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ID Date Author Type Category Subjectup
  5336   Fri Sep 2 15:56:32 2011 KojiUpdateIOOtriple resonant box : ready to install

What are the reflected RF powers for those frequencies? 
Is the 29.5MHz more problem than the 55MHz, considering the required modulation depth?

 

  2523   Mon Jan 18 23:44:19 2010 kiwamuUpdateElectronicstriple resonant circuit for EOM

The first design of the triple resonant EOM circuit has been done.

If only EOM has a loss of 4 Ohm, the gain of the circuit is expected to be 11 at 55MHz

So far I've worked on investigation of the single resonant circuit and accumulated the knowledge about resonant circuits.

Then I started the next step, designing the triple resonant circuit.

Here I report the first design of the circuit and the expected gain.

 


( What I did )

At first in order to determine the parameters, such as inductors and capacitors, I have solved some equations with numerical ways (see the past entry).

In the calculation I put 6 boundary conditions as followers;

(first peak=11MHz, second peak=29.5MHz, third peak=55MHz, first valley=22MHz, second valley=33MHz, Cp=18pF)

The valley frequencies of 22MHz and 33MHz are chosen in order to eliminate the higher harmonics of 11MHz, and Cp of 18pF represents the capacitance of the EOM.

Basically the number of parameters to be determined is 6 ( L1, L2, ...,), therefore it is completely solved under 6 boundary conditions. And in this case, only one solution exists.

The point is calculation does not include losses because the loss does not change the resonant frequency.

 

whole_circuit.png

( results )

As a result I obtained the 6 parameters for each components shown in the table below.

Cp [pF] 18.1
C1 [pF]  45.5
C2 [pF] 10.0
Lp [uH] 2.33
L1 [uH] 1.15
L2 [uH] 2.33

Then I inserted the loss into the EOM to see how the impedance looks like. The loss is 4 Ohm and inserted in series to the EOM. This number is based on the past measurement .

Let us recall that the gain of the impedance-matched circuit with a transformer is proportional to square-root of the peak impedance.

It is represented by G = sqrt(Zres/50) where Zres is the impedance at the resonance.

 As you can see in the figure, Zres = 6.4 kOhm at 55MHz, therefore the gain will be G=11 at 55MHz.

Essentially this gain is the same as that of the single resonant circuit that I've been worked with, because its performance was also limited mainly by the EOM loss.

 An interesting thing is that all three peaks are exactly on the EOM limited line (black dash line), which is represented by Zres = L/CR = 1/ (2pi f Cp)^2 R. Where R = 4 Ohm.

 designed_circuit.png

( next plan )

There are other solutions to create the same peaks and valleys because of the similar solution.

 It is easy to understand if you put Cp' = Cp x N, the solutions must be scaled like L1'=L1/N, C1'=C1 x N, ...,  Finally such scaling gives the same resonant frequencies.

So the next plan is to study the effect of losses in each components while changing the similar solution.

After the study of the loss I will select an optimum similar solution.

  2524   Tue Jan 19 00:10:44 2010 ranaUpdateElectronicstriple resonant circuit for EOM

Very cool.         

  2526   Tue Jan 19 02:40:38 2010 KojiUpdateElectronicstriple resonant circuit for EOM

The design looks very good. I have some questions.

1. As far as I remember, you've got the gain of slightly worse than 10 for a 55MHz single resonant case. Why your expectation of the gain (G=11) for the highest resonance better than this?

Supposing the loss exists only on the EOM, the other part of the LC network for the triple work as an inductor at the resonant frequency. This is just equivalent as the single resonant case. So the expected gain at 55MHz should coincides with what we already have. Probably, the resistance of 4 Ohm that is used here had too rough precision???

2. How can you adjust the resonances precisely?

Do we need any variable components for Cs and Ls, that may have worse quality than the fixed one, generally speaking.
I myself has no experience that I had to tune the commercial EOM because of a drift or whatever. I hope if you can adjust the resonance with a fixed component it should be fine.

3. Changing Cp. What does it mean?

Do you put additional cap for Cp?

4. The resonances for the lower two look very narrow. Is that fine?

This will show up in a better shape if we look at the transfer function for the gain. Is this right?

If we have BW>100kHz, it is sufficient.

5. Impedance matching for the lower two resonances.

Yep. You know this problem already.

 

  2527   Tue Jan 19 03:04:14 2010 KojiUpdateElectronicstriple resonant circuit for EOM

Self-follow:

I got the answer of Q3 from the follow-up entry.

For Q4, once you get the impedance of the LC network lower than n^2*50, the EOM gain will be quite low. This means that the resonance is anyway narrow.
I did some simple calculation and it shows that the width of the resonance will be 100kHz~500kHz. So it maybe OK.

Quote:

The design looks very good. I have some questions.

1. As far as I remember, you've got the gain of slightly worse than 10 for a 55MHz single resonant case. Why your expectation of the gain (G=11) for the highest resonance better than this?

