40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 291 of 335  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  10849   Tue Dec 30 20:35:59 2014 ranaSummaryPSLPMC Tune Up
  1. Calibrated the Phase Adjust slider for the PMC RF Modulation; did this by putting the LO and RF Mod out on the TDS 3034 oscope and triggering on the LO. This scope has a differential phase measurement feature for periodic signals.
  2. Calibrated the RF Amp Adj slider for the PMC RF Modulation (on the phase shifter screen)
  3. The PMC 35.5 MHz Frequency reference card is now in our 40m DCC Tree.
  4.  The LO and RF signals both look fairly sinusoidal !
  5. Took photos of our Osc board - they are on the DCC page. Our board is D980353-B-C, but there are no such modern version in any DCC.
  6. The PMC board's Mixer Out shows a few mV of RF at multiples of the 35.5 MHz mod freq. This comes in via the LO, and can't be gotten rid of by using a BALUN or BP filters.
  7. In installed the LARK 35.5 MHz BP filter that Valera sent us awhile ago (Steve has the datasheet to scan and upload to this entry). It is narrow and has a 2 dB insertion loss.

For tuning the phase and amplitude of the mod. drive:

- since we don't have access to both RF phases, I just maximized the gain using the RF phase slider. First, I flipped the sign using the 'phase flip' button so that we would be near the linear range of the slider. Then I put the servo close to oscillation and adjusted the phase to maximize the height of the ~13 kHz body mode. For the amplitude, I just cranked the modulation depth until it started to show up as a reduction in the transmission by ~0.2%, then reduced it by a factor of ~3. That makes it ~5x larger than before.

Attachment 1: 17.png
17.png
Attachment 2: PMCcal.ipynb.xz
Attachment 3: PMC_Osc_Cal.pdf
PMC_Osc_Cal.pdf
  10851   Sun Jan 4 22:08:46 2015 ranaUpdateIOOMC loop characterizations: PZT/EOM crossover

 * PMC + MC were unlocked when I came in.

* I fiddled around some more with the mcup/down scripts to make locking snappier. The locking was breaking the PMC lock often, so I re-enabled the MC servo board output limiter during acquisition. It is disabled in the MC UP script.

* Re-measured the MC OLG. Still OK.

* Measured the PZT / EOM crossover (aka the FAST / PC crossover) using the connectors on Koji's summing box. With the FAST gain at 18 dB, the crossover is ~10 kHz. Looks way to shallow. Plots to follow.

* I finally discovered today that the PMC PZT stroke is what's causing the main mis-alignment of the beam going to the IMC. By relocking at a few positions, I could see that the IOO QPDs have steps when the PMC relocks. So the IO beam wander is NOT due to temperature effects on the optics mounts of the PSL table. I wonder if we have a large amount of length to angle coupling or if this is the same as the OMC PZTs ?

P.S. I found that someone is using a temporary bench power supply to power the summing box between the TTFSS and the Thorlabs HV driver...whoever did this has ~48 hours to hook up the power in the right way or else Koji is going to find out and lose it and then you have to wear the Mickey Mouse hat.

http://www.arroyoinstruments.com/files/Arroyo-UsingBenchPowerSupplies_11Apr.pdf


The first attachment shows the OLG measurements with 2 different values of the fast gain (our nominal FG is 18 dB). You can see that the higher gains produce some crossover instability; when tuning the gain we notice this as an increase in the PCDRIVE rms channel.

The second attachment shows the measurement of the 'crossover'. Its really just the direct measurement of the IN1 / IN2 from the FAST summing box, so its the crossover measurement where the OLG is high.

Attachment 1: MC_OLGs.pdf
MC_OLGs.pdf
Attachment 2: MC_xover.pdf
MC_xover.pdf
  10874   Wed Jan 7 21:13:35 2015 ranaUpdateGeneralinane LSCoffsets script removed

Quote:

 A few things that I have neglected to ELOG yet:

  • scripts/offsets/LSCoffsets is a new script that uses ezcaservo to set FM offsets of our LSC PDs. It still warns about large changes, and lets you revert. It reads the FM gain to pick the right gain for the ezcaservo call. 

