A digest of all open work permits.  If your job is complete, feel free to sign it as such.
#### - YYYY MMM DD - NAME - DETAILS
2530 - 2010 Aug 17 - Robert - Install infrasound at EX
2566 - 2010 Oct 19 - Dave - Remove H2 channels
2594 - 2010 Nov 01 - EricA - Run HEPI actuator flushing...
2642 - 2010 Dec 17 - Squeezers - Seismic tests on squeezer high legs, craning...
2645 - 2010 Dec 21 - Gerardo - Remove H2 OpLevs
2691 - 2011 Feb 15 - EricA - Pump HEPI fluid from ground to mezanine...
2699 - 2011 Feb 28 - Corey - Swap SEI support stack with aLIGO HEPI...
2719 - 2011 Mar 21 - Kyle - Vent RGA volume and remove RGA components from BSC6...
2725 - 2011 Mar 31 - Kyle - Investigate/correct pressure range drift
2724 - 2011 Mar 31 - Bubba - Welding/grinding outside of warehouse
2726 - 2011 Apr 04 - Jodi - Try propane stove for pressure-cooking Viton
2727 - 2011 Apr 05 - Kyle - Vent BSC6...

I have attached second trends of the .5 micron dust levels in the beer garden alongside the Z axis of the accelerometer installed on HAM6. One is during April 1, 2011 and the other is April 4, 2011. Using the accelerometer as an indication of the time that jack hammering took place, it seems that the initial spike in dust appears a few minutes prior to the beginning of work. This might be attributed to the powering on of the blower. On April 4, 2011, I have indicated the approximate times of when the blower was turned on and off: off at 8:40, on at 10:24 and off at 2:00 PDT.

The horizontal actuator on the NE corner of BSC 7 has been temporarily installed. There is no official procedure for installing these yet so the horizontal actuator is there merely to help size the scaffolding for the BSC. It is now held in place with 3 angle brackets. The plans are to remove the horizontal actuator once the measurements have been taken.

The old iLIGO CDS main file server (hanford2) is very slow. I did some diagnostics (error logs, network packet analyser) but could not find any errors. The raid itself is very fast when accessed by hanford2, only NFS clients are slow. I rebooted hanford2 ata 17:11, but that did not work. I killed the conlogger since that was started today, but that was not the cause.

We will have to suffer with a slow file system over the weekend (dont log out or close windows) and I'll take another look on Monday.

The Apollo crew did some degrouting work at the old HAM8 site in the LVEA.
Patrick attempted to track down a source of dust with the monitors, possibly coincident with the degrouting or a maintenance problem with the monitors themselves.
A Reiboldt contractor removed sound-dampening padding from between the LVEA and the mechanical room.

Filled well tank.  This caused a high level alarm on the well tank, but cleared later in the morning.  
Filters changed on RO unit Thursday

Investigation of a decreasing LLCV %open value resulted in the observation that the X-end LN2 dewar vapor pressure was 43psi ( < 20psi is nominal) -> Discovered that the pressure relief circuit was valved-out! -> Opened valve and boil-off venting was restored. There had been a delivery to this dewar on Tuesday and I assume that the driver closed this valve for some reason?  

Also, backed out economizer valve adjuster 1/4 turn ccw on Y-end LN2 dewar (had been running ~30psi at this dewar). 

Exercising the "span" adjustment yesterday has negated the need for a parts replacement.  X-end "Lead" pressure switch operating between 65psi - 80psi.

The HEPI Pump Servo has been running on one of the pump stations at LHO for the last week controlling the motor speed to maintain pressure for the HEPI actuator fluid. The servo box contains a single board computer running CentOS for control via EPICS. We cabled everything up, booted and started the IOC with no issues.

Initially, voltages to each adc channel input were stepped from 0 until the adc counts were maxed at 32767cts. The specifications from the manufacturer of the pressure sensors (Honeywell) gives a calibration of 3000PSI/100mV for the readout. With a +10V input, the adc maxed out at 32768cts. With a sensor measuring attempting to measure 80PSI, this gives:

(80PSI) x (.1V/3000PSI) = .00267V x (32768cts/10000 V) =~ 9cts for a pressure of 80PSI.

As it turned out, their was not enough gain on the inputs to readout the output voltage above the adc noise, even after adding a “SMOO” field to the database file. Richard McCarthy added a gain of 300 to the pressure input channels so that now a voltage of 0.034V will max the adc at 32768cts.

Next, it was noticed the sample rate was affecting the CPU load when all sensors were attached, so the EPICS database file was modified to sample at 2Hz as opposed to the initial 10Hz.

The motor controller box was modified to allow remote control and voltage input.

The EPICS database file was modified to read out PSI units using a slope calculated from stepping through the range of voltages to adc counts and the manufacturer's calibration. The output voltage was stepped in counts via medm and recorded. Maxing out at 1000cts outputs ~5.11V for a PSI of ~100. The PID servo is now maintaining the PSI at ~60PSI without deviations larger than 1PSI.

The next step is to implement a way of writing EPICS data and monitoring the PSI levels over several-day periods. 

I have attached the trends for the .5 micron particle counts per cubic foot from March 31 2011, 22:00-23:00 UTC, the approximate time that Gerardo said he was running the auto-scrubber.