Supposing the loss exists only on the EOM, the other part of the LC network for the triple work as an inductor at the resonant frequency. This is just equivalent as the single resonant case. So the expected gain at 55MHz should coincides with what we already have. Probably, the resistance of 4 Ohm that is used here had too rough precision???

2. How can you adjust the resonances precisely?

Do we need any variable components for Cs and Ls, that may have worse quality than the fixed one, generally speaking.
I myself has no experience that I had to tune the commercial EOM because of a drift or whatever. I hope if you can adjust the resonance with a fixed component it should be fine.

3. Changing Cp. What does it mean?

Do you put additional cap for Cp?

4. The resonances for the lower two look very narrow. Is that fine?

This will show up in a better shape if we look at the transfer function for the gain. Is this right?

If we have BW>100kHz, it is sufficient.

5. Impedance matching for the lower two resonances.

Yep. You know this problem already. 

 

  3462   Tue Aug 24 11:23:32 2010 steveUpdatePEMtripod leg installation completed

Bertine Robby, Bertin and Jerry completed the installation by pouring concrete yesterday and cleaning up today.

Atm1-2, steel bars, grouted feet and side forms are ready

Atm3,    bounding agent is applied for better bounding

Atm4,    pumping concrete

Atm5,    shaker is used to fill-all

Atm6,    late after noon the forms- sides were removed,     NOTE: actual table to concrete distance is 12.75"

Atm7,    construction people left and the tile man is on the way

 

The tile patching should complete today so tomorrow we can remove plastic covers.

 

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  241   Wed Jan 16 14:09:45 2008 robUpdateLSCtuesday's locking

I got a little further with the locking (PRFPMI) last night, after discovering that the cable going from the CM board to the MC board was unplugged at the MC side. This explains why we weren't able to engage the AO path last night. Tonight, I got up to the point where DARM is handed off to OMC transmission, a step which repeatedly failed.
Eventually I realized that although all the lights are the green, the OMC Trans signal was not being updated in the LSC's memory. I suspect this is because the c1ass machine was powered down. Work continues.
  1463   Thu Apr 9 12:23:49 2009 peteUpdateLockingtuning ETM common mode

Pete, Yoichi

Last night, we put the IFO in FP Michelson configuration.  We took transfer functions of CARM and DARM, first using CM excitations directly on the ETMs, and then using modulations of the laser frequency via MC excitation.  We found that there was basically no coupling into DARM using the MC excitation, but that there was coherence in DARM using the ETM excitation.  Therefore, I tuned the ETM common mode in the output matrix.  I did this by taking transfer functions of PD1_Q with PD2_I (see attached plot).  I changed the  drdown_bang script to set C1:LSC-BTMTRX_14 0.98 and C1:LSC-BTMTRX_24 1.02.

Attachment 1: FPMI-DARM-CARM-ETM-fineScan.pdf
FPMI-DARM-CARM-ETM-fineScan.pdf
  13143   Tue Jul 25 14:04:06 2017 SteveUpdateVACturbo controller installed and we are running at vac normal

Gautam and Steve,

Spare Varian turbo-V 70 controller, Model 969-9505, sn 21612 was swapped in. It is running the turbo fine @ 50Krpm but it does not allow it's V4 valve to be opened............

It turns out that TP2 @ 75Krpm will allow V4 to open and close. This must be a software issue.

So Vacuum Normal is operational if TP2 is running 75,000 rpm

We want to run at 50,000 rpm on the long term.

Note: the RS232 Dsub connector on the back of this controller is mounted 180 degrees opposite than TP3  and old failed TP2 controller

 

PS: controller is shipping out for repair 7-28-2017

 

Attachment 1: TP2@75Krpm.png
TP2@75Krpm.png
  4461   Wed Mar 30 16:57:13 2011 kiwamuUpdateGeneralturned off c1aux

[Steve / Kiwamu]

 As a part of the video cable session, we reconnected some power cords on 1Y1 rack.

During the work we momentarily turned off c1aux, which handles DMF, Illumintators, mechanical shutters and the old video epics.

I think it automatically reverted the things, but we may need to check them.

  2479   Tue Jan 5 13:23:45 2010 AlbertoOmnistructureEnvironmentturning page

In the lab there are lots of old posters with outdated autocad drawings, or printouts with schematics of old electronics hanging on the walls.

Can we get rid of those and start giving the lab a fresh and modern look?

  7949   Mon Jan 28 21:32:38 2013 jamieUpdateAlignmenttweaking of alignment into half PRC

[Koji, Jamie]

We tweaked up the alignment of the half PRC a bit.  Koji started by looking at the REFL and POP DC powers as a function of TT2 and PRM alignment. 
He found that the reflected beam for good PRC transmission was not well overlapped at REFL.  When the beam was well overlapped at REFL, there was clipping in the REFL path on the AS table.

We started by getting good overlap at REFL, and then went to the AS table to tweak up all the beams on the REFL pds and cameras.
This made the unlocked REFL DC about 40 count. This was about 10mV (=0.2mA) at the REFL55 PD.
This amazed Koji since we found the REFL DC (of the day) of 160 as the maximum of the day for a particular combination of the PRM Pitch and TT2 Pitch. So something wrong could be somewhere.

