(Corey, Greg, Mitch)

Stabilizing 200lb Masses

Vince noticed some ugliness in the transfer functions for #1 on the LVEA Test Stand.  With the big (200 & 600lb Leg Elements) masses on top of the assembly being a possible suspect, we took a look at these masses.  With the layout we have on top (see attached photos), we observed that the 200lb masses were not very secure on the table (none of these masses are bolted down, but we thought gravity would be enough to keep them secure);  one could easily rotate or "teeter" these masses where they were. 

So yesterday (Wed), we went in and lifted the 200lb masses and slipped shims under them so they would have 3-pt contacts under them.  We did this for both 200lb masses (using two different types of shims for each mass; see photos).  This noticeably secured the masses much better.

Notes: 

1) These masses are a different set from the ones used for testing in the Staging Building.

2) This morning Vincent informed me the transfer functions haven't changed much.  Perhaps we'll have to put shims underneath the 600lb masses next, or look somewhere else for noise issues.

Re-balance Of System

After work with the weights above and adding of shims, went about re-balancing of the ISI.  With this sort of re-balance, we look at the Stage1-2 Vertical Capacitive Position Sensors (via Voltmeters plugged in to them).  We adjust the payload until we can get the Sensors to have voltages of +/-0.500V (where a negative value means the gap is small...in other words the corner for this sensor would be low).

After several iterations, the best we could manage was the following:

Corner 1 (~crane east):  -0.375 V

Corner 2 (~west):  -0.340 V

Corner 3 (~south):  -0.545 V

Corner 3 was the tough one, and this was the closest we could get to under +/-0.500V (see attached photo for locations of trim masses).  Overall we're low (perhaps due to the added shims).

Noting Serial Numbers

Keeping track of sensors (i.e. Capacitive Position Sensors, GS13's, L4C's, Trilliums) is becoming a bit of a bear.  Since we are ready to install sensors on BSCISI#2, and I didn't really have a grasp of where every sensor was, I went ahead and noted where sensors on #1 were and their serial numbers (well, only for those which had S/N's viewable. 

For podded seismometers, I believe we are noting s/n's by the numbers scribed on the actual pod (vs the actual s/n of the seismometer inside or the "base" flange of the pod).  Here is what we were able to note for s/n's on BSC#1:

L4C S/N's

Corner 1 Vert:  155

Corner 1 Horiz:  22

Corner 2 Vert:  151

Corner 2 Horiz:  152

Corner 3 Vert:  153

Corner 3 Horiz:  150

GS13

Corner 1 Vert:  76

Corner 2 Vert:  84

Corner 3 Vert:  98 *

* NOTE!  This is the one which exhibited issues and needed to be opened up to repair it.  It's good for testing, but needs to be replaced with another GS13 before this ISI is installed in the Vacuum System/BSC Chamber!)

The LHO aLOG and the aLIGO project wiki will receive a security update today at 1pm Pacific [3pm Central, 4pm Eastern].

The update will require users to log into the systems again.

Users are advised to save their logbook and wiki entries prior to 1pm pacific [3pm central, 4pm eastern] to avoid losing them.  Users who are simply reading the aLOG should notice no interruption.

This message will be repeated in the LHO aLOG.  I will post a comment to the aLOG when the update is completed to avoid spamming lsc-all.
--
Jonathan Hanks
General Computing Sys Admin
LIGO Hanford Observatory

We started the morning making an initial assessment visit into the BSC-7 dome where we took pictures, figured out how to "grid" the dome for documentation purposes, and took some particle counts. The dome walls appear to be quite clean (nothing comes off the wall onto gloves) but the surface is rough enough to "cling" to a ConTec when one is used. The welds (seams and stitches) have a "sooty" residue that comes off on light contact with gloves. 

We asked John and Bubba to come out and take a look at ventilation and recommend a means of improving air flow. We'll remove a blank conflat tomorrow morning so that the dome has some internal circulation. 

After lunch, Rai "bunnied up" for visit into the chamber and the dome. Then, the crew completed the wipe down of the chamber floor and took the last of the FTIRs, which were sent off to JPL. 

• Shims added under masses on BSC ISI
• Ski to outbuildings checking water levels in tanks
• Chamber cleaning at BSC7

A new version of the "prepare quad" script is uploaded to the SVN:

/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ITMY/Common/MatlabTools/Prepare_ITMY_20110727.m

The script uses caput to change the state of the switches to our "Known Good Starting State" conditions.

