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 Author Typeup Category Subject
  8461   Thu Apr 18 15:08:14 2013 SteveUpdatePEMseismometer isolation kit in place

Quote:

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

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

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

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

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

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

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

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

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

The trigger logic is as follows: 

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

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

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

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

LSC_triggers.png

LSC_SigCond.png

 

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

RF_PD_block.png

 

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

LSC_FM_Trig.png

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

  8463   Thu Apr 18 21:12:56 2013 ManasaUpdateLockingFixed

[Den, Manasa]

TRY & TRX power measurement was redone.

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

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

  8464   Fri Apr 19 04:20:41 2013 DenUpdateLockingPRMI on sidebands

Tonight PRMI was locked on REFL55 I&Q for PRCL and MICH with POP110I as a trigger and power normalizer.

I could see power fluctuations and beam motion on the POP camera very much the same as for carrier. The difference is that carrier stays for hours while sidebands for a few minutes.

POP110:

I&Q analog gains were set to 15 dB. Relative phase was set to 25 degrees by looking at I and Q components when the cavity goes through the resonance. Q should be 0.

pop_iq.png

REFL55:

Phase rotation was measured by exciting PRM at 20 Hz and minimizing this line at REFL55_Q. I stopped at 33 degrees.

 RIN:

I compared power fluctuations of PRCL when it was locked on carrier (POP_DC) and on sidebands (POP110_I).

rin.png

 

Time series of POP110_I during one of the locks

pop110_i.png

POP camera:

  8465   Fri Apr 19 13:28:39 2013 DenUpdateASCdither alignment of yarm

I've put 4 scripts into ASS directory for YARM alignment. They should be called from !Scripts YARM button on c1ass main medm screen.

Scripts configure the servo to align the cavity and then save computed offsets. If everything goes right, no tuning of the servo is needed.

Call TRANS MON script to monitor YARM transmission, then "ON" script for aligning the cavity, then "SAVE OFFSETS" and "OFF" for turning the servo off.

ON script:

  • sets demodulation gains that I used during OL measuments
  • sets LO oscillator frequency and amplitude for each optic
  • sets demodulation phase rotation
  • sets sensing matrix
  • sets servo gains for each degree of freedom
  • sets up limits for servo outputs
  • gently increases the common gain from 0 to 1

SAVE OFFSETS script:

  • holds servo outputs
  • sets servo common gain to 0 and clears outputs
  • reads old optics DC offsets
  • computes new DC offsets
  • writes new offsets to C1:SUS-OPTIC_ANGLE_OFFSET channel
  • holds off servo outputs

OFF script:

  • sets LO amplitudes to 0
  • blocks servo outputs

Notes:

SAVE OFFSET script writes DC offsets to C1:OPTIC_ANGLE_OFFSET channel, not to _COMM channel!

LIMITS are set to 500 for cavity axis degrees of freedom and to 0.5 for input steering. Usually servo outputs is ~30% if these numbers. But if something goes wrong, check this for saturation.

DC offsets of all 8 degrees of freedom are written one by one but the whole offset of put at the same time. This works fine so far, but we might change it to ezcastep in future.

  8466   Fri Apr 19 15:19:25 2013 JamieUpdatePEMTrilliums moved from bench to concrete

I moved the two Trillium seismometers that Den left on the electronics bench out onto the new concrete blocks in the lab that will be their final resting places.  I moved one onto the slab at the vertex and the other to the slab at the Y end.  I left them both locked and just sitting on the concrete.

The pile of readout electronics that were sitting next to them I moved on to the yellow foam box half way down the MC tube, between the MC tube and the X arm tube.  This is obviously not a good place to store them, but I couldn't think of a better place to put them for the moment.

  8467   Fri Apr 19 16:58:59 2013 JenneUpdateASCArm A2L measurement scripts 90% working again

After Den's work with the ASS model this week, all of the channel names were changed (this wasn't pointed out in his elog....grrr), so none of the A2L scripts worked. 

They are now back, however there is still some problem with the plotting that I'm not sure I understand yet.  So, the measurement works, but I don't think we're saving the results and we certainly aren't plotting them yet. 

I wanted to check where the spots are on the mirrors, to make sure Den's stuff is doing what we think it's doing.  All of the numbers were within ~1.5mm of center, although Rossa keeps crashing (twice this afternoon?!?), so I can't copy and paste the numbers into the elog.

A near-term goal is to copy over Den's work on the Yarm to the Xarm, so that both arms will auto-align.  Also, I need to put the set of alignment scripts in a wrapper, and have that wrapper call-able from the IFO Configure screen.

Also, while thinking about the IFO Configure screen, the "save" scripts weren't working (on Rossa) today, even though I just made them work a week or so ago. Rossa, at least, was unhappy running csh, so I changed the "save" script over to bash.

  8470   Mon Apr 22 12:03:58 2013 KojiUpdatePSLPMC aligned too

PMC aligned. C1:PSL-PMC-PMCTRANSPD improved from 0.72ish to 0.835ish.

  8472   Mon Apr 22 17:43:09 2013 SteveUpdate40m Upgrading ETMY optical table & enclosure is ready for optics

Quote:

Quote:

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

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

 

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

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

The table is ready for optics.

Things left to do:

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

 

 I'm working on to improve the quality of the enclosure.