We then moved to the ITMX table where we cleaned up the POP path.  We noticed that the lens in the POP path is a little slow, so the beam is too big on the POP PD and on the POP camera (and on the camera pick-off mirror as well)
We moved the currently unused POP55 and POP22/110 RFPDs out of the way so we could move the POP RF PD and camera back closer to the focus.  Things are better, but we still need to get a better focus, particularly on the POP PD.

We found two irides on the oplev path. They are too big and one of these is too close to the POP beam. Since it does not make sense too to have two irides in vicinity, we pulled out that one from the post.

Other things we noticed:

  • The POP beam is definitely clipping in the vacuum, looks like on two sides.
  • We can probably get better layout on the POP table, so we're not hitting mirrors at oblique angles and can get beams on grid paths.

After the alignment work on the tables, we started locking the cavity. We already saw the improvement of the POPDC power from 1000 cnt to 2500 cnt without any realignment.
Once PRM is tweaked a little (0.01ish for pitch and yaw), the maximum POPDC of 6000 was achieved. But still the POP camera shows non-gaussian shape of the beam and the Faraday camera shows bright
scattering of the beam. It seems that the scattering at the Faraday is not from the main beam but the halo leaking from the cavity (i.e. unlocking of the cavity made the scattering disappeared)


Tomorrow Jenne and I will go into BS to tweak the alignment of the TEMP PRC flat mirror, and into ITMX to see if we can clean up the POP path.

  2707   Wed Mar 24 04:22:51 2010 kiwamu, mattUpdateGreen Lockingtwo NPRO PLL

Now some pedestals, mirrors and lenses are left on the PSL table, since we are on the middle way to construct a PLL setup which employs two NPROs instead of use of PSL laser.

So Please Don't steal any of them.

  2710   Wed Mar 24 14:52:02 2010 AlbertoUpdateGreen Lockingtwo NPRO PLL

Quote:

Now some pedestals, mirrors and lenses are left on the PSL table, since we are on the middle way to construct a PLL setup which employs two NPROs instead of use of PSL laser.

So Please Don't steal any of them.

 Can I please get the network analyzer back?

  6857   Fri Jun 22 20:00:14 2012 JamieOmnistructureElectronicstwo RG-405 cables ran from 1X2 rack to control room

[Yaakov, Eric, Jenne, Yuta]

Two of our surfs, Yaakov and Eric, pulled two unused RG-405/SMA cables that had been running from 1X2 to (mysteriously) 1Y2 racks.  They left the 1X2 end where it was and pulled the 1Y2 end and rerouted it to the control room.  We labeled both ends appropriately.

The end at 1X2 is now plugged into a splitter that is combining the RF input monitor outputs for the X and Y beatbox channels, so that we can watch the beat signals with the HP8591 in the control room.

  4483   Fri Apr 1 23:49:24 2011 kiwamuSummaryGreen Lockingtwo states in green beat-note

According to the measurement done by Aidan and me, there are two beat-note state.

One gave us a small beat signal and the other gave us a bigger signal by approximately 20 dB.

 

 A possible reason for this phenomenon is that the end laser is operating at a special temperature that somehow drives the laser with two different modes at the same time.

So that it permits the laser sometimes locked with one of the two modes and sometimes with the other mode.

For the first step we will change the temperature such that the laser can run with a single stable mode.

Then for investigating it we will put a scanning cavity on the X end table to see if it really exhibits a two modes or not.

Quote from #4472

The attached table shows the amplitude of the green beat note when the end laser was in various states. We can increase the beat note amplitude dramatically by switching to a different states.

  10433   Wed Aug 27 18:03:47 2014 ericqUpdateGreen LockinguPDH Box Checkup

 Quick post of plots and data; I'll fill in more detail tonight. 

TL;DR: I pulled both green PDH boxes and made LISO models, compared TFs and noise levels. 


Pictures of X and Y boards, respectively

uPDH_X.JPGuPDH_Y.JPG

 


TF comparison to LISO. (Normalized to coincide at 1Hz)

updhTFs.pdf

 


Noise comparison to LISO

updhNoises.pdf

 


To Do:

  • Figure out why TFs were made differently. Check PM response curves of PZTs to see if they are fine, or need tweaking.
  • Make boosts useful. Both are currently integrators with corners under 10Hz, which is already pretty suppressed. 
  • I just noticed that the X board is missing C25, which should be a 1uF cap on the positive power pin of the primary TF stage opamp. This should be inserted. 

All data, EAGLE schematics, LISO source and plots in the attached zip. 

 

Attachment 5: uPDH_Aug27.zip
  10437   Thu Aug 28 17:34:20 2014 ericqUpdateGreen LockinguPDH Box Checkup

I had noticed in the past, that the digital control signal monitor for the X end would saturate well before the ADC should saturate (C1:ALS-X_SLOW_SERVO_IN1, which is from the "output mon" BNC on the box). It turns out that there is some odd saturation happening inside the box itself.

