[Stuart A, Jeff B]

Following previous M1-M1 TF measurements taken for PRM (HSTS) which exhibited signs of environmental noise coupling into the Role and Pitch DOFs (see LHO aLOG entry 4232), TFs have now been re-taken during a quieter period. 

The first plot (2012-09-20_1215_X1SUSPRM_M1_ALL_TFs.pdf) shows a comparison between PRM and the HSTS model.

The second plot (allhstss_2012-09-20_1445_All_Phase1b_HSTSs_ALL_ZOOMED_TFs.pdf) shows a comparison between PRM and every other HSTS suspension that has completed Phase 1b testing for both sites.  

The TFs obtained for PRM are in good agreement with the model, and fall within the scatter of modal peaks observed for other suspensions. Therefore, this should now finally complete Phase 1b testing of this suspension. 

All data, plots, results and scripts have been committed to the SusSVN as of this entry.    

JimW GregG & Hugh & the fantastic Cleaning Crew Karen & Christina!

The cleanroom was spotless and the can was polished.  We pulled the lid and drove the ISI on the container base into the cleanroom.  It will start getting podded tomorrow

EricA JimP Keith Filiberto & Hugh

We continued emptying the last of the fluid in the lines.  Eric disconnected the BSC8 chamber tubing from the 4-way valves and plugged the tubing.  Then he removed the Accumulators from the Manifolds.  Jim & Keith then took the tubing out from the BSC.  The supply mains were then pulled east and cut to extract them from the OMC area.  THere are a few hangers etc on the chamber but those will be pulled in the AM.
All the cable pulling is compete, CPS racks are removed as are the Dial Indicator trees.

Do we have to pull the Cable trays to put in the Walking Plates?  Do we need the Walking Plates?

• Ken working at Y-End, electrical work.
• John W. turned off BSC10-RGA computer, see his entry.
• Filiberto working in the LVEA, test stand cabling.
• Travis working in the LVEA, BS work at test stand.
• Doug and Jason, HAM03 alignment setup, table in place "do not touch".
• HFD was here, fire hydrants test.

The old Balzers RGA mounted at YEND was powered down and valved out today to facilitate electrical work. This RGA was valved into the system ~June 8 by Kyle and I.

NOTE - this is NOT Rai's RGA - it was not disturbed.

Attached are plots of dust counts > .5 microns in particles per cubic foot.

I have uploaded a brief report on efforts to understand and diagonalize the OSEM sensor readouts on the two quadruple suspensions at LHO.  The BSC8 chamber containing ITMY is now out of vacuum and so further testing on it will not be possible for the near future.  The ETMY will still be under vacuum and is amenable to more testing that should help us understand how to fix the responses of the lower stages of the quad suspension OSEMs.

https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=t1200442&version=

EricA Hugh & Apollo JimP & Keith

We throttled down the Pump Station operating press to 30psi, then move the BSC8 4-way valves to bypass isolating the Actuators at the Chamber.  We then put the Pump Station System up on the Mechanical Room Mezzanine into recirculate mode.  Then the 1-1/2" supply lines in the LVEA were closed.  With pans and pitchers in place, we started opening up the drain and vent ports.  With a little additional help from some bottled gas in the vent port we have pretty much emptied the system.  All the port are closed for the night.  We'll let the fluid pool overnight--there is a lot of shallow sloped tube.  In the morning we'll dump the final bit that accumulates overnight and then start taking out the temporary lines.

• Ken working at EY
• Travis working in HAM3 clean rooms
• Filiberto and Gerardo Jr pulling cables
• Strangly high dust counts at EY, which are still persisting even after everyone has left the area. Someone leave a door open?

Started assembling BSC#4's lockers today and encountered a rather annoying issue, which, I vaguely recall, we may have run into before. When inserting the Stage 1-2 locker sleeves (D1000875) into the locker housing (D1000908) I could thread the sleeve down into the housing, but couldn't get it down the last 1/4 inch. I suspect that there is some manufacturing issue with the sleeve, because I had no such difficulties with the Stage 0-1 parts, which use the same housing. The sleeve does have very tight tolerances to the housing, so a small error in concentricity would totally screw this up. There are a couple of pretty easy fixes for this (lathe the interfering part down, or electropolish a couple tenths off) but the sleeve is coated with a anti-friction treatment, which will need to be re-applied and thus slow down re-processing after the fix. I was able to find enough sleeves that happened to work (3 out of 7 tried) to keep BSC#4 moving, but this job took 3 times as long as it should have.

