Part of our De-Install process has been to zero (center) the iLIGO Scissors Tables to put the In-vacuum support structure at the nominal height ready for aLIGO.  One issue though is that there may be tolerance stack ups, as well as the weird V-Block Connection, that could put the Support Tubes/Support Table at non nominal Height.

We measured heights from the North HAM10 Piers to the HAM10 Support Table and from the HAM8 NW Pier to the top of the NW Support Tube end.

The shots on the HAM10 NW pier showed the Pier level +- 0.001"
The HAM10 NE pier was within .009" of the NW Pier.
The average elevation of the HAM10 Support Table was within .004" of nominal height.
The SE/NW axis of HAM10 Support Table was tilted about the SW/NE axis +-0.047".
We weren't able to shoot the HAM10 Support Tube Tops but we did that at HAM8

The HAM8 NW Support Tube was 0.065" higher than nominal relative to the NW Pier.

I think the takeaway here is albeit with a small data set, the Support Tables [& tubes therefore] will on average be at the correct height with respect to the Piers.  However, while zeroing the Scissors Table will put things at nominal average, the V-Block connection could give the out of level condition.  My recollection is that we want a much more level table than this.

I do think we can measure the situation on the outside with just pier to support tube observations.  I need to measure the HAM10 Support Tube to Pier to confirm.

Attached is Note Book page.

• HAM6 clean room lift testing
• Cleaning on BSC4 - dome will hopefully be lifted on Monday
• Dust monitor #3 moved to inside BSC4 clean room
• Oscar baling on x-arm

I rebooted h2adcumy.

To facilitate removal of passive ISI in BSC4:
Doors were hung back on HAM12
Clean room around BSC4 was rotated 90 degrees
Clean room around HAM12 was moved to HAM10

Oscar was bailing tumbleweeds.

An electrician was scheduled to install motorized variac on 2 stages of VEA Heat at Mid X. (Richard)

A vendor from Craftsman Cabinets was scheduled to arrive at 10:00am. (Michael R.)

Throughout the day:
Recycling Bin #2 was filled with BSC and HAM stacks
Jodi and crew were cleaning the FMP chamber in the West Bay.  Work finished by 2:00pm

~10:45 Electrician out to Mid-X for some electrical work

[Chris, Corey, Mitchell, Rodney, Zak]

The max load for this bin was 24,000lbs.  In this bin we have the following:

• (3) BSC Stacks of weights (4882lbs per chamber x 3 = 14,646lbs)
• (~3) HAM stacks of weight (2,512lbs per chamber x 3 = 7536lbs - (1) small weight [234lbs] to be used for crane training = 7302lbs

So, total weight of steel loaded is ~21,948lbs.  Ski will be arranging for a pick-up.

• Praxair, UniFirst, Paradise Water, Sprauge on site
• First round of BSC4 cleaning finished
• Jodi and crew cleaning in HAM12
• Stack weights by HAM7 craned over beam tube and onto pallet
• ISCT moved into squeezer area

I have installed the backup CDS file server (cdsfs1) which is now backing up the primary control room file server (cdsfs0) and the H2 front end file server (h2boot). The h2build machine has been installed and is being configured as the build machine.

The as-built drawing of the aligo CDS computing system is available at the DCC (page 2 shows the as-built)

D1002255

-Clean room moved to BSC4...BSC4 prepped.
-Zack works on BSC8.
-HAM12 prep for link with external air compressor.
-MX PEM work.
-Ski worked on chillers.
-MichaelL gives Apollo crew a tour of LVEA.

Times in PST:
0840 - Snowvally arrives.
0908 - McCarthy to MX to look at PEM issues.
0920 - Richard rebooting ADCU's at MX.
0928 - Zack begins work at BSC8, Corey begins moving steel masses around the LVEA for recycling.
0953 - Richard done at MX.
1229 - Snovally returns.

(Corey, Dave, Randy, Rodney, Zak)

BSC8 Stack was "de-stack-ed".  Two chambers-worth of HAM weights were craned over the beamtube.  All of this steel is on its way to the recycling bin.

(Zak, Rodney)

Dome & Door were torqued down.  Chamber now handed over to Kyle so he can start pumping down.

Another issue-free extraction of the iLIGO passive internal Seismic Isolation System--Zac Rodney Chris EricA JimW CoreyG HughR

Again no issues.  This time we pre-positioned 122lbs on the Dome to level it up  and it was very much better.  Came off level and was much easier going on.