 We never, ever want to use ezcaservo to do this. IN fact, we twice have already deleted scripts where people have implemented these (sometimes) unstable servos. Also, since this change had never been committed to the SVN, I just deleted it and updated from the SVN to get back the script that doesn't use any servos.

I'm going to periodically delete locking scripts that are not committed to the SVN since anyone who is too lazy to use the SVN probably can't write code worth using.

  10899   Wed Jan 14 02:11:07 2015 ranaSummaryTreasure2-loop Algebra Loopology

I show here the matrix formalism to calculate analytically the loop TF relationships for the IMC w/ both FSS actuators so that it would be easier to interperet the results.

The attached PDF shows the Mathematica notebook and the associated block diagram.

In the notebook, I have written the single hop connection gains into the K matrix. P is the optical plant, C is the Common electronic gain, F is the 'fast' NPRO PZT path, and M is the phase Modulator.

G is the closed loop gain matrix. The notation is similar to matlab SS systems; the first index is the row and the second index is the column. If you want to find the TF from node 2 to node 3, you would ask for G[[3,2]].

As examples, I've shown how to get the FAST gain TF that I recently made with the Koji filter box as well as the usual OLG measurement that we make from the MC servo board front panel.

Attachment 1: FSSloop.pdf
FSSloop.pdf FSSloop.pdf
Attachment 2: FSSloop.png
FSSloop.png
  10949   Wed Jan 28 14:19:02 2015 ranaUpdateLSCTransitioned DARM to AS55Q

Why AS55/(TRX + TRY) instead of just TRX? Isn't (TRX+TRY) controlled by CARM?cool

(question is secretly from Kiwamu)

  10988   Sun Feb 8 21:54:50 2015 ranaSummaryPSLISS AOM driver check

This is good news. It means that the driver probably won't limit the response of the loop - I expect we'll get 20-30 deg of phase lag @ 100 kHz just because of the acoustic response of the AOM PZT + crystal.

  10998   Wed Feb 11 00:07:54 2015 ranaUpdateLSCLock Loss plot

Here is a lock loss from around 11 PM tonight. Might be due to poor PRC signals.  \oint {\frac{\partial PRCL}{\partial x}}

This is with arm powers of ~6-10. You can see that with such a large MICH offset, POP22 signal has gone done to zero. Perhaps this is why the optical gain for PRCL has also dropped by a factor of 30 crying.

This seems untenable no. We must try this whole thing with less MICH offset so that we can have a reasonable PRCL signal.cool

Attachment 1: 1107673198.png
1107673198.png
  11002   Wed Feb 11 16:49:41 2015 ranaUpdateelogELOGD restarted

No elog response from outside and no elogd process frownon nodus, so I restarted it using 'start-elog.csh'.

  11008   Thu Feb 12 01:00:18 2015 ranaUpdateLSCRFPD spectra

The nonlinearity in the LSC detection chain (cf T050268) comes from the photodetector and not the demod board. The demod board has low pass or band pass filters which Suresh installed a long time ago (we should check out what's in REFL33 demod board). 

Inside the photodetector the nonlinearity comes about because of photodiode bias modulation (aka the Grote effect) and slew rate limited distortion in the MAX4107 preamp.

  11009   Thu Feb 12 01:43:09 2015 ranaUpdateLSCNew Locking Paradigm - LSC model changes

With the Y Arm locked, we checked that we indeed can get loop decoupling using this technique.

The guess filter that we plugged in is a complex pole pair at 1 Hz. We guessed that the DC gain should be ~4.5 nm count. We then converted this number into Hz and then into deg(?) using some of Jenne's secret numbers. Then after measuring, we had to increase this number by 14.3 dB to an overall filter module gain of +9.3.

The RED trace is the usual 'open loop gain' measurement we make, but this time just on the LSC-MC path (which is the POY11_I -> ETMY path).

The BLUE trace is the TF between the ALS-Y phase tracker output and the FF cancellation signal. We want this to be equal ideally.

The GREEN trace is after the summing point of the ALS and the FF. So this would go to zero when the cancellation is perfect.

So, not bad for a first try. Looks like its good at DC and worse near the red loop UGF. It doesn't change much if I turn off the ALS loop (which I was running with ~10-15x lower than nominal gain just to keep it out of the picture). We need Jenne to think about the loop algebra a little more and give us our next filter shape iteration and then we should be good.