The short comings are: more cable feedthroughs needed, latches to anchor top covers air tight and posts to support bending bridges.

Red triangles are compression latches at 10 places to hold the top air tight on surgical tubing

Green lines represent 4  posts of Al 1" OD to support the covers and maximize their eigenfrequencies.

Black crosses are 4 spring loaded push-bottom quick release pins to anchor the top covers to the bridges. This connection will  not be air tight.

(quarter-turn wing head fastener have the same problem) I'm thinking of some solution to minimize the leak.    

Violet _ steel plate (1" wide, 15" long, 0.125" thick)  between the two posts will anchor the quick release pins and make bridge rigid.

Blue rectangle is an other cable feedthrough exiting on the chamber side.

Planning to substitute window with soft - air tight ( Aluminized thin wall hose )  connection to vacuum view port where white circle is representing the Al adaptor ring.

Updated after Wednesday meeting 4-24-2013

 

Attachment 1: more2.jpg
more2.jpg
  8473   Mon Apr 22 19:48:56 2013 JenneUpdate40m Upgrading4 pins enough?

Are 4 of these spring loaded pins enough?  I'm not sure how one pin can hold 2 lids at each point.  It seems like we need 8 pins.

  8474   Mon Apr 22 20:17:05 2013 CharlesUpdateISSNew Servo w/switching filters

 

In my previous post here, a new servo design was discussed. Although the exact design used will depend on the particular noise requirements for the 40m and the Bridge Labs (requirements will be considered separately for each application), I still have to yet to see those formalized. Despite this, I have been simulating an example servo circuit with three switchable stages. The design can be found at: New Servo.

Essentially, this circuit consists of three unity gain buffers that can be switched into different filtering states. Attached is a plot of the transfer function of this particular circuit with successive stages turned on. The curve (0) corresponds to all of the filters being switched off, so the total behavior is that of a unity gain buffer. The curve (1) corresponds to the first stage being turned on with the 2nd and 3rd still acting as unity gain buffers. This first state has a gain of ~80 dB at DC and a pole at ~10 Hz which sets the unity gain crossing at ~100 kHz. The curves (2) and (3) correspond to the second and third stage being turned on, respectively. Each of these stages has a pole at DC (i.e. ~infinite gain) and a zero at 10^4 Hz. For f > 10^4 Hz, these stages have gain ~ 1, as we can see in the transfer function below.

I have also performed some noise analysis of this circuit. Attached are a few plots produced by LISO showing the resistor and op-amp noise separately (it was too cluttered on one plot) at the output node of the servo. Both of these plots have a "Sum Noise" trace, which is the sum for every circuit element and is thus identical between plots. The third noise spectrum included is simply the noise at the output referenced to the input with the previously computed transfer function. I'm not sure if there is a simple method embedded in LISO to reference the noise at the output node to the input, but it should be as simple as numerically dividing the noise spectrum by the transfer function between input and output. 

Next, I will be attempting time-dependent simulations of this simple circuit using delayed switches instead of manually controlled ones.

Attachment 1: Servo_v0.1.png
Servo_v0.1.png
Attachment 2: Example_Filter_-_Transfer_Function_(mag).png
Example_Filter_-_Transfer_Function_(mag).png
Attachment 3: Example_Filter_-_Transfer_Function_(phase_in_final_state_only).png
Example_Filter_-_Transfer_Function_(phase_in_final_state_only).png
Attachment 4: New_Servo_-_Op-Amp_Noise.jpg
New_Servo_-_Op-Amp_Noise.jpg
Attachment 5: New_Servo_-_Resistor_Noise.jpg
New_Servo_-_Resistor_Noise.jpg
Attachment 6: New_Servo_-_Total_Noise_Input-Referenced.png
New_Servo_-_Total_Noise_Input-Referenced.png
  8475   Tue Apr 23 15:00:20 2013 JenneUpdate40m Upgrading4 pins enough?

Quote:

Are 4 of these spring loaded pins enough?  I'm not sure how one pin can hold 2 lids at each point.  It seems like we need 8 pins.

 Steve has explained to me that the pins will go in between the 2 lids, with a big washer, so that one pin holds both lids at the same time.  4 is the right number.

  8476   Tue Apr 23 15:02:19 2013 Max HortonUpdateSummary PagesImporting New Code

Duncan Macleod (original author of summary pages) has an updated version that I would like to import and work on.  The code and installation instructions are found below.

I am not sure where we want to host this.  I could put it in a new folder in /users/public_html/  on megatron, for example.  Duncan appears to have just included the summary page code in the pylal repository.  Should I reimport the whole repository?  I'm not sure if this will mess up other things on megatron that use pylal.  I am working on talking to Rana and Jamie to see what is best.

http://www.lsc-group.phys.uwm.edu/cgit/lalsuite/tree/pylal/bin/pylal_summary_page
https://www.lsc-group.phys.uwm.edu/daswg/docs/howto/lal-install.html
  8477   Tue Apr 23 16:17:45 2013 DenUpdatePEMseismometer isolation kit in place

Quote:

 

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

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

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

 To put everything in one place I add a final drawing of the base to this elog.

 Next time we continue with wiring and putting temperature and pressure sensors inside the box. Connector support plate drawing is attached. We'll have sensors inside the kit with STS-2 or Trillium as their connector is small enough (19 pin vs 26 pin for Guralps) that we can put an additional 4 pin lemo connecor (2 pins for each sensor). I think EGG.0B.304.CLL is good for this application. Temperature and pressure sensor we can by from omega.