The only hard-coded part is on Line 22:

optic = 'ITMY';

Please change to whichever "optic" (i.e. ETMY, ITMY, ETMX,ITMX) you are using it for and update any vales as necessary. Then save in whichever directory is appropriate for the optic you are working on.

0817 - Praxair arrives
0845 - H2-PSL work on Diode Room enclosure begins
0900 - RichardM at EX testing dust monitors, affecting weather stations and systems there
0930 - Paradise Water arrives
0945 - GregorioT at MY
1110 - Nor-Cal visits Hugh
1125 - MichaelR in Diode Room
1251 - Betsy and Richard out to SUS stand in LVEA
1300 - Rai Weiss lecture: "Introduction to LIGO"
1500 - EY, LSB Fiber Lab, LVEA entrance alarming erratically
1600 - Keita begins transition to Laser Hazard
1615 - JonathanB to EY to check Pcal stand
1645 - LVEA in laser hazard (PSL contractors are done)

All the H2 front end and DAQ software are recompiled using the latest tag-2.3 version of the Realtime Code Gen system.

All IOP and user models were recompiled.

All frontends and DAQ computers were rebooted to install the new software.

The H2 DAQ framewriters were modifed to write frames following the aligo naming standard

H-H2-[R,T,M]-{GPS}-{SIZE}.gwf for RAW, SECOND-TREND and MINUTE-TREND respectively.

So for example the file H-R-994483200-32.gwf becomes H-H2-R-994483200-32.gwf

All existing frame files were renamed on both fw0 and fw1 systems.

Spool connecting BSC5 to GV15 will be removed soon.  Need to decouple annulus plumbing from spool-to-GV15 flange, requires venting GV15's annulus volume, this volume has never been vented, don't know if inner O-ring(s) will leak into CP6/X2 module ->  First I isolated the ion pump body from the rest of the annulus piping, then I shut down the aux. pump cart connected to but isolated from GV15 and changed the setpoint at which the turbo starts to a value below what the diaphram backing pump could achieve.  Next I started the pump cart and let the pressure come down to the ultimate pressure of the diaphram pump (~1.5 torr).  Next, with Gerardo monitoring the pressure in CP6/X2 module, I valved-in the pump cart into GV15's annulus and Gerardo confirmed that CP6 pressure was unaffected.  Now I opened the orifice (vent port) and the hanging turbo which resulted in the annulus volume settling in to around ~200 torr.  Still no change in adjacent volume pressure.  Finally I shut down the aux. cart and let the annulus volume fully vent -> No leak.  

Decoupled piping from spool flange and blanked-off both (decoupled) flanges -> Pumped GV15 annulus volume with pump cart, opened pump body to rest of piping and restarted ion pump.  Isolated pump cart from annulus.

Removed RGA from BSC5. Now Apollo can remove spool from between BSC5 and GV15

More framing work for the diode and chiller rooms. The ceiling joists have been added. No construction work tomorrow, but on Thursday they will start cutting into the LVEA drywall. The North crane is still tied up.

Dust counts are again low. A trend of the last 10 hours is included.

We continued inspection and wipe down in BSC-7. Three additional instances of the mystery substance were found and removed: these areas were also FTIR sampled. The flooring was removed and covered (just in case we need it for something after re-installing the dome) with C-3 and placed in a cleanroom. With the floor removed, we were able to get half of the chamber bottom wiped down and FTIR samples taken. The C-3 cover on the dome was removed in preparation for work tomorrow. Carolyn worked on paperwork for the FTIR samples and on modifying the spreadsheets for record-keeping in prep for BSC-8. 

Changed prefilters for AHU1 and 2

(Corey, Hugh, Vincent)

Checked Level of the Optics Table and also took shots of the top of Stage0 (where the Alignment Pin cut-outs are).  Optical Level was used for level-checking.

While working around the table, removed the Alignment Pin Washers for Stages1-2 & Stages0-1 (thought it would be a good idea to not leave these loose items on floated stages).  There is a photo (which needs to be rotated clockwise 90deg) of where these washers are located.  The Stage1-2 Washer is a little tough to retrieve, but it was pulled out with the use of a small allen wrench.

