Helium leak tested (4) new 10" conflat joints and (1) new 2.75" joint on GV14 adapter spool (iLIGO viewports removed, (3) blanks and (1) 10"-2.75" zero-length reducer installed) -> new joints are good but found a 4x10-7 torr*L/sec leak on nearby original iLIGO blank -> Cinched flange fasteners and leak improved to 1x10-7 torr*L/sec

John, Kyle 

Found 1x10-3 torr*L/sec leak on pump side of 10" gate valve at Main Turbo Pump inlet (stem bellows area) -> Closed valved and valved-in IP1, 2, 3 and 4.  Also, valved-in HAM6 500 L/sec ion pump -> Vertex pressure normal now.  Will replace valve during next Vertex vent.

  I've turned on the damping loops, they work as a set (all 12) or one at a time, excpet for  Stage 1 rZ  which is not stable at ~11.5Hz when it is the only loop on

ITMY-ISI Tranfsfer Functions With a Quad

The Badness on stage one (19-30 peaks)  is only seen in the CPS and not the L4Cs so is presumably the test stand.

There is a not enormous cluster of peaks around 265-270 on the St1-> L4Cs TFs which are probably the spring resonance 

For the lower frequency data set, Stage 1, V2 actuator was unplugged

- Surveying work by BSC7.  Clean room not placed on it.
- BSC8 ICC complete, floor replaced, dome replaced.
- Kyle completes leak checks in HAM4, HAM5, HAM6 area.
- IAS work at EY, BramS, SamW, MattE presiding.
- SUS crew working by test stand.
- King Water arrived to work on RO.

Not too much done today, a truck carrying needed parts did not arrive and Gerbig people had to drive out to pick up the crates. More wall panels put up.

Dust counts are good.

We finished inspection and second vacuum yesterday. Jodi did a slight incursion down the manifold to check on fibers and other detritus (See pix below). The bulk of post-work FTIRs were taken then as well.

Today was spent completing the few remaining items on the checklist. We moved the dome back to the top of the chamber and snugged the bolts. The last two post-work FTIRs were taken and the paperwork completed. Samples will be sent off tomorrow. A second fit check of TCS hardware was done. Before leaving the chamber, Mark L. noted a few white specks on the chamber floor. They appeared to be similar to the specks we find when we shake-test C-3. Michael L. asked us to clean them up if possible so Mark wiped up (isopropanol-soaked ConTec)those specks he could find. The door was inspected, wiped down in a couple of spots, and replaced on the chamber. (BTW, it is a very good looking door interior.)The bolts were snugged.

Work permits were taken out for staging and ICC at BSC-6. Some items were transported to Y-end.

(Corey, Jim)

BSCISI#3

The Keel Assy was installed on the assembly completing the superstructure for the ISI.

Machining QA note: 

One of the Upper/Outer Walls D0901533 had a tapping issue, where the tapered tap was used on the wrong side.  This makes installing a screw hard/tight.  We used our screws as taps, and this opened up the threads enough for the screw (this was only seen on one Wall).  This tapping issue was also observed on parts for our Small Actuators.

Horizontal GS13 Installation

Test GS13s were installed on the assembly ("test" meaning these are GS13's which ARE NOT to be installed in the LIGO vacuum system).  The locations & serial numbers for the GS13's are as follows:

• corner 1:  s/n  14
• corner 2:  s/n  27
• corner 3:  s/n  37

Machined Arrows Finally Match Up!

On Stage0 & the Stage2 Optics Table, arrows were etched into each plate so one can orient them such that the vent lines on the Optics Table will be parralel with the Support Tubes.  For the first two assemblies, aligning these arrows had the lines angled in the wrong direction.  Assembly#3 is the first to have the arrows match correctly.  (See attached photo...which needs to be rotated clockwise 90deg)

Started seiteststand2 computer, started IOP and user model, verified timing was within tolerance.

Restarted workstation computer, verified time server status, verified file system mounts.

J. Garcia, J. Kissel

We've measured the M1 to M1 (TOP to TOP) pitch transfer function after the rehang, electronics turn on, OSEM installation, to complete the story we had last heard about two months ago. 

The executive summary (for those who have been following the story) is that the first pitch mode is now at 0.47 Hz, slightly higher than before the wire length change, so we are happy (given that we're trying to hit 0.48 Hz). However, before we give a complete blessing we must measure the remaining degrees of freedom of the top stages. The data is in the can, we're now processing the data -- hoping to have an answer by the end of the week (although initial glimpses at the results are very encouraging).