Attachment 1: Base.pdf.pdf
Base.pdf.pdf
Attachment 2: ConnectorPlate.pdf
ConnectorPlate.pdf
  8479   Tue Apr 23 22:10:54 2013 ranaUpdateComputersNancy

controls@rosalba:/users/rana/docs 0$ svn resolve --accept working nancy
Resolved conflicted state of 'nancy'

  8481   Wed Apr 24 00:42:07 2013 JenneUpdateSUSPRMI locked, ITMX pitch OpLev ringing up

Koji is working on PRMI locking, and while he was doing that I glanced at the oplevs' spectra for the ITMs and PRM.

I found that when the PRMI was locked (for only 1 second or so max lock time) on the 55MHz sideband, and the error signals show a big peak around 400Hz (definitely audible in the control room), the only OpLev that I see a similar peak in is ITMX pitch. 

In the plot below, I have grabbed a time when the PRMI was flashing as the black reference traces, and then a time when the PRMI was locked as the active traces.  You can see that there is a similar peak in both REFL55I and ITMX_OL_PIT when the cavity is locked. 

PRMI_locked_ITMXpitOpLevRingingUp.pdf

  8482   Wed Apr 24 00:44:33 2013 KojiUpdateSUSPRMI locked, ITMX pitch OpLev ringing up

I tried to reproduce the locking situation described in this entry tonight.
The momentary lock was regularly seen but there was no stable lock.

I wonder why the actuators are always saturated. The feedback signals have the dominant component at ~400Hz.

It would also be nice if the servos have some immunity to gain fluctuation.

I didn't check how the situation of the AP table is. I'll look into some details tomorrow.

  8483   Wed Apr 24 14:20:49 2013 KojiUpdateCDSFE Web view not updated?

The FE web view seems not up-to-date, does it? ( maybe for a year)

https://nodus.ligo.caltech.edu:30889/FE/c1mcs_slwebview_files/index.html

  8484   Wed Apr 24 14:24:40 2013 RijuUpdate PD frequency response

 Here I am attaching the first schematic diagram of the PD frequency response set-up, I will keep updating it with relevant informations with the progress of the work.

Description: Our objective is to set-up one simultaneous transfer-function measurement system for all the RF-PDs present in 40m lab. A diode laser will be used to illuminate the PDs. The diode laser output will be divided by 1x16 fiber splitter and will be sent to all the PDs through single-mode fiber. The transfer function of the PDs will be measured using network analyzer(Agilent 4395A). The output of the PDs will be fed to network analyzer via one RF-switch. The diode laser will be controlled by the controller ILX LDC 3744C. The scanning frequency signal will be fed to this controller from network analyzer through its external modulation port. The output of the controller will be splitted  into two parts: one will go to laser diode and the other will be used as reference signal for network analyzer.

 

 

Attachment 1: PD_freq_resp.pdf
PD_freq_resp.pdf
  8485   Wed Apr 24 14:36:06 2013 JenneUpdateRF SystemPD frequency response

I think you have the splitter that splits the RF signal from the network analyzer in the wrong place. 

Usually you split the signal immediately after the RF Out, so that half of the signal goes to the A-input of the Analyzer, and the other half goes to your controller (here, the laser diode controller).  Then you would take the output of your controller and go straight to the actual laser diode, with no splitting in this path.

  8486   Wed Apr 24 15:27:59 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : progress: New layout

Layout that will be improved upon over the next few days.

Things that need to be updated:
1. Waist size at all optics
2. Beam size at detectors and choice of lenses
3. IPANG & green PD proposed positions

 ETMY_endtable_New.png

  8488   Thu Apr 25 00:59:37 2013 RijuUpdateRF SystemPD frequency response

Quote:

I think you have the splitter that splits the RF signal from the network analyzer in the wrong place. 

Usually you split the signal immediately after the RF Out, so that half of the signal goes to the A-input of the Analyzer, and the other half goes to your controller (here, the laser diode controller).  Then you would take the output of your controller and go straight to the actual laser diode, with no splitting in this path.

 Here our device under test is the photodiode. So for the reference I wanted to retain the response of the laser diode controller. Otherwise I have to consider the transfer function of that LDC too. I may check both the options at the time of experiment.

Thanks

  8489   Thu Apr 25 03:35:28 2013 JenneUpdateLockingAngular motion does not explain RIN

Den made a nice elog about the PRMI RIN that we see a few weeks ago:  8464.  The RIN that we're seeing is typically about ~30%.  The question at hand is: what is causing this power fluctuation, and more specifically, is it the angular motion of the mirrors?

I find that no, the angular motion that we see does not explain the RIN that we see.

In the attached Mathematica notebook, I calculate the power lost due to angular misalignments of one or more mirrors.  (Math comes from Appendix A of Keita's thesis.)

From calibrated oplev spectra, our mirrors are moving about 1 microradian (RMS, which is dominated by low frequencies).  From a super sophisticated "draw on the TV, then measure" method (details below), I have estimated that the maximum static misalignment that we're seeing is about 2 microradians.

