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 Type Category Subjectup
  481   Thu May 15 16:24:18 2008 josephbSummaryCameras 
The GC750 camera is currently looking at a very small pickoff of the PSL output (transmission of a Y1-1037-45-S mirror). The plan is to take images tomorrow with it and the GC650 from the same spot and do comparisons.

For those interested, the camera can be run with two codes, from mafalda. Use ssh -X mafalda to login, to allow the live stream to work with the SampleViewer code. The codes can be found in:

/cvs/cds/caltech/target/Prosilica/40mCode/Snap

and

/cvs/cds/caltech/target/Prosilica/bin-pc/x86/SampleViewer

Type Snap --help for a list of options for that program. Click the circle looking thing in SampleViewer to start the live stream. Note only 1 of the two programs can be running at a time, and the only way to change settings (such as exposure length) is with Snap at the moment.
  492   Thu May 22 11:25:19 2008 josephbConfigurationComputers 
One of the new Netgear Prosafe 24 port switches was mounted in the 1X4 rack,, roughly in the middle, away from the top and bottom rack mounted electronics. At the moment, its IP has been set to 131.215.113.250, gateway 131.215.113.2 (which is what I saw as the only listed gateway on linux1 using route -n) and mask 255.255.255.0.

I'm planning to set the next three IP address for the switches as *.251, *.252 and *.253, which don't look to have been used yet.
  582   Fri Jun 27 14:36:39 2008 JohnSummaryLocking 
Rob, Yoichi, John

Some progress last night:

Switched back to SPOB_DC for CARM.

Shaped the MC LSC loop to reduce excess noise in the 20-30Hz band. Likely the most significant change.
Could this be due to fan noise from the laptop on the SPOB table?

Brought in the AO path earlier (at low gain).

Reduced offset to 6 and increased MC gain before handing off to SPOB. Ramped up AO and MC gain then switched off the
moving zero.

Looks like PD11 is the most promising candidate for RF CARM although the demod phase needs attention.
  606   Mon Jun 30 16:00:02 2008 josephb, samConfigurationComputers 
Sam and I setup Cat6 cable from Megatron to the 1Y6 Switch (131.215.113.252) and also connected the 1Y6 Hub to the control room switch.

While I was at it, I checked the configurations of the two switchs now connected (one in 1X4 and one in 1Y6) to the martian network. For some reason, the 1X4 had switched to DHCP enabled and was using 131.215.113.105 as an IP address. I had thought I had setup it correctly initially, so am not sure what caused the change.

The easiest way I know of to check the setup is use smartwizard discovery program from the Netgear install CD (in the equipment manual file cabinet of the control room) on a windows machine. The passwords have been set to the controls password.

Megatron should now see and be accessible through the martian network.
  824   Mon Aug 11 13:59:23 2008 josephbConfigurationComputers 
While poking around the crate, I noticed an error light on one of the c1susvme2 related boards was lit, while the corresponding light on the c1susvme1 was not. This confuses me as the c1susvme1 is the one having problems.

As a quick sanity check, I unplugged the ethernet connection from the c1susvme1 labeled board, and confirmed I couldn't log into it, and then plugged it back in, restarted it, and re-ran the startup script. This time c1susvme1 seemed to come up fine. Re-enabling the watchdogs doesn't seem to kick anything, and in fact seems to be bringing everything into line properly.

Although the error light on the c1susvme2 clk drvr board is still on. So I'm not sure what thats trying to tell us. Open to suggestions.
  992   Thu Sep 25 14:03:08 2008 josephbConfigurationComputers 

Quote:

We (Joe) need to buy a GigE card for linux1 and to also set up conlog and conlogger to run on Nodus.


A spare Intel Pro 1000/GT desktop adapter (gigabit ethernet card) has been added to Linux1 and is now using that card to connect to the network.

This was after a slight scare when I somehow reset the bios on Linux1 during the first reboot after adding the card.
After some debugging and discussion with Yoichi, the bios was fixed and the computer works again, with its new faster network connection.

