnets and dumbbells are 1.9mm in diameter. Actually, I should probably assume that they're farther than that from the edge of the optic, since the edge of the dumbbell ~touches the edge of the flat surface, but there's the bevel which is ~1mm wide, looking normal to the surface of the optic.  Anyhow, what I haven't done yet (planned for tomorrow...) is to figure out how well we need to know all of these numbers.

We shouldn't care more than ~100um, since the spots on the optics move by about that much anyway.

For now, I get the following #'s for the calibration:

Lockin1 = 7.83

Lockin2 = 9.29

Lockin3 = 8.06

Lockin4 = 8.21

Lockin5 = 10.15

Lockin6 = 6.39

The old values were:

C1:IOO-MC_ASS_LOCKIN1_SIG_GAIN = 7
C1:IOO-MC_ASS_LOCKIN2_SIG_GAIN = 9.6
C1:IOO-MC_ASS_LOCKIN3_SIG_GAIN = 8.3
C1:IOO-MC_ASS_LOCKIN4_SIG_GAIN = 7.8
C1:IOO-MC_ASS_LOCKIN5_SIG_GAIN = 9.5
C1:IOO-MC_ASS_LOCKIN6_SIG_GAIN = 8.5

The new values measured tonight are pretty far from the old values, so perhaps it is in fact useful to re-calibrate the lockins every time we try to measure the spot positions?

  7030   Wed Jul 25 16:31:01 2012 JenneUpdateLSCYarm green locking to arm - PDH box saturating

Quote:

... it was not possible to get the cavity locked in green. So we decided to do the first measurement with infrared locked only. 

 When we sat down to align the Yarm to the green, the green light was happy to flash in the cavity, but wouldn't lock, even after Jan had tweaked the mirrors such that we were flashing the TEM00 mode.  When we went down to the end to investigate, the Universal PDH box was saturating both negative and positive.  Turning down the gain knob all the way to zero didn't change anything, so I put it back to 52.5.  Curiously, when we unplugged the Servo OUT monitor cable (which was presumably going to the rack to be acquired), the saturation happened much less frequently.  I think (but I need to look at the PDH box schematic) that that's just a monitor, so I don't know why that had to do with anything, but it was repeatable - plug cable in, almost constant saturation....unplug cable, almost no saturation.

Also, even with the cable unplugged, the light wouldn't flash in the cavity.  When I blocked the beam going to the green REFL PD (used for the PDH signal), the light would flash.

Moral of the story - I'm confused.  I'm going to look up the PDH box schematic before going back down there to investigate.

  7035   Thu Jul 26 02:44:17 2012 JenneUpdateIOOCentering the MCR camera

[Yaakov, Jenne]

The short version:

Rana and Koji pointed out to us that the MCR camera view was still not good.  There were 2 problems:

(1) Diagonal stripes through the beam spot.  Yuta and I saw this a week or 2 before he left, but we were bad and didn't elog it, and didn't investigate.  Bad grad students.

(2) Clipping of the left side of the beam (as seen on the monitors).  This wasn't noticed until Yaakov's earlier camera work, since the clipped part of the beam wasn't on the monitor.

The fix for #1 was to partially close the iris which is the first "optic" the beam sees on the AP table after leaving the vacuum. 

The "fix" for #2 was that the wrong beam has been going to the camera for an unknown length of time.  We picked the correct beam, and all is well again.

We moved the 10% BS that splits the main beam into the (MC REFL PD) path and the (MCR camera + WFS) path.  It looked like the transmission through there was close to the edge of the BS.  We didn't think that this was causing the clipping that we saw on the camera (since when we stepped MC1 in Yaw, the beam spot had to move a lot before we saw any clipping), but it seemed like a good idea to make the beam not near the edge of the optic, especially since, being a 2" optic, there was plenty of room, and we were only using ~half of the optic.  We didn't touch anything else in the WFS path, since that looks at the transmission through this BS, but we had to realign the beam onto MC REFL.

The long version:

(1)  The fix for #1 was to partially close the iris which is the first "optic" the beam sees on the AP table after leaving the vacuum.  It looks like that's why the iris was there in the first place.  When we found it this evening, the iris was totally open, so my current theory is that someone was on the AP table doing something, and accidentally bumped the handle for the iris, then left it completely open when they realized that they had touched it.  I think Steve had been doing something on the AP table around then, but since Yuta and I didn't elog our observation (bad grad students!), I can't correlate it with any of Steve's elogs. We were not able to find exactly where this "glow" that the iris is used to obscure comes from, but we traced it as far as the viewport, so there's something going on inside.

(2)  The "fix" for #2 was that the wrong beam has been going to the camera for an unknown length of time.  We picked the correct beam, and all is well again. 

We spent a long time trying to figure out what was going on here.  Eventually, we moved the camera around to different places (i.e. right before the MC REFL PD, with some ND filters, and then we used a window to pick off a piece of the beam right as it comes out of the vacuum before going through the iris, put some ND filters, then the camera).  We thought that right before the MC REFL PD was also being clipped, indicating that the clipping was happening in the vacuum (since the only common things between the MC REFL PD path and the camera path are the iris, which we had removed completely, and a 2" 10% beam splitter.  However, when we looked at a pickoff of the main beam before any beamsplitters, we didn't see any evidence of clipping.  I think that when we had the camera by MC REFL, we could have been clipping on the ND filters that I had placed there.  I didn't think to check that at the time, and it was kind of a pain to mush the camera into the space, so we didn't repeat that.  Then we went back to the nominal MCR camera place to look around.  We discovered that the Y1 which splits the camera path from the WFS path has a ghost beam which is clipping on the top right side (as you look at the face of the optic) of the optic, and this is the beam that was going to the camera (it's a Y1 since we only want a teensy bit of light to go to the camera, the rest goes to the WFS).  There is another beam which is the main beam, going through the center of the optic, which is the one which also reflects and heads to the WFS.  This is the beam which we should have on the camera.  Yaakov put the camera back in it's usual place, and put the correct beam onto the center of the camera.  We did a check to make sure that the main beam isn't clipping, and when I step MC1 yaw, the beam must move ~1.5mm before we start to see any clipping on the very edge of the beam.  To see / measure this, we removed the optic which directs the beam to the camera, and taped an IR card to the inside of the black box.  This is ~about the same distance as to the nominal camera position, which means that the beam would have to move by 1.5mm on the camera to see any clipping.  The MC REFL PD is even farther from MC1 than our IR card, so the beam has to fall off the PD before we see the clipping.  Thus, I'm not worried about any clipping for this main beam.  Moral of the story, if you made it this far:  There wasn't any clipping on any beams going to either the WFS or the MC REFL PD, only the beam going to the camera.

  7048   Mon Jul 30 10:05:29 2012 JenneUpdatePSLPMC is still not fixed

Quote:

The PMC was locking right the way, but it's transmission would not go up.  Finally I get it back up by moving the "sticky" DC Gain slider up and down a few times.

 The FSS was -2.9, and the PMC won't lock happily unless you bring this back to 0.  The symptom that this is happening is that the PMC reflection camera is totally saturated, but the PMC still looks like it's locked on 00.

  7069   Wed Aug 1 15:02:29 2012 JenneUpdateIOOIP POS QPD centered

Jamie went out to look at IP POS, and the beam was *way* off.  Even though our alignment is still rough, we're kind of close right now, so Jamie put the beam back on the QPD, but we need to recenter IPPOS after we get good alignment.

ELOG V3.1.3-