The lead chiller at the corner station was changed from chiller 1 to 2. This is due to a condensing pressure fault that occurred overnight on chiller 1. The sequence is now chiller 2 - lead, chiller 1 - lag, chiller 3 - standby. Troubleshooting of chiller 1 will be done next week. 

J. Kissel, J. Warner

During SPI install we removed the following side-wall balance mass from the W9 side wall (see first bullet of LHO:90558):
    Plate              Mass [lbs.]   Mass [kg]    QTY    Total Mass [kg]
    D071200 Type 04    7.9           3.583        3      10.750
    D071200 Type 01    1.1           0.499        1       0.499
    D071200 Type 00    0.6           0.272        1       0.272
    D071201            0.1           0.045        3       0.136

    Total Mass                                           11.657

First attachment is a diagram to convey which side wall I'm talking about.

This is inaccurate with the latest version of the ballast / balance mass inventory, D1000907-v7, which states that this side wall has only 1x Type 04 (3.583 [kg]) and a 1x Type 03 (2.041 [kg]), for a total of 5.625 [kg]; much less.

Remember, from LHO:90504 that the total SPI mass is 12.599 [kg]. 
This *excludes* the mass of the lower ISI Shroud baffle (D2400106-v4) and the three upper HAM Table Baffles (D2600007) with all their bracketry and bolts, currently only represented only in e-drawings posted to D2400103-v6.

After talking with Jim, he wants more mass in this -X / +Y corner of the table, because that's where all the new stuff is. So he wants this corner "over" or "heavy" (because the new stuff must be in a fixed position) so that he can adjust the *opposite* corner of ballast mass (which has more open table and side wall access and thus is adjustable).

As such, he says "put all the at 11.657 [kg] back on the corner. 

So we will!

Second attachment is a picture of the wall mass arrangement prior to us removing it taken on 2026-06-09.

I ran the OPLEV charge measurements this morning for the both of the ETMs.

For ETMX the charge is still trending towards zero on all DOF/quadrants, LR and UR have the highest charge around ~60-70 V but they're trending down.

For ETMY the charge seems stable at or just above +50 V on most DOF/quadrants. The error bars are pretty big for EY, but the measurements all had great coherences. In each individual measurement none of the errors look very large except for LR which is broken/not used.

TITLE: 06/18 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 4mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.14 μm/s 
QUICK SUMMARY: The LVEA is still in laser hazard, but the light pipe is currently closed. SPI, BBS, SQZ chamber work continues today.

While Patrick is upgrading the EX Beckhoff power monitor IOC I have added these channels to the temporary edc_green_ioc.py to "green up" the EDC by supplying the missing 82 channels. IOC was restarted at 07:03

(Jordan, Travis, Jake, Owen, Gerardo)

After taking some RGA scans of CP1, and pushing nitrogen gas through the cryotrap (we injected nitrogen gas at the top sensor line for about 10 minutes), then we started the cooldown, or did we?  First, we opened the "bypass" valve (fully open) to measure the number of turns to guesstimate a less than 10% open valve, per procedure E960127. Then we opened the bottom draw valve to release LN2 out of the dewar.  We opened both valves around 2:00 pm, bottom draw fully open and bypass valve only 10%, but by 7:40 pm local time we terminated the cooldown, we didn't want to risk for something to go array overnight. 

We did not see a sign that the cryotrap was getting nitrogen, nothing on the exhaust (the exhaust pressure remained the same), nothing on the cryotrap level (remained at zero), pressure internal to the cryotrap remain level, and the consumption remained level at the dewar for CP1.  We are going to look more into this Thursday.

Jennie W, Josh F, Jeff K

Today we centred the beam on both QPDA and QPDB (see Josh's alog # 90659). In the process we calibrated the picomotors we use to steer onto QPD A in HAM3 and QPDB in HAM2.

We calibrated the beam steering to M_C1 (QPDA) using the picomotor M_M1 on the ISIK breadboard in HAM3.

The beam moves across the mirror (~2 inches) which corresponds to 3000 steps on the picomotor.

For future reference to move in -y global coordinates direction on QPD you move the M_M1 pciomotor down. This moves it in positive yaw or left on the photodiode, as we did small steps of 100 across the surface in yaw letting the QPD readout settle in between each step.

