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ID Date Author Type Category Subjectup
  1572   Sun May 10 13:41:17 2009 steveUpdateVACETMY damping restored, VC1 opened

ETMY damping restored.

Cryo  interlock closed VC1 ~2 days ago. P1 is 6.3 mTorr. Cryo temp 12K stable, reset photoswitch and opened VC1

  4068   Fri Dec 17 02:22:06 2010 kiwamuUpdateCDSETMY damping: not good

  I made some efforts in order to damp ETMY, however it still doesn't happily work.

 It looks like something wrong is going on around the whitening filters and the AA filter borad.

I will briefly check those analog parts tomorrow morning.

 

- - -(symptom)

Signs of the UL and the SD readouts are flipped, which I don't know why.

At the testpoints on the analog PD interface board, all the signs are the same. This is good.

But after the signals go through the whitening filters and AA filters, UL and SD become sign-flipped.

I tried compensating the sign-flips by changing the sign by means of the software, but it didn't help the damping. 

In fact the suspension got crazy when I activated the damping. So I have no idea if we are looking at exactly right readouts or some sort of different signals.

 

- - -(fixing DAC connector)

 I fixed a connector of the DAC ribbon cable since the solderless connector was loosely locked to its cable.

Before fixing this connector I couldn't apply voltages on some of the coils  but now it is working well.

  14608   Wed May 15 00:40:19 2019 gautamUpdateSUSETMY diagnosis plan

I collected some free-swinging data from earlier today evening. There are still only 3 peaks visible in the ASDs, see Attachment #1.

Plan for tomorrow:

TBH, I don't have any clear ideas as to what we are supposed to do to to fix the problem (or even what the problem is). So here is my plan for now:

  1. Take pictures of relative position of magnet and OSEM coil for all five coils
  2. Inspect positions of all EQ stops - back them well out if any look suspiciously close
  3. Inspect suspension wire for any kinks
  4. Inspect position of suspension wire in standoff

I anticipate that these will throw up some more clues 

Attachment 1: ETMY_sensorSpectra.pdf
ETMY_sensorSpectra.pdf
  2366   Tue Dec 8 13:03:26 2009 KojiUpdateCOCETMY drag wiped

Jenne, Kiwamu, Alberto, Steve, Bob, Koji

We wiped ETMY after recovery of the computer system. We take the lunch and resume at 14:00 for ITMX.
Detailed reports will follow.

  8595   Fri May 17 15:38:51 2013 SteveUpdate40m upgradingETMY enclosure is on the way back

 

 It  will arrive around 10 am Monday morning.

 

  8423   Mon Apr 8 16:37:26 2013 SteveUpdate40m UpgradingETMY enclosure wall transmission

 

 Enclosure cover #1 transmission measured  in 1064 nm,  156 mW,  P polarization and beam size ~ 1 mm

As condition:  fully assembled, protective layer removed, tinted- adhesive activated on yellow acrylic on top of each other.

T = 1.2 % in 20 minutes exposure test. This agrees with the test measurement of 6-18-2012

There is a reflected  2-3 cm circular glare that is barely visible on sensor card. It is well below 1 mW level

As we are installing the NPRO with ~350 mW of power we have to address what additional shield should be installed.

The June 2012 test with 1W power burned through of the 3 layer  IR coated films in 3-4 hours.

We 'll use Aluminum shields in the high power path till we come up with better solution.

  2956   Thu May 20 12:10:44 2010 kiwamuUpdatePhotosETMY end table

 I updated the photo of ETMY end table on the wiki.

http://lhocds.ligo-wa.caltech.edu:8000/40m/Optical_Tables

Attachment 1: ETMY_s.png
ETMY_s.png
  4848   Tue Jun 21 19:10:29 2011 SureshUpdateEnvironmentETMY end table

[Suresh, Sonali]

There were small pieces of glass, remnants of a fluorescent tube, which were lying around on the ETMY end table for a while now.  We picked up the larger pieces by hand and used the HEPA filtered vacuum cleaner to pick up the remaining glass and dust on the table. 

  5163   Wed Aug 10 01:40:40 2011 KojiUpdateSUSETMY exploration

[Rana Koji Jenne Jamie]

- The situation of the ETMY suspension is improved.
- The damping servos except for Pitch are now functional.
- We intentionally turned off the damping servos for the matrix measurements.


