[Jenne, with ample supervision by Kiwamu and Suresh]

Y-green was aligned, and is now flashing.  The ETMY trans camera was very helpful for this alignment.  I didn't end up needing to use a foil aperture. 

Kiwamu and Suresh had just closed up the IOO doors, so we don't know yet where it's hitting on the PSL table (if the beam is making it that far).  Tomorrow we'll look at ITMY to see if the green beam is centered there, and if it's coming out to the PSL table.

[Kiwamu, Suresh]

We worked on the beam path from MC to BS this evening. 

After the beam spots on MC1 and MC3 were close to the actuation nodes (<1mm away) we checked the beam position on the Faraday Isolator (FI) to make sure that it is passing through both the input and output apertures without clipping.  The beam is slightly displaced (by about half a beam diameter) downwards at the input of the FI.  The picture below is a screen shot from the MC1 monitor while Kiwamu held an IR card in front of the FI.

We then proceeded to check the beam position on various optical elements downstream.  But first we levelled the BS table and checked to see if the reflection from PJ1 (1st Piezo) is landing on the MMT1 properly.  It was and we did not make any adjustment to PJ1.  However the reflection from MMT1 was not centered on MMT2.  We adjusted the MMT1 to center the beam on it.  We then adjusted MMT2 to center the beam on PJ2.  At this point we noticed that the spot on IPPO (pick off window)  was off towards the right edge.  When we centered the beam on this it missed the center of the PRM.  In order to decide what needs to be moved, we adjusted PJ2 such that the beam hits the PR2, bounces back to PR3, and becomes co-incident with the green beam from X-arm on the BS.  Under this condition the beam is not in the center of PRM and nor is it centered on IPPO.  In fact it is being clipped at the edge of the IPPO. 

It is clear that both IPPO and the PRM need to be moved.  To be sure that the beam is centered on PR2 we plan to open the ITMX chamber tomorrow.

I'm having this problem with DTV every morning at Rosalba only. It wants to start with a negative GPS time and it can not connect to the frame builder.

Normally after a few time of starting it, it will work.

 New calibration for Guralp:

ADC: 2¹⁶counts = 20V Hence, calibration of ADC is (2¹⁵x0.1) counts/V.

GURALP

Sensitivity = 800 V/ms^-1

(2¹⁵ x 0.1) counts/V x 800  V/ms^-1 = 2621440 counts/ms^-1 ----->  3.8147e-07 ms^-1/count

Calibration = 3.8147e-07 ms^-1/count

Using the above calibration we obtain the following plot:

When we compare this plot with the old plot (see here) we see that in our calibration, we have got a factor of 10 less than the old plot. We do not know the gain of the Guralp. If we assume this missing 10 factor to be the gain of Guralp then we can get the same calibration as the old plot. But is it correct to do so?

 After pressing the auto-zero button (a lot of times) of the STS breakout box & aligning the bubble in the STS, we could finally get data from STS (Bacardi). So, now STS2 (Bacardi - Serial NR. 100151) is working!

 We just checked with a function generator the calibration of the ADC. We set a square wave with amplitude 1V. We measured the voltage with the oscilloscope and we found on the data viewer that one volt is 3208 counts. That's what we expected (+/- 10V for 16bits) but now we are more sure.

The spot positions on the MC mirrors were adjusted by steering the MC mirrors, resulting in 1 mm off-centering on each optic.

DONE.

(Requirement cleared)

One of the requirements in aligning the MC mirrors is the differential spot positions in MC1 and MC3.

It determines the beam angle after the beam exists from MC, and if it's bigger than 3 mm then the beam will be possibly clipped by the Faraday (#4674).

The measured differential spot positions on MC1 and MC3 are : PIT = 0.17 mm and YAW = 1.9 mm, so they are fine.

(Measurement and Results)

 Suresh and I aligned the MC cavity's eigen axis by using MCASS and steering the MC mirrors.

Most of the alignment was done manually by changing the DC biases

because we failed to invert the output matrix and hence unable to activate the MCASS servo (#5167).

Then I ran Valera's script to measure the amount of the off-centering (#4355), but it gave me many error messages associated with EPICS.

So a new script newsensedecenter.csh, which is based on tdsavg instead of ezcaread, was made to avoid these error messages.

