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ID Date Author Typeup Category Subject
  8902   Tue Jul 23 04:26:54 2013 JenneUpdateGeneralMC spot positions

After Koji and I lowered the power into the PMC and saw that the MC locked nicely, I remeasured the spot positions (no alignment on the PSL table, or of the MC mirrors has been done.  Also, WFS are off, since there isn't any power going to them).

spot positions in mm (MC1,2,3 pit MC1,2,3 yaw):
[1.1999406656184595, 0.63492727550953243, 1.0769104750021909, -1.0260011922577466, -1.059439987970527, -1.2717741991488549]

MCdecenter_22July2013_lowpower.png

The spot positions seem to have actually gotten a bit better in pitch (although between 2 consecutive measurements there was ~0.5mm discrepancy), and no real change in yaw.  This means that Rana was right all along (surprise!), and that decreasing the power before the PMC reduces alignment pain significantly.

  8903   Tue Jul 23 04:31:36 2013 JenneUpdateGeneralVent preparation - Ready for Vent

After everyone's work today (good teamwork everybody!!), we are a GO for the vent.

Steve, please check the jam nuts, and begin the vent when you get in.  Thanks.

  8904   Tue Jul 23 08:21:31 2013 SteveUpdateVACVent has started

 

Thanks for the good preparation.  IFO pressure P1=20 Torr

  8906   Tue Jul 23 13:55:08 2013 KojiUpdateIOOMC manually aligned

The MC was manually aligned. The spot positions were measured and it is consistent with the measurements done yesterday.

  8907   Tue Jul 23 14:00:03 2013 SteveUpdateVACthe vent is completed

 The 40m IFO has reached  atmospher in 5 hours. It is ready to open chamber condition. The RGA is pumped with the maglev.

P1 pirani gauge is contact dependent as you see it on the linear plot It will be replaced during this vent.

The venting speed was 2-4 Torr / min

Atm2 shows how the BS is sensing the venting air cylinder changes. 

The 4th cylinder of instrument  grade air  bump is overlapping with our janitor working at the BS chamber.

 

 

  8908   Tue Jul 23 16:39:31 2013 KojiUpdateGeneralFull IFO alignment recovered

[Annnalisa Koji]

Full alignment of the IFO was recovered. The arms were locked with the green beams first, and then locked with the IR.

In order to use the ASS with lower power, C1:LSC-OUTPUT_MTRX_9_6 and C1:LSC-OUTPUT_MTRX_10_7 were reduced to 0.05.
This compensates the gain imbalance between TRX/Y siganls and the A2L component in the arm feedback signals.

Despite the IFO was aligned, we don't touch the OPLEVs and green beams to the vented IFO.

  8909   Tue Jul 23 16:47:01 2013 gautamUpdateCDSExcitation points set up on c1scx

 I just compiled and installed the model with the excitation points on c1scx and then restarted framebuilder. The channels I set up are now showing up in the awggui dropdown menu. I will do the tests on the DAC channels shortly.

Just to keep things on record, these are the steps I followed:

  • opened the model c1scx (path: /opt/rtcds/userapps/release/sus/c1/models) with MATLAB
  • Added 8 excitation points and saved the model. A copy has been saved as c1scx.mdl.r2010b because of the recent upgrade to r2013a. 
  • ssh to c1iscex (computer running the model c1scx). 
  • Entered the following sequence of commands in terminal: rtcds make c1scx ,  rtcds install c1scx , rtcds start c1scx 
  • ssh to framebuilder, and restarted the framebuilder by entering telnet fb 8088   and then   shutdown.
  8910   Tue Jul 23 19:37:08 2013 AnnalisaUpdateendtable upgradeEnd table picture

Quote:

The spot on the IPANG QPD was checked. The spot is higher than the center and South side of the lens.
Some photos are found below.

The spot on the IPANG steering mirrors in the ETMY chamber was also checked.
It is clipped at the top of the steering mirror. (See attachment 4)
So basically the spot is about 1" above the center of the mirror.

 After the vent, the IPang spot position on the steering mirrors on the Yend table moved approximately by 1 inch down.

Inside the chamber, the spot position is in the center of the steering mirror. (difficult to take a picture because the PSL beam power has been reduced)

  8911   Tue Jul 23 19:38:58 2013 gautamUpdateCDSCharacterisation of DAC at 1X9

 

 I just finished carrying out the same checks for the DAC at 1X9 (with channels 9 through 16 that are unused as of now) as those I had done for the DAC at 1Y4, as the hardware prep up till now was done with the characterisation of the DAC at 1Y4. Conclusions:

  • The accessible range of output voltage are -10 V to +10V w.r.t ground --> No change needs to be made to the gain of the HV amplifier stage on the PZT Driver Board
  • The pin-outs of the DAC Adaptor Board at 1X9 is identical to that at 1Y4 --> Custom ribbons do not need to be modified.
  • The PSD of the DAC output has a peak at 64 kHz --> Notches on AI Board do not need to be moved again.

I will now proceed to install various pieces of hardware (AI Board, PZT driver board, HV Power Supply and cabling) at 1X9, while not making the connection to the PZTs till I receive the go ahead. 

  8913   Tue Jul 23 21:32:43 2013 KojiUpdateIOOFound the cause of mysterious MC motion

Thesedays we were continuously annoyed by unELOGGED activities of the interferometer.

MC2 LOCKIN was left on and has continuously injected frequency noise and beam pointing modulation
during all of the comissioning / vent preparation.

C1:SUS-MC2_LOCKIN2_OSC_FREQ was 0.075
C1:SUS-MC2_LOCKIN2_OSC_CLKGAIN was 99

For more than a week ago we noticed that the curve of the MC WFS stripchart suddenly got THICKER.
MC WFS, arm transmission, beam pointing... everything was modulated.
It was not WFS instability, and it was not the cavity mirrors.