Attachment 1: TF.gif
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  11018   Thu Feb 12 23:40:12 2015 ranaUpdateIOOBounce / Roll stopband filters added to MC ASC filter banks

The filters were already in the damping loops but missing the MC WFS path. I checked that these accurately cover the peaks at 16.5 Hz and 23.90 and 24.06 Hz.

Attachment 1: 59.png
59.png
  11020   Fri Feb 13 03:28:34 2015 ranaUpdateLSCNew Locking Paradigm - Loop-gebra

Not so fast!

In the drawing, the FF path should actually be summed in after the Phase Tracker (i.e. after S_ALS). This means that the slow response of the phase tracker needs to be taken into account in the FF cancellation filter. i.e. D = -A_REFL * P_ALS * S_ALS. Since the Phase Tracker is a 1/f loop with a 1 kHz UGF, at 100 Hz, we can only get a cancellation factor of ~10.

So, tonight we added a 666:55 boost filter into the phase tracker filter bank. I think this might even make the ALS locking loops less laggy. The boost is made to give us better tracking below ~200 Hz where we want better phase performance in the ALS and more cancellation of the ALS-Fool. If it seems to work out well we can keep it. If it makes ALS more buggy, we can just shut it off.

Its time to take this loop cartoon into OmniGraffle.

  11025   Fri Feb 13 18:56:44 2015 ranaUpdateElectronicsSecond QPD Whitening Switch enabled

Depends on the plots of the whitening I guess; if its low freq sat, then we lower the light level with ND filters. If its happening above 10 Hz, then we switch off the whitening.

Quote:

Went to zero CARM offset on ALS; transmission QPDs are still saturating :(

Maybe we need to switch off all whitening.

 

  11034   Sun Feb 15 20:55:48 2015 ranaSummaryLSC[ELOG LIST] 3f modulation cancellation

I wonder if DRMI can be locked on 3f using this lower 55 MHz modulation depth. It seems that PRMI should be unaffected, but that the 3*f2 signals for SRCL will be too puny. Is it really possible to scale up the overall modulation depths by 3x to compensate for this?

  11040   Mon Feb 16 21:52:51 2015 ranaHowToTreasurebig Dataviewer windows

Following this entry, I have made the same change in the controls account on rossa:

In the ~/.grace/gracerc file (create one if it doesn't exist), put in a line which reads:

PAGE LAYOUT FREE

Now we can scale our dataviewer live and playback plots by stretching the window with our mouse. The attached screenshot shows how I filled up one of the vertical monitors with a DV window for arm locking.

Attachment 1: bigDV.png
bigDV.png
  11057   Mon Feb 23 08:06:59 2015 ranaUpdateASCQPD frontend code unified

Might have to also get the OL screens that go with this new code to see, but the calibrations don't go into the matrix, but rather into the OLPIT/OLYAW filter banks which follow the division, but before the servo filter banks.

  11067   Wed Feb 25 14:18:28 2015 ranaUpdateLSCDelay line re-installed, measurements round 2

The Schnupp asymmetry is definitely not an important parameter (no need for Koji to explode). It only serves to give us a bigger Q phase signal slope, but is not significant for the I phase signals.

The main anomaly is that the REFL33 optical gain (W/m) seems to have been reduced so much by the phase and amplitude adjustment of the 55 MHz modulation signal. One guess is that the true 3f signal is being made not by the (2*f1 - (-f1)) beat, but by some higher order beat. In addition to the usual RF fields produced by the 2 modulations, we must consider that the sidebands on sidebands produce intermodulation fields just after the EOM and so the fields with which we interrogate the PRMI are more complicated.

Jenne's Optickle calculation today should show us what the sensing matrix contribution is from each pair of fields, so that we can have a sensing matrix signal budget.