The resultant plot is attached. The y-axis is calibrated into the amount of the off-centering in mm.

In the plot each curve experiences one bump, which is due to the intentional coil imbalance to calibrate the data from cnts to mm (#4355).

The dashed lines are the estimated amount of off-centering.

For the definition of the signs, I followed Koji's coordinate (#2864) where the UL OSEM is always in minus side.

Following is the coherence plot obtained when Guralp1 and STS2(Bacardi, Serial NR 100151) are placed very close to each other (but they aren't touching each other):

The seismometers were placed as shown in the picture below:

They are placed below the center of the mode cleaner vacuum tube.

 Gear box found, it's  lead time one week at $825    The crane may be functional round August 25

Finally, we have found the correct calibration of Guralp and STS2 seismometers.

ADC: 2¹⁶counts = 20V Hence, calibration of ADC is 3.2768e+03 counts/V.

GURALP

Sensitivity of seismometer = 800 V/ms^-1

Gain of the guralp breakout box (reference elog entry) = 20

Calibration = 3.2768e+03 counts/V x 800  V/ms^-1 x 20 = 52428800 counts/ms^-1 -----> 1.9073e-08 ms^-1/count

STS

Sensitivity = 1500 V/ms^-1

Gain of the STS electronic breakout box = 10

Calibration = 3.2768e+03 counts/V x 1500  V/ms^-1 x 10 = 49152000 counts/ms^-1 -----> 2.0345e-08 ms^-1/count

 Following is the power spectrum plot (with corrected calibration [see here]) of seismometers Guralp1 and STS2(Bacardi, Serial NR 100151):

 The seismometers are placed approximately below the center of the mode cleaner vacuum tube.

[Jamie, Koji]

ITMX OSEMs were adjusted so as to have the right DC numbers and the more uniform response to POS excitation.

It is waiting for the free-swinging test.

- ITMX was moved from its position to the north side of the table.

- The table was rebalanced.

- We found that the output of the LR OSEM has an excess noise compared with the other OSEMs.
We tried to swap the LR and SD OSEMs, but the SD OSEM (placed at the LR magnet) showed
the same excess noise at around 10-50Hz.

- We found that one of the EQ stops was touching the mirror. By removing this friction, all of the OSEMs
come to show similar power spectra. Good!

 - Then we started to use LOCKIN technique to measure the sensitivity of the OSEMs to the POS excitation.

Originally the response of the OSEMs was as follows
UL 3.4 UR 4.3 
LL 0    LR 2.5   

After the adjustment of the DC values, final values became as follows
UL 3.9 UR 4.4
LL 3.9  LR 3.2

- We decided to close the light door.

We started an ITMX freeswing run at this time

Thu Aug 11 18:58:59 PDT 2011
997149554

 But the optic did not repond to the kick.  It is possible that the earthquake stops are close to the face and/or rear of the optic and prevent it from oscillating.  We will check again and see what is up in a few hours.

We moved the STS2(Bacardi, Serial NR 100151) to his new location and laid his cable from rack 1X7 to ETMX. The seismometer was below the mode cleaner vacuum tube before.

Now, (since 6:05pm PDT) its placed near the ETMX.

 We moved the seismometer STS2(Bacardi, Serial NR 100151) as we told in this Elog Entry, so the distance between Guralp1 and STS2 is 31.1m. Following is the coherence plot for this case:

then we also moved the Guralp1 under the BS and plugged it with the Guralp2 cable (at 7:35pm PDT), so now the distance between the two seismometers is 38.5m. Following is the coherence plot for this case:

[Suresh / Kiwamu]

 We tried adjusting the OSEMs on PRM, but we didn't complete it due to a malfunction on the coils.

The UL and LL coils are not working correctly, the forces are weak.

Tomorrow we will look into the satellite box, which is one of the suspects.

 During the adjustment we found that the POS excitation force was unequal in each sensor.

At the beginning we thought it's because of the difference of the sensitivity in each OSEM due to the bad OSEM orientations.

However it turned out that it comes from the actual force imbalance on each coil.

We checked the force of each coil by putting an offset (-2000 cnts) in each output digital filter and looked at the OSEM signals in time series.

