Removed the final (high-pressure) particulate filter from the purge-air supply skid -> Inspected element and replaced (P-SRF 07/25) -> Purge-air supply to LVEA was valved-out for ~3 minutes 

This report is for Friday, 07 Dec 2012. 
On Thursday, 06 Dec, I received a phone call from Janeen, Matt H. and Danny at LLO wrt contamination in the beamtube between LHAM2 and LHAM3. We discussed methods for mitigation and they asked if we could go in and make an inspection of the beamtube between WHAM2 and WHAM3. After a brief discussion with Michael L. at morning meeting, Cheryl and I planned and executed an incursion.

After gathering materials (Stinger, Cheryl's good camera, alcohol, wipes, etc)and garbing, we carefully entered HAM3 since we figured the "cat eye" baffle gave us the best shot at getting into the beamtube without having to remove a baffle. First, we inspected the optical table and its contents. Next, we looked at the bellows convolution and the flange area. Then, we climbed through the baffle aperture and proceeded to "walk the grid" down to HAM2. Cheryl took pix when we found anything interesting (and I'm sure she will attach some when she gets a chance). Once we were at the HAM2 baffle, we looked at the flange area and the baffle surface then turned around. On the way back to HAM3, we paid special attention to the overhead nozzles where conflats are attached. Below is a list of our findings.

-Optical table: particulate contamination on table and optics
-HAM3 bellows convolutions: white speckles, some short white fibers, unknown "dust"
-HAM3/manifold flange: flange surface covered in fine "dust", large piece of glove
-Manifold bottom half from HAM3 to HAM2: white specks and larger white "fluffs", a small "pile" of stuff that looked like baking soda, a couple of short red fibers
-HAM2/manifold flange: flange surface covered in fine "dust", "fluffs" under baffle frame
-Nozzles on manifold top: fine gray patina

We mitigated where we could by wiping up white specks and fluffs along the bottom of the manifold. The HAM3 bellows convolutions were wiped as well. 

We'll continue to investigate the situation but use the H2 manifold for compare/contrast.

out backup server crashed, I have just rebooted it to permit disk-2-disk and disk-2-tape backups to continue.

[Cheryl, Deepak, Luke, Giacomo]

Yesterday morning Cheryl was helping Jodie inspecting the beam tube between HAM2 and HAM3 for (lack of) cleanliness.

Deepak and Luke assembled the viewport replicator using one of the HAM1 doors as a reference.

Using a temporary steering mirror I aligned the visible laser pointer to two iriris previously placed iusing the IR beam (one ~20 cm before IM4 and the other after PRM surrogate, pretty much at the edge of the table). I used it to align all the auxiliary beams (froward and backwards) in transmission of IM4. (note that initially I used two different placements of the laser for the forward and backward beams; later, I found a location from which I could inject the visible laser in the forward direction, use the reflection off of PRM as a backward beam, and align all beam paths at the same time).

After a late lunch, we all worked at refining the beam alignment and optics positions, and aligned the two beams that go towards the HAM2 est door using references on the table. We then moved the viewport replicator from HAM1 to HAM2 and confirmed that the beams go through the right viewport pretty much in the center. Further adjustment left to Joe, that is more familiar with the IO tables and can tweak the exit beams at his will.

Auxiliary beam paths centering as of now:

- MC2 transimitted: aligned

- MC REFL: ok down to the exit of the second periscope. Needs to e pointed to the right viewport from there (using vewport replicator)

- IM1 transmitted: not aligned. Needs to e pointed to the right viewport using vewport replicator

- FI forward rejected: not aligned. Will need to be if the beam dump (currently in C&B) is installed, otherwise we move the steering mirror away and it lands on a SiC baffle.

- IM4 forward transmitted to IO QPD: aligned

- IM4 forward transmitted to ISS PD: aligned down to last optic (ISS PD not on the table)

- IM4 forward transmitted to IOT: aligned (exit point to be tweaked?)

- IM4 backward transmitted to IOT: aligned (exit point to be tweaked?)

- REFL beam: aligned to HAM1/2 septum viewport.

Attached are some photos of the three ISI corners, concentrating on the cabling; Corner & View# in the photo names.