- Opened the light door of the ETMY chamber.

- We set up the CDS SUS lockin:

        Excite UL/UR/LL/LR equally [by setting the output matrix (1, 1, 1, 1, 0)] at 3.12Hz with 2000 cnts
        Put the OSEM PD outputs into lockin one by one. For the image rejection, 0.1Hz 4th order LPF has been used though we like to use a faster settling LPF.

- Found only UL was responding to the excitation. After fitzing with the cables and connectors, it was found that the DAC card was loose from the bus.
  By pushing the card the responses have been back. [Note we had the reboot of c1iscey almost at the same time.]

- Checked the response in the I channel of the lockin.
        UL -8ish / UR +7ish / LR +5ish / LL +2ish

- Tweaked LL sensor to get better response ==> in vain. Decided to move the lower OSEM plate for the better positioning of the LR/LL.
- Got reasonable (+5ish) response for LL.

- Confirmed that the POS/YAW/SIDE damping works with positive gains. PITCH did not work with the negative gain (but that could be a good sign.)

- Let the suspension freely swinging for a while (~30min). Checked the side/pos separation. They are not perfect but seemed diagonalizable.

- Closed the light door.

- Jenne will make a better kick/free-swing test later.

  5164   Wed Aug 10 02:29:38 2011 JenneUpdateSUSETMY exploration

Quote:

- Jenne will make a better kick/free-swing test later.

 02:27am, ran the new freeswinging-ifo.csh script.  It's just a copy of freeswinging-all.csh, but it doesn't include the MC mirrors, since Suresh and Kiwamu are still working.  

Now we have copies of the script for -all, -mc, -ifo to cover the various sections of the suspended interferometer.

  1603   Mon May 18 21:34:18 2009 ranaConfigurationSUSETMY f2pRatio script run
Now that the ETMY optical lever is not so bad, I ran the f2pRatio script and it seems to have worked.

I cleaned up the script a little also. Updated in the SVN.

ETMY's A2L scripts have to be run to reduce the A2L noise once the arm is locked again. Might also need
to set the OL UGF too.
  1605   Tue May 19 12:30:41 2009 robConfigurationSUSETMY f2pRatio script run

Quote:
Now that the ETMY optical lever is not so bad, I ran the f2pRatio script and it seems to have worked.

I cleaned up the script a little also. Updated in the SVN.

ETMY's A2L scripts have to be run to reduce the A2L noise once the arm is locked again. Might also need
to set the OL UGF too.


Just to show, in part, what the script does.

The F2A filters are turned on at 12:21, and the oplev no longer responds to large LSC drives in ETMY.
Attachment 1: f2ademo.png
f2ademo.png
  16731   Thu Mar 17 11:40:41 2022 PacoUpdateSUSETMY green PZT HV supply

[Anchal, Paco]

We installed a HV kepco power supply for the green PZT steering the YAUX beam. We did this in anticipation of the YARM alignment to take place this afternoon. We borrowed an unused DC power supply labeled "OMC Power spply" and made an appropriate SMA connection (Attachment #1), Then we set the Vset to 100.0 Volts and the current limit to 10 mA. Once we enabled the output we saw the 5.6 mA of current drawn by the eurocard in accordance with the wiki log (Attachment #2). 

It may not be possible to use the PZT as per this so this work may not have a direct impact on our upcoming alignment task.


We probably bumped the ethernet cable (martian network) on c1iscey, so the FE models stopped showing up on the medm screens. When we connected it back, it seemed like the FE kept running the model and only IPC showed error. We restarted the rtcds models on c1iscey and burtrestored to today morning 5:19 am.

burtwb -f /cvs/cds/rtcds/caltech/c1/burt/autoburt/today/05:19/c1scyepics.snap -l /tmp/controls_1220317_115006_0.write.log -o /tmp/controls_1220317_115006_0.nowrite.snap -v

ETMY is properly damping now and the oplev is roughly centered as well but the OPLEV Servos are off. We did not turn them on.
We should be able to carry out our cavity arm alignment today afternoon on both arms now.

  12412   Tue Aug 16 08:04:49 2016 SteveUpdateSUSETMY had Aluminum bridge

The SOS ETMY tower had and Aluminum bridge. How is it possible that this was true? Is SS better than Al for some quantitative scientifc reason ???

