M. Phelps, T. Sadecki, G. Traylor, B. Weaver, [and J. Kissel as photographer]

Since LHO was disconnected from the outside world this morning, I decided to tag along and recall what awesome installation work is still on-going. Here's a slide show of pictures for the H1 SUS ITMY, BSC3 install [[2014-06-10_H1SUSITMY_Install.pdf]], and I attach some of the highlights as raw images. The movie fits in between photos 3943 and 3949, and captures the move from mounted in the installation arm to staged in-chamber -- download the video from . Congrats on another successful install to Margot, Travis, Gary, and Betsy! 

#positivitytraining

J. Kissel

As per ECR E1400078, I've installed the infrastructure for damping the highest vertical and roll modes of H1 SUS BS (a BSFM triple suspension), sensed at the top (M1) stage, and actuated upon using the middle (M2) stage pitch and yaw drive. Many thanks to Stuart for prototyping; install was as simple as an update to the userapps repository, and then a recompile, reinstall, restart, and restore. A new safe.snap has been captured and committed with the input to the new filter banks turned off. The DAQ was restarted later in the afternoon to account for new channels (and other bugs from the network outage).

This closes out ECR E1400078, and completes integration issue 723.

Once we get back under vacuum, we'll begin to commission the loops in a similar fashion as LLO -- hoping that we have a similar amount of SNR and control authority.

Follow the development story from LLO:
Original Investigation: LLO aLOG 11069
Original Implementation: LLO aLOG 11076
Loop Design Description: LLO aLOG 11233
Reimplementation: LLO aLOG 12973
Integration to Library Parts: LLO aLOG 12991

HAM6 is fully payloaded. Hugh will unlock and balance the ISI and inspect the cabling.
Keita and Corey are done with HAM6 in chamber work.

ITMY is ready to come out.
ITMX will be installed today.

A first cleaning has been done in the spool area at GV7.
Kyle will install a vacuum pump.
Thomas and Jason will remove the optical lever components. Apollo will remove the optical lever piers.
Apollo will break bolts and remove the annulus piping.
A second cleaning will be done.
The spool will probably be removed tomorrow.

The H1 PSL laser diodes are reaching the end of their life.

Filiberto will be working on SUS watchdog cabling at end Y in addition to the ongoing AA/AI chassis work.

Jeff K. will add damping software infrastructure for the BS.

The storage container for the 3IFO BSC1 needs to be craned into its LTS location. The 3IFO HAM4 and 5 ISIs need to be moved from their shipping containers to their LTS containers.

GV11 and GV18 will be closed for Y2 accumulation pressure measurements.

Temporary plugs will be put in the annulus ports on the HAM5 and 6 door flanges to allow leak checking of the septum between the chambers.

Cyrus is doing maintenance on the CDS switches.

Please save or post any aLOG entries prior to 10:30.  I will be rebooting the system to apply patches.

The work is completed

no restarts reported.

Here's the presentation that I'll be giving today during the Seismic call.

I'm focusing on lock losses, and how they are linked to the ISIs trips.

I'll be starting work on the CDS core switch soon, as specified in WP4660.  This will impact most network traffic within CDS, and by extension offsite access to CDS.

Beam diverters good.

At first neither of two beam diverters worked, using Beckhoff driver. The sensors are good, the motors tried to move but they couldn't fully move the mirror.

We brought a beam diverter testor, and one of them (OMC_REFL_AIR_BDIV) moved slowly, but the other (AS_AIR_BDIV) didn't. The difference between the testor and the Beckhof thing is that the latter has a maximum current set in software, thus the tester is beefier.

When pushing the BDV by hand, it was obvious that the friction was big (and they both squeaked and squauked screeched). I loosened the front/back plate screws to make the plates more aligned with the axle, tightened them, and loosened the axle collar screw so there was more space between the front/back plate and the jewel bearing. This seemed to help, and after doing this for both BDVs the one that worked slowly started moving smoothly, and the one that didn't move started to move.

Switching back to Beckhof, the AS_AIR_BDIV didn't move. After another round of loosening screws and aligning, it finally started moving.

