I installed the RTD temperature sensors on HAM 4 and 5. The existing HAM 4 RTD that was broken, Alog 11942, was replaced with a new RTD (D1102257-01 V1 SN# S1201366). HAM 5 had a functional RTD hooked up to the cable mount thanks to SUS, so the install went quickly enough. All of the sensor ends seemed to survive, but confirmation will have to wait until at least tomorrow when an impedance test can be done.

The particle counts were good going into chamber.
HAM 4 clean room: 0
HAM 4 chamber: 0

HAM 5 clean room: 0
HAM 5 chamber: 0

For the alignment work, all particle counts read zero in chamber in HAMs2, 3, and 5 (I was suprised at this being the case for 5)

Prior to balancing work beginning on HAM5, I locked the SRM and SR3 intermediate and bottom stage masses. I also tried to dress the cables as best that I could. Unfortunately the bolt holding the peek cable clamp feels galled so cant do up clamp well, so the cables are kind of just hooked onto the clamp. its not at all pretty, but hopefully will be fine. If had more time would of liked it to be better.

The SEI guys balanced HAM 5 and I then went and unlocked SRM and SR3. Hugh then unlocked the ISI and pulled the covers off the ISI  for testing to begin

For HAM4 balancing we decided to leave SR2 unlocked because we didnt think the ISI would have to have much adjustment, if any at all. So it was left unlocked during balancing, the ISI balance checked and the covers are now pulled back from the ISI for testing to begin

Thus SR2, SRM, and SR3 should all be unlocked....and hopefully free. I have not unlocked them into their "final state" as they need to be locked up again so that they can be first contacted

WHAM4

The HAM4 level balance was fine.  There is one horizontal locker that shifts 1750counts (our spec is 1600) but all others are less than a few 100.  Adjusting the locker to correct this will only change the locked position; the floating position will not change.  See the first attached plot for the shift from locked (whence alignment has been done) at the start of these trends, to the unlocked position at the end of the traces.  The Rz is the likely most significant at 15urads, Rx is 10urads with Ry at 3urads.

WHAM5

HAM5 required some mass shifting to balance the level.  HAM5 H1 is a bit worse than HAM4 with a shift of 2500counts.  See the second attached for the cartesian shifts.  Note Rz is 30urads.

M. Heintze, K. Izumi, J. Kissel

Ah what wonders a break can bring. Kiwamu did some trending during the break to discover I was reading the OSEM Witness Sensors incorrectly. We had way over-shot where we needed to be in pitch, which we believe to be the source of the yaw misalignment. After a few more turns of the pitch adjuster back towards where we needed to be, we regained a spot on the REFL WFSs, and were able to restore the IM4 mechanical alignment to the former, close-to-saturation digital alignment. See attached screenshots of REFL WFS screens, for a before and after. 

IM4 baffle has been restored, and tools removed from the table. As an act of caution, we'll keep the bypass path in until tomorrow lest we need it again for some terrible, terrible reason.

Final alignment values for all suspensions are also attached.

P.S. Next time we bypass the IMC, let's use optic mounts which are less sensitive to fairy kisses.

During the process of changing the IMC incident power in the past few days, I noticed that the rotational stage had not been calibrated. So I calibrated it by using old data (see alog 9306).

It now gives a coarse estimation of the angle-power relation. The calibration is, sadly to say, not so accurate any more at the point --  I saw an expected power of 600 mW even though the actual power is now at 1 W. Anyway, it should at least give us which direction to go when we need to rotate it.

=== some details ===

I used a least square fitting from gnuplot.

It looks like the data from the ETMY STS is not getting saved to the frames correctly. If you look at the attached plot, it shows an ASD of the ETMY STS. I've plotted  both the data (5 minutes of data starting at 17 July 00:00 UTC) from the SENSCOR channels (H1:ISI-ETMY_ST1_SENSCOR_GND_STS_X/Y/Z_FIR_IN1_DQ) and ISI-GND channels (H1:ISI-GND_STS_ETMY_X/Y/Z_DQ) - no filters have been applied, this is just the raw data. The SENSCOR channel looks fine so we do not think the sensor is broken, but the data isn't being saved correctly to the H1:ISI-GND_STS_ETMY_X/Y/Z_DQ channels. 

