Once the Arm Cavity Baffle crew and gear started to pile up at the dam and door, we decide it was time to secure things.
EricA locked down the ISI above.  Then Betsy & crew locked down both the ITM and FM suspensions.  They also put some shielding and covers over the ITM for protection.  Finally, I locked down the HEPI.

Doug, Jason
The ETMy cartridge location is 7.047 inches (toward the LVEA) with respect to the test stand center monuments.
Additional monuments were placed in the Y-end station to accommodate H2 ETMy alignment using the end door access rather than having to pull a spool piece.

Today, when we stuffed the ERM mass into the ETMy lower suspension, we noticed that one of the 5 pins had been somewhat dislodged from it's soldering pool on the gold tab.  Gerardo and Margot believe that this is from the "flipping fixture" which is used to handle the mass.  The fixture apparently sits across some or all of these solder joints.  In the picture attached, the pin is the one towards the 4th one from the right.  
Long story short, Margot thinks we need to revisit the soldering of this pin. 
...to be continued.

(Andres, Corey, G2, Jim, Mitch)

HAMISI#3 was removed from the Test Stand and installed within a Storage Container.  This went fairly smoothly without much issues, EXCEPT Mitch discovered that some of the cleanroom legs were near failure.

The two eastern legs of the eastern cleanroom have severe damage done to the legs of the cleanroom due to the castors.  We have added cribbing under both legs as best as we could do, and do not plan to move this cleanroom until it gets addressed.  Extreme caution must also be exercised when working around this cleanroom in the meantime.

A. Effler, J. Garcia

Transfer function measurements on the H2 ITMY R0 top mass were completed last night with the results attached.  Damping loops on the M0 mass was ON as well as for the FMY M1 stage.  The BSC ISI was UNlocked for this measurement as well.  Resonances for this measurement are more prominent than the previous night's, which were incomplete due to the watchdogs tripping in the morning work hours.  Initial observations indicate the DC scaling calibration factor is still slightly lower than the model with the exception of the Longitudinal and Yaw DoFs.  The second Longitudinal mode is about ~0.2Hz lower than the model. The first Yaw mode is slightly higher (~0.05Hz) than the model prediction. Comparisons of this measurement with previous data from the LVEA test stand and Staging Building are still to come.

The monolithic main chain of the ETMy has been suspended under the BSC6 ISI table.  We corrected some coarse pitch, but see that the chain looks to be suspending the test mass a few mm high.  IAS will take some more concrete numbers, while we track down why this is possible.  Currently, the main chain is hanging with the HR FirstContact peeled down ~2inches at the top for IAS viewing.

The ERM has been loaded into the reaction lower suspension and is awaiting a triple hang to look for any pitch errors prior to attaching it to the main chain/upper QUAD on the ISI.

In the SUS group** currently, we have 7 chains worth of TOP masses about the aLIGO project hooked up to electronics, with their damping loops closed:

H2 SUS ITMY M0     (Installed in H2 BSC8, production electronics)
H2 SUS ITMY R0     (Installed in H2 BSC8, production electronics)
X1 SUS QUAD03 M0   (Read out on LHO X1 QUAD Test stand, AA/AI filters at Rev 1)
X1 SUS QUAD03 R0   (Read out on LHO X1 QUAD Test stand, AA/AI filters at Rev 1)
H2 SUS FMY M1      (Installed in H2 BSC8, production electronics)
X2 SUS FMY M1      (Read out on LLO X2 QUAD Test stand, AA/AI filters at Rev 1)
X2 SUS PR3 M1      (Read out on LLO X2 Triple Test stand, production electronics)


These are examples of all of the four different OSEM/magnet arrangement types:

QUAD M0 (See E1000617)
QUAD R0 (See E1000617)
BSFM M1 (See E1100108)
HXTS/OMCS M1 (See E1100109)


In trying to understand what the heck is going on with FMY, and noticing some inconsistency in H2 SUS ITMY M0, I've put together a document that uses information from the above linked arrangement posters that explicitly spells out every single sign flip in the signal chains of all of these types of suspensions, see T1200015. In this document (which is for now just pictures, I'll fill in the writing later), it is assumed that the following is true:

(1) Retracting the flag from the OSEM (i.e. current on PD increases, because more light allowed to pass) creates a positive (+) signal.
(2) (a) A positive (+) current through the OSEM coil, paired with a North (N) magnet, forces the magnet away from the coil ("Push")
    (b) A negative (-) current through the OSEM coil, paired with a South (S) magnet, forces the magnet away from the coil ("Push")

(Note that these are known truths, not really assumptions.)

