On the NE pillar of the SRM, spotted the witness optic looking pinker than it should and maybe even seeing the pull tab.  Decided to ignore my growling stomach and call my bet. Sure enough, while the front surface FC was removed, the back side was still in place.  See the attached photo after I flipped the Optic in the holder on the bench.  I looked through the ham5 alogs and see no indication of anyone setting up the CC witness optic although I may have missed it or that was not logged.  And, someone may have the scheme of pulling the backside FC and plan to remove and flipped the optic at the last minute but I'm not so sure.  If correct, this means we had this batch of FC under vacuum for about 20 days.  I was going to replace everything with new but realized that was unnecessary.  The optic is ready to have its FC pulled to exposed the clean surface.

This morning Ken D. de-energized the additional 10 kW heater in the CP4 bake enclosure by simply switching the breaker off inside the panel. This supplemental heater did not seem to hinder the termperature profile - the original 20 kW heater ramped up from 20% output to 40% output (note:  before we added insulation, we could not ramp past 100C without this added heat due to leaks). Also this morning MCE fixed the ramp software by removing the limit programmed in during testing on Monday. Lost some heat in the process; soak set point is 110C (to match TC#4) - will ramp to that, soak for 1 hr and then start ramp down.

Here it so round two of ramping down at 1C/hr.

Lock/Unlock tilt is just a couple urads.  Ended up taking off 600 grams of mass.  ISI left locked.

Bubba, Dave:

Due to on-going work on the reverse osmosis system in the wood-shed, I have bypassed the cell phone alarms for the RO system through to 11am PDT Thursday.

Her are the TFs repeated this morning--The horizontal local TFs look good just as they did last night; all three verticals are ratty while yesterday afternoon first V2 look ratty and the others were fine then after rebalance V3 looked okay and the the other to looked ratty and then they all looked bad.  Not sure if it was conditions or something in and out of being too close.

Attached are the TFs from this morning.  Will inspect the in chamber conditions shortly.   FWIIW, JimW thinks these are fine.

Sheila, Georgia, Craig, Dan Brown

Tonight we attempted to find out where the astigmatism in HAM5 is coming from. We rolled SQZT6 back to HAM6 and reconnected the fibers to try and lock the OPO. However, the seed/clf and green beam are not going out the central viewport on the south HAM6 door. These beams are hitting right at the edge of the viewport and are strongly scattered. Sheila thinks the viewport emulators may not have been positioned correctly when these were aligned. So unfortunately a HAM6 door will need to come off again...

We continued to try and use the OPO beam flashing and using the Wincam-D and cards to find any obvious clipping. Initially everything looked ok, the beam was clearing the SRM baffles and looked well centered on everything. We then checked the full range of ZM2 yaw and found that at ~800 the beam began to strongly clip inside the OFI faraday. We attempted to take some astigmatism measurements between the OFI and SRM but the software wasn't working well with the flashing beam. The beam size measurements were varying my more than 2mm in diameter and the profiles were very noisy, so we gave up.

After the SR2 Baffle swap, the TFs on the ISI looked all good, except, V2.  GS13 was saturating and above the resonance the coherence really dropped out.  Suspecting the balanced changed enough to get the lockers close enough to start hitting, the CPS positions were checked and the balanced was in fact changed by 100 & 50 urads in RX & RY.  Does not really seem like a lot when you consider the ISI lockers have a clearance of 600um on the radius.  The three vertical local sensors shifted 2000, 1500 & 500cts,  hmmm not sure the calibration off hand.  But the weird thing is the ISI actually went down in the corner were the baffle was replaced with one with a larger hole (less material, you would think.)  Anyway, pulled 200 grams off the SE corner and put 100 of it back on the NW corner and 50 on the SW corner.  This shift put the ISI right back where it had been.

TF for V2 looked good but then the V1 and V3 TFs went south.  There is a lot of purge going on and checking the cover, sure enough it had popped off our cover holder but there was so much purge the cover was not touching anyway.  Latest look has V3 looking okay but V2 and V1 looking pretty ratty.  Like to reserve final judgment now after a closer scan in chamber and TFs with less purge.  Crew is back in HAM5 right now so will regroup in the am.