In this scope trace, the servo input is being driven with a 0.02Vpp, 0.1Hz sine wave, gain knob at 1.0. This is bad. 

TEK00006.PNG

Evan and I poked around the board, and discover that for some reason currently unknown to us, the variable gain amplifier (AD8336) can't reach its negative rail, despite the +-12V arriving safely at its power supply pins. 

I also realized that the LF356 in the integrator stage in this box had been replaced with a LT1792 by Kiwamu in ELOG 4373. I've updated my schematic, and will upload both boxes' schematics to the DCC page Jenne created for them. (D1400293 and D1400294)

  10438   Fri Aug 29 17:28:07 2014 ranaUpdateGreen LockinguPDH Box Checkup

 

 I've been having trouble locking the X - green for the past few hours. Has there been some configuration change down there that anyone knows about?

I'm thinking that perhaps I need to replace the SHG crystal or perhaps remove the PZT alignment mirrors perhaps. Another possibility is that the NPRO down there is going bad. I'll start swapping the Y-end NPRO for the X-end one and see if that makes things better.

  10439   Fri Aug 29 23:53:35 2014 ericqUpdateGreen LockinguPDH Box Checkup

I had pulled out both X and Y servo boxes for inspection, put the Y box back, soldered in a missing op amp power capacitor on the X end box, and had not yet put back the X end box yet because of the saturation issue I was looking into. Otherwise nothing was changed at the ends; I didn't open the tables at all, or touch laser/SHG settings, just unplugged the servo boxes. 

  10441   Tue Sep 2 20:02:06 2014 ericqUpdateGreen LockinguPDH Box Checkup

I narrowed down the saturation point in the X green PDH box to the preamp inside the AD8336, but there is still no clear answer as to why it's happening. 

As per Jenne's request, I put the X end PDH box back for tonight's work. It locks, but we have an artificially low actuation range. With SR785, I confirmed a PDH UGF around 5k. Higher than that, and I couldn't reliably measure the UGF due to SR560 saturations. The analyzer is not currently in the loop. 

Both arms lock to green, but I haven't looked at beatnotes today. 

  10443   Wed Sep 3 00:17:22 2014 ranaUpdateGreen LockinguPDH Box Checkup

What monitor point is being plotted here? Or is it a scope probe output?

If this saturation is in the uPDH-X but not in the uPDH-Y, then just replace the VGA chip. Because these things have fixed attenuation inside, they often can't go the rails even when the chip is new.

In any case, we need to make a fix to get this box on the air in a fixed state before tomorrow evening.

Quote:

I had noticed in the past, that the digital control signal monitor for the X end would saturate well before the ADC should saturate (C1:ALS-X_SLOW_SERVO_IN1, which is from the "output mon" BNC on the box). It turns out that there is some odd saturation happening inside the box itself.

In this scope trace, the servo input is being driven with a 0.02Vpp, 0.1Hz sine wave, gain knob at 1.0. This is bad. 

TEK00006.PNG

Evan and I poked around the board, and discover that for some reason currently unknown to us, the variable gain amplifier (AD8336) can't reach its negative rail, despite the +-12V arriving safely at its power supply pins. 

I also realized that the LF356 in the integrator stage in this box had been replaced with a LT1792 by Kiwamu in ELOG 4373. I've updated my schematic, and will upload both boxes' schematics to the DCC page Jenne created for them. (D1400293 and D1400294)

 

  10447   Wed Sep 3 20:38:40 2014 ericqUpdateGreen LockinguPDH Box Checkup

The traces were from the front panel output BNCs, but the VGA preamp exhibited this asymmetric saturation at its output.  

In any case, I tried to replace the Xend box's AD8336 with a new one, and in doing so, did some irreparable damage to the traces on the board  I was not able to get a new AD8336 into the board. There are some ATF ELOGs where Zach found the AD8336 noise to be bad at low frequencies (link), and its form factor is totally unsuitable for any design that may involve hand modification, since it doesn't even have legs, just tiny little pads. I suggest we never use it for anything in the future. 

Instead, I've hacked on a little daughter board with an OP27 as an inverting op-amp with the gain resistor on the front panel as its feedback resistor, which can swing from 0 to x20 gain (the old gain setting was around 15dB=~x6). I've checked out the TF and output noise, and they look ok. The board can output both rails as well. 

I don't really like this as a long term solution, but I didn't want to leave things in a totally broken state when I left for dinner. 