The UL and LL coils are too weak and the responses are almost buried in the noise of the OSEMs in time series.

We briefly checked some analog electronics and found the DAC, AI board and deWhitening board were healthy.

We were able to see the right amount of voltage from the monitor pin on the front panel of the coil driver.

So something downstream are suspicious, including the satellite box, feedthrough and coils.

- - -

Although the coil issue, it could be worth trying to check the input matrix.

Excited all optics - -
Fri Aug 12 03:34:12 PDT 2011
997180467

Here's an update of the suspensions, after yesterdays in-vacuum work and OSEM tweaking:

• PRM and ETMY are completely messed up.  The spectra are so bad that I'm not going to bother posting anything.   ETMY has extreme sensor voltages that indicate that it's maybe stuck to one of the OSEMS.  PRM voltages look nominal, so I have no idea what's going on there.
• ITMY is much improved, but it could still use some work
• SRM is a little worse than what it was yesterday, but we've done a lot of work on the ITMY table, such as moving ITMY suspension and rebalancing the table.
• BS looks for some reason slightly better than it did yesterday

TM		M	cond(B)
SRM		pit     yaw     pos     side    butt UL    0.828   1.041   1.142  -0.135   1.057  UR    1.061  -0.959   1.081  -0.063  -1.058  LR   -0.939  -0.956   0.858  -0.036   0.849  LL   -1.172   1.044   0.919  -0.108  -1.035  SD    0.196  -0.024   1.861   1.000   0.043	4.20951
ITMY		pit     yaw     pos     side    butt UL    1.141   0.177   1.193  -0.058   0.922  UR    0.052  -1.823   0.766  -0.031  -0.974  LR   -1.948  -0.082   0.807  -0.013   1.147  LL   -0.859   1.918   1.234  -0.040  -0.957  SD   -1.916   2.178   3.558   1.000   0.635	7.70705
BS		pit     yaw     pos     side    butt UL    1.589   0.694   0.182   0.302   1.042  UR    0.157  -1.306   1.842  -0.176  -0.963  LR   -1.843  -0.322   1.818  -0.213   0.957  LL   -0.411   1.678   0.158   0.265  -1.038  SD    0.754   0.298  -3.142   1.000   0.053	6.12779

According to Rana, the following is the "new" (should always have been used, but now we're going to enforce it) earthquake stop backing-off procedure:

1. Back all EQ stops away from the optic, so that it is fully free-swinging.

2. Confirm on dataviewer that the optic is truely free-swinging.

3. One at a time, slowly move the EQ stop in until it barely touches the optic.  Watch dataviewer during this procedure - as soon as the time series of the OSEMs gets a 'kink', you've just barely touched the optic.

4. Back the EQ stop off by the calculated number of turns.  No inspections, no creativity, just math.  Each EQ stop should be between 1.5m and 2.0mm away from the optic.

5. Repeat steps 3 and 4 for each EQ stop.

Note: The amount that you need to turn the screws depends on what the threads are.

FACE and TOP stops are all 1/4-20, so 1.5 turns is 1.90mm

BOTTOM stops are either #4-40 or #6-32 (depending on the suspension tower).  If #4-40, 3 turns is 1.90mm.  If #6-32, 2.5 turns is 1.98mm

I'm looking for an ether net based  power switch for turning lights on and off for the vacuum system from MEDM screen.  This is what I found

Jamie please take a look at it.

[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.

Adjustment of the PRM OSEMs are done. The coils turned out to be healthy.

The malfunction was fixed. It was because the UL OSEM was too deeply inserted and barely touching the AR surface of the mirror.

(OSEM adjustment)

 + Excited POS at 6.5 Hz with an amplitude of 3000 cnts by the LOCKIN oscillator.

 + Looked at the signal of each sensor in frequency domain.

 + Maximized the excitation peak for each of the four face OSEMs by rotating them.

 + Minimized the excitation peak in the SIDE signal by rotating it.

 + Adjusted the OSEM translational position so that they are in the midpoint of the OSEM range.

(POS sensitivity check)

From the view point of the matrix inversion, one thing we want to have is the equally sensitive face sensors and insensitive SIDE OSEM to the POS motion.