Summary - Data is not being saved correctly to the H1:ISI-GND_STS_ETMY_X/Y/Z_DQ channels.

800 - Kate Gushwa working on baffles @HAM4
845 - Manny to end stations to work on property management checklist
911 - Jeff B to LVEA test stands to work on BS Baffle
958 - NathanZ working with NPRO in OSB optics lab
1008 - Betsy on walkabout in LVEA
1009 - Gerardo tracking down viewports in LVEA
1020 - Jeff shaking HAM2, engaging and resetting countdown timer on IOP SWWD
1024 - Sheila says she is finished with green light at EX, transitioned to laser SAFE
1100 - Praxair delivery
1310 - SR crew breaking for lunch, will continue at HAM 2 in one hour
1310 - SR handing off output arm to GregG for RTD install
1316 - Arnaud on moth overwatch duty at HAM 2
1327 - Karen cleaning at EY
1328 - Hugh and Jim moving to HAM 4 to hurry along the RTD cable install and prep for balancing
1419 - Jeff/Andres/Dan moving to output arm work

1500 - Ops meeting

Enough of the alignment of the corner station optics had been completed enough to free up the BS and ITMy for chamber closeout preps.  So, I locked the ITMy test mass and CP mass in prep for First Contact cleaning.  Although the ISI is not yet locked, we all decided it was OK for me to lock the BS optic and it's PUM, so I did that too while I was in the BSCs.

Betsy, Filiberto, Rai, Calum, Rich

We successfully repaired two elements (1&5) that were shorted by one of the wires that suspends the compensation plate (CP) on ITMY.  Rai machined two tools (2mm wide razor chisel and a carbide cutting tool fashioned into another tiny chisel) for us to use to remove a small portion of the gold mask on the CP.  The tools worked very well and we were able to cut two ~2mm gaps in the gold traces thus eliminating the short circuit path.

Everything went well.  After cutting the gaps, we checked that each wire had proper continuity from the airside of the vacuum feedthrough all the way to each pattern on the CP ESD mask.  From the airside of the vacuum feedthrough, each of the 5 center conductors were HIPOT tested at 1kV to chamber ground for 1 second with the tester set to alarm at 300uA.  The same HIPOT test was performed between each isolated shield and chamber ground.  All connections are normal.

There was a report of at least one problem with the 5-way coaxial connector on the vacuum side of the vacuum feedthrough that will require rework at a later date.  Once the majority of the doors are back on the chambers, there will be decent positive pressure such that the feedthrough can be taken off and the cable pulled through into the air and reworked in situ.  We have done this successfully on other similar connections.  Filiberto and I went through the necessary steps to repair that connector when the time is right.

Betsy is taking a couple of photos of the repair to be posted soon.

(Corey, Filiberto)

Keita walked us through a ground loop he noticed on the TMS (the cable which goes to 4 [of 6] BOSEMs on the TMS).  I went in chamber and Filiberto went to the air-side of the flange for this cable. 

• Filiberto first confirmed that there was indeed a short.
• I then disconnected the Seismically Responsible (SR) Cable from the BOSEM cable to try and narrow down to the culprit and luckily we were able to see that it was the SR Cable (this cable goes from a Cable Bracket on the Optics table and then up around the ISI Stages upstairs and then off to the Chamber Flange.
• Didn't find anything on the Optics Table side.
• Started to unscrew the cable from flange, and before removing Filiberto noted that the short was gone. 
• Completely removed the cable to make sure the slot-head screws were screwed in tight and were not causing the short (they were fine)
• Reinstalled the cable by pushing it in completely (no short observed).  Then started screwing in the cable (no short observed, at first).  Then a short was observed when the the set screws were screwed more. 
• So, I simply engaged these screws enough to keep the connector on the flange and called it good.
• Ground Loop eliminated.