  10426   Fri Aug 22 18:00:08 2014 jamieOmnistructureCDSubuntu12 awgstream installed

I installed awgstream-2.16.14 in /ligo/apps/ubuntu12.  As with all the ubuntu12 "packages", you need to source the ubuntu12 ligoapps environment script:

controls@pianosa|~ > . /ligo/apps/ubuntu12/ligoapps-user-env.sh
controls@pianosa|~ > which awgstream
/ligo/apps/ubuntu12/awgstream-2.16.14/bin/awgstream
controls@pianosa|~ > 

I tested it on the SRM LSC filter bank.  In one terminal I opened the following camonitor on C1:SUS-SRM_LSC_OUTMON.  In another terminal I ran the following:

controls@pianosa|~ > seq 0 .1 16384  | awgstream C1:SUS-SRM_LSC_EXC 16384 -
Channel = C1:SUS-SRM_LSC_EXC
File    = -
Scale   =          1.000000
Start   = 1092790384.000000
controls@pianosa|~ > 

The camonitor output was:

controls@pianosa|~ > camonitor C1:SUS-SRM_LSC_OUTMON
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:44:50.997418 0  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:49.155525 218.8  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:49.393404 628.4  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:49.629822 935.6  
...
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:58.210810 15066.8  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:58.489501 15476.4  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:58.747095 15886  
C1:SUS-SRM_LSC_OUTMON          2014-08-22 17:52:59.011415 0 

In other words, it seems to work.

  10177   Thu Jul 10 17:33:26 2014 jamieOmnistructureComputer Scripts / Programsubuntu12 software installed, gds 2.16.3.2

Rana wanted the latest GDS installed (for newest DTT), so I made an ubuntu 12 install directory into which I installed

  • gds-2.16.3.2
  • root_v5.34.03

I installed this stuff in

/ligo/apps/ubuntu12

which is the "official" location for stuff compiled specifically for ubuntu12.

Given that the workstations are diverging in OS (some ubuntu10, some ubuntu12), we're going to have to start supporting different software packages for the different versions, thus the new ubuntu12 directory.  This will be a pain in the butt, and will certainly lead to different versions of things for different machines, different features, etc.  We should really try to keep things at the same OS.

In any event, if you want to enable the GDS on an ubuntu 12 machine, source the ubuntu12 ligoapps-user-env.sh file:

controls@ottavia|~ > . /ligo/apps/ubuntu12/ligoapps-user-env.sh

  9966   Fri May 16 20:55:18 2014 JamieFrogsloreun-full-screening Ubuntu windows with F11

Last week Rana and I struggled to figure out how to un-full-screen windows on the Ubuntu workstations that appeared to be stuck in some sort of full screen mode such that the "Titlebar" was not on the screen.  Nothing seemed to work.  We were in despair.

Well, there is now hope: it appears that this really is a "fullscreen" mode that can be activated by hitting F11.  It can therefore easily be undone by hitting F11 again.

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

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

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

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

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

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

Attachment 1: xasstune_150426.png
xasstune_150426.png
Attachment 2: xassnoise.pdf
xassnoise.pdf
  11255   Sun Apr 26 15:05:35 2015 JenneUpdateASCunBroken Xass?

Thank you both.

I have updated the .snap file, so that it'll use these parameters, as Rana left them.  Also, so that the "unfreeze" script works without changes (since it wants to make the overall gain 1), I have changed the Xarm input matrix elements from 1 to 0.1, for all of them.  This should be equivalent to the overall gain being 0.1.

  6571   Thu Apr 26 09:22:17 2012 steveUpdate under the east end optical table

Quote:

I added an U channel based bottom shelf at the south end today.

 I'm working on similar shelf at ETMY.  Precondition: NPRO in bypass mode, heater for doubling in bypass........since power outage?  Optical level servo turned off.......

U-channel based shelf in place.  Oplev servo is back on at 11:15am    The table may moved.  The oplev return is missing the quad by a few milimeter.

  6282   Wed Feb 15 11:34:01 2012 steveUpdate under the shouth end optical table

I added an U channel based bottom shelf at the south end today.

Attachment 1: P1080535.JPG
P1080535.JPG
Attachment 2: P1080537.JPG
P1080537.JPG
  1654   Fri Jun 5 01:10:13 2009 rob, peteUpdateLockingundermined

We were stymied early in the evening by a surreptitiously placed, verbo-visually obfuscated command in the drstep script. 

  13171   Tue Aug 8 17:04:26 2017 SteveUpdateVACunintended pump down

IFO pressure 2 Torr,    PSL  shutter closed.  I'm pumping down with 2 roughing pumps with ion pump gate valves open and annulosses at atm.

The vacuum envelope was vented to 17 Torr while I was replacing the USP battery stack. More about this later.....

Do not plan on using the interferrometer tonight.  I will complete the pumpdown tomorrow morning.

 

Attachment 1: pumping_down.png
pumping_down.png
  13172   Tue Aug 8 17:44:11 2017 SteveUpdateVACunintended pump down

Pumpdown stopped for over night  at ~  1 Torr

The roughing line disconnected.  Valves condition indicator  "moving " means that it is closed and it's cable disconnected so it can not move.

The RGA is off and VM1 is stuck.

Quote:

IFO pressure 2 Torr,    PSL  shutter closed.  I'm pumping down with 2 roughing pumps with ion pump gate valves open and annulosses at atm.

The vacuum envelope was vented to 17 Torr while I was replacing the USP battery stack. More about this later.....