Although we both noted that Linux1 is a rather old machine, with only half a gig of Ram and reaching about 80% capacity on its 58 gigabyte hard drive (raid). Might be worth upgrading in general.

Need to figure out how to install conlog/conlogger programs next...
  1253   Mon Jan 26 14:51:54 2009 josephbConfigurationVAC 
We need a new RS-232 to Ethernet bridge in order to interface properly with the new RGA. The RGA has a fixed baud rate of 28.8k, and the current bridge (which used to work with the old RGA) doesn't have that baud rate as an option. Currently looking into purchasing a new bridge, and trying to make sure it can meet the communications requirements of the RGA.
  1385   Wed Mar 11 11:30:15 2009 josephbConfigurationCameras 

I modified the Video.db file used by c1aux located in  /cvs/cds/caltech/target/c1aux.

I added the following channels to the db file, intended for either read in or read out by the digital camera scripts.

C1:VID-ETMY_X_COM
C1:VID-ETMY_Y_COM

C1:VID-ETMY_X_STDEV

C1:VID-ETMY_Y_STDEV

C1:VID-ETMY_XY_COVAR

C1:VID-ETMY_EXPOSURE

C1:VID-ETMY_GAIN

C1:VID-ETMY_X_UL

C1:VID-ETMY_Y_UL

C1:VID_ETMY_X_SIZE

C1:VID_ETMY_Y_SIZE

A better naming scheme can probably be devised, but these will do for now.

  2832   Thu Apr 22 15:44:34 2010 josephbUpdateComputers 

I updated the default FILTER.adl file located in /home/controls/cds/advLigo/src/epics/util/ on megatron.  I moved the yellow ! button up slightly, and fixed the time string in the upper right.

  3165   Wed Jul 7 11:23:08 2010 Sharmila, KatharineUpdateWIKI-40M Update 

Weekly Update:

Last Weds-Thurs, we wrote and edited our progress reports.

Tuesday (and Weds morning):  Continued circuit analysis of Haixing's circuit and plotting transfer functions (almost have one for entire circuit).  Hooked up OSEM and circuit to power supply, but the LED didn't appear to light up in IR.  Now we are going to hook the OSEM directly to the power supply, sans circuit, to see if the problem is with the circuit or OSEM.

  3181   Thu Jul 8 17:29:20 2010 Katharine, SharmilaUpdateelog 


Last night, we successfully connected and powered our circuit, which allowed us to test whether our OSEMs were working.  Previously, we had been unable to accomplish this because (1) we weren't driving it sufficiently high voltage, and  (2) we didn't check that the colored leads on our circuit actually corresponded to the colored ports on the power supply (they were all switched, which we are in the process of rectifying), so our circuit was improperly connected to the supply .  Unfortunately, we didn't learn this until after nearly cooking our circuit, but luckily there appears to have been no permanent damage .

Our circuit specs suggested powering it with a voltage difference of 48V, so we needed to run our circuit at a difference of at least 36-40 V.  Since our power supply only supplied a difference of up to 30V in each terminal, we combined them in order to produce a voltage of up to double that.  We decided to power our circuit with a voltage difference of 40V (+/- 20V referenced to true ground).  The current at the terminals were 0.06 and 0.13 A. 

To test our circuit, we used a multimeter to check the supplied voltage at different test points, to confirm that an appropriate input bias was given to various circuit elements.  We identified the direction of LED bias on our OSEM, and connected it to our circuit. We were extremely gratified when we looked through the IR viewer and saw that, in fact, the LED in the OSEM was glowing happily .

P7070240.JPG P7070242.JPG

We hooked up two oscilloscopes and measured the current through the coil, and also through the LED and photodiode in the OSEM.  We observed a change in the photodiode signal when we blocked the LED light, which was expected.  The signal at the PD and the LED were both sinusoidal waves around ~3 kHz.

