ETMX has some periodic oscillation. It's damping was found tripped this morning. 

We tracked this down to the power normalization stuff that Yoichi added over the weekend.

With a non-zero normalization factor, and a small TRX transmission, the input the XARM controller gets really big.  When XARM is then triggered, a huge impulse is sent into the SUS_ETMX_LSC input, which causes the Vio2 filter in FM0 to ring like crazy.  This probably also explains why Yoichi was seeing trouble locking the arm when the normalization is on

The solution, as Yoichi also mentions, is probably to trigger the normalization like we trigger the rest of the boost filters.

Oplevs centered in flashing condition, except PRM and SRM.  IP POS centered also,

I like this new summing screen of Jenne.

  It looks like we may lost 1 (or 3 )  magnets? Do not panic, it's not for sure

After shaking ITMX by the alignment bias in yaw, it came back.

As ETMX seems to be largely misaligned yaw (and did not come back with the alignment impact),
the condition of the magnets are not clear. Only the side OSEM is responding nicely.

I tried to take some photos through the window of ETMX's chamber, to see if I could see any magnets.  What we have learned is that Jenne is still not the world's best photographer.  I was holding the camera at ~max zoom inside the beam tube between the table and the window, so that's my excuse for the photos being fuzzy.  The only thing that I can really conclude is that the magnets look like they are still there, but Jamie thinks they may be stuck on the PDs/LEDs (now looking at the photos myself, I agree, especially with UL and LR). 

It looks like the best thing to do at this point, since Koji already tried jerking ETMX around in yaw a little bit, is just wait and open the door, to see what's going on in there.  I posted the photos on Picasa:

https://picasaweb.google.com/foteee/ETMX_MaybeStuck_ThroughWindow_27Aug2012

I propose that, if the magnets are broken, we pull the ETM out of the camber and fix it up in the cleanroom while we pump back down.  This would restrict us from doing any Xarm work, but will force me to focus on DRMI, and we can put the ETM back when we vent to install the tip tilts.

ETMX appears to be fine.  It was stuck to its OSEMs in the usual way.  I touched it and it dislodged and is now swinging freely.  Damping loops have been re-engaged.

Earthquake m4.1 test for ETMX and moves ITMX.  ITMX-LR sensor 0.3V

[EricQ, Jenne]

We placed the Watek camera on the SE viewport of the ITMX chamber, and focused it on the face of PRM.  We are not able to see any scattered light transmitted through the PRM, so this camera was an ineffective way to try to check spot centering on the PRM.  Jamie placed one of the new targets on the PRM cage - see his elog for details.

To get more use of the camera, we need to mount it on something, at the 5.5 inch beam height, and then cover that something with clean foil so we can place the camera on the table, in the beamline in various places.  We also need to carefully wrap the cables in foil so the don't dirty anything inside.

We installed beam targets on PRM and BS suspension cages.

On both suspensions one of the screw holes for the target actually houses the set screw for the side OSEM.  This means that the screw on one side of the target only goes in partial way.

The target installed on BS is wrong!  It has a center hole, instead of two 45 deg holes.  I forgot to remove it, but it will obvious it's wrong to the next person who tries to use it.  I believe we're supposed to have a correct target for BS, Steve?

The earthquake stop screws on PRM were too short and were preventing installation of the PRM target.  Therefore, in order to install the target on PRM I had to replace the earthquake stops with ones Jenne and I found in the bake lab clean room that were longer, but have little springs instead of viton inserts at the ends.  This is ok for now, but

WE NEED TO REMEMBER TO REPLACE EARTHQUAKE STOPS ON PRM WHEN WE CLOSE UP.

We checked the beam through PRM and it's a little high to the right (as viewed from behind).  Tomorrow we're going to open ITMX chamber so that we can get a closer look at the spot on PR2.

 The two eye  target for  the BS is in the clean tool box. It actually has irises.

The SOS centering target is 1.9 mm lower than it should be! 

