First some background; there are two ways of installing an ADC card in the front end IO Chassis: either as a single PCIe card or as a PCIX card sitting on a PCIe adapter card. Recent ADC errors when running RCG2.9 on the IOP model for SUS EY have been resolved by Keith and Rolf as being caused by ADC/adapter cards being used in certain slots. The hope was that the installed H1 system was not using any adapted ADCs, but when I scanned all the front end IOCs I found the following front ends do indeed have cards on adapters:

h1susey (2 ADC)

h1seiex (3 ADC)

h1oaf0 (1 DAC-16bit)

During next Tuesday's maintenance, we will replace these with PCIe cards to ensure all front ends are hardware identical. We will also check the 3rd IFO IO Chassis are hardware identical to H1 and L1.

no restarts reported

We tried locking PRMI with no success. Some optics seem loud. More details will be posted later.

32 channels added

Will continue tomorrow

With Dave's help, and Hugh struggling along with me, I've set a tf to start on ITMX ISI. Should start at 12:30, some time after Kiwamu leaves tonight. It should also: pause the SEI guardian, ctrldown the ISI, undamp the ISI, set the GS-13's to low gain and bump up the watchdog threshold on the GS-13's before starting the excitation. All any commissioners need do is make sure the ISI is in its normal operating state before they leave, and not interfere with the measurement while it's running. Running from opsws0

08:40 Peter King - to H2 enclosure

08:52 Jeff/Andres - craning over X-Arm

09:01 Kiwamu - doing alignment work @ ISCT1

09:20 Fil - doing camera work in LVEA

09:49 Hugh - to Ey

10:00 Jason - starting work @SR3 op/lev

10:10 Betsy/Travis - working in West bayl

10:19 Sudarshian - to EX tiltmeter

11:11 Fil - to Ex to look at Gig-E cabling

11:23 temp loss of read access to Conlog

12:00 HFD - investigatingtrouble  alarms at Ex/My

12:32 Cyrus - restarting camera servers

12:34 R McCarthy - Ey HEPI investigation

12:37 King Soft taking samples

13:16 Restarting Ey HEPI controller - Richard?

13:26 D Barker/J Batch - to Ex

13:37 Karen - @ My

13:43 Cyrus - into CER for camera/video switch

13:47 J Bartlett - to W bay rummaging for parts

13:56 R McCarthy -  back from Ex

14:13 Cyrus - back from CER

14:18 P King - back to H2 enclosure

15:11 Sudarshian/Christine - to beam tube between corner and Mid y

15:35 Sudarshian/Christine - back from beam tube

When Kiwamu locked PR-X (CH16), POP_A (CH1-7) saw some decent beam, about right in PIT and off in YAW.

POP_B (CH9-15) also saw something, it's not clear if it was the real beam or some ghost, the power is about a factor of 10 smaller than POP_A, and mostly in seg1 and 2.

Anyway, the important thing is that the POP_A already see the beam and POP_B is close.

Don't use pico to center these, though, as POP sled might be a good initial alignment reference.

We should first align the IFO to the POP sled and see if it makes things better. POP sled was aligned perfectly in the last days of HIFO-X/Y. Though a beam splitter was inserted after the vent, the insertion procedure was written such that the sled centering is preserved.

S. Karki

The zeroing of Applied Geomechanics Tiltmeter is completed at ENDX and should be up and running. It was so off-scale, using a bubble-level and voltmeter did the trick to bring it down to reasonable level and after that I used the DTT to level it more. 

As planned (see alog from yesterday), I restored the POP path on ISCT1. The POP beam is now detectable with both POPAIR_A and POPAIR_B. Also, I did some clean up on the table.

Here are summary of the work:

• Moved the POP camera from the temporary position to the permanent one.
• Realigned the bottom periscope of the POP path. It needed a slight touch in yaw.
• Took out a BS which was intended for a measurement of Doppler noise for ALS comm.
  • Put it in a stash in the squeezer bay.
• Centered the beam on POPAIR_A and POPAIR_B
• Increased the gain for the DC signal of POPAIR_B by a factor of 10 as the signal was puny.
  • This was done by toggling the mechanical switch on the front panel of the generic PD interface box.
• Cleaned up apparently-not-in-use optics and put them in the stash in the squeezer bay.
• Moved the REFL PD camera back in place and focused it.
  • This is the one which had been used for monitoring green light for ALS temporarily.

Summary

- OM1/2/3 showed huge angle to angle off-diagonal coupling of the order of 100% during the commissioning last week.

- Yesterday I figured out that the reason was incorrectly and sneakily set non-identity DRIVEALIGN matrix.

