Commissioning of the HEPI Pump servo continues at LHO with the tweaking of PID control loop parameters.  Spectra of the voltage output from the Honeywell Pressure sensors are attached below.  The maximum allowed pump pressure fluctuations in PSI/sqrt(HZ) are calculated in the document T1100198.  The data was taken from the pressure sensor transducer outputs in-line with the servo box.  Data was then converted from Volts to PSI per the manufacturer's specifications (3000PSI/1V) .  A Dataq Instruments interface was used to record voltage input and record data in a text file using its software on a laptop separate from the single board computer in the servo box.  

The first plot is with no PID servo enabled; it is simply with the motor controller set at a speed that read out ~80 PSI.  The subsequent plots have PID parameters listed in title of the plot.  The maximum allowed PSI fluctuations curve calculated from the above-mentioned paper is plotted as well.  So far, the conservative PID gains have not brought the performance to the maximum allowed fluctuations.  The spectra does decrease in magnitude over all frequencies with increasing PID gains. Next, more aggressive PID gains will be implemented (several 10s to 100s) and data collected.  Also of note, new accumulators were installed Monday and pressurised to 75 PSI.  

Removed 10" to 4.5" skewed reducing nipple and the 2 1/2" angle isolation valve connected to it from the middle port of the SW corner of BSC6 and installed a 10"CFF blank in their place.  These items were the remaining fittings of BSC6's RGA (the RGA "tree" was removed a few weeks ago).  The RGA removal facilitates the relocation of BSC6.

Framing of the laser room is nearly complete. They have to finish half of the roof and then they can start installing the sheetrock.

There have been some concerns about dust levels, but a trend of the past three weeks shows that this weeks construction activity has not been abnormally dirty. I plotted dust monitors 9 (2k PSL), 7 (iLIGO HAM8 position), and 5 (beer garden).

Replaced NC solenoid valve on left tower of X-mid instrument air drying unit.  Building pressure maintained by use of portable compressor (4cfm oiless)

• Wood recylcing bin emptied
• H2adcumy had crashed, I powercycled and ran the startup script to get it going. Interestingly, the status box on the overview screen goes black instead of red when this computer goes down
• Diamond frieght pickup
• Clean room parts craned over beam tube to HAM12 area
• Ongoing construction for H2 PSL enclosure

One of the project controls team created a tribute to our assembly techs and the great work they have been doing.

Please note, this was done on her personal time.  Everything is edible except for the bolt and the tool.

Dave and Jonathan,

we repurposed the lhocds.ligo-wa.caltech.edu IP name from the old iligo system to the new aligo system. Users of the old servers will have to substitute "blue" for "lhocds" in their URLs to get to the old wiki, web pages.

We also ligo.org converted the new aligo CDS web/wiki server. Anyone with a ligo.org account can view the web pages and post wiki entries. In the future, when the wiki contains sensitive reboot instructions we may further restrict the number of subscribers.

King Soft water
Unifirst
Construction started on H2 PSL enclosure
Field trip
Praxair delivery to CP2 and CP5
Camera can removed from HAM4 squeezing table
Preparation for moving BSC6
Finished unloading clean room parts for end stations

Noticed that the instrument air at the X-mid was wet -> Investigation showed a switching failure between the drying towers.  I reset the electronics and observed a few cycles of tower switching.  Also observed that the regeneration flow valve was set for near 0 psi -> adjusted for ~50 psi. -> checked a few hours later and working normally.  Why was valve setting so far off nominal???

Construction began on the H2 PSL laser enclosure today. Contractors started laying the framing down, bolting the support structures to the floor.

Yesterday, BSC6 South door was pulled, after a couple rounds of chamber cleaning.
We installed the Support Tube 'Pillows' which fit under the Support Tubes in the chamber nozzles.  Once in place, the Scissors tables are used to lower the Support Tubes onto the pillows.  To lock them down, A cable goes around the Support Tube and shackles to a Bracket bolted to a chamber interior flange.  See photo, this is not tensioned up yet and there will be one on each corner.

Once the Exterior support structure is removed, further positioning constraint and bellows protection will be installed.

Hugh for
Terry & Christina; Jim, Randy, Scott & Bubba

Ran well pump today
Programed North crane so lights will stay on

The H2 PSL table was installed into its aLIGO position today. It was wrapped up in plastic to seal it from any dust, and we will add a protective layer of lacquered wood to cover the table during construction of the laser room.

H2PSL table was placed and epoxied in position.
Staging work was done at MY for the BSC6 move.

Finished cleaning H2 PSL table
Cleaning at end Y
Moved test squeezer table from H1 PSL area to next to HAM 4 and HAM 5.
Drilling for anchor bolts behind HAM 12

The H2 PSL table is now clean. Every hole was brushed with a gun bore brush, and then cleaned by using the dust-off cans of compressed air  to shoot out any particles while a HEPA vac was over it to collect them. This was made much more difficult by the ugly rust stain  that was sitting on the table and required lots of attention. A big thanks to Terry, Christina, and Gerardo Jr for helping with all this!

The springs have been pulled down and the barrel nuts inserted, so the optics table is ready to be installed on the test stand.

Position sensors 30 & 36 were removed after it was found they weren't working correctly.

Throughout the day:
cleaning at Mid-Y completed by 12:00
Jodi and crew out by HAM12 
Michael Rodruck and Gerardo Jr. cleaning on H2 PSL table

9:30 – M. Landry to EY to lock down GS-13s so initial alignment of BSC can begin

1:30 – Kyle out to X-End to replace a mechanical level gauge for CP8.

I discovered while attempting to replace CP8's magnehelic diff. pressure (mechanical level gauge) gauge that the recent reboot/overpressure episodes had caused a previously unnoticed soft rubber plug to pop out of the back of the gauge.  I reinstalled this plug and now the gauge is working normally and won't requre replacement.  Obviously, this device is designed to pop out and prevent damage to the measuring diaphram in the event of overpressure.