Assuming that the sensing matrix was correctly measured, from the filter shape it looked as if the UGF of WFSs were set to a mHz or two. This was because Alberto and Bram found that setting gain higher made things unstable.

Today I and Alberto reproduced the problem by simply setting the UGF higher: Apparently 0.54Hz PIT mode and 0.64 Hz YAW mode goes unstable because of high Q (attached, glue traces).

The PIT mode number looks like it's in good agreement with JeffK's SUS resonance plots, though for YAW 0.64 Hz in our data looks more like 0.6Hz in JeffK's.

Anyway, I made some notches (0.54Hz and 0.44 Hz for PIT, 0.63 Hz for YAW) and brought the gain up by a factor of 10 or so and they didn't oscillate (red). With this setting, the UGF for PIT should be about 20 mHz and for YAW it should be about 55mHz.

I haven't tried to push anything further.

BTW 2Hz on the plot is caused by Robert's injection.

I did some analysis on the ring heater cavity scan measurements from yesterday. I've plotted the region around [0.37, 0.63] FSRs. This region encompasses the PDH TEM00 sideband resonances [0.45 FSRs and 0.55 FSRs] and also the LG10 sideband resonances. I've taken this section of data for each cavity scan and removed the constant phase offset and also the linear variation in phase with FSR. I've then plotted the scans as a movie. Despite the noise and the relatively quick speed, you can clearly see the response of a higher order mode shifting in frequency [0.53 FSRs to 0.58 FSRs] as time progresses. This is consistent with the cavity g-factor changing as the ring heater is applied.

I've yet to quantify the frequency shift.

Lisa Austin, Rodney Haux, Scott (Apollo), Thomas Vo

We finished installing the aperture baffles for MCA2 and MCB2 this morning, and tightened up all the fasteners. This completes the entirety of our install for the output mode cleaner baffle.  

We were unable to screw in one button head cap screw on the MCA2 side due to alignment issues, pictures will be posted soon. Lisa Austin has documented this.

8:15 - 1:30pm Activities (Thomas relieving for end of shift)

Morning Activities:  Installing 3 doors, & heating tests for OAT

• Doors:
  • HAM2East:  815-945
  • HAM2West:  1000-1030 (wow, they were fast on this one!)
  • HAM3West:  1040-1115
• get three doors on by noon
• Maybe MC2 testing in afternoon
• MC Baffle:  frames installed, aperatures today
• HAM2 east door8:15
• Ski going to MY to investigate Instrument Air PT299 (it's been alarming the last two days)
• Patrick doing Dust Monitor work in LVEA
• 9:45 Filiberto picking up stuff at MY
• Hugo running transfer fn on HAM2 from 11-1
• Rodruck dropping off revised SOPs
• 11:50 Eric A doing work with items on pallet near HAM4 (~1hr)
• Dave adding PSL Environmental slow channels to frame
• 1pm Filiberto driving to EY at 1pm (not into VEA)

I have implemented the sensor correction at HEPI-BSC8. Sensor correction improves the isolation performances of the HEPI in the X, Y and Z directions. In attachment, spectra of the L4C installed in the HEPI boots are presented in different configurations:

• Isolation without sensor correction (blue)
• Isolation with sensor correction (red)

There is no plots in the uncontrolled configuration (Robert S wants to keep the cavity locked).

Doors were returned to HAM2 East, HAM2 West and HAM3 West, in that order. The task was completed by 11:20 AM. We reported to the Control Room at the start of each door. The main crane was returned to the parking position. The forklift is sitting on the West side of HAM3.

David and I measured the reflection off the PMC window as 1.7W. When we had the 35W laser running this beam was 100mW. The razor blade dump was warm to the touch.

For the 200W beam

Note that the peak in the ISS at ~120Hz is back indicating noise eater noise. This is odd as I had already reset the noise eater once today and it already went back into oscillation.

After talking to Jan I left the PMC heater off. The temperature is still coming to equilibrium.

[Giacomo, Deepak]

Owing to the invaluable help of Deepak and the support of a lot of people on- and off-site (thanks all for searching, investigating, procuring, shipping, etc.,..), HAUX build has gone smoothly and swiftly.

As of yesterday night, we have 5 complete suspensions, that you can admire in the attached pictures.