Their weight ratio as measured  =  922 / 307 g = 3

Destinies:  SS 304 / Al 6061  >  0.289 / 0.098  [ lb /in3 ] =  2.94

Attachment 1: AlBridge.jpg
AlBridge.jpg
  5215   Fri Aug 12 17:37:11 2011 JenneUpdateSUSETMY hopefully good again

[Jamie, Jenne]

We went in to have a look-see at ETMY since it looked stuck-ish.  Jamie noticed that the side magnet was pretty close to the teflon plates of the OSEM.  We rotated it a bit, and now its all better.  We also adjusted the OSEMs until their mid-ranges were happy.  The U's were a little low, and the L's were a little high, as if the optic were a bit pitched backward.  Anyhow, we checked that the table is level, and tweaked the OSEMs.  We're starting the free-swinging test now...

Excited all optics

Fri Aug 12 17:38:53 PDT 2011
997231148

  5216   Fri Aug 12 20:28:13 2011 JenneUpdateSUSETMY hopefully good again

Quote:

[Jamie, Jenne]

We went in to have a look-see at ETMY since it looked stuck-ish.  Jamie noticed that the side magnet was pretty close to the teflon plates of the OSEM.  We rotated it a bit, and now its all better.  We also adjusted the OSEMs until their mid-ranges were happy.  The U's were a little low, and the L's were a little high, as if the optic were a bit pitched backward.  Anyhow, we checked that the table is level, and tweaked the OSEMs.  We're starting the free-swinging test now...

Excited all optics

Fri Aug 12 17:38:53 PDT 2011
997231148

 Hmmm.  I'm no longer convinced that ETMY is healthy.  I think that when I gave it a kick, it's bouncing against something.  I can't fit the peaks to get the input matrix.  I guess step 1 is to try giving it a smaller kick for the free swinging spectra.  But if the owl shift folk feel like it, they might have a look-see.

  14611   Wed May 15 17:46:24 2019 gautamUpdateSUSETMY inspection

I setup the usual mini-cleanroom setup around the ETMY chamber. Then I carried out the investigative plan outlined here.

Main finding: I saw a fiber of what looks like first contact on the bottom left (as viewed from HR side) of ETMY, connecting the optic to the cage. See Attachment #1. I don't know that this can explain the problem with the missing eigenmode, it's not a hard constraint.  Seems like something that should be addressed in any case. How do we want to remove this? Just use a tweezer and pull it off, or apply a larger FC patch and then pull it off? I'm pretty sure it's first contact and not a piece of PEEK mesh because I can see it is adhered to the HR side of the optic, but couldn't capture that detail in a photo.

There weren't any obvious problem with the magnet positioning inside the OSEM, or the suspension wire. All the EQ stop tips were >3mm away from the optic.

I also backed out the bottom EQ stops on the far (south side) of the optic by ~2 full turns of the screw. Taking another free-swinging dataset now to see if anything has changed. I will upload all the photos I took, with annotations, to the gPhotos later today eve. Light doors back on at ~1730.

Update 10pm: the photos have been uploaded. I've added a "description" to each photo which should convey the message of that particualr shot, it shows up in my browser on the bottom left of the photo but can also be accessed by clicking the "info" icon. Please have a look and comment if something sticks out as odd / requires correction.

Update 1045pm: I looked at the freeswinging data from earlier today. Still only 3 peaks around 1 Hz.

The following optics were kicked:
ETMY
Wed May 15 17:45:51 PDT 2019
1242002769
Attachment 1: firstContactFiber.JPG
firstContactFiber.JPG
Attachment 2: ETMY_sensorSpectra.pdf
ETMY_sensorSpectra.pdf
  14612   Wed May 15 19:36:29 2019 KojiUpdateSUSETMY instepction

A pair of tweezer is OK as long as there is no magnets around. You need to (somewhat) constrain the mirror with the EQ stops so that you can pull the fiber without dragging the mirror.

  5704   Wed Oct 19 17:33:07 2011 kiwamuUpdateGreen LockingETMY mechanical shutter : fully functional

The mechanical shutter on the Y end is now fully functional.

 

 It is newly named to 'C1AUX_GREEN_Y_Shutter' in the EPICS world.

It uses the same binary output channel which had been served for the POY shutter.

To change the EPICS name I edited a db file called ShutterInterLock.db, which resides in /cvs/cds/caltech/target/c1aux.