P7070255.JPG 

P7070257.JPG

 

We then went back to our levitation setup, and crudely tried to levitate a magnet with attached flag by using our hands and adjusting the gain (though we also could have been watching the PD current).  The first flag we tried was a soldering tip; we couldn't levitate this but achieved an interesting sort of baby-step "levitation" (levitation .15) which allowed us to balance the conical flag on its tip on top of the OSEM (stable to small disturbances).  After learning that conical flags are a poor idea, we switched our flag to a smaller-radius cylindrical magnet.  We were much closer to levitating this magnet, but were unable to conclusively levitate it .

 P7070249.JPG
Current plan:

Adjust the preset resistors to stabilize feedback

Check LED drive circuit.

Finish calculating the transfer function, and hook up the circuit to the spectrum analyzer to measure it as well.

Observe the signal from the photocurrent as disturbances block the LED light.

Play with the gain of the feedback to see how it affects levitation.

 

  3214   Wed Jul 14 11:32:36 2010 Sharmila, KatharineUpdateWIKI-40M Update 

Weekly update:

We correctly connected our circuit to power source to verify that it was functional and that our LED in the shadow sensor turned on.  It did, but we also noticed a funky signal from the LED driver.  We continued to attempt 1x1 levitation, but determined that the temporary flag we were using out of convenience (a long, thin cylindrical magnet) was weakly attracted to residually magnetized OSEM components.  We then switched to an aluminum screw as our flag.

We resoldered and applied heat shrink to the wires connecting our coil to the BNC terminal, since they were falling apart.

We sat down with Rana and removed circuit components in the LED drive part by part to determine what was tripping up the circuit.  We determined a rogue capacitor to be at fault and removed it from the circuit.

We used a spectrum analyzer to measure the frequency response of our circuit (see details in last elog).  We are currently making a Simulink block diagram so we can check the stability of our setup, but are temporarily set back because our plotted calculation of the transfer function clearly doesn't match the measured one.

  3309   Wed Jul 28 13:06:47 2010 RazibUpdatePhase Camera 

Attached are some calculation that I did previously for the phasecamera setup. This shows the nature of the beat signal that we are measuring.

I am also trying to characterize the noise source of the camera also. Following images shows the mean dark noise (with no light on the camera) and the standard deviation for 100 snaps at an exposure time of 500 µs.

mean_100_snaps.pngstd_100_snaps.png

My target now is to measure the response gain of each pixel and how they vary over intensity. I already have a simplified setup on the table and will work on it today. Details will follow at the end of the day.

  3577   Wed Sep 15 16:00:26 2010 koji, steveUpdateMOPA 

We removed the Lightwave MOPA Controller from 1X1 (south)  It was a real painfully messy job to pull out the umbilical.

Note: the umbilical is shading it plastic cover. It is functional but it has to be taken out side and cleaned. Do not remove it from it's plastic bag in a clean environment.

Now Joe has room for IOO chassy  in this rack.

We also removed the Minco temp controller and ref. cavity ion pump power supply.

 

  4033   Thu Dec 9 01:14:42 2010 OsamuUpdateSUS 

After Kiwamu had set the free swinging mode for ITMX and ETMX, I found a big jump of ITMX pitch and yaw. This jump is shown on oplev and OSEM plots.

20101208_ITMX_jump2.png

I talked with Kiwamu on the phone that a shutdown of suspensions does not add a big offset, and so that it should not make a big jump.

We were not sure that this jump was due to the shutdown or drift or something else. Anyway I put ITMY oplev on center again at 0;57am.

  4035   Thu Dec 9 11:13:37 2010 OsamuUpdateSUS 

Quote:

After Kiwamu had set the free swinging mode for ITMX and ETMX, I found a big jump of ITMX pitch and yaw. This jump is shown on oplev and OSEM plots.

20101208_ITMX_jump2.png

I talked with Kiwamu on the phone that a shutdown of suspensions does not add a big offset, and so that it should not make a big jump.

