(follow-up on previous mentions) 
Using a "feeler" gauge I measured the "gap" on the feed-through flange previously discussed which I was concerned may eventually leak due to (possible) bottomed-out flange screws.  The gap was 0.004".  These flange bolts seemed bottomed-out in their blind holes and I was concerned that I would strip the threads or break the screws if I continued to torque them -> knowing that we were venting anyway to fix the 2 x 10-7 torr*L/sec leaking triax feed-through, I went ahead and "stood on the wrench" and was able to close the 0.004" gap on this feed-through flange -> I leak tested this flange afterwards and it still didn't leak.  I don't know why this felt sooo... different than normal-perhaps the gasket was full-hard and didn't get tempered for some reason?  Slightly out-of-round?

I "fire hose" sprayed helium on all of the metal joints on the YBM to see if I could get any response other than the known leaking feed-through on BSC8.  I found nothing -> We'll vent tomorrow and replace the leaking triax feed-through flange.  Some evidence suggests that GV1's gate annulus volume might leak into the YBM -> I pumped it with an aux. cart but didn't note the time line unfortunately.  

Also, I soft-closed GV6 and opened GV5 to allow me to leak test the joints between these two valves -> I found a small (1.3 x 10-8 torr*L/sec) leak on GV6's lead-screw nipple CF joint(s) but this size of leak is smaller than I was expecting -> we might "bag" these joints in the future or maybe check the calibration of PT-114 and PT-124 in an attempt to explain their apparent discrepancy in this pumping configuration.

Hunting for the ETMy rubbing source, I removed the UIM (L2) LL Flag from the BOSEM (one of the last suspects).  Garcia ran a quick TF and observed that the mystery peaks were gone.  I replaced the flag, and the peaks still were vacant from a subsequent TF.  We then tweaked the alignment of the UIM UR flag since it was still a bit out and ran another quick TF.  Still no extra peaks.  Garcia is now going to run longer sets - hopefully the mystery peaks were just from the LL UIM flag brushing prior to this afternoon.

The default version of epics for the Mac OS X workstations has been changed to version 3.14.12.2.  This was done to allow more applications to be run on iMac workstations.  

In particular, StripTool now works properly on Mac OS X.  

This does affect medm as well, although no differences in functionality should be seen.

AFter attempting to get ahold of SEI testing people for a while this morning (phone calls, alogs, emails came up empty handed), we finally went to diagnose the ETMy rubbing at 10:15am.  This tripped the watchdogs and apparently the SEI measurements that were running.  Once we did hear word that we had stopped the measurement we stopped our work, waited for more word, then left.  Still waiting to hear what to do.  Is SEI restarting measurements, or now that they are killed should we continue our work??

200W beam

Yesterday Rick and I fixed swapped out a broken fitting on the diode chiller line to fix a water leak. PSL was brought back up after this, but ILS would not lock. Reference value for the PZT was changed from -1.65 to -1.40. The laser locked immediately, and has been running since then.

Fabrice, Hugo,

A GS13 huddle test was performed in order to pursue the investigation of the gain difference observed on the TFs measured on HAM-ISI Unit#2 (alog #2308)

Three horizontal GS13s were tested on the “bench”

• Pod #94, Production

Initially installed on this unit. Gain is half too small. One of its two op-amp could be malfunctioning.

• Pod #71, Production Spare

Response lower by a factor of 100 to 10000 below 20Hz. The seismic mass can be felt/heard when tilting the instrument, hence it is not stuck. The instrument will be opened at LHO for inspection. It will have to go back to LLO to pass the leak-checking-test before being installed on a Unit.   

• Pod #66: Test instrument

Locked test-mass got unlocked after manipulation. Acceptable power-spectrum. Not vacuum-compatible.

Conclusion:

Production GS13s are malfunctioning. The Test GS13 Pod #66 will be used temporarily for this testing phase of HAM-ISI Unit #2 testing. It will be removed before storage of the unit. Later on, a production GS13 will be installed for the side-chamber testing.

Attached are plots of dust counts > .5 microns.

Gerbig has finished the framing for both rooms, though some panels are still missing. Light fixtures for the laser room were put up. Electrical work is ongoing. HEPAs are slated to arrive Tuesday, acoustic door is still scheduled for early next week.

Yesterday, the first set of transfer functions on ISI-BSC8 was measured in vacuum. Here are the links to a comparison with the previous measurements in air. TFs are presented in Cartesian basis.

https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/Comparisons/C2C/

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_CPS_H_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_L4C_H_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_CPS_V_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_L4C_V_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_H_to_ST2_CPS_H_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_H_to_ST2_GS13_H_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_V_to_ST2_CPS_V_20120203_vs_20120227.fig

-          LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_V_to_ST2_GS13_V_20120203_vs_20120227.fig

Main differences on main couplings:

-          ST1 ACT to ST1 CPS: HEPI in different state for the two measurements (Locked vs Unlocked) => Resonances between 7 and 60Hz

-          ST1 ACT to ST1 L4C: No difference between the 2 measurements

-          ST2 ACT to ST2 CPS: No difference between the 2 measurements

-          ST2 ACT to ST2 GS13: Some Qs at high frequencies slightly higher in vacuum than in air (resolution may need to be changed at HF)

Tonight, the section 700mHz to 10Hz will be re measured with a better resolution. The goal is to get a nice measurement in order to calculate all the filters (Symmetrization, blend, damping and isolation) using one unique set of measurements.