After editing the file I rebooted the c1aux machine, by telnet and the reboot command in order to make the change effective.

Also I added this new shutter on the ALS overview screen (see the attachment below)

MechShutter.png

Quote from #5701

The ETMY  shutter can be remotely switched from medm screen POY of mechanical shutters.

The new cable from ETMY controller goes to east vertex EV-ISCT where it is connected to POY shutter hook up BNC cable.

  5701   Wed Oct 19 16:28:35 2011 steveUpdateGreen LockingETMY mechanical shutter is working

Quote:

Uniblitz mechanical shutter installed in the green beam path at ETMY-ISCT  The remote control cable has not been connected.

The ETMY  shutter can be remotely switched from medm screen POY of mechanical shutters.

The new cable from ETMY controller goes to east vertex EV-ISCT where it is connected to POY shutter hook up BNC cable.

  5177   Wed Aug 10 18:25:45 2011 JenneUpdateSUSETMY mini-update

[Jenne, Jamie]

ETMY is now in its new nominal position, according to the rails that Kiwamu put in the other day.  OSEM voltages are all centered, and the magnets looked pretty well centered in the OSEM bores.  We're taking data for some free swinging spectra, to check the decoupling. 

Next up: Align Y-green to the arm, then move on to fixing the other optics that Jamie pointed out.

  8590   Thu May 16 08:32:05 2013 SteveUpdate40m upgradingETMY op table disabled

 

All ETMY optical table electronics- lasers-pds turned off, disconnected in order to remove enclosure.

linguaa.jpg

  8596   Fri May 17 16:06:14 2013 ranaUpdate40m upgradingETMY op table disabled

 

 TODO:

  1. We need to replace all of the floppy anodized Al dumps with clean razor blade dumps on stiff mounts. BOTH of the rejected ports of the 1064 FI need some kind of custom dump.
  2. All of the leakthrough beams of the HR mirrors also need razor dumps. A good rule of thumb is that your first notion of how to implement the beam dump is NOT good enough.
  3. The whole lens / modematching situation for the 1064 and 532 paths will have to be redone so as to put the beam waists inside the Faraday crystal (NOT outside). The beam waist in the 4.7 mm diameter Faraday should be ~0.3-0.4 mm.
  4. The efficiency that we got for the doubling shows that we don't need the cylindrical lenses - they are nice, but not needed to get 90% of the max power.
  5. The lenses between the 1064 FI and the doubler should be put onto a base that can be used to adjust the lens position for MM optimization. Nothing fancy, just something slideable.
  6. For this iteration of the table, we can do as Annalisa has written so as to get the green MM lenses ordered ASAP. After next week we can come up with a new plan before dismantling the EX table.
  250   Fri Jan 18 20:53:56 2008 tobinConfigurationGeneralETMY oplev
I monkeyed around with the ETMY oplev, adding a folding mirror and moving the HeNe so that John, Sam, and I have more room for our auxiliary laser setup. (The ISCT-EY has more room than ISCT-EX; the latter has an extra photodiode for IP ANG.) I believe I successfully recommissioned the oplev, though it might not be up to the SV standard. I verified that wiggling the ETMY alignment sliders showed corresponding wiggles in the oplev signals. However, it seems poorly diagonalized.

Our current plan is to have an NPRO, EOM, and fiber coupler on the SP table. This fiber will take light to ISCT-EY where we'll have a mode-matching telescope and inject light to the Y arm via a polarized beamsplitter. This auxiliary beam will have polarization orthogonal to the beam from the PSL.
  9281   Thu Oct 24 17:18:44 2013 SteveUpdateSUSETMY oplev error signals are still bad

Quote:

 Just plot.

RA: I'm not sure how to interperet this; I think that the SUM channel is divided by the SUM so that this is supposed to be RIN, but not sure. Can someone please take a look into the SUS model and then explain in the elog what the SUM normalization algorithm is?

 

Attachment 1: ETMY_OPLEV_ERRORS.png
ETMY_OPLEV_ERRORS.png
  4087   Wed Dec 22 15:30:47 2010 OsamuUpdateASCETMY oplev fixed

According to c1scy.mdl, OL signals should be connected to adc_0_24 to adc_0_27 but they were connected to adc_0_16 to adc_0_19 which are assigned to QPD signals.