Today I made the investigation and finally tracked down the cause of this issue to be on MC2 suspension.
Then it was found that this LOCKIN was ON.

There is no direct record of this lockin in the frame files.
From the recorded channel "C1:IOO-WFS2-YAW_OUT16" (which is the trace on the StripTool chart on the wall)
It was turned on at July 10th, 2:00UTC (July 9th, 7PM PDT)

  8914   Tue Jul 23 22:55:13 2013 JenneUpdateVACBS, ITMY doors to be opened in the morning

We will open the BS and ITMY doors first thing tomorrow morning. I plan to try to be in around 9 am. The first order of business will be to flip the folding mirrors that are not currently flipped (SR2, SR3, PR3).

  8915   Wed Jul 24 10:35:41 2013 SteveUpdateVACBS, ITMY doors are removed

Quote:

We will open the BS and ITMY doors first thing tomorrow morning. I plan to try to be in around 9 am. The first order of business will be to flip the folding mirrors that are not currently flipped (SR2, SR3, PR3).

 Jenne, Annalisa & Steve

  8916   Wed Jul 24 13:41:13 2013 JenneUpdateSUSSR2 flipped

[Jenne, Annalisa]

SR2 is flipped, and reinstalled.  We did that before lunch, and we're about to go in and work on SR3 and PR3.

EDITS / Notes:

I set dog clamps to have a reference position of where the tip tilt was, then I removed SR3 from the chamber.  Once out, I followed the same procedure I used for PR2 during the last vent - I removed the whole suspension (top mount, wires, optic) from the cage, and laid it down flat.  Then I loosened the set screw which pushes on the teflon nudge, removed the mirror, inspected it, and put it back in, with the HR side facing the back side of the ring.  Then I replaced the suspension system in the cage, and put the mirror back into the chamber. 

When I loosened the teflon nudge at the top of the mirror holder ring, the optic seemed to fall down a tiny bit.  I think this implies that the HR surface of the optic did not used to be parallel to the front face of the mirror holder ring.  When I put the suspension back onto the cage, the pitch balancing was very bad.  We checked the level of the table that I had the cage on, and it was miraculously pretty level, so I did the pitch balancing out of the chamber. 

Also, during my quick inspection of the mirror (not thorough, just using room lights), I noticed a small fleck of lint near the edge of the optic on the HR surface.  The HR surface is now on the outside of the SRC, but we should still blow at the optic with the ionized nitrogen to get it off.

I did not think to check the fine-tuning alignment of SR2....Koji did that after lunch (which I will elog about in a separate elog).

 

  8917   Wed Jul 24 14:26:24 2013 ranaUpdateIOOFound the cause of mysterious MC motion

Yes, this was not ELOG'd by me, unfortunately. This was the MC tickler which I described to some people in the control room when I turned it on.

As Koji points out, with the MCL path turned off this injects frequency noise and pointing fluctuations into the MC. With the MCL path back on it would have very small effect. After the pumpdown we can turn it back on and have it disabled after lock is acquired. Unfortunately, our LOCKIN modules don't have a ramp available for the excitation and so this will produce some transients (or perhaps we can ezcastep it for now). Eventually, we will modify this CDS part so that we can ramp the sine wave.

  8918   Wed Jul 24 15:07:54 2013 KojiUpdateSUSSR2 flipped

After the first flipping, X/Y arms were aligned and locked. Then the ASS aligned the arms.

  8920   Wed Jul 24 22:58:03 2013 CharlesUpdateISSISS - Full Schematic - Updated

 I have made significant changes to the ISS schematic, mostly in the form of adding necessary subsystems.

Some changes I have made:

  • Added a front page with sheet symbols that are representations of the other schematic sheets.
  • Added an 'Excitation' subsystem for use in determining the closed-loop transfer function
  • Added an instrumentation amplifier (with ADA4004s at Rana's recent suggestion) to handle the differential input from the PD
  • Included a switchable inverting amplifier (Gain of 1 or -1) to ensure we have the correct polarity
  • Made it so the first filtering stage is immediately active when the ISS loop is closed
  • Added LP filters with large time constants to buffer/delay trigger signals
  • Added test points all over the board
  • Refined a few buffer amplifiers

On the front page, all inputs and outputs are currently BNC ports, although this is most likely not the final design that will be used. For instance, the ports ENABLE, INPUT GND and INVERT are supposed to be logic inputs for a MAX333a switch. These will most likely be front panel switches that either connect the switch's logic pin to GND (Logic 0) or something like a +5 V supply (Logic 1).

I also have not included power regulation for my board although I have some of the actual D1000217 Chasis Power Regulator boards and I'll incorporate those in my design soon.

  8921   Thu Jul 25 02:53:00 2013 KojiUpdateGeneralIFO Alignment after TT flipping - no progress

There was no progress tonight after Jenne left.
I could not find any reasonable fringes of the IFO after 3 hours of optics jiggling.

* I jiggled TT1 and TT2. The slider has not been restored.
We should probably look at the value in the day time and revert them.
(Still this does not ensure the recovery of the previous pointing because of the hysteresis)

* The arms are still aligned for the green.
It's not TEM00 any more because of the vent/drift but the fringe is visible (i.e. eigenaxis is on the mirror)

* As we touched PR3, the input pointing is totally misaligned.

To Do / Plan

* We need to find the resonance of the yarm by the input TTs. Once the resonance is found, we will align the PRM.

* Move the BS to find the xarm resonance.

* Finally align SRM

* It was not possible to find the resonance of the yarm without going into the chamber. Definitely we can find the spot on the ITMY by a card, but we are not sure the beam can hit the ETMY. And the baffles makes the work difficult.

* One possibility is to align the input beam so that the ITMY beam is retroreflected to the PRM. I tried it but the beam was not visible form the camera.