Do not plan on using the interferrometer tonight.  I will complete the pumpdown tomorrow morning.

 

 

Attachment 1: stopped_pumping.png
stopped_pumping.png
  13175   Wed Aug 9 11:59:51 2017 SteveUpdateVACunintended pump down at vacuum normal

pd80b has reached Vac Normal. IFO pressure 0.5 mTorr

We need our vauum channels back in dataviewer.

Quote:

Pumpdown stopped for over night  at ~  1 Torr

The roughing line disconnected.  Valves condition indicator  "moving " means that it is closed and it's cable disconnected so it can not move.

The RGA is off and VM1 is stuck.

Quote:

IFO pressure 2 Torr,    PSL  shutter closed.  I'm pumping down with 2 roughing pumps with ion pump gate valves open and annulosses at atm.

The vacuum envelope was vented to 17 Torr while I was replacing the USP battery stack. More about this later.....

Do not plan on using the interferrometer tonight.  I will complete the pumpdown tomorrow morning.

 

 

 

Attachment 1: pdc.png
pdc.png
Attachment 2: pd80b@vacnormal.png
pd80b@vacnormal.png
  11429   Sat Jul 18 16:59:01 2015 jamieUpdateCDSunloaded, turned off loading of, symmetricom kernel module on fb

fb has been loading a 'symmetricom' kernel module, presumably because it was once being used to help with timing.  It's no longer needed, so I unloaded it and commented out the lines that loaded it in /etc/conf.d/local.start.

  1585   Thu May 14 02:36:05 2009 peteUpdateLockingunstable IFO

It seems that the MC3 problem is intermittent (one-day trend attached).  I tried to take advantage of a "clean MC3" night, but the watch script would usually fail at the transition to DC CARM and DARM.  It got past this twice and then failed later, during powering up.   I need to check the handoff.

 

Attachment 1: mc3.jpg
mc3.jpg
  14805   Wed Jul 24 12:24:43 2019 MilindUpdateIOOunstick.py and ifotest

Moved the unstick.py code to the ifotest repository here. It now handles signals like those generated by Ctrl-C and so forth. It can still be run as python unstick.py <machine1> <machine2> etc.

  1955   Thu Aug 27 12:34:48 2009 YoichiUpdateLockingup to arm power 70
Last night, I tried to run locking scripts.
The power went up to 70 a couple of times .
Then it failed to switch to RF CARM.
I was too tired at that time to figure out what is the problem with the switching.
But it seemed to me that the problem could be solved by some gain tweaking.
Looks like the IFO is back to a good state.
  12358   Sun Jul 31 17:28:38 2016 ranaOmnistructureGeneralupclean

I cleaned up the south Electronics bench today.

The other two, as well as several of the desks are in some chaotic state of degradationno. Please clean up your areas and put away projects which do not need to remain staged for several months. Try to eliminate "that's not mine" and "I don't know who's that is" from your vocabulary.  angry Fight back against entropy!

  6286   Thu Feb 16 04:29:30 2012 kiwamuUpdateLSCupconversion noise from BS motion

Sometimes ago I reported that there have been a kind of upconversion noise when PRM was excited (#6211).

This time I found another one, which showed up when BS was excited.

Assuming this is related to some kind of scattering process and also assuming this is from the same scattering body as that for the PRM driven case,

we may be able to localize and perhaps identify the scattering body.

 

 

(Measurement Condition)

All the suspended optics are intentionally misaligned except for ITMY so that the laser directly goes through to the dark port without any interference.
Then BS_POS is excited at 3 Hz with amplitude of 1000 counts by an oscillator in the realtime lockin system.
 I also excited PITCH and YAW of BS and found that driving the angular motions didn't produce any upconversion noise.
 I didn't excite ITMY to do the same test because I was too lazy.

(Noise spectrum)

The plot below shows the upconversion noise observed at AS55 and REFL11.
The reference curves were obtained when no excitation were applied on BS_POS.
It is obvious that the AS55 signal shows a typical upconversion behavior.
 
Untitled.png

 

  3556   Fri Sep 10 02:35:30 2010 rana, kiwamu, valera, taraConfigurationPSLupdate

Over the last couple nights we got the beam into the FSS path and all the way to the IMC and out onto the AP table.

Tara and Valera have calculated a mode-matching solution for the reference cavity. It utilizes only a single lens between the AOM and the reference cavity. Valera and Steve will move the reference cavity into place in the morning.

We noticed that the layout was too tight on the end going into the MC and so we adjusted the angle of the final zig-zag. This will put the final mode-matching lens in between the final steering mirrors (which is generally undesirable) but the lens in this case is only f=400 mm. In addition, this lens may provide some more decoupling between the steering mirrors.

The whole layout has to be a little adjusted because of a calculation mistake I made in the mode-matching. I used only the nominal focal lengths from the CVI catalog and not the effective one. For the UV-grade fused silica lenses, the effective focal length is actually 20-30% longer. Today we measured that the "f=200 mm" lens we got is actually f = 238 mm. The BK7 lenses are much closer to the nominal.