The hole is 10mm for the  ~6 mm beam

Q and I aligned the BS such that we were hitting the center of ETMX. The ETMX cage does not have OSEM setscrew holes on the front, so it is not possible to put the targets that Steve made on this optic.  So, I put the freestanding ruler in front of the optic, with the edge of the ruler at the center (as viewed from above) of the optic.  Then Eric steered the BS until we were hitting the 5.5" mark, and roughly half of the beam was obscured by the ruler.

We then aligned ITMX such that the prompt reflection was colinear with the incoming beam. 

I checked the 2 spots through the BS, heading to the AS port.  (2 spots since MICH hasn't been locked / finely aligned yet).  They were being clipped on the 2nd output PZT.  I adjusted the knobs of the first output PZT to center the spots on the 2nd PZT.  Note that the output PZTs' power is still off, and has been off for some unknown length of time.  I had found them off when prepping for the vent a week or two ago.  So the current alignment depends on them staying off.  We don't really need them on until we're ready to employ our OMC.

The beams now look nicely unclipped on the AS camera, and we're aligning MICH.

I have given Den 4 G&H R>99.99% mirrors to be installed on the 4 active tip tilts.  He's in there working on things (incl. installing and balancing the pitch of the mirrors) right now.  He'll elog his work later.

 I've installed the mirrors on 4 tip-tilts. I was able to align 3 of them in pitch, the last one has a screw with damaged thread, I'll continue with it tomorrow.

Alignment accuracy in pitch is ~0.1 mrad. Mirrors oscillate a lot probably due to air flow coming from the side wall.

I was helping Den get started in the cleanroom yesterday, and I noticed that the new active TTs, like the old passive ones, are set to be 4" from the table.  So, like the old ones, we need 1.5" risers to get the center of the mirror up to our in-vac 5.5" beam height.  I didn't see any risers in there when I was looking around. 

Steve says he still has the drawing that he gave to the shop for the old tip tilts, so he'll double check that the dimensions are the same, and then ask the shop to make 4 more.

SOS alignment tool with ID 9.5 and 6.3 mm

I did TT alignment using red laser and QPD.

 I had a problem aligning TT with frame number SN-035 as some screws are damaged so all what I could move were 2 blades on the sides of the mirrors. But this was not enough to align pitch and yaw simultaneously.  It is possible to align pitch only, but then I got a huge yaw angle (~0.05-0.1 rad). The only option I had was to make a reasonable alignment in yaw and then suspend several washes on the screw on the bottom of the mirror to align pitch.

Attached are flag positions inside coils. 1 - SN034, 2 - SN012, 3 - SN006, 4 - SN035. For each TT there are 4 pictures with flag 1-4: UL, LL, UR, LR

  [Koji, Steve, Den]

TT alignment is fine, yaw damping is satisfactory, pitch damping is slow. We might want to add magnets to the mirror and attach blades to the frame for pitch edge current damping.

We are moving towards electronics testing.

Atm1,  TT 1.5" high adaptor base will be back from the shop in 10 days.

Atm2,  There is no PITCH damping, YAW edie current damping works well at 0.5 mm gap

Atm3,  Adjustable Al -disc that contains a small magnet is purely designed.

We have to come up with a solution to have damping in PITCH

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

This is the third morning in a row that the MC2 was tripped.  Would you look at it Koji?

This may be cause by the impact of crazy WFS signal after the lock loss.
The auto locker is not fast enough to shut the WFS down before the mirrors are kicked.

Jenne and I discussed the issue and agreed that this can be solved by implementing
the same triggering algorithm as the LSC triggers.

Give us a bit more time to work on this.

All suspension damping has been restored.

One terrible concern of mine is that the slow machines were rebooted at the power interruption.
Based on the elog entries, I assume they have not been burtrestored...

If this is true, they may cause some weird behaviors of the PSL/IOO electronics.

 Do you know how to burtrestore or restart slow machines?

Edit by Den: I did burtrestore of c1psl.snap from 2 days ago. Still slow machines behave not normal. For example, if I sweep C1:PSL-FSS_SLOWDC, SLOW monitor value does not change.

 Problems with Slow Machines?

Read ELOG

 MC2 was tripped again. I think the answer is that watchdog's critical value was too small C1:SUS-MC2_PD_MAX_VAR = 10, so seismic could trip MC2. I've changed the value to 100.