All four fibers have been welded in.  We will continue tomorrow with de-stressing and pitch corrections if needed.  Stay tuned.

Betsy, Slawek, Sebastien

AMD1 and AMD2 have been installed in the ITMX and ITMY test masses. The install went well, and the epoxy curing passed the dynamic test. 24h of curing is required before moving to the next AMDs. Tomorrow, we will continue the work and install AMD3 and AMD4 in both chambers.

PT-245 has been noisy of late (see attached).  Hopefully the electronics aren't finally succumbing to the hot ambient surroundings after all of these weeks?

Current work on site:

• EX: welding crew not back, likely to return shortly
• CS: SQZ crew making preparations for working this evening
• CS: SQZ crew is going to be working with the LVEA in Laser Hazard, and will transition back

Details Site Activities:

• 01-05-18 15:31 doors on HAM4 BSC1 BSC3 coming off this morning
• 01-05-18 15:32 Desert Green here for weeds
• 01-05-18 15:32 APS at MY
• 01-05-18 15:37 contractor for portable facilities on site
• 01-05-18 16:04 TJ and Jim to HAM4 to place the SR2 scraper baffle
• 01-05-18 16:06 Karen to EY
• 01-05-18 16:50 JeffK to HAM4 to help TJ
• 01-05-18 16:50 Jim locking ISIs
• 01-05-18 16:50 Fil and Daniel going to PLS to look at the racks
• 01-05-18 16:51 Fil moving PSL DBB electronics to make room for EOM electronics
• 01-05-18 16:55 person going to look for TCS optics on LVEA and Optics lab
• 01-05-18 16:58 Peter and Rick to PSL
• 01-05-18 17:03 EY cold cathodes tripped - Gerardo re-engaged
• 01-05-18 17:15 liquid nitrogen delivery to CP1
• 01-05-18 17:59 Hugh back from EX
• 01-05-18 17:59 Bubba to EY and MY
• 01-05-18 18:28 Keita Corey out of HAM5
• 01-05-18 18:36 Sheila to LVEA - ITMX
• 01-05-18 18:36 Betsy to LVEA to ITMX
• 01-05-18 18:36 Gerardo to HAM6 and HAM2 to swap viewports
• 01-05-18 18:57 Ed out of the LVEA for lunch
• 01-05-18 18:58 Tyler and Mark out of LVEA for lunch
• 01-05-18 19:08 TJ and Jeff are done in HAM4 and the soft cover is not touching the table so its ready for a measurement
• 01-05-18 19:16 Sheila out of the LVEA
• 01-05-18 19:19 liquid nitrogen truck has left
• 01-05-18 19:23 TJ and JeffK out of LVEA
• 01-05-18 19:23 Sebastian out of LVEA
• 01-05-18 19:24 Travis - Jason - Angus - Steven all back from EX
• 01-05-18 19:56 Fil to MY to talk to ASP
• 01-05-18 20:10 Mark and Tyler starting the IP1 and IP2 valve replacement
• 01-05-18 20:22 Weld crew heading back to EX
• 01-05-18 20:25 Peter and Rick to PSL
• 01-05-18 20:28 Keita to HAM5 for ZM2 beam dump
• 01-05-18 21:07 Chandra to MY
• 01-05-18 21:15 Fil and Georgia to EY for ESD
• 01-05-18 21:54 Keita-Sheila-Corey out of HAM5
• 01-05-18 22:06 Fil and Georgia back from EY for ESD
• 01-05-18 22:13 MY cold cathodes tripped - Chandra re-engaged
• 01-05-18 22:18 Gerardo continuing with viewports
• 01-05-18 22:53 Mark and Tyler out of LVEA
• 01-05-18 23:02 Fil to HAM6 to engage high power

(Corey, Niko)

This refers to FRS Ticket #9647.

We needed to make a modification to the HAM5 OFI Baffle (D0902845) by using a nibbler tool (desired modification is attached & labeled as "OFIREFLBAFFLE(MODS)".  This tool was to be used to "nibble"-cut into 18 Guage (0.048" thick) stainless steel of a baffle part.  I was working in HAM5 with Keita on another task so I recruited Niko to tackle this job.  I helped him get set up and I tried one cut (each cut made about 3-4mm wide x 1-2mm long cut....needless to say it would be a slow process), and it was do-able, but hard.  

