damped sus at atm1 and freeswingging sus at atm2

I ran "freeswing all" at Fri Aug 19 01:09:28 PDT 2011 (997776583)  and "opticshutdown"  as well.

Free swingging OSEM sensors LL at atm

excited all the optics ---

Tue Aug 23 01:08:00 PDT 2011
998122096

SUS update before closing up:

• MC1, MC2, ITMX look good
• MC3, PRM look ok
• SRM pos and side peaks are too close together to distinguish, so the matrix is not diagnalizable.  I think with more data it should be ok, though.
• all ITMY elements have imaginary components
• ITMY, ETMX, ETMY appear to have modest that swapped position:
  • ITMY: pit/yaw
  • ETMX: yaw/side
  • ETMY: pos/side
• MC3, ETMX, ETMY have some very large/small elements

Not particularly good.  We're going to work on ETMY at least, since that one is clearly bad.

OPTIC		M	cond(B)
MC1		pit     yaw     pos     side    butt UL    0.733   1.198   1.168   0.050   1.057  UR    1.165  -0.802   0.896   0.015  -0.925  LR   -0.835  -1.278   0.832  -0.002   0.954  LL   -1.267   0.722   1.104   0.032  -1.064  SD    0.115   0.153  -0.436   1.000  -0.044	4.02107
MC2		pit     yaw     pos     side    butt UL    1.051   0.765   1.027   0.128   0.952   UR    0.641  -1.235   1.089  -0.089  -0.942   LR   -1.359  -0.677   0.973  -0.097   1.011   LL   -0.949   1.323   0.911   0.121  -1.096   SD   -0.091  -0.147  -0.792   1.000  -0.066	4.02254
MC3		pit     yaw     pos     side    butt UL    1.589   0.353   1.148   0.170   1.099   UR    0.039  -1.647   1.145   0.207  -1.010   LR   -1.961  -0.000   0.852   0.113   0.896   LL   -0.411   2.000   0.855   0.076  -0.994   SD   -0.418   0.396  -1.624   1.000   0.019	3.60876
PRM		pit     yaw     pos     side    butt UL    0.532   1.424   1.808  -0.334   0.839   UR    1.355  -0.576   0.546  -0.052  -0.890   LR   -0.645  -0.979   0.192   0.015   0.881   LL   -1.468   1.021   1.454  -0.267  -1.391   SD    0.679  -0.546  -0.674   1.000   0.590	5.54281
BS		pit     yaw     pos     side    butt UL    1.596   0.666   0.416   0.277   1.037   UR    0.201  -1.334   1.679  -0.047  -0.934   LR   -1.799  -0.203   1.584  -0.077   0.952   LL   -0.404   1.797   0.321   0.247  -1.077   SD    0.711   0.301  -3.397   1.000   0.034	5.46234
SRM	NA	NA	NA
ITMX		pit     yaw     pos     side    butt UL    0.458   1.025   1.060  -0.065   0.753   UR    0.849  -0.975   1.152  -0.199  -0.978   LR   -1.151  -1.245   0.940  -0.243   1.217   LL   -1.542   0.755   0.848  -0.109  -1.052   SD   -0.501  -0.719   2.278   1.000  -0.153	4.4212
ITMY		pit     yaw     pos     side    butt UL    0.164   1.320   1.218  -0.086   0.963   UR    1.748  -0.497   0.889  -0.034  -1.043   LR   -0.252  -2.000   0.782  -0.005   1.066   LL   -1.836  -0.183   1.111  -0.058  -0.929   SD   -0.961  -0.194   1.385   1.000   0.239	4.33051
ETMX		pit     yaw     pos     side    butt UL    0.623   1.552   1.596  -0.033   1.027   UR    0.194  -0.448   1.841   0.491  -1.170   LR   -1.806  -0.478   0.404   0.520   0.943   LL   -1.377   1.522   0.159  -0.005  -0.860   SD    1.425   3.638  -0.762   1.000  -0.132	4.89418
ETMY		pit     yaw     pos     side    butt UL    0.856   0.007   1.799   0.241   1.005   UR   -0.082  -1.914  -0.201  -0.352  -1.128   LR   -2.000   0.079  -0.104  -0.162   0.748   LL   -1.063   2.000   1.896   0.432  -1.119   SD   -0.491  -1.546   2.926   1.000   0.169	9.11516

excited all the optics. (with ITMY WTF OFF)

Tue Aug 23 11:52:52 PDT 2011
998160788

Before lunch we took a closer look at two of the suspensions that were most problematic: ITMY and ETMY.  Over lunch we took new free swinging data.  Results below:

• For ITMY we discovered that the whitening on the UL sensor was not switching.  This was causing the UL sensor to have a different response, with a steeper roll of, which was causing all of the transfer function estimates to the other sensors to have large imaginary components.   We took new free swing data with all of the whitening turned OFF.  The result is a much improved matrix and diagnalization.  The input matrix elements are mostly the same, but the coupling is basically gone.  We'll fix the whitening after the pump down.