  8922   Thu Jul 25 12:53:45 2013 CharlesUpdateISSComparator + Triggering Prototype

 I realized I totally forgot to post this last week, but I prototyped the comparator and boost triggering portion of the ISS, at least in part. Below is a schematic that shows the prototype circuit I made. Note that it includes ports for the oscilloscope channels that appear in the second image included. Essentially, I was able to verify that the output from the LT1016, as it's currently constructed in the ISS schematic, would be sufficient logic to switch the MAX333a.

Comparator_Prototype.png

Below, we can first see that the comparator is switching its output as desired. When the DC level of the input drops below a certain threshold (~1.6 V) the output of the comparator switches on to ~4 V. When the DC level of the input goes back up above the upper threshold (~3.2 V), the comparator switches off to ~0.3 V. The exact values of the threshold voltages can be determined/tuned at a later date, but this is the basic behavior that the comparator circuit will have.

To detect whether or not the MAX333a was switching properly, I connected the common terminal of one of the switches to a +5 V supply, and looked at the voltage coming off both the 'open' and 'closed' terminals of said SPDT switch. We can see that with Logic 0 (comparator output ~0.3 V) Channel 4 exhibits a ~5 V signal, just as we would expect from the above schematic. With Logic 1 (comparator output ~4 V), Channel 3 exhibits the characteristic 5 V signal.

Comp_Triggering_Behavior.jpg

  8923   Thu Jul 25 13:54:35 2013 manasaUpdateGeneralPR3 clamped and Y arm is back flashing

[Jenne, Annalisa, Manasa]

After yesterday's flipping of PR3, we lost our input pointing. Koji spent a few hours last night but couldn't restore the Y arm. I did my set of trials this morning which also didn't help.

So Jenne and I went ahead and requested Steve to get the ETMY door off.

We set the tiptilts TT1 and TT2 to the slider values from yesterday and started aligning the PR3 to hit the center of ITMY.
When we were hitting close to the center of ITMY, we decide to use the tip-tilts because the movement of PR3 was coarse at this point.
We used TT1 to get the beam to the center of ITMY and TT2 to get the beam at the center of ETMY. We did this iteratively until we were at the center of both the ITMY and ETMY.
We then went to fix IPANG.
The IPANG steering mirror on the BS table was steered to hit the center of the steering mirrors at the ETMY table. We aligned the beam to the IPANG QPD on the green endtable. The steering mirror on the BS table was then steered to misalign the beam in pitch by an inch at the last IPANG steering mirror. This should fix the IPANG clipping we have everytime we pump down.
We closed the chambers with light doors and saw IR flashing in the arm cavity. Koji is now trying to lock the cavity with IR.

  8924   Thu Jul 25 14:02:53 2013 JenneUpdateSUSSR3, PR3 flipped

Yesterday afternoon, I went back into the BS chamber, and flipped both PR3 and SR3. Now all of the recycling cavity folding mirrors have been flipped.

For PR3, I followed the same procedure as SR2, setting a reference position, removing the optic, flipping it, etc.  When I put it back in, I realized that since this has a 41 degree angle of incidence, the beam going to the BS had translated north by ~1cm.  After some fiddling, Koji pointed out that the 2 degree wedge probably had a more significant effect than just the HR surface having moved back a small amount.  Anyhow, we adjusted PR3 such that we were going through the BS aperture, as well as the ITMY aperture. 

During the flip of PR3, Annalisa and I noticed that the arrow on the barrel of the LaserOptik mirrors also indicates the thickest part of the wedgeThis is opposite of our SOS optics, where the arrow's position on the barrel indicates the thinnest part of the wedge.  For both PR3 and SR3, I kept the arrow on the same side of the optic as it was originally.

I then flipped SR3, following again the same procedure.  PR3 I had done a tiny bit of pitch rebalancing, although I think it was unneccessary, since it is within what we can do with the poking/hysterisis method.  SR3 I did not do any pitch rebalancing.  With PR3 aligned at least to the ITM, Koji and I aligned SR3 and SR2 so that the AS beam was hitting the center of all the SRC optics.  We also adjusted the steering mirrors after the SRM to get the beam centered on PZT3, the last optic on the BS table, which launches the beam over to the OMC chamber.  We scanned around a bit by turning the PZT's knobs, but we were unable to see the AS beam on the camera. 

 

  8925   Thu Jul 25 14:45:06 2013 ranaUpdatePEMGuralp specgram with ligoDV and NDS2

 Once you install a matlab newer than 2012a, you can install ligoDV as a matlab app and get the NDS2 client software for free. So you can easily get the 40m data from the outside world now and do the analysis on your own computer rather than login through nodus.

  8926   Fri Jul 26 13:39:30 2013 KojiUpdateASCPOP QPD analysis

It was not actually easy to see from the entry what signal was taken in what condition but from the shape of the spectra
I had the impression that the ASC & OPLEV signals were measured under the presence of the ASC control.
That is (moderately to say) tricky as the ASC control imprints the angular noise
from unkown mirror on the PRM, and then the oplev observes it. The original stability of the oplev is
obscured by the injection from the servo and the fair comparison of the stability is almost impossible.

So the true comparison between the ASC and oplev signals should be done without the control loop.
http://nodus.ligo.caltech.edu:8080/40m/8532

http://nodus.ligo.caltech.edu:8080/40m/8535

We can recover the free running spectrum of the ASC signals by compensating the loop transfer functions
because the ASC signals are the in-loop error signals. The oplev signals should be measured without
the ASC loop engaged.

  8927   Fri Jul 26 14:39:08 2013 CharlesUpdateISSPower Regulation for ISS Board

I constructed a regulator board that can take ±24 V and supply a regulated ±15 V or ±5 V. I followed the schematics from LIGO-D1000217-v1.