In the other degree of freedom, the beam moves across the mirror 2 inches with 2000 counts right on the picomotor. This move is in +z in global coordinates, and therefore down in pitch on the QPD.

I took another short calibration series of steps to calibrate the QPD with the picomotor and moving up or right with the picomotor moves up in pitch on QPD A.

Then we moved to HAM3 and did the same calibration for pitch and yaw on M_B4 and QPDB.

The calibration in M_B4 is 1500 counts of picomotor drive for the 1 inch optic. When driving up on picomotor, you drive in -z direction on M_B4, which should be up in pitch on QPD

We got another calibration in the x direction, with 1700 counts of picomotor to go across the optic, when driving picomotor right you move in +x on M_B4. which should be down in yaw on QPD.

J. Freed, J. Kissel, J, Wright,

Continuing from 90645(Notes are stored here). Today we calibrated the picos on M_M1 and M_C1, got the beams centered on both QPDs, saw our first beat notes in the Meas IFO.

In order we did:

• Calibrated the picos on M_M1 both with physical distance and power read on the QPD1s quadrants
• Centered the the beam on QPD1
• Used the M_C1 picos to center the beam on M_M5
• Manually Adjusted M_M5 to send the beam towords the center QPD2. This was a difficult process as:
  • The "shelf" which is the back rest that the 45 degree adaptor uses when it attaches to the mirror mount is small and hard to get a feel for. This means that when we adjust the 45 degree adaptor manually to direct the laser light at the QPD, its hard to adjust to the correct angle for the light and make it flush with the shelf. The result we eventually got to work infack looks like this Periscope_Alignment.jpg. Where M_M5 is on the left and the 45 deg adaptor sits crooked in it. 
  • The QPD quadrents would saturate well before the beam was fully on a quadrent. This made estimating where the light was on a quadrent difficult 
  • There is no fine adjust except for 1 degree of freedom from the mirror mount knobs. And that degree of freedom is diagonal across the QPD plane. Both knobs move the beam across this diagonal. Our strategy that worked was to put the light fully in one quadrant and move the knobs in the diagonal direction towards the center. It did work after a few attempts.
• Used the M_C1 Picos to make the last fine adjustments. Of course the light is no longer center on M_M5 Beam_on_M_M5.jpg.
• Calibrated the picos on M_C1 both with physical distance and power read on the QPD2s quadrants
• Saw the first beat nots on the Meas IFO

TITLE: 06/17 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
SHIFT SUMMARY: SPI workmain beam in vac checks, and HAM7 work keeping the LVEA in laser hazard today. CP1 cool down began. Other various activities throughout the day.
LOG:                                                                                                                                                                                                                                                

Ibrahim, Betsy, Keita

The BBSS Oplevs aren't to be trusted (alog 90648). 

Today, we went into BSC2 to attempt to use ITMX and ITMY as a lever using the PSL beam. We put in 500mW flashes with the rotation stage locked out.

We found the beam nicely (multiple modes) on both ITMs, albeit a bit yawed. We moved PR3 from -233 to -583 in Yaw, which recovered the beam on the center of both ITMX and ITMY.

For context, we had already centered the BBSS to the structure on the test stand but found that we were not on the oplev once we went back into the cartridge.

We're now working on seeing if we can trust this BBSS alignment, or if we have to make mechanical or offset changes.

(Randy, Jordan, Jake, Owen, Travis, Gerardo)

Both doors were installed on HAM2, no issues to report.  The usual dance, take one door off, to then move the cleanroom to be able to remove the other door, thank you all for the help moving this cleanroom.  

There are some pecularities that we like to note about the doors, we noted some rust on both flanges of HAM2 -Y and +Y, and some embeded particulate on some of the O-rings, metal type all over, the particles were removed with a clean wipe, however there was a "green" fiber on the +Y door O-ring, outer O-ring, around 11 O'clock, this fiber runs with the seal and not across, so we did not poke at it.

Then we connected an aux cart to the annulus system, and started the pump down, we will add second aux cart to help with pump down.

Next, we like to inspect the viewports on this chamber, but this job is going to require laser safe and no table near the door.  We did note something on the central high quality viewport and we like to take a closer look at it.

