This morning, Jason discovered that the OMC in HAM6 blocked 1 of the 4 of his lines-of-sight thru HAM6 to HAM4 and 5.  Travis and I went into HAM6 and pushed the OMC out of the currently needed beam path.  We will likely need to push it again for the next beam paths...  (Note, we also had to move on of the 2" steering mirror assys on the HAM6 table which also blocked the beam.)

Then, Travis and I wrestled the PLX periscope assembly into HAM 4 and aligned it to the incoming IAS beam - this took a couple hours.  The PLX wrapped the IAS beam around to bounce off of the relatively flat SR-AR surface.  We spent a few hours aligning SR2 in yaw and pitch via twisting the suspension tower on the table and pushing weight around in the suspended intermediate mass pitch mechanics.  BOSEMs were adjusted to accomodate the pitch correction - this involved also tweeking the table cloth plane which holds some of the BOSEMs.  After a few rounds of adjustments and mechanical interferences checks and fixes, we finally have the SR2 pointing within tolerance, with clean looking longitudinal and vertical transfer functions.

AOSEMs are not currently aligned and are pulled back to show no swinging signal.

Jason will add details of the beam pointing and the subsequent SR2 final alignment measurement.

Arnaud has started a full sweep of TFs on SR2 with will run for the evening.  We'll evalute them on Monday to determine if we can move on to the next suspension in HAM5.

A picture of the PLX assembly is attached and should be incorporated into IAS documentation since we had to rebuild the PLX to get it at the correct height a few times with a variety of spacers.  LLO reports that they had to do the same with a different variety of spacers, but there are no pix of that assy to date.

Since I've installed the new BSC-ISI model here at LHO (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=11630), I wanted to check if the T240 simultaneous gain switching was working when the T240 are in the loop.

It works fine when I switch from high to low gain, but it doesn't work when I go from low gain to high gain: you can see a glitch appearing in the drive.

I've done this test 3 times and it's repeatable. We might want to implement something to take care of those drive glitches.

Sebastien found that individual users could not edit files under /ligo/svncommon. I have made the appropriate file/directory permission changes to permit this.

Modified the user environment script for OS X to include /opt/rtcds/userapps/release/etc/userapps-user-env.sh

I rebooted cdsxegw0 at 11:35AM PDT to track down a problem with the console video (turned out to be a faulty KVM dongle).  Before the reboot I went ahead and applied the latest OS/security updates as well.

Have noticed odd behavior with the HAM4 Dust Monitor (listed as #1).  Have gotten MAJOR alarms for 0.3um particles (several hundred up to a few thousand counts!).  Conversely, 0.5um particles has been virtually 0 for days.  Mentioned high counts to Betsy before she went out to HAM4 today, and she mentioned that she only saw small counts out there on the floor.  So there seems to be a discrepency some where. 

Attached is a trend of the last 5-days.  Will send an email to Jeff B.

We tripped the ETMX and ISI and HEPI las tnight when hitting load coeffiients on the suspension filters

this is Sheila

Very short (under 5min meeting!)

• HAM5 alignment work continues:  Setting up for pit/yaw check of SR2 (Jason & crew)
• TCS:  hartman sensor table work most of the day; TCSy Table/Laser work in afternoon by Alastair
• SEI in LVEA on hold until SR2 work done (Hugh)
• EY ESD work continues in morning (Richard)
• Locking ongoing; saturation investigations (Stefan reporting)

Corey reported it went down around 10 PM last night. Telneting into the procServer for the IOC on h0epics restarted it. I burtrestored it to 9 PM last night.

No restarts reported.

Stefan, Alexa, Sheila, Arnaud, Kiwamu

Since we have loaded the blend filters and plant inversion filters on ETMX QUAD, we tried the hierarchical control on ETMX in order to close the ALS diff loop with a high gain. We didn't really see a good sign of suppression yet.

What we did:

• Arnaud and Stefan loaded the inversion plant filters (alog 11676), which makes every stage look like a single pendulum with a resonance at 1 Hz and Q of 1.
• Arnaud set up the relative gains of the stages such that all the stages are identical to TST.
  • This was implemented in the filter bank.
• To confine the ALS diff beatnote within the VCO range, we used the local slow feedback onto ETMY. As we knew, this worked well.
  • Sheila changed the gain from -95 to -24 in order to reduce a kick on the suspension.
  • We also copied the M0 L2P filer of ETMX over to ETMY because the high frequency part had too much gain, which could saturate the DAC.
• We changed the calibration of the ALS diff signal.
  • Now this is calibrated into meters.
• We tried closing the loop.
  • We used TOP, UIM and TST on ETMX with Jeff's blend filters in.
  • We designed a simple servo filter, which gives us a wide 1/f range from DC to 40 Hz in the open loop transfer function for the initial trial.
  • The positive gain seemed right. The gain needed to be more than 1e9 because the signal is already tiny tiny by the new calibration.
  • As we increase the gain, something become unstable and eventually saturates the ETMY DAC (I forgot which stage saturated mostly).
  • Another thing is that, because the inversion plant on TST has a high Q in it, it takes 1 min or so to ring itself down. This easily saturated the DAC. Sad.

The commissioning of ALS diff continues. We will/should attack ALS diff more quantitatively.