ITMY

pit     yaw     pos     side    butt UL    0.157   1.311   1.213  -0.090   0.956  UR    1.749  -0.490   0.886  -0.038  -1.042  LR   -0.251  -2.000   0.787  -0.007   1.066  LL   -1.843  -0.199   1.114  -0.059  -0.936  SD   -0.973  -0.205   1.428   1.000   0.239

4.34779

• ETMY has a very problematic SIDE OSEM.  The magnet does not line up with the OSEM axis, and since there is no lateral adjustment in the side OSEMs, there's not much we can do about this.  We're using aluminum foil to wedge the OSEM over as far as possible, but it's not quite enough.  With the OSEM plates horizontal there is a lot of POS->SIDE coupling.  With the OSEM plates vertical, the magnetic sits a little too close to the rear face, which can cause the magnet to get stuck to the LED plate.  We're trying to decide where to leave it now, but the new diagnalization with the OSEM plates vertical is definitely better: 

ETMX

pit     yaw     pos     side    butt UL   -0.138   1.224   1.463  -0.086   0.944   UR    0.867  -0.776   1.501  -0.072  -1.051   LR   -0.995  -0.896   0.537  -0.045   0.754   LL   -2.000   1.104   0.499  -0.059  -1.251   SD    0.011   0.220   1.917   1.000   0.224

4.42482

Excited ETMY

Tue Aug 23 17:20:45 PDT 2011
998180460

 

In preparation for tomorrow's drag wiping and door closing, I have clamped ITMX, ITMY, and ETMX with their earthquake stops and moved the suspension cages to the door-edge of their respective tables.  They will remain clamped through drag wiping.

ETMY was left free-swinging, so we will clamp and move it directly prior to drag wiping tomorrow morning.

By looking at a longer data stretch for the SRM (6 hours instead of just one), we were able to get enough extra resolution to make fits to the very close POS and SIDE peaks.  This allowed us to do the matrix inversion.  The result is that SRM looks pretty good, and agrees with what was measured previously:

SRM

pit     yaw     pos     side    butt UL    0.869   0.975   1.140  -0.253   1.085   UR    1.028  -1.025   1.083  -0.128  -1.063   LR   -0.972  -0.993   0.860  -0.080   0.834   LL   -1.131   1.007   0.917  -0.205  -1.018   SD    0.106   0.064   3.188   1.000  -0.011

4.24889

We ran one more free swing test on ETMY last night, after the last bit of tweaking on the SIDE OSEM.  It now looks pretty good:

ETMY

pit     yaw     pos     side    butt UL   -0.323   1.274   1.459  -0.019   0.932  UR    1.013  -0.726   1.410  -0.050  -1.099  LR   -0.664  -1.353   0.541  -0.036   0.750  LL   -2.000   0.647   0.590  -0.004  -1.219  SD    0.021  -0.035   1.174   1.000   0.137

4.23371

 So I declare: WE'RE NOW READY TO CLOSE UP.

We've closed up ETMX:

• the optic was drag wiped
• the suspension tower was put back in place
• earthquake stops were backed off the appropriate number of turns, and de-ionized
• chamber door was put on

ITMX was drag wiped, and the suspension was put back into place.  However, after removing all of the earthquake stops we found that the suspension was hanging in a very strange way.

The optic appears to heavily pitched forward in the suspension.  All of the rear face magnets are high in their OSEMs, while the SIDE OSEM appears fine.  When first inspected, some of the magnets appeared to be stuck to their top OSEM plates, which was definitely causing it to pitch forward severely.  After gently touching the top of the optic I could get the magnets to sit in a more reasonable position in the OSEMs.  However, they still seem to be sitting a little high.  All of the PDMon values are also too low:

Taking a free swing measurement now.

ITMX: 998245556

ETMX, ETMY: 998248032

I broke the UL magnet on ITMX

The ITMX tower was shipped into the Bob's clean room to put the magnet back on.

 Since we found that all the magnets were relatively high (#5296) in the shadow sensors, we decided to slide the OSEM holder bar upward.

