I noticed condensed water vapor collecting at the exhaust of the QDP80 -> My measuring of the purge air dew-point prior to pumping yesterday was of the air exhausting into the room from the check valve (acting as a point-of-use pressure relief).  This had been the nominal procedure until recent years after we had observed that the purge air drying towers could be "starved" in a maximum demand case, such as full-open purge air valves in conjunction with one or more chamber doors being removed.  We found then that the measured dew-point of air sourced only from the VE (during pressure equalization "blow-down" prior to pump-down) could be different than that of the air sourced only from the purge air header.  This could result from those scenarios where the drying towers were starved at the time that the door(s) were reinstalled.  Once the doors are installed, there is minimal air exchange between the relative "wet" air in the VE and the relatively "dry" air that the, now not-starved drying towers, were supplying to the header.  

This has not been observed at the Corner Station as we haven't been able to "starve" the drying towers with nominal purge air demands.  

We intended to make it standard practice to measure the dew-point of the air exhausting into the room during the "blow-down" step when preparing to pump down a -mid or -end volume.  

See if I can post a plot......

Attached are plots of dust counts > .5 microns.

Hugh, Hugo,

LLO observed grounding issues with actuators on HAM-ISIs (see LLO aLog #2890) . Actuator cables have their shielding covered by a fairly large mesh. If the cable is pinched against a wall, or set in tight contact with a CPS sheild (which is grounded to the ISI), the actuator gets grounded to the ISI.

We checked the grounding status of all actuators of HAM-ISI Unit #4 (HAM2 Chamber) by testing the continuity between the shielding pin of the actuator cable and the ISI. Even though most actuator cables are tied with CPS shields (picture 1), no actuator were grounded to the ISI on this unit.

We also noticed remains of aluminium bands at the connection between the actuator and its cable, that we removed. To do so, we had to open the door of Act-H1 (picture 2). This door still has to be torqued down with a torque wrench. It will be taken care of tomorrow.

I restarted H1 DAQ, now h1fw0 and h1fw1 are writing identical frames.

h2susb78 (FMY) remains unstable. We have been making incremental changes to pin down the problem:

Reattached to Dolphin network

only run the IOP model

reseat all ADC/DAC cards

rearrange ADC/DAC cards to LHO CDS standard (ref Rolf's IO Chassis document)

We have been stable for 2.5 hours with the latest configuration: Dolphin attached, IOP model only, LHO-CDS card layout. Will run with this overnight.

Kyle
Purge air dewpoint measured <-35C now that doors and dome have been on for a few days and the flow demand is low enough for the drying towers to be effective (found pressure relief valve for scroll compressor #2 is stuck open and won't re-seat -> valved-out output of compressor #2 and de-energized it).  

Began pumping Y-end this morning.  

Kyle
~1600 hrs local 
Y-end pressure at 2.8 torr, going home now -> Closed O-ring valve at Turbo header, closed 10" gate valve at MTP inlet, switched safety valve switch to "Closed" position to close the safety valve, cracked open valve between Purge Air header and Turbo header to let the QDP80 pump a slight viscous load overnight. 

Will restore roughing configuration in the morning then switch over to MTP when pressure low enough.

Powered down HEPI valve drive chassis and ±24V power going to HEPI Interface modules. Replaced R13 from a 2 KOhm resistor to a 33.2K Ohm resistor on D080521 units. This changes the gain of the L4C channels from 22 to 333, per document E1200420-v1. Tested units after mods, gain ~330. Serial Numbers of units modified: S0900178, S0900236, S0900202, and S0900234. Will reinstall units tomorrow morning.

(corey, eric, greg, hugo, jim, mitch)

#6

Now that we had some hardware processsed, we were able to continue building up Actuators.

#7

Stiffener Assembly completed.  The Support Posts were installed (discovered we were missing a Gang Barrel Nut [it was in our "dirty" bin]); will want to get it processed before we pull down springs.

Stage0 Assembly moved to Test Stand.

Stage1 plate put on Assembly Stand.

The set of 6 horizontal L4Cs received in shipment load #3880 were huddle tested this morning, 

We noted a few points that we need to be careful about in order to perform this test correctly:

• Level the instruments
• Have them properly seated (check that they do not rock)
• Direct the instruments towards the same direction

Spectra are attached.

On Friday, after spending some time with Hugh, Bubba and I made a brief checklist (See below) to coordinate our efforts in the BSC1-HAM2 area.

1. Friday pm
     -Second cleaning BSC1
2. Friday pm
     -Move A-frames and I-beams to HAM 2 area
3. Monday am
     -Move cleanroom from HAM4 to HAM5
     -Remove doors and dome from BSC1
     -Stage Optics extract equipment at BSC1 South
     -Install SEI Soft Roof and adjust cleanroom location at HAM2
4. Tuesday am
     -Move Garbing/Staging cleanroom from HAM2 to BSC1 South
     -Optics de-install BSC1 (Lead: Cheryl, Apollo help)
     -Move Garbing/Staging cleanroom from BSC1 to HAM2
5. Tuesday pm
     -BSC1 ISI de-install (Contact Dale)
6. Wednesday am
     -Set up A-frames, etc at HAM2 
7. Wednesday pm
     -Install HAM2 ISI

The attached are the latest M0/R0 transfer function measurements on H2SUSETMY taken on the night of 06/02/2012.  Both chains appear to have no sign of rubbing and have most of their resonances coinciding with the predicted model.  The R0 chain appears to have a cross-coupled resonance in the Longitudinal DoF, but otherwise a very clean measurement.  This measurement suggests the top masses on H2SUSETMY are free-swinging without obstructing forces.  H2SUSETMY is ready for the BSC 6 pump-down. 

Dan, Jim and Dave

We have built up the primary H1 frame writer system, which consists of

Sataboy QFS file system in LDAS server room.
Solaris QFS writer in MSR room.
h1fw0 frame writer, on the 10GigE DAQ network and writing to the solaris box over a private 1GigE NFS link.

h1fw0 is writing frames which are identical to h1fw1.

h2susb78, the replaced front end computer for FMY, crashed again at 5:55pm after just over 6 hours operational. So it looks like the problem may be in the IO Chassis or the communications with it.

Attached are plots of dust counts > .5 microns.

J. Garcia, S. Steplewski

We made a set of TOP transfer function measurements on ITMY Tuesday.  This was the first time we tested ITMY since this chamber was pumped down.  Measurements were clean and the results match up reasonably well with the (fiber) model - although this is a wire rehang after the fiber break.

The .mat files are located in:
~/SusSVN/trunk/QUAD/H2/ITMY/SAGM0/Data/
~/SusSVN/trunk/QUAD/H2/ITMY/SAGR0/Data/

The .pdf files are located in:

~/SusSVN/trunk/QUAD/H2/ITMY/SAGM0/Results
~/SusSVN/trunk/QUAD/H2/ITMY/SAGR0/Results

D070081 S1102755, the e-traveler of which is available here: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=58957.