I was going to make 2 boards, one for ±15 V and one for ±5, but Chub just gave me a second assembled board when I asked him for the parts to construct it 

 

  8928   Fri Jul 26 22:19:24 2013 CharlesUpdateISSISS - Full Schematic - Updated

Quote:

 I have made significant changes to the ISS schematic, mostly in the form of adding necessary subsystems.

Some changes I have made:

  • Added a front page with sheet symbols that are representations of the other schematic sheets.
  • Added an 'Excitation' subsystem for use in determining the closed-loop transfer function
  • Added an instrumentation amplifier (with ADA4004s at Rana's recent suggestion) to handle the differential input from the PD
  • Included a switchable inverting amplifier (Gain of 1 or -1) to ensure we have the correct polarity
  • Made it so the first filtering stage is immediately active when the ISS loop is closed
  • Added LP filters with large time constants to buffer/delay trigger signals
  • Added test points all over the board
  • Refined a few buffer amplifiers

On the front page, all inputs and outputs are currently BNC ports, although this is most likely not the final design that will be used. For instance, the ports ENABLE, INPUT GND and INVERT are supposed to be logic inputs for a MAX333a switch. These will most likely be front panel switches that either connect the switch's logic pin to GND (Logic 0) or something like a +5 V supply (Logic 1).

I also have not included power regulation for my board although I have some of the actual D1000217 Chasis Power Regulator boards and I'll incorporate those in my design soon.

 More changes that I've made:

  • Added daughter boards for power regulation. Currently I have ±24V going into two boards, with ±15V coming out of one and ±5V coming out of the other. Again, these are based off of LIGO-D1000217
  • Added an optional Dewhitening filter (with p=1Hz and z=100Hz, although these can easily be changed) to accommodate any PD's that have whitening
  • Added a bypass to allow the boosts (stages 2 and 3 of the filtering servo) to be enabled/disabled by a front panel switch
  • I also put in jumpers that can be used to provide Logic 1 (boost enabled) to both Boost 1 and Boost 2 without depending on the internal RMS detection/triggering
  • Changed the input grounding switch so that it's set up correctly. Before, it was taking the PD signal and sending it to GND, not actually grounding the input to the rest of the ISS 
  8929   Fri Jul 26 22:45:14 2013 manasaUpdateGeneralVent progress

[Koji, Manasa]

The arms were brought back to resonance after yesterday's vent work.
DCPD gains were changed (TRX gain from -0.002 to -0.04; TRY gain changed from 0.002 to 0.04) to lock the arm with low power. 
 
X arm and Y arm were locked for IR.

We then decided to align IPANG because the input pointing seemed good - the right time to fix IPANG. The IPANG spot at the last in-vac steering mirror was aligned to be an inch low in pitch.
 
We then aligned SRC. SR2 and SR3 were adjusted to center the beam at SRM. SRM was aligned to the retro-reflected beam until we saw flashes. But this position of SRM is not at the good OSEM range. We should correct the SRM suspensions. We postponed this activity for next week and went ahead to look at the status of the AS beam.
 
Looking through the window and using IR viewer were not convincing enough. We will have to get the access connector out on Monday to do the AS alignment.
We then closed the chamber with light doors and locked the arm cavities again. We brought SRC and PRC to resonance and saw strong flashes at the BS_PRM camera. 
 
To do:
SRM need to be moved in order to remove the big bias in yaw
SRM OSEMS need to be adjusted
Access connector should come out
AS needs to be aligned satisfactorily
ITMX oplev steering mirrors in vacuum should be checked.
  8930   Sun Jul 28 19:39:04 2013 AnnalisaUpdateendtable upgradePicture

 Yend table picture updated on the wiki page

  8931   Sun Jul 28 20:13:41 2013 AnnalisaUpdateGreen LockingY Phase tracker calibration

I did a calibration measurement for the Y part of the BeatBox using a Marconi. This is in order to get a more accurate calibration for the arm cavity scan measurement.

The calibration factor I found is:

C1:ALS-BEATX_FINE_PHASE_OUT   50.801 +/- 0.009 deg/MHz

Procedure

During my cavity scan measurement, I had recorded the beat frequency and amplitude from the Spectrum Analyzer at each zero crossing.

I connected the Marconi to the RF in of the Y part of the BeatBox, and I set the Marconi carrier frequency at one of this zero-crossing frequency that I had recorded, while I set the amplitude in way to have on the spectrum analyzer the same beat amplitude that I read during the measurements or, equivalently, in order to have C1:ALS_BEATY_FINE_Q of the order of 1200 (which is the same value I had during my measurements).

I started with

  • Carrier frequency = 80.2 MHz
  • Amplitude = -3dBm

Then I monitored the C1:ALS_BEATY_FINE_I on the oscilloscope and I adjusted the carrier frequency so that I had zero signal on the oscilloscope. Eventually the frequency corresponding to the zero crossing was 79.989 MHz.

I resetted the phase (clear history in the BEATY_FINE_PHASE panel) and I started changing the frequency by steps of 0.2 MHz, and I spanned about 70 MHz (from 32 to 102 MHz).

Resutls

The calibration coefficient I found is not so different from the one that Yuta measured (elog 8199).

Here are the fit parameters:

y = a + bx

a = -4239.7 +/- 0.6 deg

b = 50.801 +/- 0.009 deg/MHz

  8933   Mon Jul 29 16:04:40 2013 SteveUpdateVACAC removed

 Manasa, Eric, Evan, Koji and Steve,

Access connector removed in order to complete alignment. Light aluminum with acetate windows AC installed.

 

 

  8934   Mon Jul 29 16:15:13 2013 KojiUpdateVACAC removed

Prior to the access connector removal, Manasa and I aligned the IFO mirrors.
The arms were locked and aligned by ASS.

  8936   Tue Jul 30 00:21:15 2013 KojiUpdateGeneralVent progress

[Koji, Manasa, Sujan] 

Tomorrow we'll make final checks of the optics inside the chamber.
Then we will pump down the chamber.