With all of this, I find that for a g-parameter of 0.94, the power lost due to misalignments should, at maximum, be 0.6%.  I need a g-parameter of 0.995 to get a power loss of 23%.  Alternatively, if I take the derivative of the power coupling function, to find the static misalignment at the steepest slope of the curve (and thus, the place where any AC misalignment would have the most effect), for 1urad of AC misalignment, I get 40% power loss. 

So, in order for the AC angular motion that we see to explain the RIN that we see, either our mirrors are very, very misaligned (so much so that we couldn't really be locking), or our cavity is much closer to unstable than expected from Jamie's calculations.  Since both of these cases (static misalignment or incorrect g-parameter calculation) have to be taken to extremes before they approximate the RIN that we see, I do not think that this power loss is due to angular fluctuations.

This means that we have to think of another potential cause for this RIN that we're seeing.

Details on the "draw on TV and measure" technique for determining static cavity misalignments:  Looking at the POP camera view, with the PRM significantly misaligned, I traced the straight-through beam spot.  I then restored the PRM, and during several momentary locks, I traced the beam spot, which I took to be the saturated area of the camera.  The idea here is that the straight-through beam represents the incident beam axis, while the locked beam represents the cavity axis.  I'm assuming that the camera image plane is at the face of PR2. I approximately found the center of each of my tracings, and found them to be ~1/4 inch apart.  I also measured the "spot size" of the sideband-locked PRMI, and found it to be ~3.5 inches.  So, very roughly, the ratio of (distance between spots)/(size of beam) is ~0.07. This corresponds to a static misalignment of either the ITM or the PRM of ~2urad, rounding up. (I use the Jamie's calculated g-parameters from elog 8316, the case of flipped PR2, tangential = 0.94 to calculate the effective RoC of the PRM). 

Attachment 1: RIN_estimation_from_angular_motion.nb.zip
  8490   Thu Apr 25 04:10:09 2013 JenneUpdateLockingMICH_CTRL drifting away??

Koji is elogging separately of his exploration of different configurations.  The lock stretch that I'm looking at here uses the same parameters as Koji had for PRMI sb lock, using AS55Q for MICH and REFL33I for PRCL, with MICH gain of -0.8 and PRCL gain of 0.05 .

All of these plots are the same few second lock stretch, with different zooming.  Jamie's super-sweet getdata python script only accepts integers for the start time and duration parameters, so lots of this zooming happened by hand, but I tried to always keep the time axis aligned within each screenshot.  Sometimes the plot axis labels say differently, but they're lying to you.

Plot 1:  gps start time is 1050915916, duration = 6 seconds.  Overall view of the lock stretch.

1050915916-6.png

Plot 2:  gps start time is 1050915921, duration = 1 second.  We're looking at the lockloss that happens at the left side of the plots.

1050915921-1.png

Plot 3:  zoomed in (along the time-axis) version of plot 2, so much shorter time duration.  Some zooming on y-axes.

1050915921-zoom.png

Plot 4:  zoomed in (along y-axes) version of plot 2.

1050915921-1-zoom.png

It seems to me from these plots that maybe MICH CTRL is drifting away?  It seems like we lose the MICH lock, and that destroys the whole thing. 

Koji made some comments to me earlier, regarding his work this evening, that the MICH signal quality is poor in general, and that we should calculate/think about changing our schnupp asymmetry. 

  8494   Thu Apr 25 20:48:48 2013 KojiUpdateASSDen fixed the Yarm ASS scripts

I contacted Den about malfunctioning of the Yarm ASS.

He found the scripts were modified during the attempt to make it available for Xarm (cf. a related elog entry)
So far, he could manage to make the current scripts being modified to run.
A striptool file is still missing but this is what we can handle locally.

I thank Den for the remote caring of the issue despite the limited network bandwidth.

  8495   Fri Apr 26 10:50:07 2013 AnnalisaUpdateABSLATF laser on PSL

The ATF NPRO auxiliary laser has been moved on the PSL table. All the optics for beat note measurement are in place and alignment has been done.

The setup for this measurement is the same as described in elog 8333.

  8496   Fri Apr 26 15:50:48 2013 Max HortonUpdateSummary PagesImporting New Code

 

I am following the instructions here:

https://www.lsc-group.phys.uwm.edu/daswg/docs/howto/lal-install.html#test

But there as an error when I run the ./00boot command near the beginning.  I have asked Duncan Macleod about this and am waiting to hear back.

For now, I am putting things into /home/controls on allegra.  My understanding is that this is not shared, so I don't have a chance of messing up anyone else's work.  I have been moving slow and being extra cautious about what I do because I don't want to accidentally nuke anything.

  8498   Fri Apr 26 20:43:51 2013 JenneUpdateLSCRemeasuring the Schnupp asymmetry

[Jenne, Annalisa, with guidance from Koji]

We took data to remeasure the Schnupp asymmetry, using the Valera method that Jamie described in elog 4821

1  First, we locked the arms each with their PO(X,Y) signals, to get the alignment of each arm. 

2.  Then, we locked the Xarm with AS55I (Yarm optics, and PRM very misaligned, more than the misalign script).  Since AS55 was saturating, I changed the analog gain from 24dB to 21dB. (After work was completed, the analog gain was put back to the nominal 24dB for both I&Q.)