Otherwise BSC#4 is going well, the superstructure is assembled and is now waiting to be populated with sensors, springs, lockers, etc. We are also slowly working towards getting the other staging building test stand converted so we can start on #5, whose Stage 0 plates are currently waiting on the floor for some free table space.

Wipe down started this morning.

We moved the green iLIGO cleanroom from the HAM6 Laser Bay so that we could use it on the E Module at BSC8. I also worked on the cleanroom curtains.

This morning, Bubba and I moved three optic table enclosures from the LEA to the LVEA. One went to the HAM6 Laser Bay and two will be craned over into the West Bay for dis-assembly and storage since they are destined for LIGO India. 

This afternoon, Bubba fired up Big Red and moved the BSC ISI from Y-mid to the LEA.

Attached are plots of dust counts > .5 microns in particles per cubic foot.

The bug has been fixed, so I've reinstalled new gds tools for Ubuntu workstations.  Mac OS X to follow in the morning.  See note from earlier today describing changes.

Something is causing the iLIGO HAM1 Optical Table to be too low.

First I measured the weights of the masses I'm using for the payload.  A drawing error has me 11.254lbs heavy; I don't think this is enough to make a large effect.  D080001 & 2, HAM Trim Mass Large & Small have their weights noted in lbs; looks to me they should have been Kg.  So D080001 is noted to be 1.14lb, I measured 1.106kg; D080002 is noted to be 0.26lbs, I measured 0.25kg.  I'll put redlines in the DCC.
The Spacer D1200530 (between Support Tubes and Support Table) measured as drawn as I remember Mitchell confirming when we received these.
I measured the Gap between the two Leg Elements (large masses in the isolation stack) in a few places to measure the compressed height of the Spring.  This value is 1.86+-0.01".  I did not measure an uncompressed Spring.  T1000310 (PeterF's HAM1 Isolation Stack doc) notes a 2.03" tall Spring with 0.14" of compression.  So about 3/4mm more compression (still early days too) x 3 for the three layers of Springs in the system.  So, this would put us 2.5mm low...OK not enough there.
Sam Barnum of MIT reports to me the compressed Spring height in the model (used to determine the Spacer height?) is 1.93" putting us 5.25mm (over 3 layers) lower than expected....
So I don't see enough from these listed issues to get us to 15mm, maybe 6mm low...
Other possibilities are the leg elements and Optical Table are heavier than modeled...maybe I can put some numbers on that soon.

JimW, HugoP,

We recently huddle-tested the T240s received in LLO's shipment #4386. We took power specra that look fine. We also checked the pressure readouts which appeared surprisingly low: ~40kPa instead of the usual ~100kPa.

We investigated this issue and found that it was caused by a model discrepancy at X1, which does not match what is installed at ETMY and ITMY (see attached screenshots of the models: X1, ETMY, ITMY).
Pressure signal processing at X1:                      Pressure_Displayed   =   Pressure_Input * 2.879e-3
Pressure signal processing at ETMY/ITMY:       Pressure_Displayed   =  (Pressure_Input * 5.065e-3 ) + 30.625

If we reverse the processing applied at X1, and then apply the one of ETMY/ITMY we then obtain:
( 40kPa / 2.879e-3 * 5.065e-3) + 30.625 = 101 kPa    
... Which is what we expected in the first place. The four T240 pods received in shipment #4386 were huddle-tested OK at recption. Results are available under the seismic SVN.

Other measurements performed during the investigation, at X1:
-We read 0 kPa when nothing is plugged into the T240 interface
-We read ~40 kPa with the T240s are plugged in
-We measured 8.36V at the T240 interface (D1002696) "to-Anti-Alias" output
-The power supplied to the T240 interface is:
   -17.96V
   +17.75V

Today marked the official end of the 1-Arm Test (laser powered down at EY [laser safe there now], venting of Y-Beam Manifold, etc.)

• SUS:  Betsy worked Chamber-side (& possibly in HAM3)
• SUS Input Mirror computer needed to be rebooted by Barker
• Contractors:  Ace Portable Toilets, Praxir (CP1), Paradise Water, Unifirst

   There was a transverse to yaw cross coupling noted in the TFs for H1-PRM (orange trace). To isolate the problem we moved the side BOSEM to the other side of the suspension and re-tested. With the BOSEM on the opposite side, the cross coupling disappeared (black trace). Before moving the BOSEM back to its correct side position, I found the magnet/flag base to be misaligned. This was corrected and the BOSEM was re-centered to 50% light. Subsequent testing shows the cross coupling has been removed (purple trace). 
 
   H1-MC3 and H1-PR2 also show the same cross coupling. We will check the side magnet/flag base alignment on these two suspensions and re-align as necessary.