Actually cable connections were messed up. One ribbon cable was connected from QPD driver and ADC ports assigned for OL, and another ribbon cable was connected from the board combining the signals of oplev and QPD to ADC port assigned for QPD.

Now ETMY oplev is working well and aligned to center.

  6656   Tue May 22 08:03:01 2012 steveUpdateSUSETMY oplev gets new laser

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

  1786   Fri Jul 24 17:20:48 2009 JenneUpdateoplevsETMY oplev is iffy

ETMY oplev is currently a work in progress.  The HeNe beam is hitting the photodiode, but the spot size there is pretty much the size of the entire QPD.  Thus, the ETMY oplev isn't really useful right now.  I'm re-figuring things out (note to self: close to the laser, you have to use Gaussian optics...regular ray tracing doesn't really work), and hopefully will have the oplev back under control by the time Alberto is finished realigning the IFO, so this doesn't keep anyone from doing any exciting locking work.

  1798   Mon Jul 27 17:48:44 2009 JenneUpdateoplevsETMY oplev is still down for the count

ETMY oplev is still out of order.  Hopefully I'll get it under control by tomorrow. 

  6649   Fri May 18 11:19:17 2012 steveUpdateSUSETMY oplev laser is dead

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

  9196   Thu Oct 3 09:49:49 2013 SteveUpdateSUSETMY oplev laser is sick

Quote:

As another proof that sometime is ill with ETMX Optical Lever:

We scanned the ETMX bias in PIT using ezcastep and saw that the OL response is very screwy. In the attached, you can see that the ETMX SUSPIT signal shows that the actual motion is good and linear. In fact, our sus diagonalization is extermely good and there's almost no signal in SUSYAW.

 ETMY oplev laser clearly showing a tail when it was projected up the sealing.

PS (10-4-2013): I checked the beam quality again as it was removed from the table: it had a good image at 3 meters

  8668   Tue Jun 4 10:33:09 2013 ranaUpdateSUSETMY oplev path redone

 We also redid the oplev path.

Someone had used the illegal tactic of using aluminum dogs to hold down mounts which already have screw holes in the bases. This is too flimsy to use.

We then adjusted the position of the second lens to get a ~1 mm spot on the QPD. There is a lot of stray red light from extra reflections, but so be it.

Its possible that we are now clipping the IPANG path, but we will need to lock the Y arm and verify the input pointing to be sure. At this point we are ready to measure the ETMY OL loop gain and tune, etc.

  6587   Mon Apr 30 21:05:32 2012 JenneUpdateSUSETMY oplev power supply dead

[Jenne, MikeJ]

The ETMY oplev quad sum was ~0, so we went to investigate.  The power supply was dead.  Keying it on and off didn't fix things, and it was certainly getting power since the front indicator light was flickering.  We replaced it with a different power supply, and the oplev is back.

Also, the Y-green AUX laser was off, presumably from the power outage a while back.  I turned it back on.

 

EDIT JD:  The first power supply we used didn't work....the oplev was on for a few minutes, then went off again.  We switched to one of the new (still JDSU) power supplies from Edmund Optics, and it's been happily working for at least an hour now.

  6588   Mon Apr 30 21:24:43 2012 KojiUpdateSUSETMY oplev power supply dead

And has the temp controller of the green been recovered too? (Push enable button)

 

  6589   Mon Apr 30 22:41:34 2012 JenneUpdateSUSETMY oplev power supply dead

Quote:

And has the temp controller of the green been recovered too? (Push enable button)

 

 Just now, yes.

  253   Tue Jan 22 13:11:03 2008 tobinUpdateASCETMY oplev recentered
The light wasn't even on the diode.
  7458   Mon Oct 1 17:03:01 2012 steveUpdateSUSETMY oplev relayed

Quote:

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

There was no IP-ANG coming out of the chamber at this time!

 I did relayed the oplev path with new  f 500 mm lens

Attachment 1: IMG_1673oplevETMY.jpg
IMG_1673oplevETMY.jpg
  8734   Thu Jun 20 17:47:44 2013 AnnalisaConfigurationSUSETMY oplev servo

[Jenne, Annalisa]

The ETMY Oplev servo didn't work properly, when it was activated the ETMY moved too much.

We measured the oplev TF for Pitch and Yaw and it turned out that the gain was too low by a factor 3, so we increased the gain from -.250 to -.750 on both.