3.  We set up the Lockin similar to Jamie's description, with a few differences.  We used the same f = 103.1313, but used ampl=10cts.  Sin and cos gain were each 100.  We changed the lowpass filter from 0.1Hz to 0.05Hz (so each measurement had a settling time of at least 20sec).  We were using LSC-Lockin4, so the Lockin matrix was set so Lockin4 was reading from AS55Q, and the LSC output matrix was such that we were actuating on the ETM (X, then Y when we switched arms later).

4.  By hand, we roughly found the zero crossing of the lockin-q output (which corresponded also to zero of the lockin-I, since this is the place where all of the PDH signal was in AS55I, and the lockin was reading AS55Q). 

5.  We took points separated by 0.2 degrees, plus and minus 1 degree from the zero-crossing phase we had found (i.e., for the Xarm, we roughly found the zero crossing at -14.39 deg, so took data from -15.39 to -13.39degrees).  For each phase, we took 5 measurements (using ezcaread), at least 20 seconds apart.  After moving the phase, we waited at least ~40 seconds (watching the lockin outputs on striptool, they had completely settled after 30 or 40 seconds).

6.  We then repeated steps 2, 4 and 5 for the Y arm.  The lockin setup didn't change, except that now we actuate on ETMY.

We did a quick estimate calculation, from our rough zero-crossings to get a rough measurement of the Schnupp asymmetry.  DeltaPhi = (-14.39 -   -19.79) = 5.40 . This gives us (using F_sideband = 5*11066134, the current 11MHz marconi freq) a rough Schnupp asymmetry of 4 cm. 

Analysis to follow.

EDIT, JCD:  The Xarm gain at this time was -0.160, and the Yarm gain was -0.170

  8500   Sat Apr 27 00:21:06 2013 KojiUpdateLSCLocking activity on Apr 26th

When I talked with Den via phone, he recommended to use the trigger and normalization with POP110I.
So I decided to try this approach. Also I investigated how the REFL33 signals are useful.

I could find the state where the PRMI(sb) locks regularly, although the lock is ~1min at most.

PRCL: REFL33I
whitening gain 30dB, -14.0deg (finely tuned in lock)
-> x1.0 -> Triggered by POP110I (20up, 1down)
-> Normalized by POP110I x0.04
-> Gain 0.2~0.12 FM3, 4, 5, 6 always on, no triggered FMs
-> PRM

MICH: REFL33Q
whitening gain 30dB, -14.0deg (finely tuned in lock)
-> x1.0 -> Triggered by POP110I (20up, 1down)
-> Normalized by POP110I x0.04
-> Gain -20 FM4, 5 always on, no triggered FM
-> ITMX (-1.0) and ITMY (+1.0)

I needed to tune the phase very precisely to reach this state. Also the alignment of the michelson and PRM
was very crtiical to acquire the lock.

Later in the same night I was plagued by PRM alignment drift. It seems that the PRM alignment is bistable or
slightly drifting in pitch. I had to align PRM continuously. When the PRMI is locked, the alignment fluctuation
was mainly in yaw. This was as people commented before.

Attachment 1: Screenshot.png
Screenshot.png
  8501   Sat Apr 27 00:29:40 2013 KojiUpdateLSCLSCoffset script fixed

Prior to the locking trials...

scripts/LSC/LSCoffset script had behaved peculiarly:

This script spawns LSC/offset3 in order to remove the dark offset from the channels.
How ever the offsets had been nulled every other PDs
(i.e. The offsets REFL11 I&Q were nulled.
The offsets REFL33 I&Q had been left untouched
The offset REFL55 I&Q had been nulled
and so on.)

I found that the script run many instances of "offset3" scripts in background.
It seemed that tdsavg did not like too many averaging channels at once.

So the "&"s in the LSCoffsets were removed and now the script runs much more slowly,
but works for all of the PDs listed.

I think I have never seen the offsets in REFL33 and REFL165 nulled down to this level before.

  8502   Mon Apr 29 08:17:40 2013 AlbertUpdateoptical tablesOptical Table Toolboxes Update

Quote:

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

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

photo.JPG

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

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

 

  8503   Mon Apr 29 08:22:57 2013 SteveUpdateSAFETYsafety training

 

 Albert, our new undergrad work force received 40m specific- basic safety training last week. Please read and sign 40m procedures booklet.

  8504   Mon Apr 29 15:35:31 2013 Max HortonUpdateSummary PagesImporting New Code

 

 I installed the new version of LAL on allegra.  I don't think it has interfered with the existing version, but if anyone has problems, let me know.  The old version on allegra was 6.9.1, but the new code uses 6.10.0.1.  To use it, add . /opt/lscsoft/lal/etc/lal-user-ench.sh to the end of the .bashrc file (this is the simplest way, since it will automatically pull the new version).

I am having a little trouble getting some other unmet dependencies for the summary pages such as the new lalframe, etc.  But I am working on it.

Once I get it working on allegra and know that I can get it without messing up current versions of lal, I will do this again on megatron so I can test and edit the new version of the summary pages.

  8505   Mon Apr 29 15:53:49 2013 AlbertUpdateoptical tablesOptical Table Boxes

Quote:

 

 Albert, our new undergrad work force received 40m specific- basic safety training last week. Please read and sign 40m procedures booklet.

 These are the tentative box placements. Roughly. I don't actually have the box finalized yet, but the box should be around that size.

AS1.jpg AS1

BSPRM.jpgBSPRM

ETMX.jpgETMX

ETMY.jpgETMY

MC2.jpgMC2

POX.jpgPOX

POY.jpgPOY

 

How do I perspective ._.