We were not sure that this jump was due to the shutdown or drift or something else. Anyway I put ITMY oplev on center again at 0;57am.

In this morning, the same thing happened but to opposit direction when Kiwamu activated ITMX and ETMX. Then it turned out that 1000ct offset was existing on pit of ITMX. Erasing the offset fixed ITMX to normal position.

However a big drift exists in 11hours plot on ITMX 0.1->-0.25 at OLPIT, -580->-605 at SUSPIT and 0.08->0.15 at OLYAW, no significan drift at SUSYAW. On the other hand, ETMX has no big drift but has 10-30minites order fluctuations.

After 6am both the drift and the fluctuation became, roughly saying, 10 times larger, probably due to the human activity.

 

jump_oplev_offset.png

  6016   Sat Nov 26 07:22:20 2011 sureshUpdateComputers 

c1sus has been shutdown so that the optics dont bang around.  This is because the watch dogs are not working.

  8905   Tue Jul 23 13:29:58 2013 KojiSummaryGeneral 

record of the initial state

  9805   Sun Apr 13 13:03:34 2014 ranaUpdateLSC 

That's a very smooth DARM transition - its good news that the dALS signals don't have a huge offset w.r.t the real error signal.

It would be interesting to see if the MICH can be locked and stay locked which CARM is ramped in. We would want to hold it with the Q phase of the CARM PD once its on.

May not be a milestone, but its cool anyway. 

+2 points.

Will also be cool to see how soon the CM servo can be switched on in the acquisition sequence. Maybe ALS_COMM -> CM board, gets mixed with TRXY for low frequencies in the intermediate stage before final RF?

  13460   Fri Dec 1 17:09:29 2017 Udit KhandelwalSummaryGeneral 

Current objectives and statuses:

  • CAD Model of 40m lab (facility, chambers, invacuum components etc)
    • Status: On hold since I'm unable to acquire general dimensions of 
  13928   Thu Jun 7 20:19:53 2018 poojaUpdate  

Just to inform, I'm working in optimus to develop python code to train the neural network since it requires a lot of memory.

  14040   Thu Jul 5 17:58:04 2018 keerthana, sandrineUpdateelog 

(Analisa, Sandrine, Keerthana)

Today Annalisa helped us to understand the new set up used to make the frequency scans of the AUX laser. While tracking the cables it seemed that there were quite a lot of cables near the mixer. So we have reconnected one of the splitter which was splitting the RF out put signal from the Agilent and have placed it just near the Agilent itself. A picture of the changed setup is provided below. The splitter divides the signal into two components. One goes to the LO port of the mixer and the other goes to the R port of the Agilent. We have tried locking the PLL after the change and it works fine. We are trying to make a diagram of the setup now, which we will upload shortly.

 

  14420   Tue Jan 29 16:12:21 2019 ChubUpdate  

The foam in the cable tray wall passage had been falling on the floor in little bite-sized pieces, so I investigated and found a fiber cable that had be chewed/clawed through.  I didn't find any droppings anywhere in the 40m, but I decided to bait an un-set trap and see if we'd find activity around it. There has been none so far.  If there is still none tomorrow, I will move the trap and keep looking for signs of rodentia.  At the moment, the trap is in a box in front of the double doors at the north end of the control room.  Next it will be place in the IFO room, up in the cable tray. 

gautam: the fiber that was damaged was the one from the LSC rack FiBox to the control room FiBox. So no DAFI action for a bit...

  14505   Mon Apr 1 12:01:52 2019 JonUpdateCDS 

I brought c1susaux back online this morning for suspension-channel test scripting. It had been dead for some time. I followed the procedure outlined in #12542. ITMY became stuck during this process, which Gautam tells me always happens since the last vacuum access, but ITMX is not stuck.

