Beginning at 9:57a I began receiving alarms for a fire pump run and a few minutes later alarms for end and corner station chilled water pumps. Initially, FAC systems looked ok. After combing FMCS remotely following persistent alarms, end station pumps were alarmed out, and chillers were naturally in run inhibit. Because I could not reset remotely, I went to site to investigate. I observed that both VFD's on the EX CWP were not receiving power. The electrical service at EX in the AHU was not tripped, but the power light was not illuminated. I reset both and they stayed on without issue. Revisiting the VFD's confirmed they were back online. These issues were mirrored at EY, and the solution was the same.

Despite the same alarms at the corner, there were no observable issues with the corner chilled water system. Nor were the fire pumps running. Mid stations seem to be insulated from any issues or alarms. As of 12:45p FAC systems have returned to their nominal state.

R. McCarthy T. Guidry

Here is what we know is not running (in no particular order)

h1cdsrfm (end station adnaco boxes not responding)

ncalex

brs_ex, brs_ey

hws_ex, hws_ey

mains_ex

chiller_ex, chiller_cs

MSR timing master 9th port has no link, missing DTS fanout?

Following the power issue I came out to the site to check on the purge air, pump carts, RGAs, etc.

The Kobelco had an audible alarm, but was still running. Since the interface screen is dead I could not see what the exact alarm was. Drying towers were also not running, though the dewpoint monitor was still reading -75C. I isolated the purge air at the ball valve past the drying towers, then reset both the compressor and the drying towers. I let the system run isolated for ~30 minutes to make sure dewpoint was stable, then opened the line back to the LVEA.

The CP1 turbo was still running, but the solenoid valves on the foreline had closed. I closed the gate valve to the CP volume, and closed the manual o-ring valve on the turbo foreline. Then reset the cart to open the solenoid valves. Once foreline pressure was stable I then opened the foreline o-ring valve and finally opened the CP gate valve. The pressure internal to the cryopump quickly stabilized, and the pressure never got above 1E-7 Torr since the turbo was still spinning. See attached striptool plot (Thanks Gerardo).

Next up was the XBM turbostation which had tripped completely, the turbo/forepumps/and solenoid valves all tripped, so again I closed the gate valve to the XBM and restarted the turbo station. Once the turbo was back to full speed and pressures on either side of the gate valve looked ok, I opened the gate valve.

The three aux carts in use (GV5 annulus/corner rga/HAM6 rga) all had the pumps still running but the solenoid valve had tripped and closed. Pressures were all still ok (<1e-4 Torr) so I reopened the solenoid valves, waited for pressure to drop and stabilize, then set the carts back on the interlocks. RGA trees were isolated from aux carts and were pumped by small ion pump, so no potential backstreaming into RGA volumes.

Finally, I went to the VPW to check on the vacuum ovens. VBOB had no issues, the turbopumps, forepump, and heaters were all running normally. VBOD is vented and was not baking, though the RGA scroll pump had tripped off, turbo was still running. I closed the foreline valve, and restarted the scroll pump and then opened the foreline valve once the foreline pressure was ok. VBOC had a couple issues, the RGA scroll and turbo both tripped off, so I isolated the turbo and restarted the scroll pump first then spun up the turbo and opened back to the RGA tree. The oven heaters had also tripped off. The oven was baking at 150C and the temp had dropped to 130C by the time I arrived, so I reset the heaters and made sure temperature was ramping back up to 150C.

I also verified all of the chamber cleanrooms were still running ok (HAM1/2, HAM3, biergarten, BBSS test stand cleanroom, BSC2 fan bank, and HAM6 cleanroom).

Leaving site now.

We are investigating a power issue on site which took down all the front ends. We are starting the recovery process.

Initially we thought it was contained to the MSR, but the DTS, Mech Room and end stations are showing problems and reboots.

Erik is on his way to the site. Jordan is on site looking at the vacuum system.

WP13772 TWO Offload

Dave

This morning I started the copy of TW0's raw minute files which have accumulated since 09dec2025 from local SSD-RAID to archive spinning media (h1ldasgw0).

As was done for the last offload in December 2025, following the DC0/FW0 consolidation done 18nov2025 by Jonathan, I am again using h1daqtw0 itself to do the copy. Normally the offload is done by the framewriter, which is still the case on the 1-leg.