  8507   Mon Apr 29 18:53:03 2013 JenneUpdateElectronics1pps timing fiber to OMC rack may be bent

While helping Riju out this afternoon, I noticed that the timing fiber that goes to the OMC rack (near the AP table) was bent, and is now possibly kinked, after the installation of the fiber splitter box. 

The fiber was hanging from the back of the rack, and had been strain relieved.  However, the path that the fiber was taking is now occupied by the fiber splitter for the RF PD diagnostic stuff.  So, the installation of the fiber splitter box put the old timing fiber under tension, causing the fiber to be bent at a little over 90 degrees, since it was pulled tightly against the corner of the splitter's front panel. 

I adjusted the strain relief so that the fiber is loose again, although there is still a bit of a kink that you can feel.  Things (for now) seem to be working, since the 1pps light on the front of the box at the top of the OMC rack is still blinking happily, indicating that the 1pps is still getting there. 

We are not using most of the stuff in that rack right now, but if we have problems in the future, we should check out the fiber to make sure it is still good.

  8508   Mon Apr 29 22:13:41 2013 KojiUpdateLSCLocking with ASDC

Today the locking was not as easy as that was last Friday.
So I tried something new. Today Rana talked about the ASDC locking with POPDC normalization.
This technique was tried. (This is somewhat similar to DC readout.)

PRCL
Signal source: REFL33I / Normalization POP110I x 0.04 / Trigger POP110I 20up 3down, otherwise  untouched from Friday locking
Servo: input matrix 1.00 -> PRCL Servo FM3/4/5/6 Always ON G=+0.06
Actuator: output matrix 1.00 -> PRM

MICH
Signal source: ASDC Offset -109.5 (nominal of the day -49.5) / Normalization POPDC x 1.00 / Trigger POP110I 20up 3down
Servo: input matrix 1.00 -> MICH Servo FM5 Always On G=+10000
ActuaroL output matrix -1.00 -> ITMX / +1.00 -> ITMY

Observation

- POP110I was ~120 during the lock (cf 170 on Friday). So there is some small leakage from the dark port.

- Lock was easier when FM4 of the MICH loop was turned off.

- During the lock horizontal motion of the intracavity mode was visible as usual.

Screenshot.png

  8510   Tue Apr 30 10:54:35 2013 JenneUpdateSUSETMX restored

I'm not sure why or when it was tripped, but I have restored the ETMX watchdog.

  8511   Tue Apr 30 12:25:23 2013 ChloeUpdate QPD

Annalisa and I met yesterday and fixed the voltage regulator on the breadboard so the QPD circuit is working. We will meet with Eric on Thursday to determine the course of action with measurements.

  8514   Tue Apr 30 22:40:57 2013 JenneUpdateSUSoplev XY-plots reflect new calibration

Back when Gabriele was here, he and I implemented online calibration of the oplevs, into microradians.  A consequence of this is that all of the XY-plots on the medm screens were too small. 

I have gone through all the screens that I could think of (SUS_SINGLE, SUS_SINGLE_OPTLEV_SERVO, OPLEV_MASTER, OPLEV_SUMMARY, OPLEV_SUMMARY_SMALL_SCALE, IFO_OVERVIEW) and made the range of the XY-plots +/- 100, rather than the old scale of +/-1. 

I have also added red boxes behind the numbers on many (but not yet all) of these screens, so that you can see when (a) the oplev sum is too low, or (b) either the pit or yaw value is over 50 microradians. 

While I was putzing around on the IFO overview screen, I also made the oplev sum numbers clickable, with the related display being that optic's oplev servo screen.

  8516   Tue Apr 30 23:17:25 2013 JenneUpdateLSCPRCL LSC filters copied to CARM bank temporarily

Koji is working on PRMI locking with different photodiodes, and rather than typing different numbers into the input matrix, it is more convenient to just be able to click on/off buttons for different filter banks.  So, the CARM filter bank in the LSC model is currently being borrowed as a secondary PRCL filter bank.  I have copied all of the current PRCL filters over to the CARM filter bank. 

Just for reference, although we have not yet used CARM for CARM, the previous filters were the "default" set, +6dB, 0:1, 1:5, 1:50, 1000:10, RG3.2, RG16.5, RG24, empty, empty.  These are currently the same in the DARM and MC filter banks, so we can copy them back over in the future.

  8517   Wed May 1 00:05:03 2013 KojiUpdateLSCMore stable lock of PRMI (REF33I and AS55Q)

[Jenne Koji]

- Today the spots were moving more than the usual. The OPLEV screens showed that the spots are too much off from the center.

- Each vertex OPLEVs were checked and OPLEV wonderland was discovered: Other than the usual misalignment of the spots,
it was found that PRM/ITMX/ITMY beams were clipped somewhere in the paths, BS/PRM oplevs had many loose components
including the input lenses (they are still clamped by a single dog clamp THIS SHOULD BE FIXED ASAP).

- On the ITMY table there were so many stray optics. They were removed and put on the wagon next to the ITMY table.
THIS SHOULD BE CLEARED ON THE WEDNESDAY CLEANING SESSION.

- During this OPLEV session, LSCoffset nulling was run.

- After the OPLEV session, the locking became really instantaneous. We wonder which of the OPLEV cleaning, LSC offset nulling,
and the usual seismic activity decay in the evening was effective to make it better.