 

  11071   Wed Feb 25 23:48:57 2015 ranaUpdateLSCsome thoughts
  • Comparing just the 2 cases with locking on 33, it seems that the 55 MHz gain has changed by 14 dB instead of the 10 dB that we expected. Is it that we need to measure the modulation drive change more carefully, or just that the PRMI was aligned differently?
  • The 165 signal changed by a factor of 60 (35 dB) which is more consistent with a ~12 dB change in Gamma2, so not so far off.
  • The fact that the whole sensing matrix increases in amplitude between 33 and 55 lock makes me think that either the alignment was very bad for the 33 lock, or that the 33 signals have a significant offset; if that's the case, then we should do as LLO and set the digital offsets in the 33 signals by locking first on 55.
  • How does the REFL33 demod phase change by 70 deg?
  11081   Fri Feb 27 01:59:57 2015 ranaHowToLSCiPython Notebook for LSC Sensing Matrix

I have adapted one of Evan's python scripts into an ipython notebook for calculating our PRMI sensing matrix - the work is ~half done.

The script gets the data from the various PD channels (like REFL33_I) and demdoulates it at the modulation frequencies. At the moment its using just the sensing channels, but with the recent addition of the SUS-LSC_OUT_DQ channels, we can demod the actuation channels as well and not have to hand code the exc amplitudes and the basolute phase. Please ignore the phase for the moment.

The attached PDF shows the demod (including lowpass) outputs for a 2 minute stretch of PRMI locked on f2. Next step is to average these numbers and make the radar plots with the error bars. The script is scripts/LSC/SensingMatrix/PRMIsensMat.ipynb and is in the SVN now.

** along the way, I noticed that the reason this notebook hasn't been working since last night is that someone sadly installed a new anaconda python distro today  without telling anyone by ELOG. This new distro didn't have all the packages of the previous one.no I've updated it with astropy and uncertainties packages.

I've fixed the Radar plot making part, so that's now included too. The radial direction is linear, so you can see from the smearing of the blobs that the uncertainty is represented in the graphics due to each measurement being a small semi-transparent dot. Next, we'll put the output of the statistics on the plot: mean, std, and kurtosis.

Attachment 1: Plots_1109056456.pdf
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Attachment 2: Radar_1109056456.pdf
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  11096   Wed Mar 4 00:50:36 2015 ranaBureaucracyTreasureTransitioned DARM to AS55Q, some other work

Just in case there was some confusion, the champagne on my desk is not to be opened before I get back, no matter how many signals are transitioned to RF.

  11103   Thu Mar 5 19:13:17 2015 ranaUpdateCDSmxStream all restart at ~7:10 pm
  11106   Fri Mar 6 00:59:13 2015 ranaSummaryIOOMC alignment not drifting; PSL beam is drifting

In the attached plot you can see that the MC REFL fluctuations started getting larger on Feb 24 just after midnight. Its been bad ever since. What happened that night or the afternoon of Feb 23?
The WFS DC spot positions were far off (~0.9), so I unlocked the IMC and aligned the spots on there using the nearby steering mirrors - lets see if this helps.

Also, these mounts should be improved. Steve, can you please prepare 5 mounts with the Thorlabs BA2 or BA3 base, the 3/4" diameter steel posts, and the Polanski steel mirror mounts? We should replace the mirror mounts for the 1" diameter mirrors during the daytime next week to reduce drift.

Attachment 1: MCdrfit.png
MCdrfit.png
  11107   Fri Mar 6 02:10:35 2015 ranaUpdateLSCArm length remeasurement

This has been done before:

http://nodus.ligo.caltech.edu:8080/40m/6938

Arm length measurements and g-factor estimates in 2012, but only with an accuracy of ~30 cm. However, Yuta was able to get many FSRs somehow.

  11112   Fri Mar 6 19:54:15 2015 ranaSummaryIOOMC alignment not drifting; PSL beam is drifting

MC Refl alignment follow up: the alignment from last night seems still good today. We should keep an cool on the MC WFS DC spots and not let them get beyond 0.5.

Attachment 1: Untitled.png
Untitled.png
  11121   Sun Mar 8 13:51:41 2015 ranaUpdateLSCError signal blending for CARM/DARM transitions

According to the official rules, we only need 8 seconds to declare it "locked".

I wonder if the double cavity pole compensation filter for CARM was on for all the attempts yesterday? IF it looks like it will not saturate, it would be more stable to have the whitening on for REFL11 / AS55. Since on Friday, I set the REFL165 demod phase just by minimizing the MICH control signal with the arms on resonance, we ought to check out the PRMI degeneracy with the ETMs misaligned.

