aLIGO HAM 2 has had the old iLIGO stacks removed and replaced with fancy new HEPI piers, frames, and crossbeams. The support tube positions will be checked and fine tuned within the week. Hopefully work can begin on removing the iLIGO HAM 3 stacks and installing the new HEPI structures soon.

A new version of awgstream has been installed for Ubuntu workstations which corrects a bug in which not all channel names are read from the nds.  New version is 2.15.5. 

While working on the ETMy today, we also found that one of the 4 PUM flags had a failed glue joint, and one of the PenRe AOSEMs has a broken PD filter.  We reglued the flag and set the heat lamp for overnight.  We'll need to get a replacement AOSEM to swap with the one with the broken filter.

J. Oberling, B. Bland, T. Sadecki

Betsy noted that a cable was rubbing on the side of the LSAT and that this cable was influencing pitch.  She corrected this and I measured the ERM pitch in the single, double and triple hang configurations:

• Single hang pitch: 6.08 mrad down
• Double hang pitch: 6.984 mrad down
• Triple hang pitch: 10.01 mrad down

Betsy then put the reaction chain in the double hang configuration and adjusted the pitch to 1.21 mrad down.  I then measured the ERM triple hang pitch again:

• Triple hang pitch: 2.6 mrad down

This was deemed acceptable for ERM pitch adjustments on the LSAT.

Travis made adjustments to the main chain to lower the ETMy in the quad assembly, then I measured the ETMy roll and vertical position.  Roll is reported as the vertical distance from the ETMy horizontal centerline (measured with an optical level and a scale attached to a carbon fiber rod hanging from the ISI optics table) and vertical position was measured as done on 1-13-2012.

• Roll: 0.65mm Clockwise
• Vertical Position: 0.63mm high

JimW, ScottS, Hugh

See the attached which is a zoom in of D0900894 sht2.  The upper right cloud area is the SW corner of the SEI ISI Stage0(+Y,-X) looking up.

We tapped and helicoiled the three holes in the right cloud and one of the 'A' holes in the left (not exactly sure which) to accommodate the planned mounting of the ACB dog clamp and alignment pushers.  These holes were vent holes and were never planned to be tapped.  We were lucky in that they were close enough in size to only lose maybe 25% of the thread holding in the aluminum--plenty fine for the 200lb ACB.
The story is this clamp and these pushers can be removed as there is another clamp on the mounting plate.  And we could swap out the hardware later with vented bolts.

Attached are plots of dust counts > .5 microns.

Rick S, Michael R

Water filters for the chilled water lines were swapped out today. This includes the small filter located inside the diode chiller itself. The old filters looked pretty ugly, pictures are attached. We threw in a new unused filter in the photo to show the difference between clean and dirty. We can still see gold flecks in the crystal chiller's new filter.

New flow rates

Crystal chiller: 16 lpm

Diode chiller: 28.3 lpm

Michael R, Bubba G, Robert S

Table was set in place today. Tuesday we will have contractors out to start construction of the acoustic enclosure.

The table top has been fully cleaned and is covered in ameristat.

After the ACB crew had finished their work in BSC8, I entered the chamber to unlock FMy.  So, until further update, the status of the suspensions is: ITMy is LOCKED, FMy is UNLOCKED.  I'll leave it to the ACB and SEI crews to independently report their status.

J. Oberling, T. Sadecki

Set up the LSAT for the ERM at End Y this afternoon: leveled the LSAT structure and the Reaction Chain (RC) lower structure using an optical level.  We then looked at both the double-hang and triple hang pitch of the ERM:

• Double-hang pitch: 1.08 mrad up
• Triple-hang pitch: Pitched down too far to measure
  • Was off the scale of the Laser Autocollimator (LAC) and when I attempted to pitch the total station up to compensate for the ERM pitch, the LAC went off the edge of the optic.  Would need to adjust the stand the total station was mounted on (completely taking it apart and putting shorter legs on the stand then re-build the stand, re-level and re-align the total station and LAC).  We decided this was unecessary as we had the important information: the ERM is pitched too far down in the triple hang configuration and adjustments are necessary.