Alastair, Greg, Thomas

The laser on the TCS Y table was made operational today, giving a power output of 55W at 95% duty cycle.  However the laser controller (serial #1302122) was found to not function as it should.  This was confirmed by swapping the unit with the one from TCSx table.  There should be a spare unit (3 were shipped according to ICS) so we are working to track down the third one.  In the meantime we are able to make the laser function, though without the protection against the chiller being shutdown.  This should only be a temporary workaround if we really need to run the laser to do any alignment (ie it shouldn't be left unattended in this configuration).  Tomorrow we'll work on solving the problem with the controller and tracking down the spare.

Matt, Thomas, David H

Okay so maybe I was a little optimistic yesterday when I said I would be able to finish all the alignment today. Im closer to the end than I was yesterday but the alignment continues. No issues, its just a time consuming task.

Thomas has mounted the periscope gold mirrors into their mounts and roughly bolted the mounts onto the periscope

J. Kissel, A. Pele, S. Ballmer, K. Izumi, S. Dwyer

We're slowly but surely chugging through implementation of a well-understood ALS DIFF control scheme. On Monday, I designed a control system that used the real ALS DIFF noise, the increased UIM driver strength, and 2 QUADs worth of actuation (see first attachment for design plots). Over the past few days, Arnaud, Sheila, Stefan, and Kiwamu have been measuring all the necessary transfer functions to confirm my model of the plant. I've compiled the results and attached the comparison of what we have thus far (see second attachment for comparison of model against measurement). There is excellent* agreement between model and measurement. We have installed the complementary distribution filters, and we're now fitting the measurement results to obtain plant inversion filters (as mine were just low-Q guesses, because I knew optical lever damping, different top-mass local damping, etc. would cause subtly different frequency dependence).

Of note: 
- *There is still a factor-of-4 discrepancy between the model and measurement at the test mass. Kiwamu and I have modeled the ESD in two different conceptual ways, and come up with the same factor of discrepancy. For now, we'll just accept the measurement as canon and move on, but it would be really nice to understand this mismatch.
- Unlike what I've modeled, Stefan has convinced me to go forward with inverting the frequency dependent plant to look like a 1 [Hz], Q=1 single pendulum transfer function, with a DC actuation strength of 1e-12 [m / ct]. 

The DC gains between the stages are as follows:
TOP: 4.769e-10  [m / ct_{TOP}]
UIM: 5.328e-11  [m / ct_{UIM}]
TST: 1.760e-13  [m / ct_{TST}]

For gain ratios of:
TOP / TST:  3.69e-4 [ct_{TOP} / ct_{TST}]
UIM / TST:  3.30e-3 [ct_{UIM} / ct_{TST}]

Taking over afternoon for Thomas

• SR2 Alignment work done for the day (Jason O)
• Dust Alarms at EX (probably due to Ken?)
• Dust Alarms near HAM4 (the 0.3um counts have been a few hundred counts most of the day)
• TCSx Table Hartman work (David H)
• Transitioned LVEA to Laser HAZARD around 2pm (Kiwamu)
• TCS laser work (Alastair & Matt)
• Ops Meeting from 3:00-3:30

Installed the ESD drive at EY.  The interlock to the Pressure Gauge functions properly.  Again had a problem the a Neg HV supply.  Similar to EX the unit powered up and worked for a while then tripped off and never turned back on.  Replaced it and everything seems to be working.  Drove excitations through the ESD out filterbank and saw signals on the oplev.  Left further testing to Kiwamu.  I was not completely satisfied with our results.

- Aidan turning on laser with enclosure locked to remain in laser safe, going to lock the intensity of the laser.
- Fil and McCarthy working on ESD at EY
- Hugh to the west bay test stand area
- Betsy to HAM4
- Dale to HAM4

Corey took over at 12:00 PM PT

• Y (longitudinal): +0.4 mm (west)
  • Tolerance: ±3.0 mm
• X (lateral): -1.2 mm (south)
  • Tolerance: ±5.1 mm
• Z (vertical): +0.4 mm (high)
  • Tolerance: ±3.4 mm

I have started the setup for the SR2 pitch/yaw alignment (it differs from the position alignment) and hope to finish tomorrow morning so we can get a first look at SR2 pitch/yaw before the afternoon transition to laser hazard.

Patrick Thomas, Thomas Vo

We checked the CoE parameters in the Beckhoff system manager and verified that they matched the same values as those for the PSL rotation stage.
We went out to the TCSX table and used medm on a laptop to move the rotation stage.
The rotation stage would move again, but not to the requested angle.
We power cycled the Beckhoff chassis twice. (We weren't sure we left it off long enough the first time.)
We tried to move the rotation stage again. It moved to the correct requested angle.
A motor warning was reported and the rotation stage would no longer move.
Thomas forced the motor warning variable in the PLC to FALSE, which allowed the stage to start working again.  It was decided in the code review that we will only stop the motor on motor errors not warnings.  The strange thing is that the motor is working pretty well now even if I don't force the warning to be false.  The long term solution to the problem of why motor warnings stop the stage is not quite figured out yet but it seems to be working now.  Also, we don't know why the stage was moving in opposite directions, but rebooting the chassis worked to fix the problem.


Interlock:
We noticed that the medm readback for the safety interlock indicated that the rotation stage was locked out, but it was still able to move and the interlock jumper has no effect on the status on the MEDM screen.  We think it's a problem with the Beckhoff wiring or software because we tested the continuity of the interlock signal in the on/off state (closed with jumper in, open with jumper out) from the floor all the way to the CER up till the Beckhoff chassis and it looked normal to us.  For now, we can just remove the interlock signal from the MEDM screens so it doesn't confuse people