Once we convinced ourselves that the TFs looked acceptable and we could do no more to improve the Cable dressing, we called an end to the fussing.
We covered the ISI with a HAM-ISI cover (made in LLO) and thought it might be large enough to make it to the Chamber Flange.  There is a whole in the top of the ISI cover so we draped a BSC door cover over that hole.  We then pulled the Walking plates out.  The West plate was tight on the West Work Platforms so the Work platform must have shifted East somehow.  Anyway it wasn't too difficult to get it free.
With the Walking Plates out we then were able to get the HAM-ISI cover to the flange of the chamber.  So that is a nice backup to the BSC Dome Tall but we need to confirm that the LHO fabricated model will work--they were sewn by two different houses.
OK, we are ready for the Dome!
So it flies overhead, we pull off the Cleanroom Ceiling, lower the Dome and attach its ceiling to the Cleanroom.  Once things are quiet and the dust settles, we pull the Dome cover off, dwell a bit and then pull away the ISI & Chamber cover.  We then gave one final inspection of the cabling to make sure the soft covers had done no harm.  Lower away!
One problem at the end of this task: the Cleanroom is pushed way North and the HAM3 Cleanroom is right up against it on the South.  So much so that the Cleanroom had to be twisted (West Side to the South) so the Dome Spreader and Clevis Pin don't hang up on the Cleanroom.  That Clevis was installed out-to-in and so was right against the Cleanroom top frame once the Dome was down.  It took some finagling but was extracted.  There is one bolt that needs a nut but all the others are in place and can be torqued first thing Monday.

Richard transitioned to laser safe early this morning; this status remained unchanged throughout the day.
PSL diode room temperatures remain stable near 67 F for a time and then will start fluctuating between 65F and 70F, producing alarms.  Michael R is aware of this.
Hugo locked the HAM3 ISI late this morning for Jodi and Cheryl to do some cleanliness tests.  They finished by lunch; Hugo restored the unlocked state and will launch tests this evening.
Keita is preparing to use a 10mW IR laser in the optics lab.  See his work permit.
LHO/Apollo returned the dome to BSC1 this afternoon.  At the close of the day the bolts are in but not torqued.
ITMY SUS watchdogs were triggered through the early afternoon by the dome restoration.  The actuator watchdog was red throughout. The position watchdog alternated between red and green.  All are green now.  Tha alarm handler shows yellow next to OSEM4.

For the 35W laser.

Changed gear-drive oil -> both Corner Station pumps -> 400CC Krytox 1525 -> routine maintenance

It was noticed yesterday that the Left and Right OSEMs on ITMy MO stage were  noisier than the other OSEMs.  I began to investigate this looking at the signal into the AA chassis and it to exhibited noise but looked like it was missing the - part of the signal.  I was able to trace it back to the Sat box.  I replaced the box and will look into the noise problem on it with a full blown test.  The signal should be okay now.  

Of particular note.  The MEDM screen for the sus did not show this only the IOP at he higher sampling rate saw the noise.

Yesterday, it was mentionned in LHO aLOG 4858 that transfer functions measured on BSC1 were different from what we expected. This morning, I ran some simulations to evaluate if the extra modes seen in the [5-8]Hz frequency band would create some difficulties in the control design.

For the test, I used the BSC6 damping and isolation filters.

The 12 main transfer functions once the ISI is damped:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H1/ITMY/Data/Figures/Transfer_Functions/Simulations/Damped/

• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RX_to_ST1_L4C_RX_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RY_to_ST1_L4C_RY_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_RZ_to_ST1_L4C_RZ_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_X_to_ST1_L4C_X_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_Y_to_ST1_L4C_Y_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST1_ACT_Z_to_ST1_L4C_Z_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RX_to_ST2_GS13_RX_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RY_to_ST2_GS13_RY_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_RZ_to_ST2_GS13_RZ_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_X_to_ST2_GS13_X_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_Y_to_ST2_GS13_Y_2012_12_04.fig
• H1_ISI_ITMY_Damping_TF_MIMO_ST2_ACT_Z_to_ST2_GS13_Z_2012_12_04.fig

The 12 main SISO TF used for the control design (between every steps, the MIMO response is used) are given below:

https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H1/ITMY/Data/Figures/Transfer_Functions/Simulations/Isolated/

• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RX_to_ST1_SS_RX_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RY_to_ST1_SS_RY_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_RZ_to_ST1_SS_RZ_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_X_to_ST1_SS_X_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_Y_to_ST1_SS_Y_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST1_ACT_Z_to_ST1_SS_Z_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RX_to_ST2_SS_RX_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RY_to_ST2_SS_RY_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_RZ_to_ST2_SS_RZ_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_X_to_ST2_SS_X_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_Y_to_ST2_SS_Y_2012_12_04.fig
• H1_ISI_ITMY_Isolation_Loops_TF_SISO_ST2_ACT_Z_to_ST2_SS_Z_2012_12_04.fig

Transfer functions and a linearity tests were measured on HAM3-ISI earlier this week.

The linearity tests looks good. Variations in slope are within requirements.

Transfer functions look good too. Concordance with LLO HAM3-ISI are satisfying. Some noise can be seen in high frequencies on the TFs measured with the vertical GS13s. These sensors saturated a bit during the measurement. 

HAM3-ISI has been re-locked, and worked on, since. It is currently locked. We are planning on running a new set of transfer functions, with a slightly lower gain in high frequencies, when HAM3-ISI can be unlocked.

Early this morning, Cheryl check the alignemnt. She found the beam to be:

- good on all three irises before IM1

- misaligned in the FI

- good in the two irises after the faraday (before and after IM4)

All suspension had unchanged offsets wrt yesterday, in particular:

She checked again and more thoroughly mid-morning, with the same conclusion. She took some picture (to be posted soon)

HAM3 ISI was then locked, which did not visibly change the beam reaching HAM2. This allowed David and Luke to torque to spec (100 in lb) all clamps on HAM3 ISI: MC2, PR2, all IO components, cable clamps and ISC breadboard to the table (but not the componenets to the breadboard).

HAM3 ISI was then unlocked (again with no visible shift in the beam) and we proceeded to re-aligning the FI, using IM1 and IM2 (only yaw, as pitvh looked good). Then we used IM3 (again, only yaw) to center the beam on the iris between IM3 and IM4. Finally we centered the beam on PR2 using IM4 in both pitch and yaw (we replaced the PRM surrogate with an AR-AR optic with the same wedge and thickness, to increase the visibility of the transmitted baem). Final offsets:

And it was lunch time...

After lunch, we placed an iris after the PRM surrogate to be used as a reference for the beam out of IM4, and for red laser alignment. We then removed the yaw offset from IM4, and used the pushers to rotate it back untill the beam was centered again on the iris (about 1/4 mm, or less than half a turn). Other miscellana:

- clamp adapeter and clamp placed on the short east side of MC1

- all non-temporary (and a few temporary) clamps torque to spec (100 in lb): MC1, MC3, IM1-4 (at present, with 2 temporary clamps each), MC refl telescopes, IO telescope, IO steering mirrors.

- visble laser set-up ans aligned to the irises. Form now on we can work in laser safe codnition using the red laser.

I have attached the transfer functions measured on BSC1. They are slightly different (rigid body modes ~5Hz) from those measured at LLO on BSC1 (similar payload) and BSC8 (the same ISI).

LHO BSC1:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H1/ITMY/Data/Figures/Transfer_Functions/Measurements/Undamped
H1_ISI_ITMY_TF_L2L_Raw_from_ST1_ACT_to_ST1_CPS_2012_12_04.fig
H1_ISI_ITMY_TF_L2L_Raw_from_ST1_ACT_to_ST1_L4C_2012_12_04.fig
H1_ISI_ITMY_TF_L2L_Raw_from_ST1_ACT_to_ST1_T240_2012_12_04.fig
H1_ISI_ITMY_TF_L2L_Raw_from_ST2_ACT_to_ST2_CPS_2012_12_04.fig
H1_ISI_ITMY_TF_L2L_Raw_from_ST2_ACT_to_ST2_GS13_2012_12_04.fig

LLO BSC1:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/L1/ITMY/Data/Figures/Transfer_Functions/Measurements/Undamped
LLO_ISI_BSC1_TF_L2L_Raw_from_ST1_ACT_to_ST1_CPS_2012_11_07.fig
LLO_ISI_BSC1_TF_L2L_Raw_from_ST1_ACT_to_ST1_L4C_2012_11_07.fig
LLO_ISI_BSC1_TF_L2L_Raw_from_ST2_ACT_to_ST2_CPS_2012_11_07.fig
LLO_ISI_BSC1_TF_L2L_Raw_from_ST2_ACT_to_ST2_GS13_2012_11_07.fig