The old files were frozen at GPS 1464188058 (07:54:00 Sat 30 May 2026 PDT) prior to offload.

NDS0 was restarted at 08:03 with a temporary configuration to serve the past 6 months of data from its temporary location on TW0 while the copy proceeds.

The copy was started on TW0 at 08:54. It usually takes just over a day to complete.

TITLE: 05/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Today, HAM7 was vented and most bolts removed from doors while beam alignment continued in HAMs 2 and 3. The LVEA remains Laser HAZARD.
LOG:

J. Kissel, S. Koehlenbeck [remote], J. Wright, M. Simmonds 

Here, we post an aLOG to cover the whole week's slog, picking up where we we left off at that end of last week (LHO:90332). 

%%%%%%%%%%%%%
Executive Summary: the remaining outstanding issue to solve before instal for the SPI pathfinder is the irregular and intermittent drift in heterodyne efficiency in the SPI's MEAS IFO (item (3) from the list of issues after finishing re-assembly up to D2400107-v5 after ECR E2600106). Importantly, we've seen this issue in the MEAS IFO even with the previous version of the assembly back in Mar 2026.

After a week of hard work, we've ruled out just about everything that it could be *except* for flaws in the alignment system of the picomotor-actuated IXM100 mirror mounts which steer the MEAS beam to the MEAS IFO (see D2400107 for the annotated layout).
%%%%%%%%%%%%%

I spend the rest of the aLOG summarizing what we've ruled out and how. Remember -- thru out all of these studies, the REF IFO remains a rock-solid high efficiency, and the power monitor PDs so the input power on the MEAS and REF is quite stable.
And a reminder for those not-so-versed in heterodyne interferometers, the primary metric is the efficiency, defined as 
    eta = [peak-to-peak beat note amplitude] / (2 * beat note mean)
(nominally 100% if the mode overlap between two interfered beams is perfect).
"Drift" of this efficiency means that -- without 

Electronics Issues with the IFO MEAS PDs.
    - Suspected cause: "maybe the bias voltage is drifting?" "Something's going on with the electronic ground because we're only looking at the positive leg?"
    - RULED OUT: we swapped the REF B PD (which had been measuring a rock-solid, high efficiency from the REF IFO) into the MEAS B PD position, and had it measure the MEAS IFO beam. The drift was measured by the REF B PD as well. This convinces us that "it's on the incoming interfered beam.
    - PLUS: The bias voltage is supplied by a single circuit for all PDs in the ISIK transceiver system, so the bias-related issues would be common to REF or MEAS PDs.

Spurious drive on the the picomotors
    - Suspected cause: "maybe the ambient electric field in the room is driving the floating pins of the picomotors, pushing the mirrors around?"
    - RULED OUT: At the start of the week, the picomotor signal chain was hooked up as designed from motor might-mouse to quadrupus to mock feedthru and out a ~6 ft D25 in-air cable that had been used for testing. 
       (a) Just like we'd already done with the PDs, we hooked up ever single picomotor pin to rack power supply ground via a breakout board and clip leads at the end of the in-air cable. Still see drifts. 
       (b) We also tried simply disconnecting all picomotors at their might-mouse connector. Still see drifts.

Clipping along the MEAS path into the MEAS IFO
    - Suspected cause: "If there's some sort of clipping anywhere, you lose efficiency. If it's just barely clipping, the clipper might be moving / breathing with the environment."
    - RULED OUT: 
       (a)Checked centering on M_M1, M_B4, M_M2, M_B3, and the two MEAS IFO PDs, and can confirm they're either
           :: On Optics -- offset in yaw by design (but still several beam diameters away from the optic barrel in REFL or TRANS), or 
           :: Well-centered.
       (b) We'd started the week with the M_M4 and M_M5 mirror mounts and adapters in place (with no dump in either). The beam comfortably goes through the transmission ports of both adapters. But, over the course of the week, as we ruled out "everything else" out, we removed them so now they're off the board. We still see drift.
       (c) Confirmed that "tight-squeezes" between beam dumps still allow for at least ~1x beam diameter of clearance (on an IR card).