- AS beam steering
The AS beam was aligned on the steering mirror (Piezo Jenna i.e. PZT4).
At this point we already found the beam on the AS CCD.
After checking the spots in the OMC chamber, we determined the beam is not clipped inside.
 
On the AS table, there is a weird thick lens with short focal length (like f=37.5mm), this actually clipped the beam significantly
[I take the blame for it from the last vent. The lens was installed thinking it would be temporary which it was not. -Manasa].
We removed this lens and put the CCD camera back so that the spot on the camera became smaller.
 
- SRM debiasing
 
First of all, the bias of the SRM was moved to zero.
Then the tower was rotated so that the beam is aligned in yaw.
After fine alignment of the SRM, the yaw slider was changed from -5.8 to 1.2.
The OSEMs on the SRM suspension was also checked. The OSEM insertions were
adjusted so that they show the half values of the open calibration
(the values can be found on the 40m wiki)
 
- Oplev check
 
SRM / ITMY / BS / PRM oplev paths in the chamber were checked.
The beams were aligned on the steering mirrors and the QPDs on the optical table.
The ITMX oplev was also checked from the windows without removing the door.
The beam is actually hitting the right positions of the steering mirror and the test mass
although there are lots of stray beams because of the BS oplev and some halo assciated with the ITMX He-Ne laser(!?).

- Checking the alignment
After we closed the light doors, we aligned the MC, the arms and the recycling mirrors.
Now the everything is aligned.
  8937   Tue Jul 30 11:30:55 2013 manasaUpdateGeneralITMX oplev

Quote:

[Koji, Manasa, Sujan]

The ITMX oplev was also checked from the windows without removing the door.
The beam is actually hitting the right positions of the steering mirror and the test mass
although there are lots of stray beams because of the BS oplev and some halo assciated with the ITMX He-Ne laser(!?).

[Steve, Gautam, Manasa]

While we checked the ITMX oplev situation yesterday, we found that the beam hitting the ITM and the in-vacuum steering mirrors had  a halo around them. We used the set of irides in the path of the ingoing beam and cut the stray light around the beam. This reduced the intensity of the halo around the mirrors. We noticed that the halo accounted for 2000 counts of 6500 at the oplev QPD. We tried changing the laser and this did not make the situation any better.

Also there are a couple or more strong stray beams from the BS oplev.

Thoughts:
I suspect that the BS oplev leakage is messing with the ITMX oplev. Why?? We have been seeing the breathing of transmitted beam from the X arm cavity and the shadow sensor readings have been bigger than usual since the last vent (when we changed the BS oplev path). Also, the ingoing oplev beam is close to clipping at the PR2 stack.

I think it would be best to open the ITMX chamber and modify the in-vac steering mirror layout of the oplev.

  8938   Tue Jul 30 13:41:35 2013 KojiUpdateGeneralITMX oplev

I wonder what optics is causing the halo on the oplev beam.
It this comes from any uncoated lens (or similar) it should be identified.

  8939   Tue Jul 30 15:38:24 2013 manasaUpdateGeneralITMX oplev

Quote:

I wonder what optics is causing the halo on the oplev beam.
It this comes from any uncoated lens (or similar) it should be identified.

We identified this to be coming from the uncoated concave lens that we have right after the He-Ne laser which should also be replaced in addition to the other problems with the oplev.

  8940   Tue Jul 30 16:21:46 2013 Alex ColeUpdateElectronicsPhotodetector Input Modulation

 [Eric, Alex]

We successfully used our system to modulate the input to a single photodetector. The RF Out of the network analyzer went to the Mod In of our laser, which was operating at 98 mA. The laser's output was sent to our 1x16 optical splitter. This provided input signals for both our reference detector and AS55. Our reference detector's output was sent to the network analyzer's R input, while the AS55's output was sent to the network analyzer's A input. 

We still need to work out the specifics of how the modulation works. Specifically, we want to look at the amplitude of the network analyzer's output. Additionally, we may have been saturating our reference detector, causing noise problems.

  8941   Tue Jul 30 18:56:31 2013 manasaUpdateGeneralITMX chamber vented/Closing plan

[Koji,Manasa]

We removed the ITMX heavy door to fix the oplev situation. 

My Plan for closing:

Today: I will work on the ITMX oplev situation today and go through the vent close-up checklist as far as I can get.
Tomorrow: We will do the final alignment check tomorrow with the light doors. The access connector and heavy doors should go in place late afternoon.
Thursday: We will start pumping down early in the morning on Thursday.

  8944   Wed Jul 31 00:59:58 2013 manasaUpdateGeneralITMX chamber vented/Closing plan

My Plan for closing:

Today: I will work on the ITMX oplev situation today and go through the vent close-up checklist as far as I can get.

[Alex, Sujan, Manasa]

The ITMX oplev steering mirrors were laid out such that they were out of the way of the BS oplev leakage. But the halo associated with the He-Ne laser does exist even now. I conclude that this is something that can be dealt with after we pump down as well. So I did not change the ITMX oplev optics on the POX table.

BS, PRM, ITMY and SRM oplevs were aligned and centered.

We want to do IPANG and IPPOS alignment when the IFO is aligned satisfactorily and right before we put the heavy doors.

The arms were aligned and ASS'd before I went in to fix the oplevs. I haven't done anything but deal with the oplevs tonight. So I am being lazy by assuming the alignment is still good and calling it a night.

Tomorrow: We will do the final alignment check for the arms, PRC and SRC with the light doors on. Check IPANG and IPPOS. The access connector and heavy doors should go in place late afternoon.
Thursday: We will start pumping down early in the morning on Thursday.

  8945   Wed Jul 31 09:51:43 2013 SteveUpdatesafetySujan receives safety training

Sujan got 40m specific basic safety training this morning.

