Couple Photos and brief report here.

First, the ISI is carefully placed back on the Test Stand.  The second photo shows the rebuilt Stage1 back on the Stage0.

The HAM 9 unit is currently undergoing testing.  The HAM8 unit (shown in these photos) will have its Springs pulled down today quickly followed by the installation of the Optical Table.

Jim, Corey, Mitchell, Greg, Eric, & Hugh

The H2:SUS-ITMY_*_COILOUTF_*_GAIN channels were modified on the R0 chain such that a positive drive from the Euler-basis coil outputs induced a positive response in the Euler-basis H2:SUS-ITMY_*_DAMP_*_IN1_DQ OSEM readback channels.

For the H2:SUS-ITMY_M0_COILOUTF_*_GAIN channels:
F1 = 1.0
F2 = 1.0
F3 = -1.0
LF = -1.0
RT = 1.0
SD = -1.0

For the H2:SUS-ITMY_R0_COILOUTF_*_GAIN channels:
F1 = 1.0
F2 = 1.0
F3 = -1.0
LF = 1.0
RT = -1.0
SD = -1.0

Found the 6.7mm error this morning.  The error was not in the EDM measurement, but in the design of the corner cube mount.  As the mount is currently designed, we touch off of a metal plate that is sandwiched between the corner cube and the XY translation stage of the mount with a CMM to accurately measure the distance between this metal plate and the ITM; this gives us the distance we need to add to the EDM measurement to get the total distance from the total station to the ITM (the EDM from the total station only measures to the corner cube).  This plate was thought to be at the back plane of the corner cube (most corner cubes have a constant that is the offset distance from the virtual focus of the coner cube to its back plane and this distance must be compensated for when using a corner cube for EDM; our corner cube has a 30mm constant) but in actuality the back plane of the corner cube is 10mm inside the metal plate.  This subtracted 10mm from the measured distance, indicating that the structure had to be moved in the -y direction.  We will start considering a redesign of the corner cube mount, but in the short term we were able to compensate for this using the total station.  The total station has the ability to automatically compensate for a corner cube constant, therefore we simply changed the constant from the 30mm we were using (since it was a 30mm prism constant) to 20mm, which represents the distance from the coner cube virtual focus to the front surface of the metal plate.  This also means that the FM, which was thought to have been 12.7mm too far forward, is only 2.7mm off of its ideal longitudinal position, which is within the ±3mm of error set out in E1100690.

• Longitudinal position:
  • Total Station to ITM: 7045.1mm
  • Desired distance: 7041.3mm
  • Difference from desired: 3.8mm
    • Decided that this was close enough, no structure move necessary
• Horizontal position (distance from optical axis established by total station):
  • ITM left edge: 162.88mm
  • ITM right edge: 163.63mm
  • Difference: 0.75mm
  • Distance to move ITM to properly position: 0.375mm
    • Within ±1mm error
• Vertical position (distance from optical axis established by total station):
  • ITM top edge: 169.03mm
  • ITM bottom edge: 170.98mm
  • Difference: 1.95mm
  • Distance to move ITM to properly position: 0.975mm
    • Within ±1mm error
• Pitch: ~816 µrad up
  • Within ±1 mrad rough alignment error
• Yaw: ~338 µrad right
  • Within ±1mm rough alignment error

As a result of today's work, we determined that no more structure moves are necessary and we can continue with the fine pitch and yaw alignments.

Signage at LVEA card reader requested noise source logging 

Because I don't see a current a log, I'm posting what I know for today. On Friday afternoon we completed adding the balance of the SUS payload to the ISI table.  The SEI crew then balanced the table but left it locked so we could make a round of Romer arm measurements on the ITMy.  Still hunting for the ~6mm y-axis error, we made some measurements of the upper structure structure relative to the ITMy HR surface.  We have had some manufacture errors with these upper structures, so we wondered if there were more that we had not found.  At first glance, based on these measurements, the suspension position within the structure does not seem to be the source of our error.  The ISI was unlocked and the suspensions unclamped for the night.  I believe Garcia and Vincent were going to start testing the systems but I'm not sure their status.  
Today, Dennis continued the 6mm hunt by looking at our alignment templates which were used when fixing the ITMy to the table.  These do not appear to be the source either. As of discussions this afternoon Dennis, Doug, and Jason anticipate working tomorrow morning to redo the EDM measurements.

Bram, Valera, Matt

We made a few measurements of TMSY and got some damping loops running.  The attached plots show:

1.  damping performance (REF plots are damping on)
2. screen shot showing filters and gains
3. plot of the damping filter used for all DOFs
4. damping open-loop TF and plant TF for each DOF

We've left the damping loops on for a few days and they appear to be working well.