K. Izumi, J. Kissel, M. Heintze

Picking up from where we left of yesterday, we were able to confirm full DRMI flashing with very little effort. However, upon moving towards mechanically relieving IM4 alignment biases, opening the WEST side of HAM2 bumped the IMC bypass path once again. Rather than repeat all-day yesterday, we've elected to move on -- begin the close-out process for HAMs 4 and 5, and BSC3, resume IAS alignment of ITMY reaction chain and use the *misaligned* bypass beam as a reference (using REFL WFS A and B DC signals in HAM1). We're half-way through getting IM4 de-biased, feeling lost in the weeds, and finding out again how terrible it is to balance these SUS. But we'll get it back, or die trying.

Blow-by-blow
- Went into HAM5, took a look at SRM found no beam
- Found SR3 offsets and damping off. Turned on SR3 offset and found spot and fringing immediately, with some SRM flashes
- Move to aligning PRM to get PRMI flashes, tweak alignment by removing Pitch offset (from P=-505 to P = 0), and going from Y=-408 to Y=-395
- Also saw good spots on REFL WFS A nd B DC
- Also saw good beam on ISCT1.
HAPPY HAPPY!

- Vote to declare DRMI flash victory and move on to IM4 de-biasing
- Went to HAM2 to check on REFL path going into HAM1, before debiasing, because we plan to use REFL WFS path as reference
- Found REFL beam mis-centered/clipping ALIGO IO STRAGHT HA13 baffle (D1101416) in REFL path, just before going into HAM1.
- Found beam is mis-centered in yaw only on PR2 and behind SRM.
- Conclusion: In opening and closing WEST side of HAM2, cover bumped Bypass mirrors again. 
FECAL MATTER.
- Since we see only a yaw badness, we hoped it was just one mirror that was bumped. 
- Attempted to recover by moving temporary bypass mirror 2 (the one closer to MC3) by just glancing the yaw knob, using alignment on IM4 TRANS QPD as a reference but returning IM4 trans to correct yaw did not regain PRM reflected beam at PR2 or SRM, and moving PRM by gross amounts made no difference. 
- Conclusion: both mirrors got bumped.
VERY VERY SAD.

DECISION / MOTIVATION TO MOVE FORWARD
- Given that we have seen DRMI flashing with well-aligned bypass beam, we know that all core optic suspensions are in the right place (within range of OSEM control).
- PRM only needed moving 10 [urad] in yaw and 500 [urad] in pitch from pre-vent alignment to get DRMI flashing with well-aligned bypass.
- (before opening WEST side of HAM2) We saw PRM REFL beam on REFL WFS DC and on ISCT1 (with well-aligned bypass beam).
- REFL path is determined entirely by IM1 and IM2. We know we have pitched UP IM2 (to bring beam UP on PR2 and IM4 TRANS after IMC realignment of MC1 to get good IMC flashes after MC2 2 [mm] move), but we have NOT moved yaw at all. So *real* IMC path (not bypass) should still be aligned out to REFL path 
- With the now-bumped by-pass path, we see good light still on HAM1 REFL WFS, and on IM4 TRANS QPD. So, we still have a good reference for debiasing IM4, regardless of whether its still aligned to the DRMI.

- Captured WFS REFL DC alignment references with PRM aligned to this morning's flash
- Began following instructions in E1300646
- Trouble with IM4 baffle. 
	- need to remove baffle to get at lock nut that releases pitch adjuster.
	- difficulty removing baffle
	- LHO aLOG 5633 helped determine that we needed to loosen bottom EQ stop brackets on front face to remove baffle
	- Got it off eventually.
- Began debiasing IM4, but immediately found that pitch adjuster and lock nut are fighting each other, and even worse -- pitch debiasing is causing YAW motion, as determined by the OSEMs on IM4.
- Right now, decided to take a break because we've lost the beam on REFL WFS, we're off in yaw after adjusting only pitch. So right now our only metric is the OSEMs. Deep breaths.

In the oscillator laser, the relative humidity is way too high. This means that it is still too high from the leak on 7/1 or the sensor is wet. Somebody should check this out to see if the sensor is working properly.