  14825   Fri Aug 2 17:07:33 2019 yehonathan, gautamUpdateLoss Measurement 

We run a loss measurement on the Y arm with 50 repetitions.

  14827   Mon Aug 5 14:47:36 2019 yehonathanUpdateLoss Measurement 

Summary:

I analyze the 100 reps loss measurement of the Y arm using the AnalyzeLossData.ipynb notebook.

The mean of the measured loss is ~ 100ppm and the variation between the repititions is ~ 27%.

 

In Detail

In the real measurement the misaligned and locked states are repeatedly switched between each other. I plot the misaligned and locked PD readings seperately over time.

There seems to be a drift that is correlated between the two readings. This is probably a drift in the power after the MC2. To verify, I plot the ratio between those readings and find no apparent drift:

The variation in the ratio is less than 1%. The loss figure, computed to be 1 minus this ratio times a big number, give a much worse variation. I plot the histogram of the loss figure at each repitition (excluding extremely bad measurements):

The mean is ~ 100ppm. And the variation is ~ 27%.

  14830   Mon Aug 5 17:36:04 2019 yehonathanUpdateLoss Measurement 

We check for unexpected drifts in the PD reading (clipping and such). We put a pickoff mirror where the PD used to be and place the PD at the edge of the table such that the beam is focused on it (see attachment).

The arms are completley misaligned. We note the time of start of measurement to be 1249086917.

  14834   Tue Aug 6 16:44:50 2019 yehonathanUpdateLoss Measurement 

I grab 2 hours of the PD measurements using dlData_simple.ipynb in the misaligned state.

I get pretty much a normally distributed reading without drifts (Attachements 1 and 2).

The error in the reading is ~ 0.5%.

 

I am pretty sure this amount of noise is enough to explain the big noise in the Loss figure measurement.

 

The reason is that the loss formula is #(1-P_Locked/P_Misaligned+T1)-T2) where T1 and T2 are the transmissions of the ITM and ETM.

The average of the ratio P_Locked/P_Misaligned is ~ 1.01 for a loss figure of ~ 100ppm.

The standard deviation of the ratio is ~ 1% which is also the standard deviation of the expression in the brackets.

The average of this experssion however is ~ 0.01.

The reduction of the mean amplifies the error in the loss measurments by a factor of a few 10s!

  15223   Tue Feb 25 16:17:57 2020 Gautam, HangUpdateCDS 

Seems that the GPS is out of sync on donatella. We could not get any data from diaggui...

  15262   Tue Mar 10 14:30:16 2020 yehonathanUpdateSUS 

ETMX was grossly misaligned.

I re-aligned it and the X arm now locks.

7:00PM with Koji

Both the alignment of the X and Y arms was recovered.

~>z avg 10 C1:LSC-TRX_OUT C1:LSC-TRY_OUT
C1:LSC-TRX_OUT 0.9914034307003021
C1:LSC-TRY_OUT 0.9690877735614777

We are running ass for the X arm to recover the X arm alignment.

Meanwhile, i want to block the Y arm trans PD (Thorlabs). To do it, the PD<->QPD thresholds were changed from 5.0/3.0 to 0.5/0.3.

  15263   Tue Mar 10 19:58:16 2020 yehonathanUpdateSUS 

I returned the triggering threshold to normal values (5/3).

Meanwhile, i want to block the Y arm trans PD (Thorlabs). To do it, the PD<->QPD thresholds were changed from 5.0/3.0 to 0.5/0.3.

  15919   Mon Mar 15 08:55:45 2021 Paco, AnchalSummarytraining 

[Paco, Anchal]

  • Found IMC locked upon arrival.
  • Since "allegra" was set up as an additional workstation, we tried using it but discovered the monitor ist kaput. For the sake of debugging, we tested VGA and DVI inputs and even the monitor lying around (also labeled "allegra") with no luck. So <ssh> it is for now.