On Tues Oli tracked down and made the final move step to get the BBSS (still now named the BS in controls) Oplev signal live.  I uncovered the Oplev and released any errant stops.  SInce the sum was 2k instead of it's nominal 20k, Oli tried driving the BBSS sliders around, no luck, so we went out and looked for the beam in the Oplev box with Jason.  The Oplev Beam is offset in Pitch by a beam diameter at at the diode and roughly centered in yaw.  We are chewing on this.  Since we did not restore the plane of the BBBS to the exact same spot as the BS was we should not have expected the beam to be on the Oplev even if it's pit/yaw is correct, due to translation of the beam.  That said, I would have expected more of a yeaw error, less pitch.  Today we are going to take a peek at the in-air PSL MC flashes to see if we can see anything heading to the output arm which gives us confidence in our IAS pointing alignment on the test stand (and can therefore ignore the oplev).

TITLE: 06/17 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 7mph Gusts, 5mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.12 μm/s 
QUICK SUMMARY: The LVEA is in the laser safe bifurcated state at the moment. SPI, SQZ, BBS, FARO work continues.

J. Freed,

WE HAVE DISCOVERED NEGATIVE POWER

The FBR_PWRIN_REF PD that monitors the Power coming from the REF beam of the interferometer has gains alot of noise during certain intervals. Sometimes the noise even goes negative power. The noise is corelated with the frequency difference between the ref beam and the meas beam we set. The lower the frequency difference the higher the noise

The ETMY BRS seems to be continuously ringing up. I've tried to make the changes to the thresholds which was the previous fix outlined in 87634 for the same BRS, and will check back in on it later to see if just increasing the thresholds helped at all.

Changed thresholds:

H1:ISI-GND_BRS_ETMY_LOWTHRESHOLD 800-->2000

H1:ISI-GND_BRS_ETMY_HIGHTHRESHOLD 2000-->4000 Changed

Additonally I changed the ETMX BRS drift control to 6.00V and the ETMY BRS to 2.00V to try and better center them

Ibrahim, Betsy, Anamaria

Upon first in-chamber BBS01 inspection, we found 3 large clumps of spots approximately 100mm from the edge. We're consulting GariLynn at CIT for steps on how to clean.

Acetone swab: We tried to go over the spots with a cotton swab with acetone, but the spots remained.

First contact: We then tried to first contact a small portion with one thin layer, but the spots remained.

While there's no evidence that the beamsplitter was contacted, dinked, touched or scratched in anyway, this might be a cause for the damage. There is texture to the spots upon brushing them with a swab and while it seems more likely that these are above the surface, we are not totally sure.

Hypotheses (and their problems)

1. Peek In-Vac cable scratch: maybe an in-vac cable fell on that area but they would have had to imprint multiple times with some force to show something like this. 

2. Falling foil: maybe a piece of foil fell onto the surface and scratched it that way? No foil was used or wrapped at height during BBS and again, the foil would have had to fall with some heft.

3. There-the-whole-time: Maybe the spots were there the whole time and are invisible to non-chamber conditions. Because this is on the AR side, there is no good scatter plot of the surface. Since we did not see this in normal light conditions, but immediately saw this in chamber (dark) conditions, this may have been there all along. The spots are quite large (as attachments show), so this makes that less likely.

4. Dry first contact: Maybe it's dry first contact? We went over some of the spot with acetone but it stayed. We also first contacted a thin layer on one part but it stayed. The nature of the spots do look like they're small first contact bubbles. We found the first contact sheet that we used on that side and indeed, there are some similar streaks in size but nothing conclusive. We're looking at matching the spot with the first contact to see if there is a streak in this region. Problem is - first contact wouldve come off quick with the acetone treatment. So this is also not likely it.

What to do next:

- Analyze with Dino-Lite: We're going to zoom in on the spots with our DinoLite mount to get a better look. This could tell us if they are truly scratches or stuck particulate.

- Match first contact sheet with spots: Seeing if these spots were visible during FC (done on May 6) - alog 90149. Nothing visible. 

- Anamaria suggested at any rate shining a gaussian beam at it to analyze the damage in a short experiment to characterize. 

A plexi security cover was installed over the SPI Laser Chassis. Cover will be locked under normal operating conditions.

Closes FAMIS 28639

Last checked in alog 89720

TCSX read 30.8 - nothing added

TCSY read 10.6 - nothing added\

No water in small cup under the slow leak

TCSX is reading HIGH PRESSURE FAULT. See attached picture.