Speaking of signal mixing: Although we weren't able to get the carrier term cancelled in the 3*f1 signals by the relative mod phase method, I wonder if we can do it by mixing the 3*f1 and 3*f2 signals in the input matrix. Might help to keep the PRMI more stable, if that's an issue.


P.S. I have done some scripts directory / SVN cleanup. Adding some directories that were not in (like lockloss) and then removing stuff from the repo using 'svn rm --keep-local  filenames' for the image and data files.

  11140   Fri Mar 13 14:11:59 2015 ranaUpdateLSC6+ CARM->REFL transitions, 1 DARM->AS transition

Since the DARM_OUT signal is only 500 counts_peak, I don't see why AS55 whitening needs to be switched on.cool Maybe in a couple weeks after the lock is robust. In any case, its much better to do the switching BEFORE you're using AS55, not after.

  11141   Fri Mar 13 23:49:28 2015 ranaUpdatePSLRelaxation Osc and the NPRO Noise eater

Another thought about the mystery PCDRIVE noise: we've been thinking that it could be some slow death inside the NPRO, but it might also be a broken and intermittent thing in the MC servo or MC REFL PD.

Another possibility is that its frequency noise in the old oscillator used to drive the pre-PMC EOM (which is the Pockel Cell for the FSS). To check this, we should swap in a low noise oscillator for the PMC. I have one for testing which has 36 and 37 MHz outputs.

  11142   Sat Mar 14 00:12:18 2015 ranaUpdateSUSOplevs huh?

The oplev situation still seems unresolved - notice this DTT. I guess there are still inconsistencies in the screens / models etc.

Could use some some investigation and ELOGGING from Eric.

Attachment 1: burp.png
burp.png
  11155   Sun Mar 22 13:53:44 2015 ranaUpdateSUSITMX alignment jumps

So, was there real shifting in the ITMX alignment as seen in the DV trend or just mis-diagnosis from the ETMX violin mode? Or how would the ETMX violin mode drive the ITMX with the LSC feedback disabled?

  11161   Mon Mar 23 19:30:36 2015 ranaUpdateComputer Scripts / Programsrsync frames to LDAS cluster

The rsync job to sync our frames over to the cluster has been on a 20 MB/s BW limit for awhile now.

Dan Kozak has now set up a cronjob to do this at 10 min after the hour, every hour. Let's see how this goes.

You can find the script and its logfile name by doing 'crontab -l' on nodus.

  11202   Sat Apr 4 17:54:03 2015 ranaUpdateModern ControlPreliminary PRMI angular Wiener results

This is a very cool result. I'm surprised that it can work so good. Please post what frequency dependent weighting you used on the target before running the Wiener code.

I think its important to tune it to keep the low frequencies from getting amplified by a factor of 10 (as they are in your plots). The seismometers are all just noise acting like thermometers and tilt sensors below 0.1 Hz. Temperature and tilt do not couple to our interferometer very much.

It also seems weird that you would need 20th order filters to make it work good. In any case, you can always split the SOS up into pieces before making the digital filters. For LLO, we used 3 buttons in some cases.

Quote:

Before locking for the evening, I wanted to try again implementing the Wiener filters that I had designed back in Jaunary (elog 10959). 

  11204   Mon Apr 6 13:23:40 2015 ranaUpdatePEMjackhammering at ETMX

Unfortunately, this kind of trend plot is not detailed enough to know if something has gone bad in a quantitative way. But at least we can tell that the suspension wire didn't break.

  11228   Mon Apr 20 21:26:46 2015 ranaUpdateElectronicsLow noise pre-amps: returned

+1 to both Evan and Zach for prompt info and +2 to you for getting more stuff than you started looking for. -2 karma to whomever had swiped them and hoarded without signing. You should put a 40m sticker on both of them. Make sure to check / use fresh batteries. The Busby box is BJT based and works on low impedance sources, the Rai box works on anything, but (I am guessing) has less CMRR.

Quote:

The Rai box was in the Cryo lab, and the Busby box was in the TCS lab.  Neither had been signed out.  Lame.  Anyhow, thanks to Evan and Zach's memories of having seen them recently, they have been returned to the 40m where they belong.  (Also, I grabbed a spare Marconi while I was over there, for the phase noise measurement).