  8946   Wed Jul 31 10:27:00 2013 SteveUpdateVACinstrument grade air is discontinoued

We have been using Air Liquide Instrument Grade Air for venting the 40m vacuum envelope. It is no longer available.

The replacement is Alphagas 1, total hydrocarbon <0.1% ppm

LINK TO Alphagaz

 

A- A+ Imprimer Partager

ALPHAGAZ™ Specifications

ALPHAGAZ™ range of Pure Gases for Analysis: two purity levels tailored to cover all your analytical needs.

Because each analytical application is sensitive to critical impurities that can affect your results, tests in our research center and analyzer manufacturers' studies confirm that the main impurities are moisture, oxygen and hydrocarbons.

Based on these critical impurities, Air Liquide has developed ALPHAGAZ™ brand with a Maximum Impurity Level (H2O, O2, CnHm).

  • The Maximum Impurity Level is the same across the whole product range. This constitutes a guarantee of quality with regard to major critical impurities and contamination tracers. ALPHAGAZ™ 2 offers an even greater guarantee in terms of purity (CO, CO2, H2).
  • The Minimum Total Purity is a prerequisite for product quality, but we do not stop there: Air Liquide selects and controls its gas sources by defining specifications regarding impurities that are critical for your analysis or application.

 

ALPHAGAZ™ 1 ALPHAGAZ™ 1 ALPHAGAZ™ 2 ALPHAGAZ™ 2 ALPHAGAZ™ AUTO IV ALPHAGAZ™ CO2 SFC
He, N2, H2,
Ar, O2
Air He, N2, H2,
Ar, O2
Air Air*, N2, O2 CO2
Specifications (ppm vol):
H2O < 3 ppm
O2 < 2 ppm
CnHm < 0.5 ppm
H2O< 3 ppm
CnHm< 0.1 ppm
CO2 < 1 ppm
CO < 1 ppm
H2O < 0.5 ppm
O2 < 0.1 ppm
CO2 < 0.1 ppm
CO < 0.1 ppm
CnHm < 0.1 ppm
H2 < 0.1 ppm
H2O < 0,5 ppm
CnHm < 50 ppb
CO2 < 0,1 ppm
CO < 0,1 ppm
NOx < 10 ppb *
SO2 < 10 ppb*
CnHm < 0.2 ppm
CO2 < 0.5 ppm
CO < 0.5 ppm
NO/NOx < 0.1 ppm
H2O < 5 ppm
O2 < 2 ppm
CnHm < 2 ppm
NVOC* < 2 ppm
CO < 5 ppm
NO + NO2 < 2 ppm
S Total < 1 ppm
H2 < 0.5 ppm
  20 ± 1 % O2 (Europe)
21 ± 1% O2 (North America)
  20,9 ± 1 % O2
*: Detection limit
*20 ± 1 % O2 *NVOC: Non Volatile Organic Compounds
Minimum Total Purity

 

 

  8947   Wed Jul 31 17:02:17 2013 Alex ColeUpdateElectronicsPreliminary Photodetector Frequency Reponse Measurements

[Eric, Alex]

We used our setup from yesterday (elog #8940) to measure transimpedance measurements for AS55, REFL11, REFL33, and REFL55, using our Newport 1611 FC-AC as reference. We connected the fibers to their respective telescopes such that the beams focused on their photodetectors, using a multimeter to maximize photodetector DC output. Plots are attached. At first glance, the poles seem to be where they're supposed to be.

Note that the procedure used today is similar to what the eventual automated procedure will be. The main differences are (1) The RF Switch will be used rather than manual switching (2) NWAG4395A will be used to collect data rather than netgpibdata (3) Data will be fit using vectfit4.m and compared to some canonical set.

  8948   Wed Jul 31 21:12:05 2013 manasaUpdateGeneralPump down called off

[Koji, Manasa]

We missed to check that we had the green transmitted to the PSL after flipping the SRC and PRC folding mirrors.
There is no green transmission reaching the PSL even after locking the arms to green.

We should fix this tomorrow. The BS heavy door should come off.

Steve! Do not start pump down tomorrow !

  8949   Thu Aug 1 12:12:35 2013 gautamUpdateCDSNew model for endtable PZTs

I have made a new model for the endtable PZT servo, and have put it in c1iscex. Model name is c1asx. Yesterday, Koji helped me start the model up. The model seems to be running fine now (there were some problems initially, I will post a more detailed elog about this in a bit) but some channels, which are computer generated, don't seem to exist (they show up as white blocks on the MEDM GDS_TP screen). I am attaching a screenshot of the said screen and the names of the channels. More detailed elog about what was done in making the model to follow.

 

C1ASX_GDS_TP.png

 

Channel Names:

C1:DAQ-DC0_C1ASX_STATUS (this is the channel name for the two leftmost white blocks)

C1:DAQ_DC0_C1ASX_CRC_CPS

C1:DAQ-DC0_C1ASX_CRC_SUM

  8950   Thu Aug 1 13:09:17 2013 gautamUpdateCDSNew model for endtable PZTs-procedure

 

 These are roughly the steps I followed in setting up the new model for the endtable PZT servo - C1ASX.


Simulink model:

I made a SIMULINK model of the servo, using MATLAB R2013a. The path to the model is /opt/rtcds/caltech/c1/userapps/release/isc/c1/models/c1asx.mdl. I am listing the parameters set on the CDS_PARAMETERS block:

  • host = c1iscex
  • site = c1
  • rate = 16k
  • dcuid = 44 (which I chose after making sure that this dcuid was not used on this list which was last updated end Feb 2013)
  • specific_cpu = 5 (again chosen after checking the available CPUs in the above list).
  • adc_Slave = 1
  • shmem_daq = 1
  • no_rfm_dma = 1
  • biquad = 1

 

Making, Compiling and Installing the Model:

After saving the model, I ssh-ed into c1iscex and ran the following commands:

rtcds make c1asx - this gave me a whole bunch of errors initially, which I tracked down to a naming problem in some of the from and goto flags: there should not be any spaces.

rtcds install c1asx 

rtcds start c1asx - this gave me an error which said something like 'can't start/stop model.' Koji pointed out that given that a new model is being started, there is an additional step involved, which is to add the model name to the rtsystab file (this is located at /diskless/root/etc/rtsystab on framebuilder, and is mirrored in the various computers. It would be advisable to make sure that the changes are mirrored in the corresponding file on the computer in which the new model is being installed). 