To check the success level of today's PRM adjusment, I ran swept sine measurements to take the transfer function from POS to each sensor.

The plots below are the results.  The first figure is the one measured before the adjustment and the second plot is the one after the adjustment.

As shown in the plot, before the adjustment the sensitivity of OSEMs were very different and the SIDE OSEM is quite sensitive to the POS motion.

So PRM used be in an extremely bad situation.

After the adjustment, the plot became much better.

The four face sensors have almost the same sensitivity (within factor of 3) and the SIDE is quite insensitive to the POS motion.

I am leaving all of the suspensions free swinging. They will automatically recover after 5 hours from now.

--
Excited all optics
Sat Aug 13 02:08:07 PDT 2011
997261703
--

FYI : I ran a combination of two scripts:   ./freeswing && ./opticshutdown

I guess the ETMY suspension is still fine. Their OSEM DC voltage and the free swinging spectra look healthy.

It could be a failure in the initial guess for fitting.

Below are some plots from dataviewer of temperature-step data taken over the past 32 hours. (They show minute trends). I am looking at the thermal coupling from the can surrounding the reference cavity on the PSL table to the cavity itself, and trying to measure the cavity temperature response via the control signal sent to heat the NPRO laser, which is locked to the cavity.

• Top left: out-of-loop temperature sensor on can surrounding ref cav (RCTEMP)
• Top right: control signal sent to slow drive of laser (laser heater), which is supposed to follow the cavity temperature (TMP_OUTPUT)
• Bottom left: in-loop can temperature sensors (MINCOMEAS)
• Bottom right: room temperature reading (RMTEMP)

I stepped the temperature set point from 35 to 36 deg. C for the can at 12:30am last night. Then I waited to see the cavity temperature change and the slow actuator (laser heater: TMP_OUTPUT) follow that change.

I was a bit worried about the oscillations that were occuring in the TMP_OUTPUT signal even long after this temperature step was made, but I figured that they were simply room-temperature changes propagating into the cavity, since they seemed to have a similar pattern to the room-temperature variations, and since it is clear that the out-of-loop temperature sensor on the can (RCTEMP) experiences variations, even when the in-loop sensors are recording no variation.

At 8:46pm tonight I stepped the temperature down 2 degrees to 34 deg. C. The step had a clear effect on TMP_OUTPUT. The voltage to the heater dropped and eventually railed at its lowest output. I'm worried that the loop is unstable, although I haven't ruled out other possibilities, such as that a 2 deg. C temperature step is too large for the loop. I will investigate further in the morning.

 The lock was lost when I came in around noon today to check on it. The slow actuator was still railing.

1) I got lock back for a few minutes, by varying the laser temperature set point manually. TMP_OUTPUT was still reading -30000 cts (minimum allowed) and the transmission was not as high as it had been.

2) I toggled the second filter button off. The TMP_OUTPUT started rising up to ~2000 cts. I then toggled the second filter back on, and TMP_OUTPUT jumped the positive maximum number of counts allowed.

3) I lost the lock again. I turned off the digital output to the slow actuator.

4) I have so far failed at getting the lock back. My main problem is that when the BNC cable to the slow port is plugged in, even when I'm not sending anything to that port, it makes it so that changing the temperature set point manually has almost no effect on the transmission (it looks as though changing the setpoint is not actually changing the temperature, because the monitor shows the same higher order mode even when with +-degree temperature setpoint changes).

like the subject says...

Excited all optics
Sun Aug 14 20:22:33 PDT 2011
997413768

[Suresh / Kiwamu]

 Adjustment of the OSEMs on BS has been done.

All the bad suspensions (#5176) has been adjusted. They are waiting for the matrix inversion test.

This morning Steve and I opened the doors on the IOO and OMC chamber to let the IR beam go to MC.

And found the MC flashing is way far from TEM00, there were very higher order modes.

The MC suspensions were realigned based on an assumption that the incident beam didn't change recently.

Anyways we should check the leveling of the IOO table and the spot positions on the MC mirrors again to make sure.

 Turns out I was missing a critical step in the process...running makeSUSspectra.m  After I do that, everything is back under control, and ETMY looks fine. 

I'm almost done doing the peak-fitting and matrix inversion for all optics.