 

  11231   Tue Apr 21 15:03:27 2015 ranaUpdateOptical Levers1103P noise measurement

It doesn't work with the lens in there, but it seems pretty close. Please leave it as is and I'll play with it after 5 today.

  11232   Tue Apr 21 21:46:34 2015 ranaUpdateOptical Levers1103P noise measurement

To test what the inherent angular noise of the HeNe 1103P laser is, we're testing it on a table pointing into the BS OL QPD with only a few steering mirrors.

From the setup that I found today, I've removed the lens nearest to the laser (which was used for the BS and PRM) as well as the ND filter (what was this for?) and the lens placed just before the BS QPD.

With the ND filter removed, the quadrant signals are now ~15000 if we misalign it and ~9000 each with the beam centered.

In order to calibrate the OLPIT_IN1 and OLYAW_IN1 signals into mm of beam motion, I misaligned the mirror just before the QPD. The knobs on there actuate the 100 TPI screws and the knurling on the knob itself has 10 ridges, so that's 36 deg per bump.

Pit Knob (deg) OLPIT Yaw Knob (deg) OLYAW
0 29 0 -36
45 13 36 -16
90 -16 72 19
135 -39 108 36
       

PIT cal ~ 1.55 (knob deg / count) -->> 10 microns / count --->>> 10 urad / count

YAW cal ~ 1 (knob deg / count)  -->> 6.5 microns / count --->>> 6.5 urad / count

Distance from the 45 deg turning mirror to the QPD silicon surface is 23 cm. Distance between knob tip and fixed pivot point is ~4 cm. 1 knob turn = 0.01" = 0.254 mm = 0.254/40 radians of mirror angle.

So 360 deg of knob gives 2*0.254/40 = 0.012 radians of beam angle = 0.012 * 230 mm ~2.3 mm of beam spot motion. Or 6.4 microns of translation / deg of knob.

The distance from the face of the laser to the QPD is 96 cm.


The punchline is that the laser shows a level of noise which has a similar shape to what's seen at LLO, but 10x lower.

The noise at 0.05 - 0.2 Hz is ~2-3x worse than the PR3 at LLO. Not sure if this is inherent to the HeNe or the wind in our setup.

Attachment 1: oplev1103P.png
oplev1103P.png
Attachment 2: L1-ISI_SUS_ODC_FC496F_SPECTRUM-1113523216-86400.png
L1-ISI_SUS_ODC_FC496F_SPECTRUM-1113523216-86400.png
  11237   Wed Apr 22 17:04:11 2015 ranaUpdateElectronicsMC REFL PD back from the dead

Just randomly found this old entry from 3 years ago. We should never have installed a GAP 2000 - they are an inferior type of InGaAs diode. We should add to our list replacing these with a 2 mm EG&G diode.

How many 2 mm EG&G InGaAs diodes do we have Steve? Can you please find a good clean diode case so that we can store them in the optics cabinet on the south arm?

Quote:

 [Yuta, Manasa]

We replaced the dead photodiode on MC REFL PD with a new one (GAP 2000). We measured the frequency response of the PD and tuned the resonant frequency using inductor L5 (in the circuit diagram) to be 29.575MHz - over an average of 10 measurements.

 

  11240   Thu Apr 23 21:05:23 2015 ranaUpdateComputer Scripts / ProgramsCDSutils upgrade undone

Q: please update this Wiki page with the go-back procedure:

https://wiki-40m.ligo.caltech.edu/CDSutils_Upgrade_Procedure

  11244   Fri Apr 24 18:13:36 2015 ranaUpdateGeneraltorque for 1/4-20

For 1/4-20 bolts made of 18-8 Stainless Steel, the recommended torque varies from 65-100 inch-pounds, depending upon the application, the lubrication, how loose the bolt is, if there's a washer, etc.

For our case, where we are going into a tapped, ferromagnetic stainless table, its less clear, but it will certainly by in the 60-80 range. This is close to the 5-6 foot-lbs that I recommended on Wednesday.

I've ordered 3 torque wrenches with 1/4" drive so that we can have one at each end and one in the toolbox near MC2. We'll indicate the recommended torque on there so that we can tighten everything appropriately.