This morning, the SUS crew added the remaining mass to the H2 ITMY QUAD structure by adding the stiffening sleeve with vibration absorbers.  The seismic crew has now balanced the ISI with the full ITMY and FMY structures.  The BSC-ISI is now locked so that Romer arm measurements can begin on the ITMY QUAD and Test Mass. The afternoon's goal is to have the BSC-ISI floating with the H2 ITMY fully suspended and OSEM flags to center-range.

When you look back in time using DQ channels, everything is infested by pesky 16 Hz and its harmonics, also 1Hz line for some of the signals. This was not the case when the measurement was done yesterday using live data.

It might be that the problem SUS people had and solved by a code upgrade is attacking us.

Attached are power trends for the eLIGO H1 PSL since the replacement of the pump diodes and NPRO, in early July 2010. Due to Dataviewer issues, I could not create a single plot for the channels, and instead pasted together 3 month increments of data. These plots show the power of the pump diodes and NPRO diodes, the pump diode current, and power at the amplification stages. Note that the amplification power is not calibrated properly and is relative to the other amplifcation stages.

Tuesday the ISI table level was checked and found to be within 0.2mm, and on Wednesday we performed initial yaw measurements (yaw measured at 2.61 mrad).

Yesterday we measured the ITM yaw and horizontal position.  The yaw was confirmed to be 2.6 mrad out of alignment (initial measurement done Wednesday) but the horizontal position was found to be 0.46mm from center, which is well within the ±1mm spec.

As Betsy stated in her alog we were able to correct the ITM yaw to ~400 µrad (the spec for rough yaw alignment is ±1mrad).  After this we used the Microscribe to measure the gap between the corner cube retroreflector (used for y-axis distance measurement) and the ITM so we could get an accurate meaurement of the y-axis (longitudinal) position of the ITM.  This gap was measured at 52.6mm and the total station measured 6982mm to the corner cube, resulting in a total distance from the total station to the ITM of 7034.6mm; the desired distance in 7041.3mm, so this shows the ITM structure to be to far forward on the ISI by 6.7mm.  We are currently looking for the source of this error.  Since the structure was moved in yaw, we also need to recheck the horizontal position of the ITM to ensure it is still within spec; these 3 degrees of freedom (yaw, horizontal position, and longitudinal position) need to be checked every time the structure is moved.

• The yaw was measured at 1.47 mrad
• Horizontal position was measured at 1.2mm off center
• Longitudinal position measured at 12.6mm forward

We are currently looking for the source of the FM longitudinal error as well.

Today, Jeff and Andres put the ETMy lower structure into the test stand clean room, and separated the chains, in prep for it's remodel for the monolithic.  They unloaded the Dummy TM, Dummy PUM and wire segments and parked it in the adjascent fiber welding clean room.  The ring heater crew will commence their addition to this structure tomorrow.  I anticipate loading it with glass early next week.

This morning, IAS reverified that we needed to yaw the ITMy tower a few mRAD.  We clamped both chains and took a baseline reading of the ITMy pointing in the clamped state.  We then loosened the dog clamps holding the structure to the ISI table and took another reading.  The dog clamps were still somewhat tight on the tower, no gap between the structure and table was noticeable.  Jason will post the numbers in a subsequent entry.  Using the new Pushers/Movers we were able to push opposite corners of the structure to reduce the yaw to ~20uRAD. We then tighted some of the dog clamps and observed that the yaw had walked out to ~400uRAD. We paused there and took the Y-axis reading. Unfortunately the structure appears to be out of position on the table in this direction by ~6mm.  The initial placement of the structure nor the error in how the mass is suspended inside the structure account for this large misplacement. Dennis and Doug used the microscribe to measure the distance between the corner cube and the ITMy and also started looking into the optomechanical model in hopes to pinpoint where this 6mm error comes from.

Meanwhile, they were going to continue with the foray of IAS measurements on the FMy.  Fleshing out the next few days of interwoven IAS, Testing, and cartridge prep activities, but things look tight. We could not figure out a more efficient plan than the following:
1) determine how far ITMy and FMy structures need to be pushed around on ISI table (this afternoon-tomorrow morning)
2) push structures in x,y as needed, adjusting yaw as needed (tomorrow)
3) attach sleeve, vibrationabsorber payloads, continue fine IAS alignment to finalise yaw and pitch (Sunday)
4) SEI rebalance table payload, but leave locked until COB (Monday morning)
5) IAS measure ITMy to CP gap, SUS to adjust if needed Monday afternoon)
6) unlock ISI for TESTING (Monday night)
7) TEST (Monday night? - few days)
8) during testing gaps, prep suses for cartridge install (Monday-Wed)

The same procedure for the H2 ITMY L1 Open Light voltages were recorded for the H2 ITMY L2 Open Light voltages. A 30-second average of the H2:SUS-ITMY_L2_OSEMINF_*_IN1_DQ channels with the tdsavg command-line tool was used to record their values.  Their values were halved, multiplied by (-1), and entered into the H2:SUS-ITMY_L2_OSEMINF_*_OFFSET channels.  The gains for these channels were calculated by normalizing the open light counts to 30,000cts.