We also locked the Y arm and we could see that the mirror's oscillations are actually suppressed.

 

  6706   Tue May 29 15:55:22 2012 steveUpdateSUSETMY oplev spot size reduced

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

There was no IP-ANG coming out of the chamber at this time!

Attachment 1: ETMYoplev.jpg
ETMYoplev.jpg
Attachment 2: IMG_1243.JPG
IMG_1243.JPG
  6710   Tue May 29 21:34:08 2012 JenneUpdateSUSETMY oplev spot size reduced

Quote:

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

 Flipped the sign on the ETMY oplev servo gain, since it was wrong.  (It was "-" for both, now it is "+" for both)

  5523   Thu Sep 22 20:12:54 2011 kiwamuUpdateSUSETMY oplev whitening engaged

The whitening filters for the ETMY oplevs are back.

The whitening board had been in the rack but the ADC was connected directly to the oplev interface board without going through the whitening board.

In fact the interface board and the whitening board had been already connected. So the ADC was making a shortcut.

I disconnected the ADC from the interface board and plugged it to the output of the whitening board.

Here is an example of the new open-loop transfer function with the whitening filters.

OLETMY_WF.png

 Note :

before the measurement I increased the control gain by an arbitrary number to obtain gain of more than 1 around 1 Hz.

Quote from #5521

I will check the whitening filters.

  6766   Wed Jun 6 14:36:58 2012 steveUpdateSUSETMY oplev work finished

Quote:

Quote:

Quote:

 

 The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.

Two new  JDS - Uniphase 1103P lasers ( NT64-104 )  arriving on Monday, May 21

 Yesterday I swapped in new He/Ne laser with output power 3.5 mW  The return spot on qpd is large ~6mm in diameter and 20,500 counts

The spot size reduction require similar layout as ETMX oplev.

 The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.

 Late entry for Monday morning June 4, 2012

Cables were stress relieved. Cable entry - exit ports enlarged. Air gaps were minimized.

  8827   Thu Jul 11 09:15:10 2013 SteveUpdateendtable upgradeETMY optable grounded

ETMY optical table top was grounded to the ETMY chamber through 1 Mohms this morning. I  also strain releifed relieved a few cables that were pulling on components directly.

  4722   Sun May 15 19:55:15 2011 kiwamuUpdatePhotosETMY optical bench

Just for a record. This is the latest picture of the ETMY optical bench.

I will upload this picture on the wiki after the wiki gets up.

ETMY_ss.jpg

  4723   Sun May 15 21:27:51 2011 JenneUpdatePhotosETMY optical bench

I didn't notice it the other day when I was working on putting in the trans QPD, but do we need to switch the mirror mount for the first turning mirror of the IR trans beam, which the green transmits through to go into the cavity?  It seems like we've set ourselves up for potential clipping.

Quote:

Just for a record. This is the latest picture of the ETMY optical bench.

I will upload this picture on the wiki after the wiki gets up.

ETMY_ss.jpg

 

  11897   Tue Dec 22 16:39:42 2015 SteveUpdateendtable upgradeETMY optical table enclosure

I think there should be a scientifically based aveluation of the ETMY enclosure so we can make the ETMX better.

Meanwhile I'm counting pieces to move on with the south end table cover.

 

Attachment 1: IMG_0028.JPG
IMG_0028.JPG
Attachment 2: IMG_0027.JPG
IMG_0027.JPG
Attachment 3: ETMY-ISCT_EISOL.jpg
ETMY-ISCT_EISOL.jpg
  11591   Fri Sep 11 10:56:47 2015 SteveUpdateendtable upgradeETMY optical table feedthrough

The ETMY enclosure feedthrough - north is installed. The sealing material is hard to work with.

The upper empty blocks will be replaced by something soft to make changing cables easy.

 

Attachment 1: ETMY-Nfeedt.jpg
ETMY-Nfeedt.jpg
  11600   Tue Sep 15 16:49:08 2015 SteveUpdateendtable upgradeETMY optical table feedthrough

ETMY optical table enclosure feedthrough- south is in. Now it is time to see how air tightness increases performance.

Quote:

The ETMY enclosure feedthrough - north is installed. The sealing material is hard to work with.

The upper empty blocks will be replaced by something soft to make changing cables easy.