During the work, I haven't made the OSEMs far enough from the magnets.

So the magnets and OSEMs touched as I moved the holder.

Then the UL magnets were broken off and fell into the UL coil.

 Repair work is delayed.  I need the "pickle pickers" that hold the magnet+dumbbell in the gluing fixture, for gluing them to the optic.  Here at the 40m we have a full set of SOS gluing supplies, except for pickle pickers.  We had borrowed Betsy's from Hanford for about a year, but a few months ago I returned all of the supplies we had borrowed.  Betsy said she would find them in her lab, and overnight them to us.  Since the problem occurred so late in the day, they won't get shipped until tomorrow (Thursday), and won't arrive until Friday.

I also can't find our magnet-to-dumbbell gluing fixture, so I asked her to send us her one of those, as well. 

I have 2 options for fixing ITMX.  I'll write down the pros and cons for each, and we can make a decision over the next ~36 hours.

OPTIONS:

(#1) Remove dumbbell from optic.  Reglue magnet to dumbbell. Reglue magnet+dumbbell to optic.

(#2) Carefully clean dumbbell and magnet, without breaking dumbbell off of optic.  Glue magnet to dumbbell.

PROS:

(#1) Guarantee that magnet and dumbbell are axially aligned.

(#2) Takes only 1 day of glue curing time.

CONS:

(#1) Takes 2 days of glue curing time. (one for magnet to dumbbell, one for set to optic.)

(#2) Could have slight mismatch in axis of dumbbell and magnet.  Could accidentally drop a bit of acetone onto dumbbell-to-optic glue, which forces us into option 1, since this might destroy the integrity of the glue joint (this would take only the 2 days already required for option 1, it wouldn't force us to take 2+1=3 days).

 jamie, jenne, kiwamu, suresh, steve

ETMY and ITMY were treated the same way as ETMX. The BS chamber was closed with heavy vac door yesterday also. The IOO access connector's inner jamnuts are torqued to 45 ft/lbs as all vac door bolts.

The vac envelope is ready for pumpdown condition, except ITMX chamber with light atm door cover.

Jenne will summeries the condition of dust on the  TMs before and after the drag wipes.

As we have seen in the past, both of the ITMs were more dusty than the ETMs, presumably because we have the vertex open much more often than the ends.  Kiwamu and I wiped all of the optics until we could no longer see any dust particles within a ~1.5 inch diameter area around the center. 

Since we have ITMX out for magnet gluing, I'll probably drag wipe both front and back surfaces before putting it back in the suspension cage.  All of the optics have clear dust on the AR surfaces, but we can't get to that surface while the optics are suspended.  For the ETMs this isn't too big of a deal, but it does concern me a bit for the ITMs and other transmissive optics we have.  I don't think it's bad enough yet though to warrant removing optics from suspensions just to wipe them.

Dmass just reminded me that the usual procedure is to bake the optics after the last gluing, before putting them into the chambers.  Does anyone have opinions on this? 

On the one hand, it's probably safer to do a vacuum bake, just to be sure.  On the other hand, even if we could use one of the ovens immediately, it's a 48 hour bake, plus cool down time.  But they're working on aLIGO cables, and might not have an oven for us for a while.  Thoughts?

I think we should follow the established procedure in full, even though it will cost us a few more days.  I dont think we should consider the vacuum bake as something "optional".  If the glue has any volatile components they could be deposited on the optic resulting in a change in the coating and consequently optical loss in the arm cavity.

 Follow full procedure for full strength, minimum risk

As I feared, since I couldn't see the magnet-to-dumbbell joint from all angles, they ended up being off by ~1/3 of a magnet diameter. 

Because I don't want to deal with finding another failed glue joint tomorrow, I removed the magnet and dumbbell from the optic, and broke the manget off of the dumbbell.  As with yesterday, I kept track of which end of the magnet had been glued to the dumbbell. 

I got a new dumbbell, removed all the glue from the magnet, and reglued them together, in the fixture that ensures they are well aligned. 

Tomorrow I will come in and glue the magnet dumbbell assembly to the ITM.

 Glued.

Tomorrow afternoon I'll remove the optic from the fixture, and put it in the oven.

I edited the C1SUS_SUMMARY.adl file and set the channels in alarm mode to show the values in green, yellow and red according to the values of the thresholds (LOLO, LOW, HIGH, HIHI)

I wrote a script in python, which call the command ezcawrite and ezcaread, to change the thresholds one by one.