Location 4 is outside the clean room around HAM 12.
Location 5 is in the beer garden.
Location 7 is the former location of the H2 electronic racks.
Location 8 is near the H1 electronic racks.
Location 9 is near the former location of the H2 PSL

I do not see counts as high at location 5 as when the degrouting was taking place earlier this week. I have attached a trend for the last four days for comparison.

School tour on site
Kyle investigated X end instrument air alarm
aLigo CDS training in the control room
Gerardo ran the auto-scrubber
High value alarm for OSB H0:FMC-CS_OSB_AH_HOTDECKTEMP_DEGF ~90.3
Delivery truck for the 5 crates in the LSB arrived, Corey notified

"Lead" pressure switch is failing on X-end instrument air compressor.  "Lag" switch is ok -> Will replace bad part tomorrow.  For now, I made an adjustment which should lessen the nuisance alarms overnight barring a complete component failure.  The temporary norm will be for lower than normal PT599 values overnight.  

I've been modifying the ALS enclosure (for the one-arm test) as our test case for modifying all ISC enclosures for adLIGO. The work is mostly done; as illustrated below, patch panels and small exhaust louvers have been added (made of aluminum, and with no clear optical line-of-sight) to the sides and the enclosure panels modified accordingly. The top of the enclosure has been altered to accommodate a 2'x3' HEPA fan filter (not yet wired). Cable trays and shelves are suspended near the top of the inside of the enclosure, freeing table space previously used for running cables. The panels on back which had periscope holes drilled have also been replaced with fresh panels, so the new periscopes can be positioned as need be.

Still left to do:
Implement laser safety locks on enclosure (still under discussion).
Add and wire interior lighting.
Wire up HEPA and test flow.
Add acoustic insulation back to replaced panels if needed.

CDS training continues today, mainly in the control room. We are upgrading code on the H2 system, so these computers are being rebooted.

- CDS tutorial began today.
- De-grouting work continues under H2 input optics tube area.
- EPICS channels from chiller yard aren't functioning.  Apparently, this has been the case for a while, but I didn't realize it.
- David Nolting convenes weekly safety meeting.

Ran well pump twice today.  King Soft Water out for monthly service and water check.

• Praxair, Sprague, and UniFirst on site
• RO water serviced
• More work on removing grout by HAM7. Lots of dust. Second round of jackhammering started at about 22:20 UTC, ended at about 22:35 UTC.

- Filiberto out to MX/MY to grab boards for Daniel Sigg.
- HEPI installation continues in Biergarten.
- Projector2 (itself, not the server) is out of operation. Patrick Thomas is investigating.
- A Windows machine on the CDS network was errantly sending many repeated requests to the DCC server at Caltech, inviting attention from admins at Caltech and LHO.
- (269) 978-1229 called twice, purporting to be from "Google" about updating our site listing.  It seems to be telemarketers who are not affiliated with Google.
- Swagelok delivery for Hugh Radkins.
- Crew begins to arrive for CDS aLIGO training later this week.
- Ochoa Middle School (Pasco, WA) tours the site.

BSC 7 now has all of the HEPI Assemblies installed. The South West corner saw the need for the HEPI foot position to be adjusted slightly relative to the HEPI frame.

The bottom clamps that had the bent screws have all been replaced with the HoloKrome Carbon steel screws. New torque values were used as well for all of the 1/2-13 and set screws.

Summary:

On Thursday Mar 24th, we made an attempt to fully wire-brush and sample inside iLIGO HAM12 (aLIGO HAM11).  We were partly successful in that 2/3 of the chamber is now wire brushed, and we believe the procedure outlined in T1000725 will form the baseline for cleaning fully the H2 diagonal envelope, and later, L1 and H1 volumes. However in the process we erroneously made use of a screw-type air/oil compressor which may have contaminated some interior surfaces of the chamber.  FTIRs were taken and are due back Thu Mar 31. They will inform of a solution for how to proceed with this chamber.

Some details:

Setting out to wire brush the iHAM12 interior, we defined a matrix for interior surfaces of the chamber and began wire brushing the roof.  This work is ergonomically taxing, requiring sufficient person-power in-chamber, and short shifts of about 5 minutes each, particularly when overhead.  The original (clean) compressor supplying the pneumatic tool was found to decay in air-pressure, inducing delays while the compressor regenerated, so we opted to acquire another, larger capacity unit. This second compressor (Atlas Copco XAS 185) is a screw compressor in which the pump unit employs oil in the screws and then separates it out, and cannot be employed for our clean in-chamber work.  Running the pneumatic tool with the new compressor for 20-30min yielded a failure of the tool (not unexpected as that tool had integrated ~1hr worth of activity). When inspected, oil mist contamination was noted in the tool, the operation was shut down, FTIR samples were taken of both the areas that were brushed with the clean compressor, and the two areas (approx 4 square feet each) that were cleaned with the dirty compressor.  We have ceased operations on iHAM12 and will do no more tests until any further mitigation steps are decided upon; additional assays may be required.  Hoses and garb from Thursday's cleaning operation are quarantined, as are the vacuum.

More details and pictures in a follow-up alog.