The cleanroom was moved back over the chamber and a C-3 soft roof installed. We try for two cleanings and dome removal tomorrow.

The cleaning crew got two cleanings in early this morning and the Apollo crew staged for door removal. The Apollo crew started working on door removal about 1:30 pm. By 2:30 pm, both the east and west doors had been removed from the chamber.

Summary: We have removed eddy current damper magnets from M0 of the quad in hopes of reducing magnetic coupling. However, investigations show that there is also excess coupling at levels L1 and L2. I suggest removing the blade ECD magnets from L1 and cutting slits to reduce eddy currents in certain L2 parts around the AOSEMs.

We have now removed the eddy current damping magnets from stage M0 of the quad suspensions (Figure 1). This should reduce magnetic coupling, but my investigations at ETMY suggest that M0 is not the only level that has large magnetic coupling. Figure 2 demonstrates that there is also coupling at L1: there are two peaks evident on the BOSEM signals from M0 (top plot), the one on the left is produced by a BOSEM injection, only at M0. The one on the right is produced by a magnetic field generator outside of the ETMY vacuum chamber. The bottom plot shows that the relative amplitude of the two peaks is very different on the level just below, L1: the BOSEM injection peak on the left is relatively more attenuated. If the external magnetic field coupled only at M0, then the two peaks would keep their relative sizes because both would be equally attenuated between M0 and L1 (actually, the slightly higher frequency magnetic peak would be slightly more attenuated). Instead, the magnetic peak is much bigger than would be expected if it coupled mainly to the eddy current dampers on M0. A similar experiment shows that we also have excess coupling at L2, the PUM.

Since it is clear that we will have excess magnetic coupling even after removing the M0 ECDs, I had a look at the suspension to pick out what I thought would be the worst coupling sites. Here are my two favorite sites for easy improvement, that might be possible to accomplish before reinserting ITMY.

L1:  The blade spring eddy current dampers (Figure 3). I have checked with Mark Barton to see if there are any problems removing these eddy current dampers before we reinstall ITMY.

L2: The AOSEM mount base plate should probably have a slit in it so that eddy currents can not make a loop around the AOSEM so near the actuation permanent magnet (Figure 4 and drawings: ETM PUM can, AOSEM base plate. Two secondary candidates for slits would be the AOSEM translation plate and the control ring (Figure 4 and drawings  AOSEM translation plate, control ring). The control ring would simply need a non-conducting screw to tighten it.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot for Wednesday November 7, 2012. The data was taken from approximately 6 AM to 6 PM. Also included are plots of the modes to show when the dust monitors were running, and plots of the status to show when the sensor failed for the dust monitor in the bake oven room (H0:PEM-LAB_DUST_LOC_3_STATUS). The sensor failure was reported when the status changed to 1.

The Foton filter files for HAM2-ISI and HAM3-ISI were moved

from:
opt/trtds/lho/h1/chans
to:
opt/rtcds/userapps/release/isi/h1/filterfiles/

Softlink to these filter files were created in:
opt/trtds/lho/h1/chans

Dave made changes to the RCG so the softlinks mentionned above can be preserved during the make process.

Mark B.

Set MC3 to undamped at 08:55 for a 20 minute spectrum series. (We already have a nice damped interval from last night).

EricA & Hugh
The welder finished the tubing runs Tuesday and yesterday we did a couple of the last things required.
First the Actuator Flex hoses were attached to the 4-way valves.  These valves are in recirculate mode.  This position isolates the Actuator/Hose from the housing supply/return plumbing.  The Actuator & hose have fluid in them; the housing tubing remains dry.  The 4-way valve is very stiff and takes a good effort to turn so it is unlikely they will be inadvertently moved.  Please don't do so purposely; we must flush the main lines before opening the valves.
Second we started the install of the electronics modules.  These reside out in front of the pier; please be mindful of these components.

[Luke, Paul, Giacomo]

In the late afternoon we moved the faraday isolator from the PSL enclosure to the HAM2 ISI. We used the cookie cutter place it, so it is already positioned properly. It is not clamped down though, as we don't have the right type of clamps. So, we left the cookie cutter on the table.

We also put in the periscope cookie cutter. The periscope does not have the optics and the black glass in it yet, but we temporarily place it on the ISI table to remove it from the chamberside cleanroom. It is clamped with two temporary clamps.

We couldn't place the cookie cutters for the HAUXes because of a number of issues (for which we should already have a solution), so we just positioned them such that the are (hopefully) out of the way for MC3 installation (but they can be moved easily).

Attached are a couple of pictures of the growing HAM2 population...

PAC meeting
Rick, Cheryl, installation of light pump, alignment of optics between laser enclosure and HAM1.
Sensor failure for dust monitor in Bake Oven Room.
Hugo reported DAC channels not writing correctly for h1seih23, frontend rebooted.
HAM2 viewport installation
Filiberto dressing cables in cable trays around HAM3
Operator station alarm handler moved to H1

Two visible earthquakes on seismic plots:
5.1	54km SW of Champerico, Guatemala	2012-11-07 22:42:48 UTC	13.907°N	92.225°W	35.1 km
7.4	24km S of Champerico, Guatemala	        2012-11-07 16:35:50 UTC	14.083°N	91.916°W	41.6 km

LukeW and RickS

We started the installation of the beam pipe and shutter/beam dump housing designed by Joe Gleason at UF.