Open Light (cts)
UL = 27204.7
LL = 17354.3
UR = 19496.5
LR = 20515.5

Offsets [-(open light)/2] (cts)
UL = -13602
LL = -8677
UR = -9748
LR = -10258

Gains [30000 / (open light)] 
UL = 1.103
LL = 1.729
UR = 1.539
LR = 1.462


Open Light counts after normalization [tdsavg] (should be ~15000)
UL = 14998.4
LL = 14997
UR = 14999.8
LR = 14993.3

The H2 ITMY L1 Open Light voltages were recorded with a 30-second average of the H2:SUS-ITMY_L1_OSEMINF_*_IN1_DQ channels with the OSEMs completely backed off of their flags.  Their values were halved, multiplied by (-1), and entered into the H2:SUS-ITMY_L1_OSEMINF_*_OFFSET channels.  The gains for these channels were calculated by normalizing the open light counts to 30,000cts.

controls@cdsws2:/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGR0/Data 0$ tdsavg 30 H2:SUS-ITMY_L1_OSEMINF_UL_IN1_DQ H2:SUS-ITMY_L1_OSEMINF_LL_IN1_DQ H2:SUS-ITMY_L1_OSEMINF_UR_IN1_DQ H2:SUS-ITMY_L1_OSEMINF_LR_IN1_DQ
27866.8
25170
29253.2
23004.8

Open Light (cts)
UL = 27866.8
LL = 25170
UR = 29253.2
LR = 23004.8

Offsets [(open light)/2] (cts)
UL = -13933
LL = -12585
UR = -14627
LR = -11502

Gains [30000 / (open light)] 
UL = 1.077
LL = 1.192
UR = 1.026
LR = 1.304

Open Light cts after normalization (should be ~15000cts)
UL = 15006.8
LL = 15001.3
UR = 15007.3
LR = 14999.7

MichaelR, JanP, RickS

Yesterday, we measured the drive level to the FSS EOM.  Measuring directly with an oscilloscope with the input set at 50 ohms, we found the following:

Measured drive voltage into FSS EOM at 21.5 MHz
2.12 Vp-p

2.12/(2*sqrt(2)) = 750 mVrms

1 dBm = 1 mw into 50 ohms

P=V^2/R; V in rms
.75^2/50 = 0.0112 W -> 10.5 dBm

New Focus web site states 0.1-0.3 rad/V for Model 4003 modulators

2.12 Vp-p -> 1.06 Vp -> 0.106 - 0.318 modulation index, Gamma

Thus the ratio of the power in the first order sideband to that of the carrier will be between 0.0028 to 0.0259, i. e. the first order sidebands should be a factor of 355 to 39 times lower than the carrier.

We will measure the sideband-to-carrier ratio with the reference cavity soon.

Sadecki, Bland
This morning, the 4 UIM and 4 PUM OSEMs were aligned and set to 50% OLV.  This took both of us, due to the inability to see the centering of all of the OSEMs with the FMy 6 inches away from the ITMy structure.
In the afternoon, Dennis, Doug, and Jason started IAS measurements of the ITMy relative to the ISI.  They determined that the ITMy is in-fact over 2mRad out of spec in yaw.  Documentation suggests that we should yaw the structure to reduce the error to ~1mRad before using the top stage yaw adjustment inside the suspension.  So, we pulled out and started building the QUAD pusher/mover assemblies to use tomorrow morning.

Attached are plots of dust counts > .5 microns.

Attached is a DTT whitenoise measurement of the ITMY R0 Pitch DoF with a reference from 11/23/2011.  Today's measurement is in red and with a 0.01Hz resolution.  Measurements were performed after today's mechanical adjustments.

Yesterday, seismic restarted testing HAM-ISI in the staging building. It seems that one of the horizontal GS13 is malfunctioning. The symptoms are similar to those we see when the proof mass is stuck (no low frequency response but high frequency response looks OK). After hitting the GS13 with a wrench and handling it, the mass is still stuck. I have attached Powerspectra of the 3 horizontal geophones when the ISI is locked (H3 geophone is the bad one).