Due to high wind speeds, the South Bay roll-up door was closed to mitigate the elevated dust levels in the LVEA.  Normally, this door is kept open to purge air from the LVEA, but the increased wind speeds overcame the over-pressurised LVEA.  Dust monitor levels have subsided to normal levels after the close just before noon.

ETMY M0 and R0 measurements were run today for just the L DoF with the usual drive and measurement parameters.  The drive band was limited to 0.01 to 21Hz with 0.01Hz resolution.  There appears to be some rubbing of the flags in these measurements as some added resonances are appearing in the L DoF TFs.  Investigations to come.  

I have added several control blocks to the 2stage master model. I also added the GUARD block from userapps/isc/common/models/ISC_common.mdl to start working on guardian installation.

New controls:
Stage 0 (HEPI) --> Stage 1 sensor correction
Stage 0 (HEPI) --> Stage 1 feed forward
Stage 1 (T240) --> Stage 2 sensor correction
Stage 1 (L4C & T240 Blend) --> Stage 2 feed forward
Stage 1 --> Stage 2 feed forward compensation

The outputs of these controls have been GROUNDED. This is to prevent any additional input while they are not yet operational. Many inputs are also grounded before we determine how to get the HEPI L4C signals to the BSC.

The model has built correctly. I will test installing the model tomorrow.

Work still to be done:
1. Install stage 1 and stage 2 BLRMS monitors
2. Install medm screens for new controls and blend-switching
3. Revise existing medm screens to be compatible with adjusted macro schemes

More on particulate contamination:
I suspected that the flow in the EY cartridge cleanroom area was not working as we planned.  John helped us look closer at the flow in the cleanroom "system" we have for the cartridge work.  The ETMy/SUS/ISI cartridge is sitting in a large cleanroom (CR), with a smaller CR placed on either side.  We determined that the smaller CRs on opposing sides of the main CR are forcing air into the main one.  This is because the smaller rooms have lower ceilings (thus lower fans closer to the ETM "action"), a smaller gap between the curtains and the floors, and have a higher number of fans/volume.  As well, in the main room the ISI is blocking most of the downward flow from CR fans.  We also have been pinning the curtains open between between the small and large CR, increasing the work real estate.  One of these now open walls makes a direction flow line-of sight to ETMy-HR.
Long story short, we'll need to re-think this next time we do an end station cartridge install.  Small things will help, such as purging more flow from the smaller rooms (raising them to add more gap between floor/curtain).

Today, we finished installing the sleeve, wedges, and cross braces on the ETMy structure.  We then made a cleaning attempt of the ETMy HR which was futile.  A gradient of particulate was observed over the entire surface, including the very bottom 1/4 which still had First Contact covering it.  There was ~40 particles/sq.in at the top of the optic (where it has been exposed on and off for many weeks.  There were ~10 particles/sq.in on the lower half of the optic.  ~5-10 particles/sq.in on the lowest 1/4, observed while pulling the remaining bit of FC today.  We N2 blew and swab dabbed, but to no avail.  We then repainted a fresh sheet and repeated the whole process on the ERM-AR.  Similar results on that surface.

We left the suspension fully suspended, but with the face shields in place.  Fabrice reported that they were going to finish balancing the ISI table and then would remove the face shields for TFs tonight/tomorrow.

Attached are plots of dust counts > .5 microns.

Anteroom frame went up today. The wall against the laser room has not been set up yet, as they need dimensions from the acoustic door first.

Acoustic door shipped today, and is scheduled to arrive early next week (did I say it was going to arrive today? Oops).

Transfer functions were measured on HAM-ISI unit #2. Results are close between measurements performed with CPSs of the same direction (H,V). (Page1)

However, TFs are not close enough between measurements performed with GS13s of the same direction:  (page 2)

• ST1-Act-H3_to_GS13-H3 is lower than ST1-Act-H1_to_GS13-H1 and ST1-Act-H2_to_GS13-H2, by a factor of two.
• GS13-V2 and GS13-V3 record a resonance at 0.975Hz. GS13-V1 records the same resonance at 1.075Hz.

Powerspectra were recorded on GS13s. H3 appears lower that H1 and H2 (page 3). The same measurement was performed with GS13-H2 connected on H3 interface-chassis, and vice versa (page 4). The gain difference follows the GS13s. It confirms that the gain difference observed between the GS13s does not come from the interfaces.