In the attached graph, the first spike is on the day of the leak. The humidity went down to normal after the lid was taken off and the laser was dried off, but once the lid was replaced, the humidity spiked again.

Perhaps a WatchDog should be added so that when the relative humidity is greater than 60%, somebody is notified.

This morning, with modified razor blades ala Rai, Rich and I tested how we would remove a ~2mm strip of gold/chrome coating from a CP.  We used the old, now spare, CP09 and scratched off some gold at the tip of one of the solder fingers on the barrel of the mass.  The solder finger can be reused if needed further down the finger.

It was somewhat easy to scrape away the top gold coat, but the chrome underneath took some convincing as expected.  We tried a few different methods and tools but in the end, it still looks like scratching removed all of the conductive material.  To test that we were efficient at this, Rich then HIPOT tested at 1kV to make sure there would be no arcing when used in vacuum at the designed high voltage.

There was little particulate seen during this scratching - most particulate seemed to come off with periodic wet wiping.

The glass is scratched but the ~2mm thick scratch site does not appear to be very deep into the substrate (as viewed from the inner surface of the barrel).

The process took ~30 mins of slow start and stop scratching/shaving.

1. Ground loop check

Sheila and Arnaud checked the ground loop from outside and one of the TMSX BOSEM cables was bad. Nothing was done to fix it yet.

2. Putting Pico collars and kapton washers

Though I asserted to Corey that EX picos have collars, I was wrong. We put the collars on picomotors where possible, but there was two picomotors (M14 PIT and M3 YAW) where there was not enough space. See pictures.

Then we put kapton washers to all picomotors.

3. Relieving HEPI bias by rebalancing TMS

Some change in the behavior of SUS guardian seems to mean that the SUS bias is not restored by requesting "align". Because I and Sheila were both unaware of this, we tried to "confirm" our alignment with the HEPI bias on with slightly wrong ETMX bias (turned out later that it was about 30urad too much), and we couldn't quite align the TMS, but estimated from the distance of the forward-going and back-going beam on one of the HWP that we needed 30 urad more headroom to align it. (So things were consistent in the end.)

Anyway, we ended up having to relieve about 300 urad of TMS bias in PIT by moving PIT balance masses on the TMS.

4. Setting up ISCTEX for realigning IR QPDs

First we tried to use Sheila's setup as is, but it turned out that the beam would get too large inside the TransMon telescope.

We removed the lens in the IR TRANS monitor path on ISCTEX and that made things better. After much iterations, we reasonably aligned the IR beam such that the beam retro-reflects from the ETMX and the beam position on the secondary is on top of the green beam within 2mm or so. The  IR beam diameter coming out of the arm is about 6mm on the secondary, so 2mm is not very small but should be good enough to put the beam on QPDs.

5. Aligning the steering mirrors on TMS

Not surprisingly, the IR beam was very close to one of the green beams on the QPDs.

We found that the beam was totally off on the QPD sled and was not making it to the QPDs, but just moving M14 was good enough to bring the IR beam on both QPDA and QPDB. It's somewhat puzzling that people could not center the QPDs using M14 and M4, but again it's kind of hard to turn the right knob for the right degree of freedom because two mirrors are almost degenerate (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=11897).

Two disappointments were that the beam was bigger than the 3mm QPD (it looks like 4mm or maybe more), and that the IR power seemed to be too small to be useful for centering. The latter was surprising as the OzOptic laser is nominally 10mW, and given the 95% splitter in the path the power on each QPD should be about 10E-3*0.95*0.05*0.5 = 240uW, which doesn't sound terrible.

Anyway, our mission is to bring the IR beam centered on both QPDs within 1mm, and keep the IR path to the ISCTEX at about the center of the clear aperture formed by the chamber/viewport/table enclosure, to make sure that the pico mirrors can take care of the fine centering job without destroying the in-air IR path. We will center both of the QPDs using M14 (pico) and M15 (manual) as good as can be done by eyeballing tomorrow.