IMC Input sensing matrix

  • Rana joined us and asked us to use Rossa for now so that we can sit socially distantly.
  • Attaching some intermediate results on our analysis as pdf and zip file containing all the codes we used.
  • We used channels C1:SUS-MC1_USSEN_OUTPUT  (16 Hz channels) and so on which might not be the correct way to do it as Rana pointed out today, we should have used channels like C1:SUS-MC1_SENSOR_UL etc.
  • During the input matrix calculation, we used the method of TF estimate (as mentioned in 4886) to calculate the sensor matrix and inverted it and normalized all rows with the maximum absolute value element (we tried few other ways of normalization with no better results either).
  • We found the peak frequencies by fitting lorentzian to the sensor data rotated by the current input matrix in the system. We also tried doing this directly on the sensor data (UL for POS, UR for PIT, LR for YAW and SD for SIDE as this seemed to be the case in the old matlab codes) but with no different results.
  • The fitted peak frequencies, Q and amplitude values are in fittedPeakFreqs.yml in the attached zip.
  1486   Wed Apr 15 11:25:21 2009 steveConfigurationVAC RGA cal completed

Quote:

Vacuum normal valve condition was changed to accommodate SRS-RGA calibration.

 

The annulus valves were closed to free TP3 to pump on the RGA
VM1 was closed to isolate the RGA from the IFO.
 
 
VM3 opened to TP3.
 
This condition is called back ground (BG) mode. It is where we can calibrate and see the RGA background without the IFO.

 Vacuum valve configuration is back to VACUUM NORMAL  condition. RGA  calibration  completed.

RGA  scan attached is the backgroud of the rga with std cal leak open, sn 08581

Krypton at amu 84 and Argon at amu 40 are the cal signals.

 

  13964   Thu Jun 14 15:24:32 2018 SteveUpdatePEM ADC DAC In Line Test Boards are in

We have 6 of these boards now in cabinet E7

Quote:

I wired all 32 channels going to the AA board directly to the ADC as described in the previous log. However, instead of using the old AA board and bypassing the whole circuit, I just used a breakout board as is shown in the first attachment. I put the board back in the rack and reconnected all of the cables.

The seismic BLRMs appear to be working again. A PSD of the BS seismometers is shown in attachment 2. Tomorrow I'll look at how much the ADC alone is suppressing the common mode 60 Hz noise on each of the channels.

Steve: 5 of ADC DAC In Line Test Boards [ D060124 ] ordered. They should be here within 10 days.

 

  6259   Tue Feb 7 16:30:46 2012 steveUpdateSUS ALL oplev PIT transfer functions

SUS- BS, ITMX, ITMY, PRM, SRM, ETMX & ETMY_OLPIT transfer funtion with sine wave excitation 0.1 amplitude:

 

  6263   Thu Feb 9 16:46:02 2012 steveUpdateSUS ALL oplev YAW transfer functions

Quote:

SUS- BS, ITMX, ITMY, PRM, SRM, ETMX & ETMY_OLPIT transfer funtion with sine wave excitation 0.1 amplitude:

 

OL_YAW transfer functions are here.

 I had two PHDs helping me to overlap the EXML files in DTT. We failed. This job requires professorial help.

  13785   Tue Apr 24 15:59:23 2018 SteveUpdateWiki AP table layout 20180328
Quote:

ETMX table layout uploaded with beam paths to the wiki.   laugh

The pdf file is uploaded into the wiki.

  14173   Tue Aug 21 09:16:23 2018 SteveUpdateWiki AP table layout 20180821

 

 

  11349   Tue Jun 9 10:57:12 2015 SteveUpdateSUS BS oplev laser tuned

Lenses removed from oplev beam path at elog entry 11246

 

  11719   Tue Oct 27 10:08:12 2015 SteveUpdateVAC CC vacuum gauges

CC1 and CC2 are working again. Why did they start working  again ?

 

  9709   Mon Mar 10 21:13:43 2014 nicolasSummaryLSC Composite Error Signal for ARms (2)

In order to better understand how the composite signal would behave in the presence of noise, I decided to do a simple analysis of the cavity signals while sweeping through resonance.