LHO BSC8:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/Measurements/Undamped/
LHO_ISI_BSC8_TF_L2L_Raw_from_ST1_ACT_to_ST1_CPS_2012_05_21.fig
LHO_ISI_BSC8_TF_L2L_Raw_from_ST1_ACT_to_ST1_L4C_2012_05_21.fig
LHO_ISI_BSC8_TF_L2L_Raw_from_ST2_ACT_to_ST2_CPS_2012_05_21.fig
LHO_ISI_BSC8_TF_L2L_Raw_from_ST2_ACT_to_ST2_GS13_2012_05_21.fig



 

There were some oddities in the transfer functions Vincent collected so we went to the ISI.  Corners 1 and 2 looked pretty good but Corner 3 never does.  So we reworked it some to hopefully improve the results--yet to be determined.
A couple before and after images not all that revealing.  It is obvious we did something but not that obvious in the photos that it is better--you gotta be there!

EX
In-chamber cleaning continues
New HVAC system for the Lab is now online after being serviced today

BSC1
Hugh & Vincent worked on/around cabling up on the BSC-ISI to troubleshoot some noise on the BSC-ISI

IO Work
The team planned on checking torque-ing for MC2 (requiring HAM3 ISI to be locked), and alignment work continues (so we've remained in Laser HAZARD all day)

Rest of Day's Activity

• H&N Electric on site to fix sewage lift pump at LSB
• Elec Inspector going to EX (will go with Ken)
• Since last night, we had a PSL alarm for Envdiode Temp Alarm (Rodruck notified and addressed)
• Oscar & group baling on inside of X-arm
• Filiberto routing field cables at BSC2
• Patrick--addressed dead dust monitor in LVEA (replaced with one from EY)
• Bubba removing lock & tag from GV1
• Praxair on site to fill CP1
• HAM4 & 5 doors being torqued down (in prep for pumpdown)

We air brushed lower sections 1,2,3,&4 and floor sections 1,2,&3. We also completed the hand brushing on the fins. Stand down on ICC for the day to torque bolts on HAMs 4&5 doors.

The dust monitor at location 8 in the LVEA, labeled S, gave a calibration warning and was turned off. This was in the small clean room between HAM 2 and 3 with the auxiliary optics. Today I removed the dust monitor at location 1 in the end Y VEA labeled L and replaced S with it.

Brushed with drills all sections from bottom of collar to floor and began hand brushing fins yesterday.

[David, Rodica, Luke, Giacomo]

After the HAM3 ISI was unlocked this morning, we verified that the table moved small enough that the MC was still flashing.

We then verified the alignment through the HAUX and FI up to IM4, that was still good.

We prepared two iririses at the the nominal height of the beam on the table, placed them before and after IM4 and aligned them to the IR beam to serve as references for the visible laser we will be using for alignment of the auxiliary optics. However, we then realized that IM4 only "nominally" aligned in both pitch and yaw, so this will need to be tweaked tomorrow.

After that, we aligned the REFL beam to the input beam using the PRM surrogate, and the backward rejected beam to the HAM1/2 viewport; we then measured the input beam power (505 uW), and tried to measure the power in the backward beam reflected off of MC3, but we could not distinguish it from the background. Based on the uncertainty on the background measurement (25 nW) we estimated an isolation ratio > 40 db.

Finally, we measured the power in various location of the forward beam (in uW +- 1 uW):

after MC3 = 524

after IM1 = 504

after IM2 = 505

after IM3 = 494

after IM4 = 494

after PRM sur = 15

This yield a 96.2% transmission through IM1 (but we have the wrong polarization), a 97.8% combined "transmission through FI and reflection off of IM3" (although reflection through IM3 should be basically 100%, as it is in the right polarization) and a 3% (as expected) transmission thorugh the PRM surrogate.

Based on these numbers, the REFL beam at at the HAM1/2 septum viewport should be 469 +- 5 uW.  We measured 466 uW: apparently we didn't loose any beam on the way... :-)