If you can't see the optics, it not because they are very clean: as they were not immediately available due to needed FirstContact work, we decided that the suspensions could be completed (including wiring) without the optics, and the optics added later (procedure in which we have been forced in the past to become experts). Because of that, we didn't even put in OSEMs and magnets. Altogether this would probably amount to another 1/2 to 1 hour of work per suspension.

The plan for today is probably to move the suspensions chamber-side, and then give priority to setting up electronics and cabling to exploit David Feldbaum experience (it's his last day here). After that's taken care of, we'll FC the optics, insert them and then proceed to the testing phase.

After Mike R. has transitioned to high-power operation I went ahead and aligned the FI with the CWPs, TGGs and Quartz. The straps for the magnet were not yet ready. Earlier I was not going to insert the TGGs into an unsecured magnet, however I decided that there is hardly any risk involved provided the platform is well secured in place.

To get a better CWP extinction ratio I had to get a better adjustible HWP rotator for the incoming beam. I found one in the PSL team's cabinet. With that:

Inserted Magnet with TGG+Quartz, polarization should rotate by 90 degree, p-pol should be minimized

Inserted the 2nd TGGs

In prep for a few days of dirty cabling/EE work under/around HAM3/2, we removed the HAM installation arm from HAM3.  The arm will next be used on HAM2 in another week or two.  Bubba/Hugh/Mitchell (and maybe one or two others?) put the HAM3 East door on.  Tomorrow the other HAM3 and possibly both HAM2 doors will also go on.  Other notes about MC2/MC3:

Both MC2 and PR2 in-vacuum cables have been plugged in, completing all routing.  Signals are reading out in the appropriate medms. 

Grounding was checked and mitigated on in-vacuum MC2 and MC3 cables. 

B&K Hammer measurements were run on MC2.

MC2 has been left fully suspended, PR2 is locked however.

Cleanroom vacuums were tested chamberside.  Particle counter alarmed a few times, as expected.

Attached are plots of dust counts > .5 microns in particles per cubic foot.

Lisa Austin, Scott (Apollo), Nichole Washington, Thomas Vo

We chased a few holes in the viewport frame assemblies to give room around the top portion of the threads in order to give a bit more tolerance when installing the assemblies into the chamber.  We finished all four (two per baffle) today, yay! 

We also finished assembling the aperture portions today and will be installing those tomorrow morning, which will close out this install. 

I built a new h2tcsitmy model which makes it the same as the recently updated h2tcsetmy model. The new model was started on h2tcsl0.

New DAQ channels were added for the sus aux systems (h2susauxb478 and h2susauxb6).

H2 DAQ was restarted take the new configurations.

The high power stage was turned on for faraday isolator work. The PMC and FSS are locked, the ISS is unlocked while work is ongoing in the room.

The ILS had some trouble locking, but after raising the reference level to -1.2V from -1.4V it was able to continuously hold lock. The phase of the PMC LO was moved from 67 to 276. The PMC mode matching lenses were moved to the following positions:

L2

Old position (35W) - 368mm, 10.78mm on vernier

New position (200W) - 310mm, 10.78mm on vernier

L3

Old position (35W) - 738mm, 4.10mm on vernier

New position (200W) - 728mm, 4.10 on vernier

Position was measured on the north edge (towards HAM1) of the lens block that mounted onto the rail.

After correcting for alignment we had 126W transmitted and 30W reflected. I did not try to correct for mode matching losses, I only moved the lenses into their original positions, before we moved them to mode match the 35W laser.

The PMC ref level was changed to 1.22V from 1.11V.

The high power stage will stay on overnight but will be turned off for the weekend. I will take some DBB plots tomorrow and give everything some more time to warm up.

(Jax, Elli)  At 13:59:25 local time (20:59:25 UTC) 630mA was requested from each segement of the ITM. Cavity scans are being recorded.  We'll turn the ITM ring heater off after 3 hours.

Running the ring heater is affecting the alignment of the cavity a lot, I'm having to increase the pitch offset on the ITM by about 25 counts every 2 minutes.  Wavefront sensors are on.

Electronics were troubleshooted.

SEI and SUS models were arranged to allow un-tripping HAM2-ISI Payload Watchdogs.

HAM2 model was re-compiled, installed and re-started after that. It is now running.

Matrices were filled

Input and output filters are loaded

The latest version (Version_2) of the unit-specific control scripts were copied from LASTI. They were made ready for use on HAM2. 

Spectra were taken on the ISI tilted. It is the worse configuration for GS13s and they all appear to be working fine (see attached plot).

Transfer function measurements are running overnight.