My noise model was to just assume that a given signal has some rms uncertainty (error bars) and use linear error propagation to propagate from simple signals to more complicated ones.

I used the python package uncertainties to do the error propagation.

I assumed that the ALS signal, the cavity transmission, and the cavity PDH error signal all have some constant noise that is independent of the cavity detuning. Below is a sweep through resonance (x axis is cavity detuning in units of radians).

rawsigs.png

The shaded region represents the error on each signal.

Next I calculated the 'first order' calculated error signals. These being a raw PDH, normalized PDH, an inverse square root trans, and the normal ALS again. I tuned the gains so they match appropriately.

Here, one can see how the error in the trans signal propagates to the normalized and trans signals and becomes large are the fractional error in the trans signal becomes large.

errorsigs.png

Next I did some optimization of linear combinations of these signals. I told the code to maximize the total signal to noise ratio, while ensuring that the overall signal had positive gain. I did this again as a function of the cavity detuning.

Each curve represents the optimized weight of the corresponding signal as a function of detuning.

optimalweights.png

So this is roughly doing what we expect, it prefers ALS far from the resonance, and PDH close to the resonance, while smoothly moving into square root trans in the middle.

It's a little fake, but it gives us an idea of what the 'best' we can do is.

Finally I used these weights to recombine the signals into a composite, to get an idea of the noise of the overall signal. At the same time, I plot the weighting proposed by Koji's mathematica notebook (using trans and 1-trans, and a hard switch to ALS).

compositenoise.png

So as one can see, at least for the noise levels I chose, the koji weighting is not much worse than the 'optimal' weighting. While it is much simpler.

The code for all this is in the svn at 40mSVN/nicolas/workspace/2014-03-06_compositeerror

  1548   Tue May 5 11:44:33 2009 robUpdateLocking DARM response

Here's the RF DARM optical response, on the anti-spring side, from optickle. Note that for the f1 sideband, changing the demod phase mostly adjusts the overall gain, while for the f2 sideband a change in demod phase alters the shape of the response. This is the quadrature-selecting power of using a single RF sideband as a local oscillator.
  12165   Fri Jun 10 09:52:51 2016 SteveUpdateSUS EQ 5.2 mag Borego Spring

EQ  5.2 mag at Jun 10, 8:04 am UTC, Borego Spring, CA  ~150 mi away.........no obvoius damage, damping restored, MC is locking, arms are flashing

 

  12199   Mon Jun 20 09:36:10 2016 SteveUpdateSUS EQ 3.1 m Big Bear Lake, CA

No suspention lost damping.

 

  11980   Mon Feb 8 09:37:07 2016 SteveUpdateSUS EQ 3.9m

No sign of damage

 

  12229   Wed Jun 29 16:02:29 2016 SteveUpdateSUS ETMX beam baffle

In the attached photo from 2012, one can see the installed black glass baffle. According to the drawings (LIGO-DNNNXXX) this one has a clear aperture of 40 mm.

In (someplace ?) we have clean baffles with a 50 mm aperture which can be installed during this vent. In order to be more conservative, let us choose to swap these out for all 4 test masses during the upcoming vent using the green laser as an alignment guide, as Koji described at today's lunch meeting.

They are located at the top of E1 drawer cabinet

  12890   Fri Mar 17 10:47:16 2017 SteveUpdateOptical Levers ETMX oplev laser replaced

JDSU 1103P. sn T8070866, made March 2007, output power 2.7 mW,  on pd 17,750 counts,

GV 17 March 3pm: I found the Innolight NPRO was off when I walked down to the X end earlier, possibly was accidentally tripped during the Oplev laser replacement. I turned it back on.

Quote:

 

Quote:

ETMX oplev laser is dead. It will be replaced this after noon. Sus damping recovered.

