Kyle, Gerardo 

Sensitive testing possible now that "gross" leak is fixed and pumping via turbo.  YBM pressure ~8 x 10-7 torr.  Turbo header valved-out, 100% of turbo throughput routed through leak tester -> Found a 1.1 x 10-7 torr*L/sec leak on untested 4.5" CF blank -> Torqued screws and now < 5 x 10-8 -> Found 1.7 x 10-7 torr*L/sec leak on coax feed-through appears to be left feed-through (of 2 on flange) and not CF joint-action? -> YBM viewports checked OK with indicated background 5 x 10-10 torr*L/sec at time of this testing. -> Replacement feed-through flange from Friday doesn't leak now but may in the future as I think the flange screws are bottomed out and not in tension.  We may revisit this flange the next time the YBM is vented?

Both X1 test stand computers have been restarted in the staging building following a timing system interruption to move AC power for the timing master.  All previously running models have been restarted.

Due to the need to move AC power from the old circuits to the new circuits in the MSR, the timing master was shut down this morning about 11:20 PST.  The timing system interruption resulted in the need to restart all front-end computers. Work is complete, and all models have been restarted and burt restored to 11:00 PST on Feb. 21, 2012.

Daphen P. Doug D. Joe D. Thomas V.

8 assemblies for the custom viewports were put together and proof/leak tested referencing the documents listed below.  A few minor adaptions needed to be made to the procedure for assembly, namely the torquing of the SHCS require two people, one must hold the assembly upright, while the other can torque the bolt down with 205 inch-lbs of torque (which is quite a bit, make sure you eat Wheaties beforehand). The knife edge on the bottom side of the flange must be protected from damage so we used dog clamps as spacers that prevent the knife edge from contacting the table top during the assembly phase.  

The optics were in general in good shape, except for a few particulate that were easily wiped off by drag wiping.  The flange had a few burn marks from baking but Joe had said that's pretty common and alright.

Documentation: As each viewport was assembled, we recorded the part numbers for the flange, optic, and clamp for each assembly.  The total assembly part number is D1100999 and the S/N will be recorded in ICS as each assembly is put together successively (i.e. the first 8 assembled are D1100999 S/N 001-008).  All of the assemblies were proof and leak tested by Doug, the inspection records will be attached to the assembly in ICS.

I have many pictures of the event, but a few are attached.

TMS was badly crooked for some reason. Maybe it's different cable tension, maybe the fact that we changed the wire clamp hole to make it higher by 8mm.

After making various adjustment, TMS upper mass is now only pinned at one corner. We need to slide the adjusting mass a bit. Apart from that, no touching.

Before any adjustment, Doug measured the TMS height to be about 1.5cm higher than nominal. However, just by eyeballing, it looked OK. After our adjustment, TMS came down a bit (a few mm) but not 1.5cm. Thing is, it looks somewhat lower than ERM. not higher. This needs to be revisited before making fine adjustments to the balance.

As such, the first thing in the morning is to move the slide mass in the upper mass so nothing touches and measure the TMS height. If it is really 1cm or more high, we need to lift the tele and change the wire clamp position again.

Attached are plots of dust counts > .5 microns. The connection to the dust monitors in the labs was lost for a period of time when one of the wires came unconnected in the MSR. I have attached a plot of H0:PEM-LAB_DST1_MODE to show when.

Kyle, Gerardo, John  

Found gross leak on dual 3-pin actuator power feed-through on BSC8 (NW) -> Vented YBM, replaced leaker with one that was bench tested and found not to leak.  As found, in-vacuum cables connectors were not screwed to feed-through connectors -> NOTE: flange-to-flange gap is uniform but conflat joint is not "metal-to-metal".  Seems as if flange bolts are bottomed out in blind holes, tapped holes may be too shallow on this one flange(?) -> Pumping YBM overnight with purge/vent valve "cracked" open.  

  

Kyle, Gerardo 

~0930 hrs. local

We isolated the chamber tubing from the feedline and then shut the pump down.  We drained almost two liters from the system before we decided enough for today.  We'll do some more before moving the lines next week.
We had no real problems except for having a ladder pilfered in the middle of the job.

EricA, HughR

AC units have been installed, work on make-up air ducting is in progress. Area for concrete pads for chillers to sit on has been cleared.

H2 SUS ITMY 

Open loop transfer function measurements were run on the H2 ITMY M0 & R0 top masses last night. The ISI damping loops were closed for the beginning of the measurements. There was a concern as to whether there was rubbing on the earthquake stops for ITMY after  evidence of such on FMY earlier this week.  These measurements show no preliminary signs of rubbing on the ITMY M0 & R0 masses and agree quite well with the models.