You can call this program with a button named "Change Thresholds one by one" in the menu come down when you click the  !  button.

I'm going to write another program to change the thresholds all together.

ITMY, which is supposed to be fully free-swinging at the moment, is displaying the tell-tale signs of  being stuck to one of it's OSEMs.  This is indicated by the PDMon values, one of which is zero while the others are max:

UL: 0.000
UR: 1.529
LR: 1.675
LL: 1.949
SD: 0.137

Do we have a procedure for remotely getting it unstuck?  If not, we need to open up ITMYC and unstick it before we pump.

I have restored the damping of BS and PRM. Today is janitor day. He is shaking things around the lab.

The ITMY mirror was released. The OSEM readouts became healthy.

To see what is going on, I changed the PIT DC bias slider on ITMY from 0.8 to -1 or so, and then the optic started showing a free swinging behavior.

If there were no responses to the DC bias, I was going to let people to open the chamber to look at it closer, but fortunately it released the optic.

Then I brought the slider back to 0.8, and it looked still free swinging. Possibly the optic had been stacked on some of the OSEMS as Jamie expected.

Atm1, ITMY and the SRM are on the same isolation stack.  So why does  the SRM move twice as much?

Atm2, We should check the ITMY  SIDE_OSEM before pump down. Anatomically correct, beautiful picture taken by Kiwamu on August 22

Suresh, Kiwamu and Steve

Heavy chamber doors replaced by light ones at  ITMX-west and ITMY-north locations.

The new ITMX was aligned by changing the DC biases.

The resultant DC biases are reasonably small.

C1:SUS-ITMX_PIT_COMM = -0.2909

C1:SUS-ITMX_YAW_COMM = -0.0617

The alignment was done by trying to resonate the green light in the X arm cavity.

The spot position of the green light on the ITMX mirror looked good. This was confirmed by inserting a sensor card.

I did the OSEM mid-range adjustment and the rotation adjustment but at the end the OSEM DC voltage has changed due to the DC bias operation.

The OSEM rotation was approximately optimized so that all the face shadow sensors are sensitive to the POS motion but the SIDE shadow sensor is insensitive to the POS motion.

It needs a free swinging diagnosis.

It stacked again . We should take a closer look at it.

 ITMX OSEMs   UL 1.8V,   UR 1.7V,   LR 0V,   LL 0V,   SD 1.3V  at the same bias setting shown above. May be a lose earth quake tip?or magnet is touching?

[Jenne, Katrin, Jamie]

I'm a bad kid, and forgot to elog my Friday morning work...

Bob gave me back ITMX after a 48hour bake at 80C + clean RGA scan Friday morning after coffee and doughnuts.  Katrin helped me put it back in the suspension wire. 

While I was leveling the optic (making sure the scribe lines on each side of the optic are at the same height off the table), Katrin cut some new viton for replacement EQ stops.  The optic was missing one lower earthquake stop (the one that Jamie noticed last week), and somehow one other rubber piece came out of the EQ stop on another lower screw while we were re-suspending the optic.  We put the new stops in, and then checked the balance of the test mass.

The oplev is still the HeNe laser that is leveled to the level optical table in the cleanroom.  The lever arm is ~1.5 meters, and over that distance the reflected beam was pointed "up" in pitch by ~1.5mm, which is less than one beam diameter of the HeNe.  This is well within our ability to correct using the OSEMs.

We then locked the test mass, and installed it in the chamber.  I approximately did the half-voltage centering of the OSEMs, leaving the fine-tuning to Kiwamu for after lunch. 

Tue Sep  6 17:48:02 PDT 2011
999391697

 Kiwamu excited ITMY (which Suresh had already started).  I just kicked ITMX:

Tue Sep  6 17:55:21 PDT 2011
999392136

[Rana and Kiwamu on ITMX, Jenne and Suresh on ITMY, Zombie/brains meeting on accepting the matricies]

Optic	Spectra	Matrix	"Badness"
ITMX		pit     yaw     pos     side    butt UL    0.584   0.641   1.396  -0.578   0.558  UR    0.755  -1.359   0.120  -0.286   0.262  LR   -1.245  -0.139   0.604  -0.388   0.511  LL   -1.416   1.861   1.880  -0.681  -2.669  SD   -0.753   0.492   3.263   1.000  -1.523	5.85983
ITMY		pit     yaw     pos     side    butt UL    1.000   0.572   1.134  -0.059   0.951   UR    0.578  -1.428   0.916  -0.032  -1.024   LR   -1.422  -0.531   0.866  -0.009   1.086   LL   -1.000   1.469   1.084  -0.036  -0.939   SD   -0.662   0.822   1.498   1.000   0.265	4.47727

 OSEMs were tweaked.  We have decided that both ITMs are okay in terms of their diagonalization.  ITMY isn't stellar when you look at the spectra, but it's kind of close enough.  Certainly the matrix looks fine.