With these two conventions, in addition to the pre-defined coordinate system, T1200015 defines a completely consistent sign convention across all suspension types.

---------------------------------------

Using T1200015 self consistent convention, I've then compared it with what is currently in place on the 7 suspensions across the project in order to conclude the current status, given that all of their damping loops can be closed, and are stable. See attachement.

From this assessment, I have concluded the following:

H2 SUS ITMY M0 -- F2 and F3 magnet polarities are flipped (N mistaken for S, or F2 mistaken for F3; currently compensated in the COILOUTF bank)
H2 SUS ITMY R0 -- all clear, as ideal

X1 SUS QUAD03 M0 -- All clear, as ideal (note 2 extra minus signs to account for electronics (AA/AI) gain; currently compensated for in OSEMINF and COILOUTF banks)
X1 SUS QUAD03 R0 -- All clear, as ideal (note 2 extra minus signs to account for electronics (AA/AI) gain; currently compensated for in OSEMINF and COILOUTF banks)

H2 SUS FMY M1 -- L, P, and Y signs are exactly incorrect in EUL2OSEM / OSEM2EUL basis (these matrices have the same sign, so they cancel in the conversion to-and-from the EULER basis -- we're just controlling -L, +T, +V, +R, -P, and -Y instead of the expected +L, +T, +V, +R, +P, +Y), AND overall minus sign on polarity of magnets (N mistaken for S, currently compensated in the COILOUTF bank)

X2 SUS BSFM06 M1 -- L, P, and Y signs are exactly incorrect in EUL2OSEM / OSEM2EUL basis (these matrices have the same sign, so they cancel, we're just controlling -L, -P and -Y instead of the opposite), AND F2 and F3 magnet polarities are flipped (currently compensated in the COILOUTF bank)

X2 SUS PR3 M1 -- Over all minus sign on magnets (currently compensated in the COILOUTF bank)


---------------------------------------

Why haven't we caught this before now?

(1) T1200015 is the first time (at least I've seen) the entire control loop (both analog and digital) signs have been written down, for all suspensions at once.
(2) Up until now, we have not had all of these types of SUS, covering the entire range of of possible arrangements with their damping loops closed.
(3) In our rush to get the answer -- are these SUS acceptable? -- given the plethora of things that might go wrong, and the abundance of data to absorb to determine that information, we have neglected tests that would confirm these signs, e.g.
    (a) Looking at the phase of the Top2Top Euler basis transfer functions
    (b) Taking Top2Top OSEM basis transfer functions, and looking at their phase
(4) In the confusion of old/incorrect BURT captures/restores, and hard coded scripts, copying-and-pasting between suspensions that are not the same, the range of possible electronics (Test Stand vs. Production), and the "fifty-fifty shot" problem, it has become habit to just flip the sign digitally to "whatever works at making the damping loops stable."
(5) Commissioning and assembly procedures were written before this slow, careful, big-picture assessment was made.



---------------------------------------

What do we do about it?

H2 SUS ITMY -- Leave as is for OAT. Switch magnet polarities when we take out the SUS to replace ITMY test mass.
H2 SUS FMY -- Fix flaws in matrices, but leave magnets as is for OAT. Switch magnet polarities when we take out the SUS to put in glass optic.
X2 SUS BSFM06 -- Fix flaws in matrices, and fix magnet polarity when remaining work on SUS is being done during phase 1 (nowish).
X2 SUS PR3 -- Fix polarity now, while still in phase one.


** This aLOG DOES NOT include a TMTS TOP mass, which has YET ANOTHER OSEM/magnet arrangement.

Table legs were filled with glass beads, o-rings and backer rods were set into place. Tomorrow we will hopefully set the table in place.

Attached are plots of dust counts > .5 microns. The repaired dust monitor that replaced the one in the clean room over BSC8 (H0:PEM-LVEA_DST15) has also reported an error, and is not included.