One thing is, open/close logic in AS_AIR_BDIV is reversed, which should be fixed in Beckhof.

Picos good.

We brought a picomotor driver and a testor because ISCT6 is not in position.

At first none of three AS picos (AS_A and AS_B for WFS centering, AS_C for AS QPD centering) worked, but QPD sled picos were good.

We swapped the in-air cable and the AS picos started working. Swapped the in-air cable back and the AS picos still worked.

One of the shafts for the in-air pico DB25 connector on the feed through was bent, and it was kind of hard to screw it in. Maybe the cable was not fully seated because of that.

Anyway, all picos work.

Note to self: M10 is the first pico on the QPD sled cable, M9 is the second.

Did not get as far with the modifications of the AA/AI ISC electronics in the CER. All AA/AI units are currently powered off and not connected. Will continue with work tomorrow morning and try to bring them back up around noon.

Filiberto Clara

Adhered temp recorder to Y2 BT -> Dumped unpumped volume seen be PT246 dead space into RGA assembly at port Y2-1 -> Isolated turbo pump from RGA -> Opened 10" gate valve -> Energized PT246B (eventually had to "tap" lightly with wrench to get gauge to fire) -> RGA scanning in Faraday MID, amus 2,5,14 and 28 -> will isolate Y2 BT from ion pump tomorrow by hard-closing GV11 and GV18  

This exercise is part of the Y2 pressure accumulation data collection 

8:00 Work on Genie and Forklift behind the Highbay – Mid Columbia Forklift
9:13- 11:38 Heading to HAM6 to continue on ISI work – Hugh
9:22- AA-AI Chassis modifications for ISC in Electronics room – Filiberto/Aaron
9:28- Going to EndX to grab some parts to work on HAM6 – Corey
10:00-12:11 Baffle work in LVEA (West bay) – Gerardo/Scott
10:30-Heading into HAM6 to do some testing – Corey/Keita
13:00- Back into LVEA   (West bay)  for more Baffle work– Gerardo/Scott
13:13- Installing SUS Watchdog chassis and running cable at EndY – Filiberto/Aaron
13:51- Dump unpumped volume seen by PT246 into RGA turbo*isolated turbo from RGA*open 10" BT valve thus exposing RGA and PT246 to BT* Begin scanning at MidY/EndY – Kyle
13:55- 14:45 Heading back to HAM6 to continue on ISI work – Hugh
14:07- De-install receiver pylon for PCAL welding at EndX VEA – Thomas
14:15- Heading into the LVEA to relocate dust monitor – Jeff B.
14:35-Going into the H2 PSL enclosure – Peter
14:54 SPRAGUE on site.
15:00 EX VEA transitioned to laser SAFE

I'll attempt unlocking and continue with balancing the ISI later when Keita & Corey are not working there.

  For the past few months we have been suffering from an unwanted stage 1 Z to stage 1 rZ coupling (the attached plot Z to Z Subtraction shows an example).  It seems to have two component which show up in the T240 rZ signal.

   There is a 1/f^2 component (in Force to displacement units, the plot is in force to velocity) and a flat component (again in Force to displacement)

   The 1/f^2 part does not seem to represent center of mass motion of the platform, as shown by the optical levers (the black line in the Z to OpLev Yaw plot), it is not clear

for the flat component yet.

   Speculation for the 1/f^2 has centered on magnetic coupling or local deformation of stage 1, current measurements and FEA on these two effects are off by about the same amount.

   Since we believe that the signal is not CoM motion we are going to subtract it from the T240 rZ signal.  The plot Z to Z Subtraction shows the predicted amount of subtraction based on the fitted filter.

where the red line is (TF - FIlter)/TF so we are hoping to get a factor of~ 50 subtraction.

    The plot Z to OpLev Yaw  shows some results.

  The BLUE lines shows the transfer function from ISI stage 1 Z drive to the optical lever (solid line is yaw, dotted it pitch) while the ISI is in high blend with no T240 in the control path. So we expect to see

any mechanical coupling. 