  11246   Fri Apr 24 23:40:15 2015 ranaUpdateSUSPRM and BS oplev laser replaced

Recently, Steve replaced the HeNe which was sourcing the BS & PRM OL. After replacement, no one checked the beam sizes and we've been living with a mostly broken BS OL. The beam spot on the QPD was so tiny that we were seeing the 'beam is nearly the size of the segment gap' effect.

Today I removed 2 of the lenses which were in the beam path: one removed from the common PRM/BS path, and one removed from the PRM path. The beams on both the BS & PRM got bigger. The BS beam is bigger by a factor of 7. I've increased the loop gains by a factor of 6 and now the UGFs are ~6 Hz. The loop gains were much too high with the small beam spots that Steve had left there. I would prefer for the beams to be ~1.5-2x smaller than they are now, but its not terrible.

Many of the mounts on the table are low quality and not constructed stably. One of the PRM turning mirror mounts twisted all the way around when I tried to align it. This table needs some help this summer.

In the future: never try locking after an OL laser change. Always redo the telescope and alignment and check the servo shape before the OL job is done.

Also, I reduced the height of the RG3.3 in the OL loops from 30 to 18 dB. The BS OL loops were conditionally stable before and thats a no-no. It makes it oscillate if it saturates.

Attachment 1: BSOL.pdf
BSOL.pdf
  11247   Sat Apr 25 00:20:16 2015 ranaUpdateCDSmegatron python autoMC cron

Upgraded python on megatron. Added lines to the crontab to run autoMX.py. Edited crontab to have a PYTHONPATH so that it can run .py stuff.

But autoMX.py is still not working from inside of cron, just from command line.

  11250   Sat Apr 25 22:17:49 2015 ranaUpdateCDSMXstream restart script working (beta)

Since python from crontab seemed intractableangry, I replaced autoMX.py with a soft link that points at autoMX.sh.

This is a simple BASH scriptcool that looks at the LSC FB stat (C1:DAQ-DC0_C1LSC_STATUS), and runs the restart mxstream script if its non-zero.

So far its run 5 times successfullylaugh. I guess this is good enough for now. Later on, someone ought to make it loop over other FE, but this ought to catch 99% of the FB issues.

  11251   Sun Apr 26 00:08:56 2015 ranaHowToelogTroubles with putting plots in external locations

If it all possible, don't use links to your home directory. Its not robust. It would be like if you clicked on your Google Music and it told you to ask me to sing that song to you. Imagine that on auto-repeat next time your fancy-bone itches.

Attachment 1: 48.png
48.png
  11252   Sun Apr 26 00:56:21 2015 ranaSummaryComputer Scripts / Programsproblems with new restart procedures for elogd and apache

Since the nodus upgrade, Eric/Diego changed the old csh restart procedures to be more UNIX standard. The instructions are in the wiki.

After doing some software updates on nodus today, apache and elogd didn't come back OK. Maybe because of some race condition, elog tried to start but didn't get apache. Apache couldn't start because it found that someone was already binding the ELOGD port. So I killed ELOGD several times (because it kept trying to respawn). Once it stopped trying to come back I could restart Apache using the Wiki instructions. But the instructions didn't work for ELOGD, so I had to restart that using the usual .csh script way that we used to use.

  11253   Sun Apr 26 01:10:18 2015 ranaUpdateASCunBroken Xass?

Today I tried some things, but basically, lowering the input gain by 10 made the thing stable. In the attached screenshotstrip, you can see what happens with the gain at 1. After a few cycles of oscillation, I turned the gain back to 0.1.

There still is an uncontrolled DoF, but I that's just the way it is since we only have one mirror (the BS) to steer into the x arm once the yarm pointing is fixed.

Along the way, I also changed the phase for POX, just in case that was an issue. I changed it from +86 to +101 deg. The attached spectra shows how that lowered the POX_Q noise.

I also changed the frequencies for ETM_P/Y dither from ~14/18 Hz to 11.31/14.13 Hz. This seemed to make no difference, but since the TR and PO signals were quieter there I left it like that.

This is probably OK for now and we can tune up the matrix by measuring some sensing matrix stuff again later.