For the record, following are the measured weights of the QUAD glass penultimate masses (PUM) and test masses that are currently here at LHO.  Most of this data can also be found on the CIT optics Nebula we page.  Note the labels of the masses are slightly confusing as the optics have been coated specifically for the one-arm.

MASS     LABEL              INSTALL LOCATION
39,653g ETM02 (TM)    BSC8 ITMy
Didn't measure ITMy PUM because it was the first mass bonded and we were not wise to the need for weights.
39,626g ETM04 (PUM) BSC6 ITMy PUM
39,689g D050421-001 BSC6 ETMy PUM (was lasti mass)
39,613g ETM04 (PUM) 
39,641g ETM05 (PUM)
39,633g ITM01 (PUM)
39,621g ETM03 (PUM)

Attached are plots of dust counts > .5 microns during January 10, 2012. The dust monitor in the clean room over BSC8 (H0:PEM-LVEA_DST15_5) was alarming with 'low battery', and was restarted. It then failed again later. It was replaced this morning.

I replaced the dust monitor in the clean room over BSC8. It was periodically reading 'low battery'.

Tuesday Jan 10 between 17:45 and 18:30 PST, bscsteststand2 and seiteststand2 in the staging building were rebooted and the models that had been running were restarted to correct timing.  This was done as a result of moving equipment that supply timing in the MSR, which interrupted the 1PPS timing to the staging building.  The timing signal is now supplied directly from the master fan out in the MSR.

I had set the ITMY R0 Tfs to be retaken because there wasn't enough time the previous night and the measurement ran into the morning. So people were already on top of it, tripping watchdogs left and right. I needed to leave it with a delay to run after Vincent's ISI measurements, so I wasn't here to see it crash right after the first few lines. Sad. WIll redo at next opportunity.

(Corey, Hugo, Jim)

Reinstalled H3 GS13

Previous one had issues and was removed.  This current one (S/N 66 of the pod), was a spare we happened to have available (it, like all of our GS-13's must not go into a vacuum system, since they are not acceptable for in-vacuum use).  After this one was installed, the door was re-attached.  On the GS13, I did not install the bracket which bolts to the base flange and "clamps" the cable in place (couldn't find its screw).

Rough Balancing Of The System

With the system locked, I noted Dial Indicator(DI) values:
Corner A
H:  +0.001
V:  +0.001
Corner B
H:  removed
V:  0.000
Corner C
H:  +0.001
V: +0.001
Corner D
H:  -0.001
V:  0.000

Since we looked good in this locked state and were getting ready to balance, I zeroed all the Dial Indicators, and installed the Corner B Horiz Dial Indicator.  The system was then unlocked, and then I rebalanced the system to within 0.001" on all DIs.

Wired Up And Set Gaps for CPS

The Capacitive Position Sensors (CPSs) were then cabled up, and powered on.  The gaps were then set for all the CPS (generally able to get close to 0.000V, with our requirement to have them below 0.200V).

Dressing Cabling

The cabling for Sensors/Actuators were plugged in and dressed for performance.

Stage0 Level

With the optical level, Stage0 level was checked, and ultimately deemed acceptable.

Fine Balancing Of System

With running and gapped CPSs, the DIs were backed off, and the CPSs were used to finely balance the system.  Before a fine balance, the CPS Access Doors were installed.  The system was then balanced such that Vertical CPSs had values under 0.200V.

Document Checklist

While we were working on general items for the ISI, Hugo worked on checks for his Assembly document (measuring Actuator gaps, etc.).  He continued this work after we left him with a finely balanced ISI.

A. Effler, J. Garcia

Measurements of driven transfer functions for the H2 ITMY M0 and R0 top masses were taken overnight for the suspension in the BSC8 chamber.  The ISI was locked for this measurement and both M0 & R0 masses were left undamped. The attached plots are of the M0 top mass transfer functions.  The R0 watchdog tripped during the final two DoFs and will be retaken tonight.

Last night we took FMY and ITMY TFs, but we didn't get to finish the reaction chain measurement because morning came. I am repeating that tonight, after Vincent is done with the BSC ISI.

Attached are the FMY transfer functions, compared with the new model tweaked by JeffK. All looks great except pitch is a bit off. I will check how it looks compared to the other measurements tomorrow.

JeffG will post the results for ITMY main chain, and we'll do the same for R0 once we get the data.