 

 

Attachment 1: ETMYsFeedt.jpg
ETMYsFeedt.jpg
  11608   Thu Sep 17 02:22:53 2015 SteveUpdateendtable upgradeETMY optical table feedthrough

I doubt we'll see any effect until we carefully seal the holes. If there's 1 hole in your boat it still sinks.

Quote:

ETMY optical table enclosure feedthrough- south is in. Now it is time to see how air tightness increases performance.

 

  12384   Tue Aug 9 00:44:43 2016 gautam UpdateSUSETMY patch-up

Summary:

Given that ETMX looks to be in good shape and the optic and suspension tower are ready for vacuum and air bakes respectively, I set about re-gluing the knocked off magnet of ETMY. In my previous elog, I had identified the knocked off magnet as the UL magnet. But in fact, it was the LR magnet that broke off. This is actually one of the magnets that was knocked off when Johannes was removing the optic from the vacuum chamber. I have edited the old elog accordingly. 

Step 1: Removing epoxy residue

  • I used the teflon+glass rig Steve put together for this purpose
  • After soaking for ~2 hours in acetone, I was able to remove approximately half of the ring residue by lightly pushing with a wipe.
  • The other half wouldn't budge so I let it soak for another 4 hours
  • After 6 hours of soaking, I was able to get all of the epoxy residue off - it doesn't simply dissolve in the acetone, I had to push a little with one of the cotton-tipped paddles in the cleanroom
  • I gave the portion exposed to acetone a quick drag wipe with isopropanol. I didn't spend too much time trying to clean the AR side given that we will be using first contact anyways.
  • I have not touched the HR side for now, even though a small portion of it was exposed to acetone. While cleaning the HR face with first contact, this portion can be inspected and cleaned if necessary

Step 2: Putting the optic in the magnet gluing jig

  • I transferred the optic to the magnet gluing jig
  • Given that we weren't touching any side magnets, I reasoned I did not have to go through the elaborate shimming routine to account for the wedge of the optic that we had to do in the recent past
  • However, I did not think to put a thicker teflon spacer on the lower side of the wedge, and as a result, I knocked off the UR magnet as well as the jig did not have sufficient clearance
  • Fortunately, the UR magnet came off cleanly, there was hardly any epoxy residue left on the optic. The UR magnet was NOT one of the magnets knocked off by Johannes while removing the optic from the vacuum chamber
  • I gave the area formerly occupied by the UL magnet 3-4 wipes with acetone and then 1-2 wipes with isopropanol
  • At this stage, I proceeded to re-insert the magnet-gluing jig. I used the two scribe lines on the outer side of the jig to fix the rotation of the jig, and used the remaining two attached face magnets to fix the overall position of the jig (by centering these magnets relative to the apertures on the jig). In order to center well, I had to unscrew the stuck silver plated screw on the jig by 1 turn
  • Having arranged the jig satisfactorily, I proceeded to remove epoxy residue off the dumbbell of the recently knocked off UL magnet using first a razor blade, then sandpaper and finally made some new grooves with a razor blade. I then cleaned the surface of the dumbbell to be in contact with the optic with isopropanol. All of this was done for the LR magnet two weeks ago right after it was knocked off

Step 3: Gluing the magnets

  • I prepared the magnets in the pickle pickers
  • I discarded 1 full squeeze of the epoxy after it reached the tip of the mixing fixture, and then extracted another full squeeze of the gun for mixing and gluing the magnets
  • I mixed the epoxy in an Al foil vessel for 3-4 minutes, and then placed a few drops on a piece of Al foil for a test bake at 200F for ~15 minutes
  • The test bake went well, so I proceeded to apply glue to the dumbbells and re-glue the magnets to the optic
  • The gluing was done around midnight, so we should be able to have a look at this post lunch tomorrow.

Provided the gluing goes well, the plan for tomorrow is:

  1. Bring ETMY suspension tower from the vacuum chamber to the cleanroom along with its OSEMs
  2. Suspend ETMY with a new length of wire (this should be much more straightforward than our ETMX exploits as both standoffs are already glued)
  3. Insert OSEMs, check that all 4 face magnets are well centered w.r.t. their coils and also that at least one side magnet is well aligned relative to its coil and can be used 
  4. If step 3 goes well, then ETMY is also ready for a vacuum bake. I guess we can also air bake the ETMY suspension tower, there's plenty of room in the oven
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