Aside from checking on POX, I think we're now ready to close up.  Check back later tonight for a final decision announced on the elog.

(What we did)

* Moved SUS to edge of table for OSEM adjustment.

* Leveled the table in this temporary tower position.

* Rotated all OSEMs to give some seperation between magnets and LED/PD packages.

* Moved the upper OSEM bracket a little bit upward.

* All the OSEM holding set screws were short with flat heads; this is annoying since we would like to use them more like thumbscrews. Steve took the long set-screws out of the old ITMX cage and we swapped them. Need to order ~100 silver-plated socket head spare/replacements.

* Took pictures of OSEMs.

* Moved tower back to old position.

* Releveled the table (added one rectangular weight in the NW corner of the table).

* Find that ITMX OSEMs were a couple 100 micron out of position; we adjusted them in-situ in the final position of the tower, trying not to rotate them. All mean voltages now are within 100 mV of ideal half-light.

* Back/front EQ positions adjusted by the screw method. bottom/top stops adjusted earlier.

* OSEM cables tied down with copper wire.

* Increased the incident power up to 91 mW going into MC to temporarily make the POX beam more visible.

* The POX beam was checked. It was exiting from the chamber and going through about the center of the viewport.

I just started a freeswing all, as a final check before we pump:

Wed Sep  7 00:43:21 PDT 2011
999416616

Wed Sep  7 00:43:32 PDT 2011
WATCHDOGS WILL BE RESET 5 HOURS AFTER THIS TIME
sleeping for 5 hours...

Jamie: Please do a quickie analysis (at least for the ITMs) before helping Steve with the heavy doors.

I closed the PSL shutter.

Both ITM chambers were checked for tools, so there should be nothing left to do but put the heavy doors on, and begin pumping.

All fine, except ITMX_sensor_UL's  60  counts deep hoop for an hour.

Here are all suspension diagonalization spectra before close up. Notes:

• TMX looks the worst, but I think we can live with it. The large glitch in the UL sensor at around 999423150 (#5355) is worrying. However, it seemed to recover. The spectra below were taken from data before the glitch.
• ITMY has a lot of imaginary components. We previously found that this was due to a problem with one of it's whitening filters (#5288). I assume we're seeing the same issue here.
• SRM needs a little more data to be able to distinguish the POS and SIDE peaks, but otherwise it looks ok.

ITMX		pit     yaw     pos     side    butt UL    0.355   0.539   0.976  -0.500   0.182  UR    0.833  -1.406  -0.307  -0.118   0.537  LR   -1.167   0.055   0.717  -0.445   0.286  LL   -1.645   2.000   2.000  -0.828  -2.995  SD   -0.747   0.828   2.483   1.000  -1.637	8.01148
ITMY		pit     yaw     pos     side    butt UL    1.003   0.577   1.142  -0.038   0.954   UR    0.582  -1.423   0.931  -0.013  -1.031   LR   -1.418  -0.545   0.858   0.008   1.081   LL   -0.997   1.455   1.069  -0.017  -0.934   SD   -0.638   0.797   1.246   1.000   0.264	4.46659
BS		pit     yaw     pos     side    butt UL    1.612   0.656   0.406   0.277   1.031   UR    0.176  -1.344   1.683  -0.058  -0.931   LR   -1.824  -0.187   1.594  -0.086   0.951   LL   -0.388   1.813   0.317   0.249  -1.087   SD    0.740   0.301  -3.354   1.000   0.035	5.49597
PRM		pit     yaw     pos     side    butt UL    0.546   1.436   1.862  -0.345   0.866   UR    1.350  -0.564   0.551  -0.055  -0.878   LR   -0.650  -0.977   0.138   0.023   0.858   LL   -1.454   1.023   1.449  -0.268  -1.398   SD    0.634  -0.620  -0.729   1.000   0.611	5.78216
SRM
ETMX		pit     yaw     pos     side    butt UL    0.863   1.559   1.572   0.004   1.029   UR    0.127  -0.441   1.869   0.480  -1.162   LR   -1.873  -0.440   0.428   0.493   0.939   LL   -1.137   1.560   0.131   0.017  -0.871   SD    1.838   3.447  -0.864   1.000  -0.135	5.5259
ETMY		pit     yaw     pos     side    butt UL   -0.337   1.275   1.464  -0.024   0.929   UR    1.014  -0.725   1.414  -0.055  -1.102   LR   -0.649  -1.363   0.536  -0.039   0.750   LL   -2.000   0.637   0.586  -0.007  -1.220   SD    0.057  -0.016   1.202   1.000   0.142	4.22572
MC1		pit     yaw     pos     side    butt UL    0.858   0.974   0.128   0.053  -0.000   UR    0.184  -0.763   0.911   0.018   0.001   LR   -1.816  -2.000   1.872   0.002   3.999   LL   -1.142  -0.263   1.089   0.037   0.001   SD    0.040   0.036  -0.216   1.000  -0.002	5.36332
MC2		pit     yaw     pos     side    butt UL    1.047   0.764   1.028   0.124   0.948   UR    0.644  -1.236   1.092  -0.088  -0.949   LR   -1.356  -0.680   0.972  -0.096   1.007   LL   -0.953   1.320   0.908   0.117  -1.095   SD   -0.092  -0.145  -0.787   1.000  -0.065	4.029
MC3		pit     yaw     pos     side    butt UL    1.599   0.343   1.148   0.168   1.101   UR    0.031  -1.647   1.139   0.202  -1.010   LR   -1.969   0.010   0.852   0.111   0.893   LL   -0.401   2.000   0.861   0.077  -0.995   SD   -0.414   0.392  -1.677   1.000   0.018	3.61734