The leveling was still okay. The MC mirrors were realigned and now they all are fine.

We will go ahead for the vertex alignment and extraction of the pick-off beams.

Here is a summary of the spot measurement.

The moral of the story here is that none of the suspensions are overwhelmingly awesome, but most of them will be fine if we leave them as-is.

SUS	DoF Plot	Input Matrix	"BADness" (1==good)
ITMX		pit     yaw     pos     side    butt UL    0.438   1.019   1.050  -0.059   0.717  UR    0.828  -0.981   1.128  -0.215  -0.956  LR   -1.172  -1.201   0.950  -0.275   1.241  LL   -1.562   0.799   0.872  -0.120  -1.087  SD   -0.579  -0.847   2.539   1.000  -0.170	4.68597
ITMY		pit     yaw     pos     side    butt UL    1.157   0.185   1.188  -0.109   0.922  UR    0.020  -1.815   0.745  -0.051  -0.970  LR   -1.980  -0.090   0.812  -0.024   1.158  LL   -0.843   1.910   1.255  -0.082  -0.949  SD   -0.958   1.080   1.859   1.000   0.325	4.82756
ETMX		pit     yaw     pos     side    butt UL    0.338   0.476   1.609   0.316   1.046   UR    0.274  -1.524   1.796  -0.069  -1.180   LR   -1.726  -1.565   0.391  -0.100   0.938   LL   -1.662   0.435   0.204   0.286  -0.836   SD    0.996  -2.629  -0.999   1.000  -0.111	4.32072
ETMY		pit     yaw     pos     side    butt UL    1.123   0.456   1.812   0.231   0.936  UR   -0.198  -1.489   0.492  -0.096  -1.098  LR   -2.000   0.055   0.188  -0.052   0.764  LL   -0.679   2.000   1.508   0.275  -1.201  SD    0.180  -0.591   3.355   1.000   0.200	10.643
BS		pit     yaw     pos     side    butt UL    1.575   0.697   0.230   0.294   1.045  UR    0.163  -1.303   1.829  -0.133  -0.958  LR   -1.837  -0.308   1.770  -0.171   0.944  LL   -0.425   1.692   0.171   0.257  -1.053  SD    0.769   0.345  -3.380   1.000   0.058	6.111
PRM		pit     yaw     pos     side    butt UL    0.597   1.553   2.000  -0.469   1.229   UR    1.304  -0.447   0.383  -0.043  -0.734   LR   -0.696  -1.048  -0.277   0.109   0.687   LL   -1.403   0.952   1.340  -0.317  -1.350   SD    0.518  -1.125  -1.161   1.000   0.394	8.43363
SRM		pit     yaw     pos     side    butt UL    0.831   1.039   1.153  -0.140   1.065  UR    1.071  -0.961   1.104  -0.057  -1.061  LR   -0.929  -0.946   0.847  -0.035   0.837  LL   -1.169   1.054   0.896  -0.118  -1.037  SD    0.193  -0.033   1.797   1.000   0.045	4.17396

I have updated the freeswing scripts, combining all of them into a single script that takes arguments to specify the optic to kick:

pianosa:SUS 0> ./freeswing
usage: freeswing SET
usage: freeswing OPTIC [OPTIC ...]

Kick and free-swing suspended optics.
Specify optics (i.e. 'MC1', 'ITMY') or a set:
'all' = (MC1 MC2 MC3 ETMX ETMY ITMX ITMY PRM SRM BS)
'ifo' = (ETMX ETMY ITMX ITMY PRM SRM BS)
'mc'  = (MC1 MC2 MC3)
pianosa:SUS 0>

I have removed all of the old scripts, and committed the new one to the SVN.

For some reason ETMY has changed a lot.  Not only does it now have the worst "badness" (B matrix condition number) at ~10, but the frequency of all the modes have shifted, some considerably.  I did accidentally bump the optic when Jenne and I were adjusting the OSEMs last week, but I didn't think it was that much.  The only thing I can think of that would cause the modes to move so much is that the optic has been somehow reseated in it's suspension.  I really don't know how that would have happened, though.

Jenne and I went in to investigate ETMY, to see if we could see anything obviously wrong.  Everything looks to be ok.  The magnets are all well centered in the OSEMs, and the PDMon levels look ok.