Eventually Niko found it to get harder and harder as he went.  We are thinking the tool was degrading.  He made something on the order of 0.5 - 0.75" worth of total cutting progress (photo#1 attached).  I wanted to give it a try & yes, it was really tough & could not make any progress....but on a final attempt I tried to manhandle it and manage one cut.  However on the next cut, the cutting part failed/broke (photo #2 attached).  

So perhaps another option can be tried?  Keita said Gerardo used shears on a similar type of material...but would go through several shears to complete the job.  

Fil, Georgia

Conclusion:

We believe that the ETMY LR ESD quadrant is disconnected somewhere in-chamber.

After problems with ESD-optical lever charge measurements, I tried to confirm that we are actually driving the LR quadrant by driving the individual ESD quadrants with a 4.3 Hz sine wave (30000 counts amplitude, with 100000 counts on the bias) and looking for the response on the optical lever pitch and yaw. A response was seen while driving the other 3 quadrants, but not the LR quadrant (see attached screenshot).

Fil and I went down to EY to check all the electrical connections outside the chamber. Between the HV chassis and the chamber feedthrough there is a resistor box and a pigtail connector. Everything outside the chamber is working as it should.

- We checked the connections in the resistor box, some connectors were loose but everything was connected. (Note the resistors in the box are actually bypassed, as their function (to limit current to the ESD electrodes) is now done inside the chassis. The box remains as an elaborate SHV-SHV connector.

- We drove the LL quadrant, with this signal hooked up to the LL, UL and LR quadrants at the resistor box, and only saw a response in LL and UL, confirming that we are driving up to the pigtail.

- We reseated the pigtail connector, repeated the above test, and saw nothing while driving the LR quadrant.

- Finally, we replaced the pigtail with a spare, and again saw nothing while driving the LR quadrant.

On the first try Corey and I found that the height of the beam dump is too high. The bottom of the black glass is about the same height as the center of ZM2, which is about 8.125" (first attachment, the beam dump was placed right next to ZM2 so it's easy to see the height).

This turned out to be some mixup of which variety of d1400171 should be used. What we received are (yet to be captured in DCC but) two 4" posts, giving us 8" at the bottom of the V-dump holder, and 1/8" is added by the V-dump holder itself.

We talked to Stephen, Betsy and Calum, and we decided to go with Corey's suggestion to stack up 5 pieces of V-dump holder D1000972 as a 2.5" spacer (so we use total of 6 V-damp holder). Together with 4" post, the top of V-damp holder becomes 7" high, and the black glass sticks out by about 2". It's 1/8" lower than ideal but that's not a big deal (2nd attachment, again the beam dump is misplaced intentionally).

Corey and Sheila looked at ZM2 and the new beam dump from behind OFI to check that the eddy current damper bracket and the cage are occulted by the black glass while the entire 2" optic is visible. We also made sure that the beam dump won't block the main beam path between ZM2 and the septum window.

More pictures will be posted by Corey and/or Sheila.

Now that both sites are running the 70 W, I've done a quick comparison of the periscope motion and the microphones.

The plot shows PSL periscope accelerometer (top) and mic (bottom) at LLO and LHO. LHO periscope has significantly more motion 20 - 300 Hz and around 1 kHz, though from Jenne's recent look at WFS, looks like the peaks at 350 Hz (PZT mount) and ~600 Hz are what get in as jitter. I recently did a make-up air test at LLO; there's no effect on the per acc at LLO but maybe LHO should do a quick on/off check to see if it couples in at LHO.

The orange lines in the plots show from a day before red, before Peter and Jeff did some noise reduction work, so you can see the improvement orange to red, especially at high freq.

As for microphones, it looks like LHO's is sensor limited and heavily polluted by 60 Hz. PEM runs differential, so maybe something along the way is getting onto the shield? We see this in many of the mics there. Note that LLO has different microphones that have lower sensor noise, but not enough to account for the difference we see now between the sites (the microphone-type difference is included in the calibration).

I took LHO data during the middle of the night 4/24 and 4/25; I'm told the PSL was in science mode and both sites have HAM6 clean rooms running.