Attachment 1: xasstune_150426.png
xasstune_150426.png
Attachment 2: xassnoise.pdf
xassnoise.pdf
  11261   Mon Apr 27 21:42:07 2015 ranaUpdateVACSummary pages

We want to have a VAC page in the summaries, so Steve - please put a list of important channel names for the vacuum system into the elog so that we can start monitoring for trouble.

Also, anyone that has any ideas can feel free to just add a comment to the summary pages DisQus comment section with the 40m shared account or make your own account.

  11263   Wed Apr 29 18:12:42 2015 ranaUpdateComputer Scripts / Programsnodus update

Installed libmotif3 and libmotif4 on nodus so that we can run dataviewer on there.

Also, the lscsoft stuff wasn't installed for apt-get, so I did so following the instructions on the DASWG website:

https://www.lsc-group.phys.uwm.edu/daswg/download/repositories.html#debian

Then I installed libmetaio1, libfftw3-3. Now, rather than complain about missing librarries, diaggui just silently dies.

Then I noticed that the awggui error message tells us to use 'ssh -Y' instead of 'ssh -X'. Using that I could run DTT on nodus from my office.

  11266   Fri May 1 16:42:42 2015 ranaUpdateDAQPEM Slow channels added to saved frames

Still processing, but I think it should work fine once we have a day of data. Until then, here's the summary pages so far, including Vac channels:

http://www.ligo.caltech.edu/~misi/summary/day/20150501/pem/

  11267   Fri May 1 20:33:31 2015 ranaSummaryComputer Scripts / Programsproblems with new restart procedures for elogd and apache

Same thing again todaysad. So I renamed the /etc/init/elog.conf so that it doesn't keep respawning bootlessly. Until then restart elog using the start script in /cvs/cds/caltech/elog/ as usual.

I'll let EQ debug when he gets back - probably we need to pause the elog respawn so that it waits until nodus is up for a few minutes before starting.

Quote:

Since the nodus upgrade, Eric/Diego changed the old csh restart procedures to be more UNIX standard. The instructions are in the wiki.

After doing some software updates on nodus today, apache and elogd didn't come back OK. Maybe because of some race condition, elog tried to start but didn't get apache. Apache couldn't start because it found that someone was already binding the ELOGD port. So I killed ELOGD several times (because it kept trying to respawn). Once it stopped trying to come back I could restart Apache using the Wiki instructions. But the instructions didn't work for ELOGD, so I had to restart that using the usual .csh script way that we used to use.

 

  11268   Sun May 3 01:04:19 2015 ranaSummaryPEMSeismo signals are bad

https://ldas-jobs.ligo.caltech.edu/~max.isi/summary/day/20150502/pem/seismic/

Looks like some of our seismometers are oscillating, not mounted well, or something like that. No reason for them to be so different.

Which Guralp is where? And where are our accelerometers mounted?

  11269   Sun May 3 19:40:51 2015 ranaUpdateASCSunday maintenance: alignment, OL center, seismo, temp sensors

X arm was far out in yaw, so I reran the ASS for Y and then X. Ran OK; the offload from ASS outputs to SUS bias is still pretty violent - needs smoother ramping.

After this I recentered the ITMX OL- it was off by 50 microradians in pitch. Just like the BS/PRM OLs, this one has a few badly assembled & flimsly mounts. Steve, please prepare for replacing the ITMX OL mirror mounts with the proper base/post/Polaris combo. I think we need ~3 of them. Pit/yaw loop measurements attached.

Based on the PEM-SEIS summary page, it looked like GUR1 was oscillating (and thereby saturating and suppressing the Z channel). So I power cycled both Guralps by turning off the interface box for ~30 seconds and the powering back on. Still not fixed; looks like the oscillations at 110 and 520 Hz have moved but GUR2_X/Y are suppressed above 1 Hz, and GUR1_Z is suppressed below 1 Hz. We need Jenne or Zach to come and use the Gur Paddle on these things to make them OK.

From the SUS-WatchDog summary page, it looked like the PRM tripped during the little 3.8 EQ at 4AM, so I un-tripped it.

Caryn's temperature sensors look like they're still plugged in. Does anyone know where they're connected?

Attachment 1: itmx_ol_loops_150503.png
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Attachment 2: Gur_150503.png
Gur_150503.png
ELOG V3.1.3-