- Once DRIVEALIGN was fixed, I could measure the Pitch-to-Yaw (P2Y) and Yaw-to-Pitch (Y2P) couplings.
They were about 30% and 10%, respectively.

- A small arithmetic calculation revealed that these P2Y and Y2P can't be elliminated by the four coil gains.
Namely we need different coil balance for elliminating P2Y and Y2P independently.

- This has been done by adjusting the offdiagonal elements of DRIVEALIGN. As a result the P2Y and Y2P have been reduced
  smaller than ~3%, even though the decoupling matrix (DRIVEALIGN) so far is a frequency independent one.

- One question: Why do we have the decoupling matrix only in the ISC signal chain on the every suspension?
This way, we can't enjoy the benefit of diagonalization for the other actuation signals such as alignment offsets,
damping servo outputs, test inputs. Is there a philosophie behind the current design?

Details

1. DRIVEALIGN

It turned out that the all elements of the DRIVEALIGN matrix (3x3) were the unity. Alas! This meant that any input (L, P, or Y) result in
the same actuation. This was overlooked because the matrix button still indicated only the diagonal elements were active (green)
even though that was not true. The warning in the DRIVEALIGN screen tell (in a very dark texts), the indicator criteria is different
between the diagonal and off-diagonal elements. It saids FM1 needs to be turned on to turn on the green indicator for the off-diagonal
elements. This is confusing as the frequency independent element in the off-diagonal element does not trigger the indicator. I strongly
feel that we should use the same criteria for the off-diagonals as the one for the diagonal elements.

For now, FM1 of the P2Y and Y2P elements have dummy k=1 filters so that we can activate the indicators.

2. P2Y/Y2P coupling measurements

Once the DRIVEALIGN was modified to be an identity matrix, more reasonable angle-to-angle coupling started to show up in the measurements.

The measurements have been done with no damping in order to avoid confusion caused by the coupling coming from the damping loop.

140826_TT_P2A  and 140826_TT_Y2A show the measured transfer functions from the Pitch or Yaw excitations to the Pitch and Yaw local readings.
As I did not have the beam, the OMC QPD signals were not used. The coupling ratios (P2Y/P2P or Y2P/Y2Y) were picked up at 0.5Hz and 5Hz.
P2Y is ranging from 0.18 to 0.39 while Y2P is from ~0 to 0.13. They are summarized in the following table

The OM2 Y2P coupling is basically such small that the measurement crossed the zero due to noise and had unstable sign.

For the decoupling calculation, the average of the LF (0.5Hz) and HF (5Hz) numbers were used.

3. Coil balance is incapable for P2Y/Y2P decoupling

Suppose we have perfect coil balance. The pitch and yaw actuations (P and Y below) are distributed to each coil equally (the middle matrix).
The actuation forces are recombined at the suspension (the left most matrix below). This reproduces pure pitch and yaw motions (the right most P&Y)

Now we have the actuator response modified by alpha, beta, gamma, delta.

As you can see, the decoupling terms come in symmetrically. We can't decouple P2Y and Y2P independently by the coil balance.
Note that this is obviously not true for A2L, L2A couplings.

4. Decoupling by DRIVEALIGN

For the above reason the DRIVEALIGN matrix was used for the decoupling. This was easy to implement as we just plug in
the inverse matices of the 2x2 coupling matrix. The below is the matrix plugged in.

5. Resulting improvement of the coupling

After the new DRIVEALIGN matrices were plugged in,the same measurements wererun. The result for Pitch and Yaw excitations are found
in 140826_TT_P2A_after.png and 140826_TT_Y2A_after.png. The coupling is reduced to ~0.03 or better. This is enough for the further
work on the alignment servo.

If the further decoupling we should install a frequency dependent decoupling.

6. Decoupling topology

But a question arose:

In this topology, only the ISC signals enjoy the benefit of the decoupling.
The alignment offsets (i.e. the alignment sliders), test inputs, and damping actuations do not go through the decoupling matrix.?

Is this what we want? Don't we want to have a DRIVEALIGN FM matrix after the summing node before the euler-to-osem matrix?
Of course, we can convolve the decoupling into the euler-to-osem matrix, in principle, but I don't want to mess up that matrix.
 

This has been down since 12 Aug.  The Input Line Lugs were tightened during the power outage.  The VFD while powered, does not respond in the usual manner.  It displays STOP and does not respond to the FWD button.  It should not be looking like this anyway as the the FWD lugs have been jumpered and it should just run as soon as it's given command voltage.  At McCarthy's suggestion, I toggled the main power which then required restarting the 'FE' but this changed nothing...

no restarts reported.