The OSEM pictures taken in Sep/6 have been uploaded to Picasa.

https://picasaweb.google.com/foteee

All the optcs were excited

Sat Sep 10 02:14:11 PDT 2011
999681266
 

Now that we are in a moderately stable condition, its time to design the optical lever feedback transfer functions. We should think carefully about how to do this optimally.

In the past, the feedback shape was velocity damping from 0-10 Hz, with some additional resonant gain around the pendulum and stack modes. There were some low pass filters above ~30 Hz. These were all hand tuned.

I propose that we should look into designing optimal feedback loops for the oplevs. In principle, we can do this by defining some optimal feedback cost function and then calculate the poles/zeros in matlab.

How to define the cost function (? please add more notes to this entry):

1) The ERROR signal should be reduced. We need to define a weight function for the ERROR signal: C_1(f) = W_1(f) * (ERR(f)^2)

2) The OL QPDs have a finite sensing noise, so there is no sense in suppressing the signal below this level. Need to determine what the sensing noise is.

3) The feedback signal at high frequencies (30 Hz < f < 300 Hz) should be low passed to prevent adding noise to the interferometer via the A2L coupling. It also doesn't help to reduce this below the level of the seismic noise. The cost function on the feedback should be weighted apprpriately given knowledge about the sensing noise of the OL, the seismic noise (including stack), and the interferometer noise (PRC, SRC, MICH, DARM).

4) The servo should be stable: even if there is a negligible effect on the ERROR signal, we would not want to have more than 10 dB of gain peaking around the UGFs.

5) The OL QPDs are dominated by drift of the stack, laser, etc. at some low frequencies. We should make sure the low frequency feedback is high passed appropriately.

6) Minimize transmitted power rms in single arm lock etc.

The PRM damping was restored at side sensor var 1050

I've found that a few of the screens still have Whited-Out fields due to naming changes (OL SUM and ALS-> TM OFFSET). I attach a screen shot of it.

The OL screens have the wrong SUM names and the IFO ALIGN screen is pointing to the wrong SUS screens.

I went to see what was wrong with the ITMs and found that people have been working on them and have left them in a broken state with no elog entry.

This is sad and unacceptable.

Whoever is working on these should post into the elog what the Oplev layout plan is, have someone check it, and ONLY THEN get to work on it.

The layout as it looks tonight is too complicated. With too many optics we will not have a low noise optical lever setup. The new layout should use a bare minimum number of optics and only use very stable mounts.

 The PRM sus damping restored.

The f2a filters were newly designed and installed on BS and PRM.

So the lock of PRMI will be more stable .

Once the SRM oplev project settles down, I will adjust the f2a filters on SRM too.

Today I worked on getting the ITMY and SRM oplevs back in working order. I aligned the SRM path back onto the QPD. I put excitations on the ITMY and SRM in pitch and yaw and observed the beam at the QPDs to check for clipping. They looked clean from clipping.