After adding the model name to the rtsystab file, I tried running rtcds start c1asx again. This time, no errors were output, but the model was not up and running as verified by looking at the C1:ASX_GDS_TP medm screen.


 Debugging 

Koji suggested making a simple model (1 CDS parameters block, 1 ADC block and 2 filter modules, appropriately terminated) and see if that starts up, which it did. I then tried adding my servo minus the DAC block and recompiled and restarted the model. This too worked fine. I figured that the next logical step would be to add the DAC block to the model, and restart the model. But when I tried this, c1iscex crashed .

Jenne helped in restoring things to a working state (we reverted the c1asx model to just 2 filter modules, and went to the X-end and restarted the computer. This did not work the first time so I went back in and restarted it again, at which point we were able to ssh into c1iscex again and restart the four models running on it).

Since Manasa and Koji were working on getting things set up for the pumpdown,I did not try anything again till later in the evening, when Koji helped in debugging the problem further. In the meantime, at Jenne' suggestion, I made the model once again in MATLAB R2010b. In the evening, when I tried restarting the model, Koji suggested that the DAC channels in c1asx may be used by other models, at which point I realised I had set up excitation points on channels 8 through 15 of the DAC in c1scx (detailed here) in order to test the hardware at 1X9. I removed the excitation points from channels 8-11 of the DAC block in c1scx (these are the ones used in c1asx), and recompiled and restarted c1asx (using the above sequence of commands). I then tried recompiling and starting c1asx once more, and this time, it worked . At least, the GDS_TP screen suggests that the model is running alright, except for the fact that some computer generated channels seem to be missing. This problem is unresolved for now, and probably has something to do with the fact that C1ASX channels do not appear in Dataviewer.

I do not think this has to do with restarting framebuilder (I did the usual telnel fb 8088 followed by shutdown). In any case, I have added the new model to the CDS_FE_STATUS screen, and will continue to debug the same. I have also got a template medm screen (work in progress) which I will elog about soon as I get it done.

 

Note to self: There are 4 more excitation channels still hooked up to the DAC (channels 12-15) in the c1scx model. I plan to remove these and put them in c1asx.

 

  8951   Thu Aug 1 15:06:59 2013 jamieUpdateCDSNew model for endtable PZTs

Quote:

I have made a new model for the endtable PZT servo, and have put it in c1iscex. Model name is c1asx. Yesterday, Koji helped me start the model up. The model seems to be running fine now (there were some problems initially, I will post a more detailed elog about this in a bit) but some channels, which are computer generated, don't seem to exist (they show up as white blocks on the MEDM GDS_TP screen). I am attaching a screenshot of the said screen and the names of the channels. More detailed elog about what was done in making the model to follow.

 

C1ASX_GDS_TP.png

 

Channel Names:

C1:DAQ-DC0_C1ASX_STATUS (this is the channel name for the two leftmost white blocks)

C1:DAQ_DC0_C1ASX_CRC_CPS

C1:DAQ-DC0_C1ASX_CRC_SUM

I don't know what's going on here (why the channels are white), and I don't yet have a suggestion of where to look to fix it but...

Is there a reason that you're making a new model for this?  You could just use and existing model at c1iscex, like the c1scx, and put your stuff in a top-names block.  Then you wouldn't have to worry about all of the issues with adding and integrating a new model.

  8952   Thu Aug 1 15:28:44 2013 gautamUpdateCDSNew model for endtable PZTs-problem solved

Quote:

 

I don't know what's going on here (why the channels are white), and I don't yet have a suggestion of where to look to fix it but...

Is there a reason that you're making a new model for this?  You could just use and existing model at c1iscex, like the c1scx, and put your stuff in a top-names block.  Then you wouldn't have to worry about all of the issues with adding and integrating a new model.

Koji just fixed this.

It seems that the new model's channels were not automatically added to the master file in the framebuilder (/opt/rtcds/caltech/c1/target/master). Adding the following two lines to the master file fixed the problem;

/opt/rtcds/caltech/c1/chans/daq/C1ASX.ini

/opt/rtcds/caltech/c1/target/gds/param/tpchn_c1asx.par

The box is now green. It looks like C1ASX.ini is created automatically in /opt/rtcds/caltech/c1/chans but the master file needs to be manually edited. The channels are now showing up on dataviewer etc. I have updated the information on the wiki page.


 

 

 

 

 

  8953   Thu Aug 1 16:03:52 2013 SteveUpdateGeneralreopen BS & IOO

Quote:

[Koji, Manasa]

We missed to check that we had the green transmitted to the PSL after flipping the SRC and PRC folding mirrors.
There is no green transmission reaching the PSL even after locking the arms to green.

We should fix this tomorrow. The BS heavy door should come off.

Steve! Do not start pump down tomorrow !

 We closed the chambers last night with heavy doors and reopened it today.

  8954   Thu Aug 1 16:33:39 2013 SujanUpdatePEMGuralp2 seismometer installed at North side of POX table

1)Power to the seismometers were turned down,

2)Guralp2 was moved to North side of POX table

3)Guralp2 was aligned in N-s Direction and leveled before connecting

4)Power to seismometers was turned on once Guralp2 was connected

IMG_1213.JPG

  8955   Thu Aug 1 18:55:20 2013 Alex ColeUpdateElectronicsPreliminary Photodetector Frequency Reponse Measurements

Quote:

[Eric, Alex]

We used our setup from yesterday (elog #8940) to measure transimpedance measurements for AS55, REFL11, REFL33, and REFL55, using our Newport 1611 FC-AC as reference. We connected the fibers to their respective telescopes such that the beams focused on their photodetectors, using a multimeter to maximize photodetector DC output. Plots are attached. At first glance, the poles seem to be where they're supposed to be.

