Last night, undamped transfer functions of H1 TMSY were ran (Phase 3a) with the ISI damped. 3 different drive amplitudes were tried to see if cables are not adding non linear effects.

• The first attachement shows the comparison between the three drives

In orange excitation amplitude is 10000, in black drive is 150000, in pink drive is 20000. TF is consistent throughout the drives.

• The second attachement shows how one of this measurement compares to TF taken last year on TMSY, when it was in chamber, under vacuum.

Differences in frequency of resonnances can be seen in the L V R P degrees of freedom:

First roll mode at 0.68Hz splits in three modes 0.68Hz 0.72Hz and 0.79Hz
First Pitch mode at 0.74Hz splits in two modes at 0.72Hz and 0.79Hz
First Vertical mode at 0.69Hz splits in three modes at 0.67Hz 0.72Hz and 0.79Hz
Second Long mode at 0.74Hz (pitch coupling = first pitch mode) splits in two modes at 0.72Hz and 0.79Hz

All differences can certainly be explained by the change of cable routing when moving cartridge from BSC6 to BSC10. (For details on how the current routing looks like see pictures on alog 11021). Since the actuation is working properly, and the suspension still provides passive isolation above the resonnances, it seemed acceptable to move on with installation.

• The third attachement shows how the "first article" measurement (TMSY) is different than "production". This is to check if the damping loops can stay "generic". Since the loops are simple velocity dampers with low Q boost around main resonnances, it's ok.
   
• The last attachement shows how the damping is doing, with a spectra comparing undamped/damped

This morning, SEI, TMS, and SUS gave a cursory "approval" of their systems in order to proceed with chamber close-out tasks.  So, after lunch, Margot and I applied First Contact to the ETMy-HR surface which will be pulled just before closing the door tomorrow.  The order of events this afternoon (and late morning in order to catch the alog up):

Jim locked the ISI and put final touches on chamber feedthru cable routing.

Apollo+Joe+Gerardo had a viewport party at the BSC10/6 area.

Margot and I locked the lowest masses of the ETMy QUAD.  Then we,

Secured the ACB locking bracket and used the wedge to swing it back and prop it into place.  See notes on this in attached alog.

Attached the FC QUAD cone to the structure and sprayed FC (standard 3 coats) on the HR surface.

Removed the cone from the suspension.  Finished FC layer reinforcement.

Removed the wedge from the ACB and restored it's nominal hanging position. Removed the ACB locking bracket screws.

Started stowing all left over bags of "junk" left outside of the chamber door on various table surfaces by SUS and every other team that visited this last month.  If you're missing something (and you noticed), I took ownership of it.

Jim arrived and unlocked the ISI.  The ETMy QUAD will remain locked during dome replacement.

Apollo started gearing up to remove walking plates from upstairs and crane the dome on the chamber.

Tomorrow's to-do list which Margot and I will do until the last step:

Inspect insides of viewports.

Adjust ACB to check magnet gap which may or may not have shifted slightly due to the swing back from today.

Clean the chamber, vacuum, etc.

Take final PCL swipes.

Blow various other optic surfaces.  Or not.

Swap in final 1" witness optic on QUAD structure.

Check/Remove all tools.

Remove ETMy-HR with N2 blow.

Set and lock all 64 QUAD EQ stops and nuts, accounting for buoyancy.

Set QUAD BOSEMs to account for buoyancy.

Quick QUAD health check with DTT TFs.

Lay final witness plates.

Exit chamber.

Finish stowing everything around door and move it out of the way.

Put door on.

Here is an update on the instruction for untripping seismic, with some new tips from Fabrice, especially for ETMX. 

Untrip HEPI WD, use Commands2 window to isolate level 1 on all chambers except BS which is level2

Untrip ISI WD (you may need to raise T240 Threshold)

reset CPS offsets,

• go into stage 1 bias screen hit reset CPS offsets, then hit store targets.  
• Repeat in stage 2 bias screen. 

Check that everything is in high gain: (this is also good to check if you are already isolated but have a lot of motion)

• Click on the three T240 screens, check that the filter modules labeled gain are ON
• In the L4C screen check that the filter modules labeled gain are OFF
• in the GS13 screen check that the filter modules labeled gain are OFF

If you have been struggling with switching the blend filters, you may want to zero the T240s.  You can do this in the three T240 screens by tuning on the AutoZ filter module in the X filter module, then turning it off.  

Use commands, isolate level 3 for most chambers. For ETMX start with Commands, Isolate Stage 1 Level 2.  Once this script is finished, isolate stage 2 level 3.  

Switch Blends:

• Go to stage 2 bleds switch all to Tcrappy.   If this failed you can 1st switch Z from Start to Tcrappy, once it has switched RY, RZ, RX, Y, and X.
• Wait a long time......until the T240s are have hundreds of counts. 
• Repeat for stage 2.
• There is a switch all button, that might save you from having to do one at a time, but can often trip the ISIs.   

good luck...

Shocking, I know.

While exploring data from last night (see LHO aLOG 11026), I saw what looked to be artificially clean straight lines through the performance of the ISIs. In order to confirm, I switched the windowing function in DTT from the default Hann(ing) to "BMH" (which I think is the Blackman-Harris Window), and indeed the reported ASD at those frequencies where the spectra looked artificial changed. Sadly, with this particularly huge dynamic range of a signal, the spectral leakage artifacts hide the real signal right at the frequencies where tilt bothers us (~0.5 to 10 [Hz]). I also tried the Flat Top window, and that seems to be the best for X DOF which has high dynamic range, but in RY, which doesn't, it "over" estimates the ASD at 0.05 [Hz]. Unclear whether this is a good compromise given that depending on the hour, we're interested in one band or the other affecting the performance.

