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.

Further HEPI assembly at BSC7.

[Corey, Greg]

SW Location (s/n 77)

A job we hope would be a one hour task turned into a day long endeavor (which is still ongoing).  Yesterday afternoon Greg drilled and tapped holes on the Pier (after the iLIGO Actuation Stack was removed).  This morning we hoisted the new HEPI Assy onto the Pier and discovered that the Support Bracket holding it was an unmodified one, and we had interference issues(!). 

So we lugged the HEPI Assy down to the ground and for safety/alignment reasons, re-installed the iLIGO Actuation Stack. 

We then went to the NE HEPI, confirmed all the HEPI Foot clamping bolts were securely holding the Foot, and also checked that all the Base clamps were torqued down to the Pier.  The Support Bracket here was then removed (note, this one only has the vertical slot modifications, not the cut out on the top of the Baseplate).

The SW Support Bracket was removed and handed over to Bubba for mods, and the NE one was installed at the SW corner.  Vertical Dial Indicators were installed at these two corners to monitor changes.

Once again, we hoisted the HEPI Assy up onto the Pier and we cleared the interference on top, but just as we were getting ready to drop bolts into the Foot on top, we discovered ANOTHER INTERFERENCE!  This time the base of the HEPI Assy ran into the top of the Bottom Plate of the Support Bracket (see photo).  {Crap!}

Greg then checked the position of the Foot just to confirm we didn't make a mistake with pre-positioning of the Foot (we were a little off and in a way which helped us, but still off).  So we now need to wait until we get a fully modified Support Bracket before we can continue anything at BSC7.

Bottom Clamps & Bent Bolts

At one point it was noticed that non-called out bolts were used for Bottom Clamps (see photo #3) for the NW & SE HEPIs.  As these Clamps were loosened up and the bolts were swapped it was noticed that it was hard to remove some of the bolts.  In fact, there was one bolt which was noticeably bent!  (see photo #2)

Looks like the bend in the bolt occurs at the interface between the bottom of the Bottom Clamp & the top of the Pier.  Apparently the 1/2"-20 set screws and the 35ft-lbs we'd been taking them too is just too much for the 1/2"-13 bolts here.  Unless someone else chimes in we will do the following in the future: 

-Torque 1/2"-13 bolt to 67ft-lbs

-Torque top 1/2"-20 set screws to 25ft-lbs

-Tighten the side 1/2"-20 set screws enough so they won't loosen up on their own.

For what its worth the stainless 1/2"-13 bolts were swapped out with the black HoloKrome bolts.  (Need to do this bolt swap on the SE HEPI, too).

I cleaned up the vacuum alarm handler to remove those ion pump channels which are always in alarm. All vacuum alarms from now onwards should be treated as real alarms, and hopefull they will be infrequent. I also added the cyropump fill valve alarms, if these go off a pump overfill is imminent. New alarms have guidance text attached.

I changed the alarm startup script (called from the medm site map) to only start the relevant alarm handlers (relevant to the status of the IFO and site at this time).

Table legs were grouted into place today. We attached fans to them to help them dry.