A recap of the story thus far: a requirement/goal for the BSFM is to have its first pitch mode "reasonably far away" from the first longitudinal mode, such that control for these two DOFs can be reasonably decoupled. Initial modeling of the suspension predicted the first longitudinal mode at 0.41 Hz, and the first pitch mode at 0.48 Hz. However when we had hung the BSFM for the first time (many moons ago), the pitch mode was *below* the first longitudinal mode. Several as-built parameters were then changed, to get the pitch up to 0.44 Hz. Finally, two months ago we had played around with the suspension physical parameters further, and ended up with the mode at 0.46 Hz, which was deemed good enough. The answer we had come up with to get 0.46 Hz was to lower the M2 blade tip heights by 3 mm (or a d1 of 2 mm below the COM). However, to recover the overall height decrease of the masses below (specifically M3, or the optic) from this blade tip height decrease, we needed new wire lengths. 

Cut to this week where we've installed the new wire lengths, suspended and turned on the suspension, and measured the same TOP to TOP transfer function. Here, we hope for at least the same first pitch frequency (0.46 Hz), but -- as the attachment shows -- we've surpassed it, to be that much closer (0.47 Hz) to the original model (0.48 Hz). W00T!

What to look at (in both pages): 
BLUE - Nominal model of the BSFM in pitch. This is what we would like to see out of the suspension, and served as a reference point for our physical parameter exploration.
GREEN - Modified model to try and explain the 110621 measurement. It's unclear whether having d4=0 was actually physically happening (since it would result in an unstable suspension), but it explained the measurement.
RED - 110621 measurement, that had decreased blade spring tip heights (at 23.6 mm), but wire lengths that were therefore too long, since the original design (and therefore this suspensions') lengths were for a blade tip height of 26.6 mm.
CYAN - 110823 measurement, with 23.6 mm blade tip heights and new wire lengths.

Stay tuned for analysis of remaining degrees of freedom!

In this directory:   /opt/rtcds/lho/h2/target/h2isiitmy/h2isiitmyepics/db/H2 
There is a file:     h2isiitmy1.db 
That contains a field:  grecord(ai,"H2:ISI-ITMY_ST2_PAYLOADWD_IN") 

To make a watchdog link,  we turned it into a calc field
grecord(calc,"H2:ISI-ITMY_ST2_PAYLOADWD_IN")
{
    field(PREC,"3")
    field(SCAN, "0.1 second")
    field(INPA, "H2:SUS-ITMY_M0R0_WDMON_STATE NPP NMS")
    field(CALC, "A")
}


Then we restarted the Front end.  EVERYTIME YOU REBUILD THE FRONT END YOU HAVE TO EDIT THE FILE.

Note that the mapping to the BSCWATCHDOG c-code,  medm,  and simulink don't agree.  But I leave this to SEIsters to fix.
When the Quad trips the lights behind the  ACT limit on the ISI watchdog go red.
Note - because this is hardwired,  there is no bypass so the QUAD watchdog MUST be green.

s

Replaced Y end instrument air compressor.  System restored.

K. Arai, J. Kissel

Combined Watchdog state of the QUAD M0/R0 stage has been made.

EPICS version of this signal is named like "H2:SUS-ITMY_M0R0_WDMON_STATE"
The simlulink model has the tap for the faster trigger, but not used for anyting right now.
The state signals are produced from the watchdog "blocking" signal of M0 adn R0 by taking "OR" logic of them.

This channel is designated to provide the state of the Quad suspension to ISI.
From the point of view of the suspension safety, ISI should be notified if the suspension top levels are not quiet and thus the active damping is not effective. The suspensions are enough quiet as long as the M0/R0 damping are functioningd. In that case, the L1/L2 watchdogs may trip with different reasons than the disturbance of the entire suspension, and therefore should not be included in the state notification for ISI.

K. Arai, J. Kissel

Implementing AC/DC watchdog for Quad/Triple SUS

AD/DC watchdogs have been implemented for Quad/Triple suspensions. The snapshot of one of the MEDM screens is attached.

Those watchdogs have different signal processing chains and thus have different purposes:

- DC watchdog monitors the positions of the OSEM flags and interrupt the actuation of that suspension level if any of the sensor signal hit the high or low thresholds.
- AC watchdog monitors the RMS values of certain signals and interrupt the actuation of that suspension level if the RMS reaches the threshold level.