We rechecked the balance of the table, and tweaked it a bit to make it more level.  We then tweaked the OSEMs again to put them back in the center of their range.  We also checked the response by using the lockin method to check the response to POS and SIDE drive in each of the OSEMs (we want large POS response and minimal SIDE response).  Everything looked ok.

We're going to take another freeswing measurement and see how things look now.  If there are any suggestions what should be done (if anything), about the shifted modes, please let us know.

We have placed a foil aperture in front of ETMY, to aid in aligning the Y-arm, and then the PRC.  It obviously needs to be removed before we close up.

We did several things today+night.  The final goal was to lock the PRC so that we could obtain the POX, POY and POP beams.  However there were large number of steps to get there.

1) We moved the ITMY into its place and balanced the table

2) We then aligned the Y-arm cavity to the green beam which was set up as a reference before we moved the ETMY and ITMY to adjust the OSEMS.  We had the green flashing in Y-arm

3) We checked the beam position on PR2. It was okay. This confirmed that we were ready to send the beam onto the Y arm.

4) We then roughly aligned the IR beam on ETMY where Jamie had placed an Al foil with a hole.  We got the arm flashing in both IR and green. 

5) We used the PZTs to make the green and IR beams co-incident and flashing in the Y arm.  This completed the alignment of the IR beam into the Y-arm.

6) The IPPO (pick-off) window had to be repositioned to avoid clipping.  The IPANG beam was aligned such that it exits the ETMY chamber onto the ETMY table.  It can now be easily sent to the IPANG QPD.

7) Then BS was aligned to direct the IR beam into the X-arm and had the X-arm flashing.  It had already been aligned to its green.

8) It was now the turn of the SRC.  The beam spots on all the SRC related optics were off centered.  We aligned all the optics in the AS path to get the AS beam on to the AP table.

9) The AS beam was very faint so we repositioned the AS camera to the place intended for AS11 PD, since there was a brighter beam available there. 

10) We could then obtain reflections from ITMY, ITMX and PRM at the AS camera. 

11) Problems:

      a) ITMY osems need to be readjusted to make sure that they are in mid-range.  Several are out of range and so the damping is not effective.

      b) When we tried to align SRC the yaw OSEM had to be pushed to its full range.  We therefore have to turn the SRM tower to get it back into range.

 12)  We stopped here since moving the SRM is not something to be attempted at the end of a rather long day. Kiwamu is posting a plan for the rest of the day.

The main goal of today is to extract the pick-off beams

Today's menu :

  + If necessary steer ETMs and ITMs to make the X and Y green beam flashing.

  + Open the IOO and OMC chamber and lock MC.

       => cover the place of the access connector by a large piece of aluminum foil. It will give a robust lock of MC.

  + Check the beam pointing down to Y arm by looking at the ETMY face camera.

        => If it's necessary align PZT1 and PZT2 from EPICS to make the IR beam flashing in the X arm.

  + Align BS and let the beam hit the center of ETMX to make the X arm flashing.

        => These alignment procedure will automatically gives us the MICH fringes on the AS CCD camera.

  + Rotate the SRM tower to get the SRMI fringes on the AS CCD camera.

        => This is because the required amount of the YAW correction on SRM is currently beyond the range of the DC bias.

  + Align PRM to get the PRMI fringes on AS CCD camera. Also make sure the beam comes back to the REFL CCD camera.

  + Lock the PRC to make POP/POX/POY bright enough.

     => Probably the REFL11 RFPD needs more power. To increase the power, just rotate the HWP, which is sitting before the RFPDs on the AS table.

     => If the signal on AS55 is too small, we can use REFL11_Q or REFL55 for the MICH lock.

  + OR inject and align the ABSL laser to make those pick-off beams bright enough.

     => This case we don't have to make the DRMI exactly on the resonance, what we need is just the DRMI flashing.

  + Align necessary optics for those pick-off beams.

     => In our definition (aLIGO definition) POP is the beam propagating from BS to PRM. Don't be confused by another one, which propagates from PRM to BS.

  + Steer two mirrors on the ETMY table for aligning IPANG. Also, steer some mirrors on the BS table for IPPOS.