I think the ETMX slow machine might be dead.  All of the regular FE readbacks are fine, and the c1iscex FE computer looks fine, but the slow readbacks are all whited out. 

I turned off the damping loops for ETMX, since I don't have access to the watchdog disable/enable switch.  I guess checking this out will be task #1 for Monday morning.

 For lack of a better idea, I keyed the crate.  The computer came back up just fine, ETMX is happily damped again.

 The shame:

There is no situation in which it is OK to install a mount like this. Steve had installed this flaky and shaky mount to optimize the beam size on the OL QPD.

Everyone in the lab should know better. Putting in something like this is just like sabotage - it creates extra noise in our interferometer in a sneaky way and just makes locking harder. All mounts for anything useful (including QPDs) must have highly rigid mounts. 

Use the example from the PSL relayout: use the 3/4" steel mounts and the wide aluminum bases from Newport. No more art projects using home made mounting crap, Steve.

I went inside to align the beam on WFS and noticed that oscillations in yaw are ~10 times stronger then in pitch. I've plot rms of pitch and yaw measured by LID sensors and saw that MC3 yaw rms motion is a few times larger then pitch.

Also MC1 input diag matrix does not diagonalize signals for pitch and yaw. In the spectrums of these signals all 4 resonance are equally seen during the free swinging. I think we should rediagonalize MC1.

Another thing is that if MC1 and MC3 are on the same stack,  pitch and yaw spectrums of these mirrors should be comparable. But MC1 signal is ~2-3 times larger then of MC3. I think we should correct calibration.

What are "LID" sensors?  Do you mean the OSEM shadow sensors?  I'm pretty sure that's what you meant, but I'm curious what "LID" means.

 Since we upgraded the CDS system, I guess our ADC ranges have gone up but we never did anything to the OLs to match the ADC ranges. From Liz's daily summary page of the OL, I see this:

So we need a factor of 5-10 increase in the electronics gain (why isn't the BS SUM on there?). This might be accomplished in the head, but for the ones with whitening boards, might be better to do there.

(** add to Jamie's list of long term tasks **)

I've written MC123 input matrixes to the front-end.

MC1 diagonalization is poor, better then before, but still pitch is seen in pos and yaw. Either smth is malfunctioning or flags touch sensors and do not move freely. On the plot mc1_new black lines - before, red - after rediagonalization.

 I've actuated on MC1 with UL, UR, LR, LL coils in turn and measured sensor readings. All coils separately work fine from the first look.

On the plot: black - free mirror, blue - UL coil actuation, green - UR, grey - LR, red - LL.

Tip Tilt pitch adjustment on existing-in vacuum suspension. This can be added by a simple installation of a 1.25" long 2-56 threaded rod with nuts.

 I've manually corrected MC1 input matrix by looking at UL, UR, LL, LR transfer functions between each other. This improved pos significantly and slightly yaw.

 We can only decide the need of pitch damping when the coils are activated.

Could you tell us why? Are you thinking about induced current damping?

      I  was wrong The instability will be the same when the coils are actuated.

 The PRM damping restored. Oplev  PIT gain  0.15 and YAW  gain   -0.3 turned to zero.

 Several of the suspensions were kicked pretty hard (600+ mV on some sensors) as a result of this quick vent wind.  All of the suspensions are damped now, so it doesn't look like we suffered any damage to suspensions.

Steve has promised to fix up all of the oplevs, but it hasn't happened yet, so I've turned all of the oplev gains to zero, so that when the optics are restored we don't have to quickly click them off.

Oplev values that were changed to zero:

PRM P=0.15, Y=-0.3

SRM P=-2.0, Y=2.0

BS P=0.2, Y=-0.2

ITMY P=2.1, Y=-2.0

ITMX P=1.0, Y=-0.5

ETMX P=-0.2, Y=-0.2

ETMY P=0.5, Y=0.6

Also, PRCL was changed in the LSC input matrix from REFL33I to AS55I, since there is no REFL beam out of the IFO :(

 Pitch damping solution needed! It should be in the machine shop already.