We also replaced the Klinger mount ahead of the PMC with a Polanski style so that we could get the PMC REFL beam out without hitting the mount. Valera will continue to refine this section on the weekend.

Tomorrow, we will lock the MC using feedback only to the NPRO. The 0-150 V piezo driver is on the PSL table ready for action.

I also got a LCD video monitor from Frank and hooked it up on the PSL table. If we like this kind of thing, we can get many of them. They are pretty cheap. It would be handy to have 3-4 of them on the PSL and one on every of the ISC tables. They take the standard video for input and need +12V for power. Right now the one in there is looking at the PMC transmission.

The Omnigraffle layout as of tonight is attached.

Attachment 1: 40mPSL.pdf
40mPSL.pdf
  3544   Wed Sep 8 11:46:53 2010 kiwamuUpdatePSLupdate of the layout

I put some green stuff on the layout drawing.

I continue to refine the positions of these stuff.

 

Notes :

 1. I flipped the reference cavity. So now the cavity is sitting on the left hand side of the layout.

  2. I removed the ISS stuf. We should think about where ISS should be.

Quote:

Also, Kiwamu has modified the layout drawing to add the green PLL stuff. This has collapsed the reference cavity's wave function placing it close to its original position.

WE (maybe Valera and Steve) can now put the reference cavity back on the table.

 

Attachment 1: 40mPSL.png
40mPSL.png
  6303   Wed Feb 22 01:53:57 2012 kiwamuUpdateLSCupdate on glitch table

I tried SRMI. The glitch rate wasn't as high as that of PRMI but it happened once per 10 sec or so.

 

 

 Yarm

(POY11 -->

ETMY)

Xarm

(POX11 --> ETMX)

MICH

(AS55-->BS)

or

(AS55 --> ITMs)

Half PRMI

(REFL11 --> PRM)

or

(REFL33 --> PRM)

low finesse PRMI

(ASDC --> ITMs)

(REFL33 --> PRM)

PRMI (carrier)

(AS55 --> ITMs)

(REFL33 --> PRM)

PRMI (sideband)

(AS55 --> ITMs)

(REFL33 --> PRM)

SRMI(NEW)

(AS55-->ITMs)

(REFL11I --> SRM)

DRMI
AS55 NO NO NO NO glitch (depends on finesse)
glitch glitch glitch glitch
REFL11 NO NO NO NO glitch (depends on finesse)
glitch glitch glitch glitch
REFL33 NO NO NO NO - glitch glitch glitch glitch
REFL55 NO NO NO NO glitch(depends on finesse) glitch glitch glitch glitch
REFL165 NO NO NO - - - - - -
POX11 - NO NO NO  - glitch glitch - glitch
POY11 NO - NO NO  - glitch glitch - glitch
POP55 - - - -  -  - -   -
                   

 

Quote from #6284

I updated the table which I posted some time ago (#6231). The latest table is shown below.

It seems that the glitches show up only when multiple DOFs are locked.

 

  6386   Thu Mar 8 04:13:12 2012 kiwamuUpdateLSCupdate on the locking activity

[Keiko / Kiwamu]

 Some updates on the locking activity:

  • Started summarizing the data of the Michelson lock in a wiki page:
  • Gradually moving on to the PRMI lock
    • The lock stays for reasonably a long time (~20 min or more)
    • POP22/110 demod signals seemed just ADC noise.
    • A first noise budget is in process
      • The glitches make the noise level worse above 40 Hz or so in both the MICH and PRCL budgets.
    • Sensing matrix will be measured tomorrow
    • The data will be also summarized in a wiki page
  6393   Fri Mar 9 13:34:13 2012 keikoUpdateLSCupdate on the locking activity

We tried to measure the sensing matrix for MICH and PRCL last night. They look too much mixed as we expect... the matrix may be posted later. We suspect the IX and IY of the MICH excitation is not balanced very well, although Kiwamu adjusted that about two weeks ago, and it is mixing the dof. We'll try to balance it again, ans see the matrix. 

Keiko, Kiwamu

 

Quote:

[Keiko / Kiwamu]

 Some updates on the locking activity:

  • Started summarizing the data of the Michelson lock in a wiki page:
  • Gradually moving on to the PRMI lock
    • The lock stays for reasonably a long time (~20 min or more)
    • POP22/110 demod signals seemed just ADC noise.
    • A first noise budget is in process
      • The glitches make the noise level worse above 40 Hz or so in both the MICH and PRCL budgets.
    • Sensing matrix will be measured tomorrow
    • The data will be also summarized in a wiki page

 

  6398   Sat Mar 10 02:00:03 2012 keikoUpdateLSCupdate on the locking activity

ITMX and ITMY balance for the MICH excitation (lockin) is adjusted again. Now it's ITMx = -0.992, ITMy = 1 for MICH (lockin output matrix values).

RA: what were the old values? Does this change make any difference for the signal mixing noticed before?