    => IPANG has already reached the ETMY table, so ideally we don't have to steer a mirror on the BS table.

    => IPPOS/ANG are very visible with a sensor card.

  + Align some oplevs.

     => This work is relatively independent from the other tasks. Steve can take care of it.

  + Adjust the OSEM to their mid-range.

     => This work can be done anytime, but everytime we have to recover the alignment of the interferometer.

 Since Suresh and I changed the DC biases on most of the suspension, the free swingning spectra will be different from the past.

- -

EXcited ETMX ETMY ITMX ITMY PRM SRM BS

Tue Aug 16 04:48:02 PDT 2011
997530498

Data taken from: 997530498+120

Things are actually looking ok at the moment.  "Badness" (cond(B)) is below 6 for all optics.

• We don't have results from PRM since its spectra looked bad, as if it's being clamped by the earthquake stops.
• The SRM matrix definitely looks the nicest, followed by ITMX.  All the other matrices have some abnormally high or low elements.
• cond(B) for ETMY is better than that for SRM, even though the ETMY matrix doesn't look as nice.  Does this mean that cond(B) is not necessarily the best figure of merit, or is there something else that our naive expectation for the matrix doesn't catch?

We still need to go through and adjust all the OSEM ranges once the IFO is aligned and we know what our DC biases are.  We'll repeat this one last time after that.

TM		M	cond(B)
BS		pit     yaw     pos     side    butt UL    1.456   0.770   0.296   0.303   1.035  UR    0.285  -1.230   1.773  -0.077  -0.945  LR   -1.715  -0.340   1.704  -0.115   0.951  LL   -0.544   1.660   0.227   0.265  -1.070  SD    0.612   0.275  -3.459   1.000   0.046	5.61948
SRM		pit     yaw     pos     side    butt UL    0.891   1.125   0.950  -0.077   0.984  UR    0.934  -0.875   0.987  -0.011  -0.933  LR   -1.066  -1.020   1.050   0.010   1.084  LL   -1.109   0.980   1.013  -0.056  -0.999  SD    0.257  -0.021   0.304   1.000   0.006	4.0291
ITMX		pit     yaw     pos     side    butt UL    0.436   1.035   1.042  -0.068   0.728  UR    0.855  -0.965   1.137  -0.211  -0.969  LR   -1.145  -1.228   0.958  -0.263   1.224  LL   -1.564   0.772   0.863  -0.120  -1.079  SD   -0.522  -0.763   2.495   1.000  -0.156	4.55925
ITMY		pit     yaw     pos     side    butt UL    1.375   0.095   1.245  -0.058   0.989  UR   -0.411   1.778   0.975  -0.022  -1.065  LR   -2.000  -0.222   0.755   0.006   1.001  LL   -0.214  -1.905   1.025  -0.030  -0.945  SD    0.011  -0.686   0.804   1.000   0.240	4.14139
ETMX		pit     yaw     pos     side    butt UL    0.714   0.191   1.640   0.404   1.052  UR    0.197  -1.809   1.758  -0.120  -1.133  LR   -1.803  -1.889   0.360  -0.109   0.913  LL   -1.286   0.111   0.242   0.415  -0.902  SD    1.823  -3.738  -0.714   1.000  -0.130	5.19482
ETMY		pit     yaw     pos     side    butt UL    1.104   0.384   1.417   0.351   1.013  UR   -0.287  -1.501   1.310  -0.074  -1.032  LR   -2.000   0.115   0.583  -0.045   0.777  LL   -0.609   2.000   0.690   0.380  -1.179  SD    0.043  -0.742  -0.941   1.000   0.338	3.57032

>If necessary steer ETMs and ITMs to make the X and Y green beam flashing.

Green is now flashing in both X and Y arms

>Open the IOO and OMC chamber and lock MC.

Open, and cover in place. MC is flashing and locking.

Kiwamu, Keiko, Anamaria

Looking at the I and Q signals coming from REFL11 and REFL55 we saw large offsets, which would mean we have amplitude modulation, especially at 11MHz. We checked the PD themselves with RF spectrum analyzer, and at their frequencies we see stationary peaks (even if we look only at direct reflection from PRM). We changed the attenuation of the PSL EOM, and saw the peak go down. So first check is beam out of PSL EOM, to make sure the input beam is aligned to the crystal axis and is not giving AM modulation in adition to PM.