   The PURPLE lines shows the same transfer function with the stage 1 of the ISI in low blend (~40mHz) and the T240s in the loop. Whatever extra pickup exists in the rZ T240 signal will be imposed onto the motion of the ISI

and show up in the optical lever signal (pitch as well as yaw because the suspension is not at the center of the ISI table and there is a translation to pitch coupling).

   The Black lines are the same transfer functions with the subtraction path enabled (i'm not even going to try and explain how we got 3 orders of magnitude of suppression)

   One disclaimer I calculated a filter gain of 3 and ended up using a gain of 3.24

[Mark B Jeff B Arnaud P]

Yesterday we did some software debugging in the staging building in order to run transfer functions on the assembled quad 08.
When driving the top mass, we usually monitor the lower stages osems, in both osem and euler basis. For some reason the model running for the quad doesn't record those channels (particularly the ones in the euler basis "WIT_{L/P/Y}_DQ"). We decided not to spend too much time understanding what the model situation was, and instead simply not monitor the lower stages channels during the top mass TFs.

The undamped transfer function measurements for the main and the reaction chain are attached.
 

J. Kissel, R. Bork, B. Abbott, D. Barker

In order to determine a good threshold for the new SUS Hardware Watchdog, we've shaken the ITMY chamber vigorously in various states of excitation. 
In summary, with 
- the HEPI and SUS user watchdogs disabled (actuator and inertial sensors set to un-tripably high values)
- ISI damping, SUS damping, and HEPI loops OFF (I just left the ISI tripped the whole time) and 
- driving HEPI at the limit of its DAC range (in Y, RX, and RZ), 
we shook the suspension (and ISI) enough that I would say "Wow, that's a *lot* of motion; it's giving me the willies. We should cut off SEI excitation after 10-20 minutes of this." 

This level of excitation produces roughly 110 [mV] RMS* from the RMS circuit of the SUS Hardware Watchdog. 
* The Hardware Watchdog currently does not expose the output RMS variables, either to analog or digital, so we've replicated what we believe is the SUS Hardware Watchdog's signal chain in the IOP model for the h1susb123's computer, based on the limited documentation available (namely Fig 4 of T1200306), and the DC gain of 31.2 [V/V] from the SUS Hardware Watchdog Chassis, measured on an identical setup in the H1 DAQ Test Stand (thanks Ben/Rolf!).

My figures of merit were 
- the ISI BLRMS Performance matrices, in which 
     - ST1 was solid red above the 0.3 [Hz] band in XYZ, 
     - ST1 was solid red in all frequency bands, and 
     - ST2 was solid red in all bands in all DOFs
- the QUAD M0 OSEM speed dials (the raw ADC input version), in which (for these particular DOFs of excitation from HEPI)
     - F1, F2, and F3 (which are the L, P, and Y sensors) were swinging quickly over *most* (not all) of their range (which is 0.7 [mm])
     - LF, RT, (which are the V and R sensors) showed signs of abnormally large movement, say 25% of their range
     - SD was moving minimally
- The DAC saturation counter screen for HEPI, which was showing several channels off-and-on saturating
- The ITMY Optical Lever, which was not swinging out of its range, but moving abnormally large, say 50% of its range



For future forensics, the rough times that I had this large excitation going was roughly between 
GPS: 1073411801 and 1073412182
UTC: Jan 10 2014 17:56:25 - Jan 10 2014 18:02:46
PST: Jan 10 2014 09:56:25 - Jan 10 2014 10:02:46 

Drive was 0.1 to 10 [Hz] "uniform" white noise, using three independent awggui sessions, driving channels
H1:HPI-ITMY_ISO_Y_EXC    100000 [cts]
H1:HPI-ITMY_ISO_RX_EXC   100000 [cts]
H1:HPI-ITMY_ISO_RZ_EXC   100000 [cts]

The QUAD, ISI, and HEPI survived admirably (as expected), and after the excitation was turned off, SUS and ISI damping loops were immediately functional again, and it quieted down to normal damped motion with ambient input motion from an unisolated chamber. All software watchdog values have been set back to their nominal values.