This 3 years old HeNe [ JDS 1103P, sn 351889 ]  has been dying for some time or just playing possum at age 1,126 days

I did not replace the ETMX oplev laser because I was unable to bring up the the C1ASC_ETMX_OPTLEV_SERVO  medm screen on laptops.

 

  12218   Tue Jun 28 09:14:27 2016 SteveUpdateSUS ETMX optics preparation to be rehanged

Given the effect on the contrast defect, the consensus at the meeting Wednesday 6-22  was that we should continue to use the existing ETMX optic. 

 
Does this imply that we can simply:
  • Vent
  • Remove the current ETMX suspension, and optic from the suspension
  • Replace the standoffs (and guide rod if necessary), leaving the current magnets in place
  • Re-suspend on the current, existing suspension, with new wire clamps
That is, if we are keeping the current optic, do we gain anything by replacing the whole suspension? Is there any reason to remove and replace magnets? (The wire clamps do need to be replaced, as a groove forms when they are installed.)
 
This could allow us to vent and execute this whole thing sooner. 
 
-Eric Q.
...............................
Yes, I think this is a reasonable approach. Besides the wire standoffs and wireclamps, the only other problem might by a worn groove in the top piece of the suspension (not the clamp piece, but the piece that the clamp holds the wire up against).
 
How about use the current ETM, but put it into the new suspension body with new wire standoffs?
 
Quote:

D Location

Number on

Drawing

 

Component

Name

 

 Baked Clean

 Pieces Needed

 

Pieces

In Stock

(on tower )

Notes
         
31,20,19,13 viton tips   not cut yet baked material in stock
30 6-32x0.75" stops 4 (4)  
29 steel music wire 0.017" not baked on roll  needs good wipes
28  1/4 "washer 4 (4)  
27 lock washer 4 50 install
26 Ag plated 1/4-20x1.25 4 (4)  
25 Ag plated1/4-25x.75 & not plated 20 (20)  
24 SS 4-40x.5 2 (2)  
23 SS 4-40x.38 4 (4)  
22 spring plunger 4+2 (4+2)  
         
         
18 magnets, 1.9mm od, length 3.2 mm 5 ~30 not coated, rusty buy Ni coated ones for future use
17 guide rod, 0.635 mm od, 3.3 mm 3 6 Al
16 wire standoff, 1 mm od, 4.8 mm 2 2 Al and ruby (ruby groove not centered)
15 short OSEMs 5 6  
14 spare ETMX in 40m wiki 1 1  confirmed in cabinet
         
12 dumbbell standoff 5 6  
11 Al stiffening plate 1 (1)  
10 wire clamp B in sus block 2 (2)  
9 wire clamp A 1 (1)  
8-7 lower clamp for lifting optics 2 (2)  
6 upper clamp to hold down optic 1 (1)  
5-4 left-right side of tower  1 ea (1ea)  
3 tower base 1 (1)  
2 sus block 1 (1)  
1 lower and upper OSEM holders 1ea (1ea)  
         
48 sandind fixture for magnet&dumbbell      
45 magnet-dumbbell assemblly fixture 1 1  
43 guide rod gluing fixture     shipped from LOH .... D000335...needs cleaning
         
  First contact   3-15-2013 purchase check expiration date OK
  FCPEEK peeler ring disk for TM cleaning 10 front,10 back side  have sheets only 32&19mm ID punches ordered
  GordonBrush custom for LIGO optical cleaning ~5 1 (3/8wide nylonSS) more from Calum available
  EP30-2 epoxy have  have expiration date 9-24-2016

NOT finished, last edited 6-28

 

  13776   Fri Apr 20 16:25:08 2018 SteveUpdateWiki ETMX table layout uploaded to wiki

ETMX table layout uploaded with beam paths to the wiki.   laugh

  8416   Thu Apr 4 17:23:05 2013 SteveUpdate40m Upgrading ETMY optical table & enclosure is ready for optics

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

 

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