So, I guess I'll have to use asd2.m found here because "[when not computationally limited,] the spectral [leakage] of a single, long-time window is much smaller than the spectral [leakage] of many short, overlapping windows (like you get with pwelch)". Which really means we should just get the live noise budget up and running.

#yakshaving

Aidan, Dave H, Thomas

More cabling and plumbing.  The leaky laser from ALOG 11019 was replaced with a new one and a matching RF driver. We're in a position to be able to turn on the laser mid-morning tomorrow.

All view ports on the spool between BSC 6 & 10 were removed and replaced with blanks and torqued. The dome went on BSC 10 and 90% of the bolts were inserted with 4 of them snugged with the remainder to be tightend tomorrow morning.

The new ITMx monolithic welding has been successfully completed and was left suspended overnight last night.  The majority of the modal measurements have also been completed today, with the exception of the violin modes, which are proving to be trickier to measure than in previous suspensions.  We will continue with these measurements tomorrow with some different equipment.  Stay tuned for subsequent posts with IAS and modal measurement numbers.

08:57 Aidan and Dave H. working on TCSX table enclosure
09:14 Jeff and Andres working on SR3
09:34 Corey to end X TMS lab to bag and inventory parts
09:53 Jeff done working on SR3, Andres finishing up
10:18 Betsy going to work in LVEA test stand
10:20 Jim done taking measurements on end Y ISI, to end Y to work on cable routing
10:24 Jax transitioning end Y to laser safe
10:29 Hugh to HAM4 to install vertical L4Cs
10:30 Kyle to crane RGA over YBM (WP 4529)
10:41 end Y is laser safe
11:07 Kyle done craning
11:59 Andres, Arnaud starting transfer function measurement on SR3
12:00 Guardian code is running on ITMY ISI
12:36 Betsy and Margo leaving to go into BSC 10
12:47 Karen going to end Y to clean in VEA
12:59 Ski to end Y (not in VEA)
13:04 Tour in CR
13:45 Ski back from end Y
13:49 Dave H., Aidan and Thomas starting work again on TCSX
15:05 Karen back from end Y
15:25 Dick and Jax going to end Y to install electronics, too much other work going on, left electronics there
15:46 Apollo installing dome at end Y

High dust count alarms at end Y most of the afternoon, parties involved informed

I have started an rsync of the /opt filesystem on h1boot, to the new backup boot server starting at 16:14PDT.  The filesystem on h1boot may be a little slow while the transfer runs, on a timescale probably measured in hours as it is about 300GB of data.

Mitchell with Apollo help until lunch,
The newly assembled optical table was moved and placed on stage 0. After lunch I shopped for the parts at the interferometer emporium, moved the Stage 1 base plate onto the granite table and attached the plate flipping gear. 

Laser is on
Output power is 28.1 W (should be 30 W)
Watchdog is active
No warnings in PSL SYSSTAT.adl other than "VB program online" 

PMC
Locked for 4 days 3 hours (should be days/weeks)
Reflected power is 12.7% of transmitted power (should be 10% or less)

FSS
Reference cavity is not locked
Trans PD threshold is .4 V (should be at least .9 V)

ISS
Diffracted power is around 7.8% (should be around 10%)
Last saturation event was 11 minutes ago (should be days/weeks)

J. Kissel

While using the channels that project the ISI ST2 GS13s in the Cartesian basis to the Test Mass QUAD suspension point in the Euler basis for the X-arm QUADs, i.e. H1:SUS-?TMX_M0_ISIWIT_?_DQ, I noticed that the projection matrices that create these channels were a copy-and-paste from the Y-arm, and therefore wrong by 90 [deg]. I've corrected the matrices at around 2014-03-27 21:55 UTC, saved, and committed a new safe.snap such that they stick.

Details for the record:
-----------------------
These matrices are calculated using the script
/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/make_ISI2SUS_projections.m
which takes in the locations of each SUS from the parameter file
/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/SEI2SUScoordinates.m
based on the systems SolidWorks drawings for that suspension. 

They are pre-calculated and stored in the mat file
/opt/rtcds/userapps/release/isc/common/projections/ISI2SUS_projection_file.mat
which I loaded into a matlab and ran the function 
/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/fill_matrix_values.m
to automatically fill in the epics values.

The theory behind these projections can be found in T1100617

#yakshaving

Installed these this morning, leveled, torqued, wired, protected, labeled.  No issues except the TCS rack 3" from Pier1.  That rack will need to move.

Richard, Sheila

Richard noticed that the arm was locked pretty stably on IR when he came in this morning, and made a trend over night (first screen shot).  There was a half hour lock, second screen shot.

Valera called and asked for a measurement of the arm losses.  I used REFL_AIR, meaured 0 counts when the IMC was unlocked, 1.539 when the arm was locked with ALS off resonance, and 1.471 when the arm was locked on resonance.  The IR trans power was only 70% of the nominal, so the arm was not well aligned and this only gives us an upper limit on the losses, which is 159ppm, assuming the ITM transmission is 1.4%. 

A more accurate measurement shoud probably be done. 

Not sure what the deal is with my photos, but for some reason alog chooses to not let some of my photos upload to an entry.  Have used original names of images, and changed names of files.  Have tried from home and from work to no avail.  Will keep trying.  Attached is the error message I get afer I try uploading the file I select.

Entries made via MacBook Pro & with Firefox.

Dave O, Gerado,

The performance of the Output Faraday Isolator was tweaked and a transmission of 96.5 +/- 0.5% was recorded and an isolation of 9e-5 was measured. See attached report for more details.