Note that the procedure used today is similar to what the eventual automated procedure will be. The main differences are (1) The RF Switch will be used rather than manual switching (2) NWAG4395A will be used to collect data rather than netgpibdata (3) Data will be fit using vectfit4.m and compared to some canonical set.

 [Alex, Eric]

Today I spent some time mounting the launcher and performing the same data collection for POX11. I think I still need to focus the launcher so the photodetector gets a good signal, but the data from today wasn't too bad.  Additionally, I worked on matlab scripts to improve PDFR data analysis.

This time I collected data from the network analyzer using NWAG4395A in the netgpibdata directory. The advantage of this is that the computer tells the network analyzer to perform the sweep as well as retrieving the data.

For analysis, I improved my implementation of vectfit4.m so that it focuses in on the particular photodetector's predicted peaks and thus ignores much of the noise, giving a better fit. The raw data is the red circles in the 2nd attachment, while the fit is the blue line. I also had the program return the frequency value of the peak. For POX11, this was 1.106e+07 Hz.

I also finagled copies of existing programs to enable one to plot multiple transfer functions on the same axes. This function is /users/alex.cole/plottwo.m. I will eventually use this to compare new data to some canonical data so that we may monitor photodetector performance over time.

The eventual plan is to generate two plots per photodetector, one of which will compare new data to the canonical set, the other of which will show the fit of the data. Both will have subplots that zoom in around regions of interest (known peaks and notches), and the plot which displays the canonical set will also have Q's of peaks and their locations.

  8956   Thu Aug 1 20:58:56 2013 gautamUpdateCDSNew model for endtable PZTs-MEDM Screens setup

 

I have made some minor changes to the model, made all the MEDM screens, and linked monitors on these to the appropriate channels. I have borrowed heavily from the C1ASS MEDM screens (particularly for the small filter modules-it was convenient to just copy and paste an existing module, and edit the channel names using EMACS/GEDIT), and have edited these to suit the needs of this servo. Some features:

  • The feedback signal (only the output of the servo to the PZTs, plus any contribution from the on-screen sliders, and not including the LO output) is monitored with both a slow (using CDS_EPICS_OUTPUT block from the CDS_PARTS library) and fast channel (using Test Point from the same library). The idea is that it would be useful to know the output to the PZTs such that if coarse adjustment ever needs to be done at the endtable, the PZTs can be restored to the middle of its operating range by means of the sliders.
  • Sliders are incorporated into the master screen for adjusting the output to the PZTs. There are text-input fields below the sliders as well, which control the same channel.
  • I have removed the 4 remaining excitation points to the DAC set up in C1SCX, and have relocated them to channels 12-15 of the DAC in C1ASX.

I think I am now ready to take some measurements and try and optimize this servo. There is no green transmission at the PSL table at the moment, so not much can be done, though the first step would be to take the power spectrum of the error signal, which would help me decide the appropriate frequencies for the LOs. I would then have to add the appropriate filters to the model. The last, and most difficult step, would be the measurement of the output matrix, though Koji has given me some ideas about how this measurement can be done. I also have a template script ready, though I will only finalise this after optimising the servo and running it a couple of times manually.

 

Attached are screenshots of the MEDM screens.

 

MAIN_SCREEN.pdf      MATRICES.pdf   

LOCKINS.pdf      CONTROL_FILTERS.pdf

 

  8957   Thu Aug 1 21:28:09 2013 gautamUpdateCDSSlow channels set-up in ALS

The following slow channels have been added and are now being recorded by FB.

 

C1:ALS-X_OVEN_TEMP

C1:ALS-Y_OVEN_TEMP

C1:ALS-BEATX_FREQ

C1:ALS-BEATY_FREQ


Details:

In order to integrate the data collected by the Raspberry-Pi from the Y-end doubling oven temperature controller and also the data from the frequency counter which will be hooked up to monitor the beat frequency, Koji helped me set up some slow EPICS record channels (in ALS as we felt this was most appropriate). The procedure for setting up slow channels was as follows (virtually identical to what is detailed in this elog:

  1. Add the channel names to the file C0EDCU.ini (path = /opt/rtcds/caltech/c1/chans/daq/C0EDCU.ini).
  2. Make a database (.db) file so that these channels are actually recorded (path = /cvs/cds/caltech/target/c1aux/als.db).
  3. Restart framebuilder. 
  4. Verify that the channels indeed exist and can be read and written to using ezcaread and ezcawrite.

I will now integrate these channels into my scripts, and make some simple MEDM screens.

 

  8958   Thu Aug 1 22:49:31 2013 manasaUpdateGeneralGreen status after PR3 flipping investigated

[EricQ, Koji, Manasa]

We opened the BS chamber to check the status of the green beams. The X green has 3 steering mirrors before they hit periscope1 and the Y green transmits through all the optics giving no way to steer it.

We agreed to start fixing the Y green. The wedge angle of PR3 is steering the transmitted beam away in both pitch and yaw. Since we are restricted only to yaw movement (done by moving the periscope), we want he wedge angle to be oriented in the yaw as well.

Right now, the wedge is oriented at about 20-30 deg off (The mark on the side of the mirror does not indicate the wedge). So we see a pitch as well as yaw misalignment in the transmitted beam. The pitch misalignment is making the beam fall off the mirrors in periscope2. 

We have decided to get the wedge angle set right for PR3 and redo the alignment for IR. Once we are aligned for the IR, we will modify the green layout.

ELOG V3.1.3-