Data:
~/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGM0/Data/2012-02-16_1013494514_H2SUSITMY_M0_0p01to50Hz_AllDOFs_tf.mat
~/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGR0/Data/2012-02-17-1013510837_H2SUSITMY_R0_0p01to50Hz_AllDOFs_tf.mat

PDF Plots:
~/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGM0/Results/2012-02-16_H2SUSITMY_M0_ALL_TFs.pdf
~/SusSVN/sus/trunk/QUAD/H2/ITMY/SAGR0/Results/2012-02-17_H2SUSITMY_R0_ALL_TFs.pdf

• Watched Apollo install H1 Mode Cleaner B Tube (and probably take FTIRs on MC A Tube). 
• Lost connection to the Vacuum Rack near H2 PSL.  Dave/Filiberto was able to get it back online
• 8:44 Rebolt on site
• Stoneway also came on site with delivery for Ken
• Several Annulus Pump alarms, but Kyle says only to worry about are the Beam Tube Gate Valve Annulus Ion Pumps
• Had several Chiller Yard Pump Failure & an RO Alarm (Ski said this was due to reboots)
• BSC8 ISI Cables disconnected for Leak investigations

Filiberto will be disconnecting external ISI cables from their respective feedthrus to help Kyle with his leak-checking work of BSC8.  Cables will be re-connected when Kyle gives the ok.

During phase I and II, the ISIs are tested in clean rooms and are subjected to an important airflow disturbance.  Consequently, it is quite difficult to have good quality measurements at high frequencies (100Hz to 1KHz). To improve the quality of the transfer functions, we can split the high frequencies transfer functions measurements into multiple frequency bands but the “quick high frequency transfer functions measurements” become time consuming.

Measurement limitations:
- at HF, the drive is the limit
- at LF, the drive is small and the sensors saturate easily

To reduce the measurement time, we can drive 1 DOF at low frequency and different DOF at high frequency simultaneously. During a test, stage 1 was driven at low frequency while Stage 2 was driven at high frequencies. In the attached plots, there is a comparison when the TFs are measured by exciting one DOF at the time and 2 DOFs simultaneously. It matches. Only, a light difference is observed on the 2 first resonances of the ISI (probablydue to a light change of the plant between the two measurements)

HEPI transfer functions
The first set of transfer functions was measured on BSC8 from 2mHz to 500Hz. The 700mHz-10Hz frequency band was measured in 2 configurations:
- ISI undamped (2012_02_15)
- ISI damped (2012_02_16)

The HEPI transfer functions can be seen at:

https://svn.ligo.caltech.edu/svn/seismic/HEPI/H2/ITMY/Data/Figures/Transfer_Functions/Measurements/Undamped/

-          LHO_HEPI_BSC8_TF_L2L_Raw_from_ACT_to_IPS_2012_02_16.fig

-          LHO_HEPI_BSC8_TF_L2L_Raw_from_ACT_to_IPS_2012_02_16.pdf

-          LHO_HEPI_BSC8_TF_L2L_Raw_from_ACT_to_L4C_2012_02_16.fig

-          LHO_HEPI_BSC8_TF_L2L_Raw_from_ACT_to_L4C_2012_02_16.pdf

The ISI damping loops are effective between 1Hz and 8Hz. The effect on HEPI transfer functions is limited but visible on the 1.25Hz and 5 Hz resonances. A comparison between the two configuration can be found at:

https://svn.ligo.caltech.edu/svn/seismic/HEPI/H2/ITMY/Data/Figures/Transfer_Functions/Comparisons/L2L/

-          LHO_ISI_BSC8_Comparison_TF_L2L_ACT_H_to_L4C_H_20120215_vs_20120216.fig

-          LHO_ISI_BSC8_Comparison_TF_L2L_ACT_H_to_L4C_H_20120215_vs_20120216.pdf

-          LHO_ISI_BSC8_Comparison_TF_L2L_ACT_V_to_L4C_V_20120215_vs_20120216.fig

-          LHO_ISI_BSC8_Comparison_TF_L2L_ACT_V_to_L4C_V_20120215_vs_20120216.pdf

If you look carefully, you can see light bumps at the junctions between the different sections (10mHz for instance) of the transfer functions. To evaluate the non linearity, I drove a sine wave at 200mHz and 4Hz using different amplitudes (100cts, 300cts, 1000cts, 3000cts, 5000cts) (attachment).

PSL is shut off for the night to allow Robert S. to make accelerometer measurements on the periscope, without interference from the chilled water lines. PMC, ISS, FSS servos are off, everything will be started back up tomorrow morning.

HEPA units are off, make up air is set to 30%, creating a ~0.01" water pressure differential between laser and anteroom. AC units were shut off via touchpad interface, but they may still be on.

Jim, Hugo

Issue: 
LLO have a BSC-ISI that is under-loaded by 400lbs. They noticed that its small blades where lifted from their clamp-plates. They measured this gap by inserting shims at the blade/clamp-plate junction. A 1.5 mils-thick shim could be inserted by approximately 18/64” in the whole length of that junction.

Test:
We did the same test here at LHO on BSC6, which is reasonably loaded, in order to help LLO diagnose. The access was limited. Only two blades were tested. They could only be tested along 2” of the junction’s length.

Result:
Observations are the same for both of the blades that were tested. A 1 mil-thick shim could be inserted by approximately 28/64”, and a 2 mils thick shim could be inserted by approximately 19/64”.

Conclusion: 
The gaps measured on LHO-BSC6 are similar to the ones measured on the unit studied at LLO. Hence, the space measured between the blades and their clamp-plates doesn’t seem to be a justification for a BSC-ISI to be under-loaded. 

Suggestion:
Further discussion revealed that our bolts were lubricated before torqueing. Lubrication allows reaching a higher level of compression before tripping the torque wrench. It also revealed that our bolts were torqued to a higher torque value.