Usual Tuesday deliveries.  Work continues on H2 PSL enclosure and chamber cleaning tests.  Dust monitor trends attached for 0730-0430 local time, same locations as previous entries.

Marielle and Margot are visiting this week to bond the first test mass, the one arm ITM.  Pictures are of the the optic with First Contact applied to the HR surface (by Margot yesterday), and of Marielle and Gerardo using the Romer CMM Arm to measure the thickness of the optic in a few places (verifying wedge, etc, in prep for locating the ears for bonding).

Ran well ump to fill well tank.

[Corey, Jeff, Jim, Stephany]

BSC#1 Assembly Work

Lots of shuffling took place today as plates were moved within the Staging Bldg and from the Vacuum Prep Warehouse.

Helicoiling and dowel pins were finished off on the Stage0 Top Plate.  The Top Plate was then installed & torqued onto the Bottom Plate.

The Optics Table was brought onto the Granite Table and now helicoiling begins!

BSC Work Area Space Creation

This section covers work to reassemble HAMISI#3 (i.e. clearing shelf space for upcoming BSC work). 

All of the Sensor Assemblies were installed.  It was determined earlier that two of the Sensors for #3 were bad, so new ones were swapped in for #3.  The new Sensors are S/N# 12029--->H3 & S/N# 12040--->V3.

During disassembly it was noticed that the small screws in the cable plugs which connect to the GS13 looked pretty damaged (their threads were really eaten up during assembly).  It was decided we don't want to use these screws, and want to just plug in the connectors.  But to do this, the damaged screws have to be pulled out because they don't allow the plugs to be connected.  This was done for all (6) plugs.

All of the Horizontal GS13's were installed. 

Note On Broken Tangs:

A few times during the reassembly of #3, rogue broken tangs have been found on several occasions (i.e. when you're installing a part, one finds that a bolt won't screw in---usually damaging the bolt).  This has happened while installing an Actuator and while installing a GS13.  So, eventhough we may be thorough, not all broken tangs are being accounted for.

Today the contractors installed insulation on the roof, later covering this with another layer of sheetrock. Aluminum standoffs were also installed on the 4 sides of the building - the floating exterior wall will attach to these.

As Dani mentioned, dust levels remain normal. One week trend is attached.

Cleaning preparation work was done on aHAM12 (iHAM11).
Construction continued on the H2PSL enclosure with laying of drywall.
I tracked dust monitors during this activity to see if dust from drywall laying was potentially getting into open HAM. Attached is a chart showing today's dust monitor trends, the only significant spike inside the clean room was when the forklift was maneuvering through the doors. Other than that activity was really low (<500) and drywall work doesn't seem to have interfered.

A MicroVac Portable ULPA Cleanroom Vacuum/Blower was purchased from Terra Universal.  After Class B'ing a TFE hose, we confirmed that particle counts coming out of the exhaust and through the TFE hose were near zero (after making sure that surrounding dust wasn't being picked up and slewing the counts).  Friday, we attempted to take some video/pictures of the blower hose blowing off particulate collected on a tabled QUAD UIM subassembly (see attached pictures). The field of view of the surface in the video is on the order of a few square inches.

On several occasions I have set up seismometers on a building slab and on the ground near the slab and found that the slab follows the ground below a few Hz. However, I don’t think that I have previously put these results in the log. 

Recently Jan Harms and I were making Newtonian-noise related measurements and set up seismometers at the locations indicated on the attached plan of the corner station. The top plots in the figures X,Y and Z show calibrated velocity spectra for the X, Y and Z axes (directions indicated on the plan) for seismometers at locations indicated by arrows on the plan in colors matching the spectrum trace colors. The lower plots in each figure show coherence between the seismometer on the slab edge and the one 3.5 meters away, off of the slab in the gravel (RED). For comparison, the figures also show (BLACK) coherence with the seismometer that is 3.5 m in the opposite direction on the slab. Because we used only 2 seismometers, the black traces were taken at a different time. Coherence between the slab-edge seismometer and the off-slab seismometer drops faster with frequency than for the slab-edge and the other seismometer on the slab. 

The frequency at which coherence drops off between the slab-edge and the other on-slab seismometer at a distance of 3.5m away, is typical for 3.5m spacing, even at the center of the slab, and does not result from one of the seismometers being at the edge of the slab. The drops in coherence in the 1 Hz region, where the velocity is lowest, are also present in spectra from the huddled seismometers, indicating that a significant fraction of the signals in these regions are due to electronic noise. The black traces were made at lower resolution than the other traces and so do not extend down to the lower frequencies.

The on-slab and off-slab spectra are very similar and the coherence is high below about 3 Hz in X, 5 hz in Y, and 8 Hz in Z. For fundamental Rayleigh waves, the wavelengths at these cutoff frequencies are thought to be of order 100 meters, based on propagation velocity measurements.

Robert S., Jan H.

Last week we mounted the H2 iLIGO PSL table on a new leg system for aLIGO, discussed here.