Took opportunity to pull lots of lingering hardware and tools which were "stored" on Stage0. 

Vincent wanted to check the big masses (Leg Elements) on top of the Keel (Stage2) for any possible vibrations.  Sure enough, the smaller (~200lb) masses on top of the bigger masses did have some observable gaps underneath them.  [tried to snap some camera-phone photos to illustrate this].

The DAQ system for the Oplev Mid-y test has encountered an unexpected shutdown. The DAQ card and electronics have been brought back to the corner station for troubleshooting and will be put back 'online' as soon as possible. Our stand-alone system had been running for almost a week without interruptions. The last successful data log was taken around 16:07:02 (PDT) on 7-25-2011. 

We completed the 2nd wipe down of the upper sections of BSC-7. Work was slowed by the discovery of a mystery substance (Jodi calls it goopies, Mike L. calls it snot: see pix below) found during inspection.  It required special attention to remove as it was very tightly adhered to the chamber, in some cases appearing to be baked on. It seems likely that this material was left over from iLIGO install. We will continue to investigate. We ended the day by taking eight FTIR samples.

Framework for the chiller and diode rooms is being laid down. The North crane is temporarily tagged out, as it is supporting the make-up air ducting for the acoustic enclosure.

No dusty work, a trend of the last 10 hours is attached.

Today drove all M0 and R0 Top OSEM Basis Channels with a Uniform White Noise TF from 0.1Hz to 50Hz with the De-Whitening Filters disabled, first with Binary I/O LP Disabled and then with the Binary I/O LP Enabled. Then drove each M0 and R0 Top OSEM Basis Channel with a Uniform White Noise TF from 10Hz to 50Hz at twice the amplitude with the De-Whitening Filters Disabled, first with the Binary I/O LP Disabled and then with the Binary I/O LP Enabled.

Overlaid the 10Hz to 50Hz data on the plots.

Results Below.

The crew re-installed the BSC flooring and worked on the second wipe-down starting from the collar section. Cheryl got TCS fit check taken care of just after lunch and then wipe-down continued. The upper section was completed before end of shift. We also continued to move equipment from BSC-7 to BSC-8 as time permitted.

Summary: With a lowest resonance of 35 Hz, the new pier avoided the 4-pole motor region at 30 Hz. Reducing payload at the top could at most increase the resonance by 10% to 38 Hz.

We examined the motion of the new leaning optical lever pylon that is grouted to the floor at MY for testing (see photo). A breadboard and translation stage for the photodiode at the top of the pylon appear larger than necessary, weighing about 15.7 kg, so we investigated the maximum gain possible from using lighter equipment by measuring without this load. We also measured with and without the 15 kg dummy photon calibrator.

The figures show accelerometer spectra from near the top of the pylon for the nominal and modified configurations, as well as corresponding spectra for the floor below the pylon. The peak at just below 30 Hz is on the ground and likely produced by a four-pole motor. It is good that the peak for the nominal configuration mostly avoids 30 Hz because such peaks occur at all stations. The transient peak on the ground at 34 Hz is atypical and of unknown source.

The lowest resonant frequencies are tabulated below:
Equipment on pylon                                       Lowest frequency (Hz)

Diode assembly and photon calibrator (nominal).....34.9 
Diode assembly only................................................36.4
Photon calibrator only...............................................38.1
Nothing on pylon.......................................................38.1

We were a little surprised that the lowest frequencies for the pylon alone and for the pylon with the mock photon calibrator in place were virtually the same. We added various masses at different levels and found that mass at the level just above the photon calibrator (see photo, the mock photon calibrator is at the level where the caution tape attaches) moved the peak at 42 Hz, but had little effect on the lowest peak at 38.1 Hz. On the other hand, moving the same mass to the top of the pylon did move the peak at 38.1 Hz down.

Thus, without stiffening the upper stage of the pylon, a lighter diode assembly could, at most, raise the lowest resonance from 34.9 to 38.1, about 10%.

Robert Schofield and Gregorio Tellez

- Mid-Columbia Forklift arrives for RodneyH
- Lots of kids on site for a tour...Riverton residents join them
- Drilling by H2-PSL begins at ~1:20pm
- Richard, Keita working on syncing OMC and LSC, AWG reboots involved
- Fred leads tour for UW students into LVEA
- Laser Hazard at ~4:30pm
- ICC by BSC7