 Kiwamu aligned things for me, and I rotated the SRM tower so that the reflected beam was pretty much totally overlapping the incident beam.  The SRC was aligned to make sure things were good.  Now the DC bias for SRM Yaw is ~1.4, so we're totally good. 

To rotate SRM, Jamie had the idea of using 2 screws so I could push the tower on one side, and back off the screw an equal amount on the other side and push the tower to be touching both screws again, to ensure that I was rotating about the center of the tower and wasn't introducing any Pos action. 

While I was at it, I also moved the OSEM connector tower back to its normal place on the table, so it's not in the way of oplev beams.  It had been moved previously to accommodate ITMY near the door.

[Keiko / Suresh / Anamaria / Kiwamu]

 The AM components do exist also on the beam after the EOM.

The peaks were found at 11, 29 and 55 MHz, where the PM are supposed to be imposed.

Suresh and Keiko minimized them by rotating the HWP, which is in front of the EOM.

Also Anamaria and I tried minimizing them by adjusting the EOM crystal alignment.

However everytime after we minimized the AM peaks, they grew back in a time scale of ~ 1 min.

Potentially it could be a problem of the HWP and/or EOM alignment.

Since we wanted to proceed the in-vac work anyways, we stopped investigating it and decided to postpone it for tomorrow.

We again adjusted the incident power to 20 mW.

-- P.S.

 The incident power going to MC went down to 7 mW for some reasons. This was found after ~ 6 hours from our works on the PSL table.

We haven't touched anything on the PSL table since the daytime work.

Possibly the angle of the HWP is drifting (why?) and changed the amount of the P-polarizing beam power.

Suresh locked the angles of two HWPs, which are the one just after the EOM and the one after the attenuation PBS.

[Jamie / Suresh / Kiwamu] 

The in-vac work is ongoing.

Before we run out our energy we are posting this entry to briefly report the current status.

- (done) BS earthquake stop adjustment.

- (done) PRM earthquake stop adjustment

- (done) MC spot position check => They are almost the same within 10 %.

- (done) Injection and alignment of the ABSL laser to make the beam brighter in the vertex region.

- (done) POY => We repositioned an in-vac steering mirror to get the POY beam hitting the center of the steering mirror.

                           It's now coming out from the chamber.

-  (done)  IPANG => realigned two mirrors on the ETMY table to get the IPANG out from the chamber. Now it's reaching the ETMY optical table.

                             It needs a final touch before we pump down.  We revisited it later in the night after realigning the IFO and it is well aligned now.

- (done)  POP => We have aligned the ABSL laser injected from the AS port to reach the REFL camera.  We turned it up to max power of 300mW and used it as a substitute for the PRC beam.

                         Even this was not enough to see anything in the POP beam path after the PR2 (tip-tilt).  So we used a green beam from the Y-arm as a guide of the POP beam path because the ABSL (POP) beam was too dim to work with.

                         We placed a lens and a CCD camera to detect the green and then blocked the Y-green.  It was then possible to see the ABSL-POP beam in the CCD camera.  The lens and the CCD are markers for this beam. 

                         Do not remove these markers unless absolutely necessary.

-(done) POX => We located the ABSL (mimicking POX) beam on the POXM1 mirror and adjusted the mirror to ensure that the beam exits at the right height and a convenient location on the POX table. 

- (0%) OSEM mid-range adjustment

- (0%) IPPOS

- (0%) oplev re-alignment

We will pump down the chambers on Thursday morning.

Today will be a day of the OSEM and oplev party.

 -- to do list for today --

 + OSEM mid-range adjustment

 + oplev realignment

 + placement of beam traps

 + extraction of IPPOS

 + table leveling

 + interferometer alignment

 + AM-PM mystery

 + preparation for drag and wipe

Jenne, Anamaria

We aligned the ETMX OSEMs and ran into this issue. Looking at the SENSOR_SIDE channel, we pulled out the OSEM and determined that the open light voltage is 874 counts, so we centered it around 440 as well as we could. This is same channel as its slow counterpart SDSEN_OUTPUT (grey number immediately to the right on SUS medms).