There is a slight alignment issue that appears to be partly due to an error in the clocking of the housing where it mounts to the (double window) viewport adapter.

The housing was intended to mount vertically, but is off by one half hole spacing on the 24-hole bolt pattern of the 10" conflat - 7.5 deg.

Tomorrow, if time allows, we may slot or re-drill the flange of the housing so that it mounts vertically (as intended) and relieves some of the misalignment with respect to the opening in the Laser Area Enclosure (LAE).

For now, the lock and tag for the plug that blocks the opening in the LAE has been moved to inside end of the tube, i.e. inside the Laser Room.

The IO work on the Faraday Isolator on the PSL/IO table is finished, so today I started the transition to low-power mode.

The high-power oscillator was shut down (to conserve pump diode lifetime).

The PMC modematching lenses have not been moved yet and the alignment into the PMC has not been adjusted.

For now, the front-end internal and external (manual, mechanical) shutters have been closed for installation of the beam tube between the Laser Area Enclosure and the HAM1 chamber.

Tomorrow, we plan to complete the transition to low-power mode.

I've enabled the damping on MC3 at 4:45pm, so we should be able to get spectra for past this time.

While the Main chain damps, we can't engage the reaction chain damping.  We've carefully poured over settings to see if there is a sign, filter, or gain setting incorrect but all looks well.  Example Symptom: When engaging Transverse (only uses SIDE BOSEM), we see no ring up or down.  When flipping the sign on the damping we see a large ring up.  This indicates the SIDE magnet polarity is correct.  More forensics tomorrow morning, but I'm hoping to solicit Richard to help me see actuation out on the floor...

I've also re-checked that there is no rubbing on this chain, and that it appears to be floating freely when pushed.

Disconnected SUS SEI field cabling from HAM3 feedthrus to dress cabling inside cable trays around HAM3. All electronics were powered off before cables were disconnected. When reconnecting cables, had Corner 1 and 2 for ISI driver (Coarse and Fine) connected backwards. Hugo is trying to bring HAM3 ISI back up.

[Giacomo, Paul]

We installed the parking beam viewport baffle in HAM 2 this afternoon. The installation went smoothly; it was easy to access the viewport standoffs by sitting on the table with our feet on the HAM1 side nozzle. Just in case, we had put a C3 sheet over most of the the table to protect against dropped screws. I attached some images of the installation process. 

We did however notice a slight issue with the standoff posts. The posts have to be screwed into the viewport reducer by hand, and since they are cylindrical it is not easy to torque them very much. The silver coated screws that screw the baffle assembly to the standoffs are quite tight within the standoff thread though. Since the baffle assembly should be adjusted in rotation to pass the beam through the aperture, one may be required to unscrew these screws. Unless a pair of pliers or similar is used to hold the standoff in place, attempting to unscrew the screw that fixes the baffle assembly to the standoffs will instead unscrew the standoffs from the viewport reducer. This should be kept in mind for anyone adjusting the baffle rotation, and potentially for LLO / India installation too. It was suggested to look into a small redesign of the standoffs to fix this issue.

(Jim, Chris, Giacomo, Douglas, Gerardo)

We installed the REFL parking beam viewport, first the aLIGO IO reducer was installed, part number D1201195 on port D8 of HAM02, on top of the reducer a viewport was installed, assembly D1101670, the following just for posterity, we used 5/16-24 x 1.5", 12 point, silver plated bolts to hold the assembly to the reducer.

The viewport is now covered with a viewport protector and a safety cover (yellow type).

Leak check needs to be performed on this viewport.

It seems that the ISI foton files have been moved to the userapps directory, and the old location is now a softlink to the new location. e.g.
/opt/rtcds/lho/h1/chans/H1ISIITMY.txt is a softlink to 
/opt/rtcds/userapps/release/isi/h1/filterfiles/H1ISIITMY.txt

(see https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=4093 for more info about this change, real documentation will be forthcoming.)

To support this file move, I have updated the SEI tool get_filenames.m so that it will follow a softlink for the foton file location. It will not work on a windows machine, and will only follow the link one step, but it should work, once the {SeismicSVN}/Seismic/Common/MatlabTools/ directory is svn up ed.

See the SEI log for some more info: https://alog.ligo-la.caltech.edu/SEI/index.php?callRep=126

SEI diagrams are built such that SUS watchdogs trip SEI watchdogs. During testing, the QUAD can be installed on one teststand while the ISI is installed on a second teststand. The connection between SUS and ISI is not necessary in this case. For convenience (no need to modify/recompile the model after every change), I added in the diagram of h1isitst.mdl a switch that disables the ISI-SUS watchdogs connection.
By default (variable at 0, case after recompiling a model without any burt restore), the ISI will read the SUS watchdog. If the variable H2:ISI-TST_SUS_WATCHDOG_DISABLE is set to one, the state of the SUS watchdog is ignored.