The signals being monitored (i.e. OSEM sensor signals, OPLEV sensor signals, Coil outputs, etc) are individually processed by the filters called "band limiting filters". The AC watchdog employs the RMS module to obtain the RMS value of the signal. This RMS block has the time constant of ~7sec (See this entry). Then the output of the bandlim filters or those of the RMS blocks are compared with the thresholds.

Bandlim filters: For the DC one, this filter cleans up the sensor signals by attenuating at the high frequency (e.g. f>~10Hz) band where the sensor noise dominates the sensor output.  For the AC one, the filter usually employs "AC coupling" as we may not want to include the huge DC value of the OSEM output in the RMS calculation. One possible configuration for the OSEMs is to calculate the velocity of the signal by differentiating the OSEM signals (i.e. to multiply (2 pi f)). Again the high frequency components are to be attenuatedfor the same reason as the DC case.

Currently the bandlim filters are mostly empty (= do nothing). They are to be filled by the preparations scripts with easyquack.

B. Bland, J. Garcia, J. Kissel, T. Sadecki

Using 3 of the 199" D1000225 that landed at LHO, we've connected up the TOP stages (M0, R0) of H2SUSITMY for the first time since mating, the satellite amplifier swap, and a whole ton of infrastructure changes (most notably the watchdog -- see subsequent eLOG by Koji).

All OSEMs appear functional. Because of the gain change in the satellite amplifier gain change, we had to remeasure the open light current (OLC) of the PDs using the ADC. At first glance, all OSEMs show counts *under* the 32768. Will post details later. We then record OLC, and installed the appropriate offset using
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ITMY/Common/MatlabTools/getWhiteCounts.m 

After then re-engaging the OSEMs back to half light, we freed up the suspension. 

After running
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H2/ITMY/Common/Scripts/prepare_H2SUSITMY_20110819.m
which restored a few incorrect MEDM values, and easyquacking in bandlimiting filters to the AC coupled OSEM wathcdogs, we were able to get damping loops running.

Rich is taking a long high-frequency measurement of the now free ISI overnight (of which I've sat through watching the QUAD for a few hours now), and there appears to be no obvious effects on the QUAD (makes sense -- > 100 Hz measurment, at least 1 stage of passive isolation in between, suspension works!).

Will post more details later. Struggling to commission the BSFM01 at the same time; running out of time to write aLOGs. 

   The ITMY ISI is now floating with the Quad on the optics table. The mass on the keel is now 2 stack masses, one large, one small ('820lbs), and 12 keel ballast masses, which I think

are 40lbs each, so that would be 480lbs.

  there isn't currently a lot of trim mass on the walls

  the pictures that I included are of the mass on the keel plate and the wall mass in each corner

More work on setting up wall panels, building pipe chases for conduits. The diode room clean room has been set on its vibration isolators.

Dust counts for this week are attached, everything looks normal.

Pumped to rough vacuum the annulus volumes of HAM1,2 and 3 yesterday.  

Today I roughed down HAM4,5 and 6 annulus volumes.  Later, I continued pumping these using hung turbos (backed with aux. pump carts).

Turned on annulus ion pump controllers for HAM4,5 and 6.

Opened GV1 gate annulus volume to remaining GV1 annulus volumes such that all of GV1 annulus volumes are actively pumped by a hung turbo (backed by aux. pump cart).  



Operators: 

Expect and ignore annulus ion pump alarms for HAM1,2,3,4,5 and 6 over the next few days.    

Had issues with the signal input selection monitor bits for the PUM. A test bit controls where the drive signal for each channel comes from. The PUM has two DB9 connectors, "DRIVE IN" or "TEST IN". See Jeff Kissel Alog - QUAD BIO I/O Simulink/MEDM Upgrade for further details.

This test bit controls a relay that selects from "DRIVE IN" or "TEST IN". Attached to this circuit are two transistors that output the state of the relay. When the relay was activated, it would respond by switching. The problem came from the rest of the circuit, where the input voltage on this bit was around 0.8V. This was enough voltage to keep the base of the transistor "on" regardless of the state. Jay Heefner recommended we switched out R111 on all four channels from 10K to 100K. Did modifications on PUM Chassis SN S102650. Unit is back in SUS rack and monitor channels are all working.

F. Clara, J. Heefner, R. McCarthy