The OM1 and OM2 coil drivers were found to have bad Vmon channels. Chassis S1200614 was found to have -14VDC present on the output of IC5 (OP27) on Ch2. Similarly, S1200612 exhibited the same symptoms on Chs 2&3 (-13V and +14V respectively). In all cases, IC5 was replaced and this DC issue was reolved and the chassis were placed back into service. IC5 is the Vmon-N circuit. All Vmon circuits were examined (P & N).  If there are any further issues with this circuit please let me or Filiberto know. Original post: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=13585

I continued working on the PRMI alignment (see alog 13592) today and finally obtained good alignment. This should be good enough for proceeding with the next steps.

With the new alignment, the PRMI flashes without loosing the POP beam at ISCT1. In fact, one can now see PRMI fringing in the POP camera.

We are almost ready for some locking activity.

(Next steps)

• Re-configure the POP path on ISCT1. (Right now, an analog camera is blocking the beam and no beam is on the POP photodiodes.)
  • POP is necessary for triggering the LSC feedback.
• Setup a digital camera in the ASAIR path.
• Align and lock MICH
  • We can now use the AS demodulated signals !
• Lock PRMI

(alignment)

From the experience yesterday, I learned that a combination of PR2 and PR3 did not improve the POP/PRMI alignment situation for some reason. In fact, it made the forward propagating beam hit the west side of the PR3 suspension cage. Therefore, I wanted to move the input pointing in order to introduce a translation in the cavity axis in the downstream after PR2 while keeping the POP beam angle (almost) the same. To do so, I touched IM4 in yaw. This then required re-alignment of PRM in order to maintain the beam at the REFL port. Also, every time I changed the alignment of IM4, I compensated it by steering PR2 such that I keep the POP beam at ISCT1. I repeated this process multiple times. This was successful. I could eventually obtain an alignment setting where the PRMI flashes with the POP still visible at ISCT1. The attached is the new alignment settings.

After the PRMI alignment, I re-adjusted the PR3 alignment such that the beam reaches HAM6 and ISCT6. I did not check the beam centering on the SR mirrors.

(fun locking)

Since I was running out my energy, I decided not to try the PRMI locking tonight. Instead, I locked PRX for fun. I just used REFL_A_RF45 for now. The ASAIR_LF signal was used to check if it is locked on the carrier or rf sidebands. The attached is time series of some DC signals at the AS port when locking PRX. It is locked on the carrier.

Kyle, John, Keita, Dan, Koji, Filiberto, Gerardo, Kiwamu

The ISCT6 enclosure is now in place by HAM6 with two light pipes installed. ASAIR and OMC_R are successfully extracted to the table.

We craned the ISCT6 table from the squeezer bay over to the north side of HAM6. We carefully adjusted the position of the table by rolling it. The table legs were then secured on the floor. With help from Gerardo and Filiberto (a big thank you for Gerardo and Filiberto who machined the holes for us even though the working hour was over !), we made a 10 inch beam penetration hole on two back panels of the enclosure . These are for the ASAIR and OMC_R beams respectively. Note that we could not see a bright enough OMC_T beam this time and therefore we did not try to make a hole on the last back panel. This will be don once we reliably confirm the OMC_T beam position. We put the flanges and light pipes for the two beams and now the beams are successfully coming out to the table.

Also, in the process of trying to find the OMC_T beam, we turned on the PZT high voltage. We need to make sure that the high voltage is off when we pump down the chamber tomorrow.

Borja

I just came back from a quick visit to End-X (UTC 2014-08-27 00:25:00).

I took some pictures (see attached) at the feedthrough wiring for the ESD at BSC9 (ETMX chamber). I compare it with the ones I took a while back at ETMY (see attached).

There is an obvious difference, the red insulating tape at ETMY wiring which does not show at ETMX. The wire which has the insulating tape carries VBIAS to the ESD at ETMY. The reason for the insulation is that the coax cable's shield is cut off because the corresponding coax cable inside the chamber has the known issue of having the shield connected to the center lead. This problem is non existen at ETMX.

This is another big difference between both masses which may be related to the more stable results on the charge measurements observed at ETMX.

Removed the Ring Heater Assembly from the ITMy quad structure going into 3IFO storage. Before starting I noticed the lower ring heater assembly had a crack in the glass former. Not sure when the break happened, but this one also displayed a lot of movement inside the ring heater shield. The pictures show how the former has pushed pretty far out of position. 

The ring heater cables were also removed. This includes the "antlers" (D1001755) but not the plate (D1002420) which the earthquake stop is attached to.

The assemblies removed were:

ASSY-D1001895-V5 #001 (lower ring heater, broken)
ASSY-D1001517-V7 #612 (cable assembly)
ASSY-D1001838-V6 #005 (upper ring heater)