We uninstalled everything on HAM4.

The followings were bagged and labeled for later reuse for aLIGO itself as well as aLIGO related researches at here and elsewhere:

• AS path steering mirrors and periscope
• POB path steering mirrors and periscope
• POX path steering mirrors and periscope
• Squeezing path steering mirrors
• First article aLIGO Faraday
• H2 iLIGO Faraday which was used as H1 SQZ faraday
• Black glass beam dumps

These are all stored in plastic bins and are temporarily put in the ALS/SQZ work area.

There was a mirror-like thing mounted on one of the side viewports from inside. What is this? It was bagged, but if there's no taker I'll throw it away.

The beam reducing telescopes were roughly wrapped with foils and left in the clean room. Store them wherever you want.

All counter balance masses will go to the recycle bin.

HAM5 baffles was not removed this time.

Corey will post pictures, Sheila will notify Carolyn which iLIGO parts are kept.

J. Oberling

At Betsy's request, I measured the pitch and the vertical position of the ETMy as a check of where the ETM is sitting with respect to the ideal vertical position (1742mm from the ISI optics table).  Pitch was measured to ensure a gross pitch error was not causing the appearance of the ETMy sitting in the wrong vertical position.

To measure the vertical position I used the total station to measure the elevation angles required to sight the top and bottom edges of the ETMy.  The tangent of the angle is multiplied by the distance from the total station to the optic to give the vertical distance from the ideal center, as established by the total station, to the respective edge of the ETMy.  To get the distance to the ETMy I used the total station's Electronc Distance Measurement (EDM) feature, which has the ability to measure a distance without using a corner cube prism (the reflectorless EDM has a 3mm error bar).  I sighted the right side of the quad cage, in the recessed portion and measured the distance; this distance was then multiplied by the cosine of the azimuth angle to sight the quad cage to give the distance from the total station to the ETMy.  This is not ideal and does introduce error into the vertical position measurement, not only due to the 3mm error bar of the reflectorless EDM but also due to the fact that the HR surface of the ETMy does not align to the recessed surface of the quad cage but is actually several mm behind it (I assume the ETMy HR surface is within 10mm of the recessed surface), but will give a general idea of where the ETMy is with respect to the ideal vertical position (when measuring a distance of ~7m, a change of 10mm in either direction only results in a change of the vertical distance from ideal center to ETMy edge of ~0.3mm).  The distance from the ideal center to the top and bottom edges should be 170mm (the radius of the ETMy).

• Pitch: 2.02 mrad up
• EDM distance: 6921mm
  • T.S. to ETMy distance: 6918.3mm
• Vertical position
  • Ideal center to top edge: 172.9mm
  • Ideal center to bottom edge: 167.1mm
  • ETM vertical position: 2.9mm high

The result here is that the measured pitch of 2.02 mrad is not enough to cause the ETM to appear to be sitting ~2.9mm too high in the quad assembly, therefore the ETMy is actually sitting ~2.9mm too high in the quad assembly.

We took a first set of transfer functions (Local to Local) between 10Hz and 1000Hz (without baffle – No TMD – No vibration absorbers – No Viton pads under the keel masses - ITMY and FMY damped). After comparing with the measurements before the cartridge install, we can notice:

-          No extra resonance created by the HEPI Post between 10Hz and 1KHz (ST1 CPS transfer functions). Obviously, the resonances of the teststand are not visible anymore (first resonance at 19Hz).

-          First resonance of stage 1 is 217Hz (it will be damped by the vibration absorbers on the door of stage 1)

-          Second resonance observed on stage 1 at ~250 Hz (blade 0-1). The HAM-ISI TMDs retuned for BSC-ISI (E1100963-v1) will be later installed.

-          New resonances in the stage 2 transfer functions (53Hz). It is most visible in the Cartesian to Cartesian transfer functions.