Our design philosophy was to minimize RMS motion in the aLIGO band by raising the table sway resonances from iLIGO’s 20 Hz to about 100 Hz, and the vertical bounce on the legs from the 40-60 Hz region to about 200 Hz. We did not want to raise the resonances much higher, because they would overlap with the periscope resonance. We chose not to float the table because the system we have experience with only controls 3 degrees of freedom and it increases low frequency motion in the 1 Hz region and below.

Figures 1 and 2 show displacement spectra and RMS from accelerometers mounted on the H1 (iLIGO) table (red), and the H2 aLIGO table (blue) for comparable locations near the periscope position, taken at the same time, and a spectrum from the floor near the H2 table, taken at a slightly different time (black). Clean rooms were off for these spectra. The lowest of the sway resonances of the new table is at about 95 Hz, not quite 100 Hz, but acceptable, and the bounce mode is at about 200 Hz. 

The RMS motion of the new H2 aLIGO table above 10 Hz is about 20% greater than the rms for the black floor trace, while the RMS motion of the iLIGO H1 table is 730% greater. 

These results were comparable with those from the first installation, made at LLO, discussed here.

Robert Schofield, Rick Savage, Michael Rodruck, Mark Dodson

If you type an entry into the "Quick search" box and hit enter, the page refreshes instead of executing a search. You have to click the search button to actually do a search.

Work was finished on the first layer of exterior sheetrock, as well as the interior ceiling sheetrock. More sheetrock work to be done on Monday.

Dust levels are normal. Plot shows one week of data.

- H2 PSL: Work was finished on the first layer of exterior sheetrock, as well as the interior ceiling sheetrock. (MichaelR)
- Group from WSU touring site, including LVEA.
- Terry Santini at EY to fix water pump.
- Electronics delivery expected for Richard hasn't arrived yet (or at least when I was here).

After running the balance of the test procedure on Q3 on Thur, we dropped the ECD blocks onto both chains.  New TFs revealed than something was then touching.  After another few hours of BOSEM/ECD plate alignment (which basically pushed us back through a portion of the test procedure), we finally found the slight interference.  Rob is back to running the TF gamut.  Of the 12 he had to re-take, he has 3 left for Monday.  

[Corey, Jim, Stephany]

BSC #1 Stage 0 Top Plate

This plate was placed on the granite table for pre-assembly work.  1/4"-20 & 3/8"-16 helicoils were installed on this plate.  Unfortunately, we did not have a tool to install the 5/8" helicoils.  Additionally, we also installed dowel pins.

HAM#3 Re-assembly

Last week one of the eyebolts installed on the Optics Table was found to be stuck in the table.  Today a 6' bar was used to attempt to turn it out and this 3/4"-10 Eye Bolt ended up breaking in the table.  There is probably ~1" Class B "threaded rod" now stuck in the Optics Table.  Initially thinking we would pull out this Table and swap it, ~130 of the bolts were pulled out of the table, but in this time, it was decided that we would probably keep this Table in place (so the ~130 bolts were re-installed).

The eye bolts we use for lifting plates have tons of thread (~2"), and each thread is an opportunity for galling a part in a plate.  In the future we should use nuts (as spacers) on these eye bolts, or cut these eye bolts down to a useful and safer length.

Since we decided to proceed with this Optics Table, we can now continue with assembling HAM#3 (install  Actuators, Sensors, Walls, weight for GS13's, release Springs, etc.).

Attached is the final positioning observations for BSC8.  Thanks to Scott David & Bubba.

The numbers in the top plan view show the measurements from the ends of the Support Tubes to the Chamber "D" nozzle.  Mirror numbers indicate a balanced location.  Accuracy is typically 1/32".  This system is in very good initial position.

The lower numbers are the vertical positions of the Support Tube.  We purposely leave these a several mils high to allow for sinking when the ISI is added.

To understand why the design elevation is 1060.5mm, see T1100194.

Betsy, Jeff and I did a measurement of the maximum obtainable pitch and yaw range on the rebuilt Quad #2 using an optical lever. According to Norna's write up, T1000268-v1 ( https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=11868 ) we should be able to get 1.4 mrad in each direction at the optic. At the DOF Test screen we applied successively offsets of +2556 and -2556 in pitch and +7863 and -7863 in yaw, which with the usual output matrix maxes out (32K) at least one of the OSEMs. The resulting deflections of the optical lever spot were +9.5 and -11.5 cm in vertical (+=down) and +5.5 and -6.5 cm in yaw (+=left). The optical lever baseline was 4.98 m. 

This implies a total range of 1 mrad in pitch and 0.5 mrad in yaw, which is rather less than expected. A big chunk of this is that the actual UK driver boxes for the test stand were not built to the 200 mA max output assumed in T1000268. To check this, the voltage across the face1 coil was measured at the simulated vacuum flange, with 32K-1 of offset applied at the Output Filters screen. The resistance (including that of the cables) was 39.9 ohms and the voltage was 3.69 V implying a maximum current of 92.5 mA.

The fact that the pitch range is larger than the yaw is probably connected with the fact that the fundamental pitch mode frequency is rather lower than in the model, i.e., there is more pitch compliance than expected.