  3254   Tue Jul 20 23:52:36 2010 kiwamuUpdateVACupdate: slow vent has started

The vent is still going on. At this moment the pressure inside of the chambers is about 630 Torr.

Koji and I have replaced the 2nd instrument grade compressed air cylinder by the 3rd cylinder around 9 pm.

So far the vent speed has been nicely kept at about 1 Torr / min.

Attachment 1: untitled.png
untitled.png
  9897   Fri May 2 01:58:52 2014 ranaConfigurationComputer Scripts / ProgramsupdateDB configured to index NFS during CRON daily

I wanted to use locate to find some files today, but found that it doesn't index any of our NFS mounted files (i.e. the whole /cvs/cds/ and /opt/rtcds/ ).

So I went into /etc/updatedb.conf and edited it like so, so that it no longer ignores NFS type file systems:

controls@rossa:/etc 0$ diff updatedb.conf updatedb.conf~
4c4
< PRUNEFS="nfs4 rpc_pipefs afs binfmt_misc proc smbfs autofs iso9660 ncpfs coda devpts ftpfs devfs mfs shfs sysfs cifs lustre_lite tmpfs usbfs udf fuse.glusterfs fuse.sshfs ecryptfs fusesmb devtmpfs"
---
> PRUNEFS="NFS nfs nfs4 rpc_pipefs afs binfmt_misc proc smbfs autofs iso9660 ncpfs coda devpts ftpfs devfs mfs shfs sysfs cifs lustre_lite tmpfs usbfs udf fuse.glusterfs fuse.sshfs ecryptfs fusesmb devtmpfs"

The CRON.daily on ROSSA only should run each morning at 6:25 (under the ionice class 3 protocol as usual). If this seems OK after a week or so, we can do the same for the other CDS workstations (remembering to adjust their cron.daily times so that not every one hammers the NFS at the same time).

  8398   Wed Apr 3 01:32:04 2013 JenneUpdateComputersupdated EPICS database (channels selected for saving)

I modified /opt/rtcds/caltech/c1/chans/daq/C0EDCU.ini to include the C1:LSC-DegreeOfFreedom_TRIG_MON channels.  These are the same channel that cause the LSC screen trigger indicators to light up. 

I vaguely followed Koji's directions in elog 5991, although I didn't add new grecords, since these channels are already included in the .db file as a result of EpicsOut blocks in the simulink model.  So really, I only did Step 2.  I still need to restart the framebuilder, but locking (attempt at locking) is happening.

The idea here is that we should be able to search through this channel, and when we get a trigger, we can go back and plot useful signals (PDs, error signals, cotrol signals,....), and try to figure out why we're losing lock. 

Rana tells me that this is similar to an old LockAcq script that would run DTT and get data.

EDIT:  I restarted the daqd on the fb, and I now see the channel in dataviewer, but I can only get live data, no past data, even though it says that it is (16,float).  Here's what Dataviewer is telling me:

Connecting to NDS Server fb (TCP port 8088)
Connecting.... done
read(); errno=0
LONG: DataRead = -1
No data found

read(); errno=9
read(); errno=9
T0=13-03-29-08-59-43; Length=432010 (s)
No data output.

 

  8400   Wed Apr 3 14:45:34 2013 JamieUpdateComputersupdated EPICS database (channels selected for saving)

Quote:

I modified /opt/rtcds/caltech/c1/chans/daq/C0EDCU.ini to include the C1:LSC-DegreeOfFreedom_TRIG_MON channels.  These are the same channel that cause the LSC screen trigger indicators to light up. 

I vaguely followed Koji's directions in elog 5991, although I didn't add new grecords, since these channels are already included in the .db file as a result of EpicsOut blocks in the simulink model.  So really, I only did Step 2.  I still need to restart the framebuilder, but locking (attempt at locking) is happening.

The idea here is that we should be able to search through this channel, and when we get a trigger, we can go back and plot useful signals (PDs, error signals, cotrol signals,....), and try to figure out why we're losing lock. 

Rana tells me that this is similar to an old LockAcq script that would run DTT and get data.

EDIT:  I restarted the daqd on the fb, and I now see the channel in dataviewer, but I can only get live data, no past data, even though it says that it is (16,float).  Here's what Dataviewer is telling me:

Connecting to NDS Server fb (TCP port 8088)
Connecting.... done
read(); errno=0
LONG: DataRead = -1
No data found

read(); errno=9
read(); errno=9
T0=13-03-29-08-59-43; Length=432010 (s)
No data output.
 

I seem to be able to retrieve these channels ok from the past:

controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ tconvert 1049050000
Apr 03 2013 18:46:24 UTC
controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ ./general/getdata -s 1049050000 -d 10 --noplot C1:LSC-PRCL_TRIG_MON
Connecting to server fb:8088 ...
nds_logging_init: Entrynds_logging_init: Exit
fetching... 1049050000.0
Hit any key to exit: 
controls@pianosa:/opt/rtcds/caltech/c1/scripts 0$ 

Maybe DTT just needed to be reloaded/restarted?

ELOG V3.1.3-