The vibration absorbers were installed on the 3 doors of stage 1 (2 per doors). For the first test, masses are resting on 4 Viton pads (0.25”x0.25”x.0125”) and the lid is not added. Transfer functions show a reduction of the resonance at 214Hz by a factor of 6 in the X, Y, RX, RY. Tests with differentpads will be performed when the ISI will be available.

Reference Transfer functions (L2L) without baffle – No TMD – No vibration absorbers – No Viton under the keel masses - ITMY and FMY damped

In the local basis

seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/Measurements/Comparison/

LHO_ISI_BSC8_Comparison_TF_L2L_ST1_ACT_H_to_ST1_CPS_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST1_ACT_V_to_ST1_CPS_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST1_ACT_H_to_ST1_L4C_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST1_ACT_V_to_ST1_L4C_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST2_ACT_H_to_ST2_CPS_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST2_ACT_V_to_ST2_CPS_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST2_ACT_H_to_ST2_GS13_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST2_ACT_V_to_ST2_GS13_V_20111206_vs_20120106.fig

In the Cartesian basis – Recomputed from Local measurements:

seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/Measurements/Comparison/

LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_CPS_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_CPS_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_L4C_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_L4C_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_H_to_ST2_CPS_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_V_to_ST2_CPS_V_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_H_to_ST2_GS13_H_20111206_vs_20120106.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_V_to_ST2_GS13_V_20111206_vs_20120106.fig

Transfer functions L2L without baffle – No TMD – Vibration absorbers (0.25”x0.25”x0.125”) – no lid (cables touching the mass of the 2x1 vibration absorbers in corner ) – No Viton under the keel masses - ITMY and FMY damped:

seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/Measurements/Comparison/

LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_CPS_H_20120106_vs_20120110.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_CPS_V_20120106_vs_20120110.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_L4C_H_20120106_vs_20120110.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_L4C_V_20120106_vs_20120110.fig

This week at BSC8, the actuators were connected to the boots. We started to test the HEPI. First, we had to change a horizontal L4C in corner 2 (bad behavior at low frequency). We replaced L41375 by L41499. ASDs confirmed that this new geophone is working fine

After few static tests, we quickly found that the displacement created by the horizontal actuators in corner 2 is not as large as displacements created by the other horizontal actuators (verified with the dial indicators and the IPS). We checked the stops and nothing seemed to be touching. Then, we performed the linearity-hysteresis test for all 8 actuators (attached plots. SUS watchdogs tripped during the measurements – Visible on V3). The plots confirm that there is a trouble in the horizontal direction in corner 2. We are investigating.

Attached are plots of dust counts > .5 microns.

The dust monitor in the clean room over BSC8 lost power. It was swapped with the one it replaced and connected to a different break-out box with a different cable today. I do not believe the readings for it (H0:PEM-LVEA_DST15) are valid until after 15:00 local time today.

Today, when we stuffed the ERM mass into the ETMy lower suspension, we noticed that one of the 5 pins had been somewhat dislodged from it's soldering pool on the gold tab.  Gerardo and Margot believe that this is from the "flipping fixture" which is used to handle the mass.  The fixture apparently sits across some or all of these solder joints.  In the picture attached, the pin is the one towards the 4th one from the right.  
Long story short, Margot thinks we need to revisit the soldering of this pin. 
...to be continued.

For the record, following are the measured weights of the QUAD glass penultimate masses (PUM) and test masses that are currently here at LHO.  Most of this data can also be found on the CIT optics Nebula we page.  Note the labels of the masses are slightly confusing as the optics have been coated specifically for the one-arm.

MASS     LABEL              INSTALL LOCATION
39,653g ETM02 (TM)    BSC8 ITMy
Didn't measure ITMy PUM because it was the first mass bonded and we were not wise to the need for weights.
39,626g ETM04 (PUM) BSC6 ITMy PUM
39,689g D050421-001 BSC6 ETMy PUM (was lasti mass)
39,613g ETM04 (PUM) 
39,641g ETM05 (PUM)
39,633g ITM01 (PUM)
39,621g ETM03 (PUM)