Bolt extraction from the Support Tubes was easy--everything as expected.

Dome/Door back on; all bolts in and nuts on, a few bolts on the door are torqued.  Rest of bolts need torquing.  Purge air is throttled back.

Stack was removed from BSC8 and dome placed back.
Oscar baled some tumbleweeds.
Ski and the squeezers craned an ISC table over the X-arm, to be placed in the East Bay laser hazard area.

Andres and I weighed the Q2 US and UI Masses.

    (1). Upper Structure - 254lbs  Note: The Cross Braces and their corresponding fasteners are not fit.
    (2). UI Test Chain - 21.526Kg
    (3). UI Reac Chain - 21.532Kg 

Jake from SnoValley working on glycol pump
Dale took pictures in LVEA
Terry craned the auto scrubber over the beam tube
Terry, Christina, and Gerardo Jr. cleaned around BSC8
Kyle vented YBM
BSC8 door and dome were removed and covered
Dani put locks on H1 PSL enclosure

[Chris, Corey, Hugh, Jim, Kyle, Zach]

The BSC8 Door was removed.  Jim entered chamber and removed the (18) inside Support Tube bolts.  Dome was removed, and Chamber was covered.  De-install & re-install of Dome will occur tomorrow.

Kyle - Valved-in aux. pump cart to GV5 annulus, vented YBM -> Leak from YBM to Vertex (known) -> Using aux. pump cart on GV1 annulus.  

Kyle, Chris, Zak, Rodney, Hugh, Corey - Removed BSC8 south door.

In preparation for the squeezers' reactivation of the PSL, the enclosure has been modified to allow it to be mechanically locked when the laser is running, reducing our reliance on the interlock system and adding a layer of safety in place of wearing glasses in the LVEA.

Pictured below, the inner doors are held in place by aluminum 3/4" x 3/4" bars only accessible by opening the front doors, while the front doors are prevented from moving by padlocks secured through holes drilled into the sliding tracks. The padlocks are all similarly keyed and the key will be kept in the control room.

Note that even with this system in place it's still possible to move some of the doors enough to trigger a violation.

Hard-closed GV5, soft-closed GV6, isolated IP5, connected aux. pump cart to GV5 annulus (did not valve-in), spun-up YBM MTP -> all in preparation of venting YBM -> Did not vent YBM as scheduled.  Had shut down purge air compressor in the morning to inspect internals of airbox and ended up spending the rest of the day disassembling the airbox, cleaning and caulking leaks noticed between the sheet metal stitch welds which were allowing compressor cabinet air to enter the compressor downstream of the inlet air filter.  The compressor crankcase vents inside of the cabinet and this air is laden with turbine oil vapor.  This air was entering the 1st stage compressor inlet by way of small unsealed passages (gaps) which occur between the welded sheet metal airbox stitch welds. Inlet air is intended to enter from LVEA ducting only.  Evidence of condensed oil was noticed in the intercooler condensate drain bowl but nowhere else downstream -> I showed John W. the details of my concern.  In addition to caulking, I fabricated gaskets for the bolted sheet metal components of the airbox.  These steps are expected to eliminate cabinet air from entering the compressor intake.

Today I successfully fully hung the BS/FM (FM1) for the first time.  After several rebuilds of the wire loop/middle wire assembly due to kinks and breakage (2 more rebuilds today after Betsy's last post), a complete hang and rough adjustment was completed.  After setting the blade tip positions in the top mass, I released it and the top stage from their stops.  The initial pitch of the top mass was out ~10 degrees, during which time I noticed that due to the off-center position in which the wire exits through the base plate of the top mass (see pic 6), the wires were touching the edge of the base plate holes.  This is something to watch carefully for in subsequent assemblies as a more severe pitch issue could damage the wire assemblies enough to warrant a rebuild.  I would recommend slowly lowering the EQ stops until it becomes apparent that this is not an issue.  If it seems to be, stop and reclamp the mass until enough mass is shifted to hang level.  It did not seem that the contact was severe enough to gouge or bend the wires, so I proceeded to move addable masses around on the top mass, as it became apparent that that the pitch adjuster screw would not have enough range to remove all the mis-pitch.  In all, I had to move ~200 grams of masses to the OSEM side of the mass.  Having done that, all the DOFs look rather good.  However, the chain does appear to be hanging biased toward one side of the structure, so I will have a look at centering it up using the top stage adjustment tomorrow.