- Initially the lock was attempted with REFL33I/Q and some ~10sec lock streches were obtained. During this lock,
  the optical gain of AS55Q was measured in relative to REFL33Q. In deed they were calibrated to be the same
  gain at the input matrix.

- After the MICH signal source was switched to AS55Q, the lock streches became more regular and the minutes long.
We precisely tuned the phase of AS55 and REFL55 in terms of the differential excitation of ITMX/Y using lockin (FREQ 250, AMP 1000).

- We noticed that the AS port spot with AS55Q MICH was darker than the REFL33Q MICH. This suggests the existence of residual offset
in REFL33Q. In deed we observed +30cnt offset in REFL33Q when the PRMI is locked with AS55Q MICH.

- Phases and relative gains of the signals were as follows:

PRCL: REFL33I 1.00 =REFL55I +0.4
MICH: AS55Q 29deg x1.00 = REFL33Q -14deg x1.00 = REFL55Q 118deg 0.03?

- We tried to lock PRMI with AS55Q. The acquisition was not as easy as that with REFL33I. This might be from the saturation of the
REFL55I signal. This configuration should tested with different whitening gain. Handing off using the input matrix went well once the
lock was obtained by REFL33I.

- Handing off from AS55Q to REFL55Q was not successful.

- At the end of the session, Jenne told me that the POP PD still has a large diameter beam. (and a steering mirror with a peculiar reflection angle.)
==> THIS SHOULD BE FIXED ASAP
because the normalization factor can be too much susceptible to the misalignment of the spot.

- The configuration of the filters:

PRCL FM3/4/5/6 G=+0.05 / NORM 0.04 POP110I
MICH FM4/5 G=-5.00 / NORM 0.01 POP110I (or none)

Screenshot.png

  8518   Wed May 1 10:42:35 2013 SteveUpdateLSCcleanup

 

 Optics from the car were placed into glass door cabinet E0

  8519   Wed May 1 14:42:45 2013 JenneUpdateLSCPOP now has lens in front of PD

Quote:

- At the end of the session, Jenne told me that the POP PD still has a large diameter beam. (and a steering mirror with a peculiar reflection angle.)
==> THIS SHOULD BE FIXED ASAP
because the normalization factor can be too much susceptible to the misalignment of the spot.

 Koji set the IFO in a PRM-ITMY configuration for me, while I went to put a lens on the POP path.  Before putting the lens, the maximum average output that I saw from the diode (on a 'scope) was 4.40mV.  After putting in the lens and realigning the beam onto the diode, the new max DCvalue that I saw was 21.6mV.  This is a factor of 4.9. 

EDIT:  The dark value was -3.20mV, so actually the ratio is ~3.25 .

I have not yet done anything to fix the situation of the large angle of incidence on the first out-of-vac steering mirror.

  8521   Thu May 2 00:34:57 2013 KojiUpdateLSClocking

- Routine alignment

Locked the arm cavties. Ran ASS. As this was not enough precise alignment for PRMI locking, Yarm alignment was re-adjusted by sliders.
Xarm was also aligned in the same way.

- OPLEV alignment

Once the arms were aligned, OPLEV spots were adjusted. For this adjustment, PRM had to be aligned and OPLEV servos needed to be turned off.

- LSC offset nulling

While Jenne was measuring the dark output of the POP PD, LSC offset nulling script was executed.

- Compensation of the POP spot size fix

As Jenne reported the POP path now has a lens and the denominator for the normalization got bigger.
To compensate this change, PRMI(sb) was locked by the same configuration as yesterday (i.e. AS55Q for MICH, REFL33I for PRCL). 
After some try and error, configuration for stable locking was found. 

PRCL
Signal source: REFL33I / Normalization POP110I x 1.00 / Trigger POP110I 80up 10down
Servo: input matrix 1.00 -> PRCL Servo FM3/4/5/6 Always ON G=+8.00
Actuator: output matrix 1.00 -> PRM

MICH
Signal source: AS55Q / Normalization POP110I x 0.01 / Trigger POP110I 80up 10down
Servo: input matrix 1.00 -> MICH Servo FM4/5 Always On G=-30
Actuator output matrix -1.00 -> ITMX / +1.00 -> ITMY

This suggests that POP110I signal is 5~6 times more than before the lens was installed. 

- SQRTing option for POP110I was implemented

The PRMI optical gain is derived from (Carrier)x(1st order Sideband) or (2nd order SB)x(1st order SB).
Here the carrier and the 2nd order sidebands are nonresonant.
Therefore the optical gain is proportional to the amplitude power recycling gain of the 1st order sidebands.
On the other hand, POP 2f signals are derived from the product of the 1st and -1st order sidebands.
This means that we should take a sqrt of the POP signals to compensate the recycling gain fluctuation.

Screenshot.png

- Locking with SQRT(POP110I)

PRCL
Signal source: REFL33I / Normalization SQRT(POP110I) x 10 / Trigger POP110I 10up 3down
Servo: input matrix 1.00 -> PRCL Servo FM3/4/5/6 Always ON G=+8.00
Actuator: output matrix 1.00 -> PRM

MICH
Signal source: AS55Q / Normalization SQRT(POP110I) x 0.1 / Trigger POP110I 10up 3down
Servo: input matrix 1.00 -> MICH Servo FM4/5 Always On G=-30
Actuator output matrix -1.00 -> ITMX / +1.00 -> ITMY

The lock seems not so different from the ones without SQRTing.

The spot was still moving in yaw direction. If I chose a correct alignment, I could minimize the modulation of the internal power
by misalignment. As you can see in the following plot.

Screenshot2.png

When the alignment was deviated from the optimum, the misalignment induced RIN was much worse although this was the longest lock I ever had with the PRMIsb. (more than 8 min)

Screenshot3.png

- Locking with other signal sources

REF55I/Q trial:

Demodulation phase was adjusted to make the difference of the peak heights for MICH maximized.
After the lock is acquired, I tried to swap the signal source at the input matrix. PRCL swapping was successful but
MICH swapping was not successfull.

It is much more hard to lock the interferometer with REFL55I compared with REFL33I.

REFL165I/Q trial:

As REFL165 PD never produced any useful signal, I tried to swap it with the BBPD used in the green setup.

- Borrowed the PD, power supply from the green setup.

- Put REFL165PD aside. Placed the BBPD in the path. The DC output was 0.8V. This corresponds to the input power of ~5mW.

- Checked the signal but it was very litte (several counts even at the maximum whitening gain).

- Decided to use the power reduction pick off to introduce much more light on the PD.
  This PO mirror is 90% reflector. Therefore I had to be careful no to fry the diode.
  Currently there are OD1.3 (x1/20) power attenuator to reduce the input power down to 6.5V (40mW).

- The resulting signal is very wiered suggesting the saturation of the PD at the RF stages.

- Probably I need to make a new PD circuit which has the high pass filter to reject other low frequency components.

  8522   Thu May 2 01:19:41 2013 ManasaUpdate40m UpgradingEndtable upgrade for auxiliary green laser : progress

I started to put together optics at the endtable. I am attaching the layout with the green blocks showing the optics that are assembled and will not be moved henceforth unless somebody contradicts.

1. Power after HWP = 314mW
    Power before faraday = 310mW
    Power after faraday = 300mW (the power loss while aligning the faraday earlier was due to the AR coating on the focusing lens before the faraday - it was AR coated for visible and that accounted to the power lost)

2. Since we do not know the length of TGG inside faraday, I measured the beam profile after the faraday so that I can trace the beam without any errors to calculate exact mode matching solutions.

3. The NPRO beam seems to be obviously elliptical as seen on the IR card and also from beam profile measurement. So we cannot skip including cylindrical lenses in the layout.

ETMY_0502.png

 

  8523   Thu May 2 14:14:10 2013 Max HortonUpdateSummary PagesImporting New Code

 

 LALFrame was successfully installed.  Allegra had unmet dependencies with some of the library tools.  I tried to install LALMetaIO, but there were unmet dependencies with other LSC software.  After updating the LSC software, the problem has persisted.  I will try some more, and ask Duncan if I'm not successful.

Installing these packages is rather time consuming, it would be nice if there was a way to do it all at once.

  8524   Thu May 2 19:59:34 2013 JamieUpdateComputer Scripts / Programslookback: new program to look at recent past testpoint data

To aid in lock-loss studies, I made a new program called 'lookback', similar to 'getdata', to look at past data.

When called with channel name arguments, it runs continuously, storing all channel data in a ring buffer.  When the user hits Ctrl-C, all the data in the ring buffer is displayed.  There is an option to store the data in the ring buffer to disk as well.

 

controls@rosalba:/opt/rtcds/caltech/c1/scripts/general 0$ ./lookback -h
usage: lookback [-h] [-l LENGTH] [-o OUTDIR] channel [channel ...]

Lookback on testpoint data. The specified amount of data is stored in a ring
buffer. When Ctrl-C is hit, all data in the ring buffer is plotted. Both 'DQ'
and 'online' test point data is available. Use NDSSERVER environment variable
to specify host:port.

positional arguments:
  channel               Acquisition channel. Multiple channels may be
                        specified and acquired at once.

optional arguments:
  -h, --help            show this help message and exit
  -l LENGTH, --lookback LENGTH
                        Lookback time in seconds. This amount of data will be
                        stored in a ring buffer, and plotted on Ctrl-C.
                        Default is 10 seconds
  -o OUTDIR, --outdir OUTDIR
                        Output directory to write data (will be created if it
                        doesn't exist). Data from each channel stored as
                        '<channel>.txt'. Any existing data files will be
                        overwritten.
controls@rosalba:/opt/rtcds/caltech/c1/scripts/general 0$ 
  8525   Fri May 3 01:24:25 2013 KojiUpdateASSDen fixed the Yarm ASS scripts

Output matrices are added to ASS. Currently ASS is based on the mirror bases.
I prefer to have the actuator bases as the coils are more stable than the sensors.

At this point, the output matrices are identity. So Den's scripts are still working.

Striptool settings were also fixed.

  8526   Fri May 3 08:55:55 2013 SteveUpdatePEM3.2 M earthquake
Attachment 1: 3.2eqChannelIland.png
3.2eqChannelIland.png
Attachment 2: 3.2eq.png
3.2eq.png
  8527   Fri May 3 09:17:41 2013 SteveUpdateSUSETMX needs some help
Attachment 1: ETMX3.2eq.png
ETMX3.2eq.png
ELOG V3.1.3-