Optics' Quality, dust and schmutz
    - Suspected cause: "If there's a scratch or schmutz on the optic, then maybe as the beam alignment drifts, the optical quality of the reflected beam is intermittently spoiled."
    - RULED OUT: We replaced all optics in the MEAS path with just-as-good, same production/coating run, equally class-A cleaned, high quality mirrors. Still see drifts.

Beam quality and Optical Mode-shape
    - Suspected cause: "We haven't found anything, so let's look at the beam shape on a profiler. This should be the definitive answer."
    - RULED OUT: We removed IFO_MEAS_B, and projected the beam on to a WinCam beam profiler head, and read it's data out in the WinCam software. We looked at the beam both with a very slow heterodyne beat-note of 250 mHz, and the nominal 4096 Hz (adjusting the modulation frequency at our commercial RF source's digital interface).
        (a) With the MEAS IFO's alignment just tuned up, Compared mode shape and alignment during episodes of high and low efficiency, and we see nothing but excellent beam shape. (In the slow-beat-note-configuration) the only difference in profile results is the expected lower intensity when the efficiency was low.
        (b) We deliberately misaligned the REF and MEAS beams going into the MEAS IFO such that both beams still visible on the WinCam profile, but not interfering. No movement of beams, no mode shape change, no beam diameter change, nothing that would cause the efficiency drift.

Polarization
    - Suspected cause: "The last thing that it could be if it's not mode shape / quality / alignment is polarization drift..."
    - RULED OUT: With the same IFO_MEAS_B beam, we inserted a polarizing beam splitter and monitored the s-pol power in the reflected port.  S-pol (max) power (at peaks of beat note) is stable at ~10-15 [microWatt] during periods high and low efficiency. The designed p-pol light at IFO is at the 5-10 [milliWatt] level, so the extinction ratio is awesome. And we still see drifts. This also rules out, e.g. the nightmare scenario that the optics' mount PEEK set screw -- only on the MEAS path optics -- are cranked on the optic so hard that is causes birefringence.

    - PLUS: if there was a board-level polarization drift, the REF IFO would also be seeing this same drift.
 
Optical Power fluctuations (Sanity Check)
    - Suspected cause: "I know you don't see any drift in the REF IFO, but ... is the input power drifting?"
    - RULED OUT: 
        (a) The REF IFO beam samples the same beams as the MEAS IFO, and
        (b) Yes, we've had the power monitor PDs up on the o-cope for days, and we see no obvious or reproducible correlation.

RF Modulation Modulation power fluctuations (Sanity Check)
    - Suspected cause: "I know you don't see any drift in the REF IFO, but ... did you check the RF electronics?" 
    - RULED OUT: Yup, we've had the RF power monitor outputs of the laser prep chassis on the scope most of the time, and these are rock-solid and at the expected level.

Environment (Insanity Check)
    - Suspected Cause: "The only thing that intermittently drifts on the minutes time-scales you're seeing is things like air currents and thermal effects."
    - RULED OUT: We tried SO MANY different combinations of 
        (a) Clean room Lights ON/OFF
        (b) Room Lights ON/OFF
        (c) Clean room Fans ON/OFF
        (d) People in/out of clean room
        (e) People in different positions in the clean room
      and none of these showed obvious or reproducible correlation.

Conclusion -- It's gotta be the mechanical assembly of the picomotors in the IXM100 mounts.
The picomotor-actuated assembly process was documented in LHO:87497 following the assembly procedure E2500163.
 
[1] The most accurate mechanical drawing we have the IXM mount itself D1100362
[2] The vendor drawings of the picomotor E1000197
[3] The most accurate assembly of a pico-actuated IXM mounts D1500494 and D2100433
[4] The SPI's drawings for its IXM mounts D2400144 and D2400145

Looking at the assemblies:
    - We're worried that the pico-motor "stopper nut" is pushing the movable-mounting plate (item 1 in [1]), rather than the pico-motor's ball bearing. And somehow this poor kinematic connection is drifting and slipping with the environment or something.
    - The v-groove of the item 7 in [1] carbide plate faces toward the pitch actuator, and away from the yaw actuator. While this is the right thing to do to prevent over constraint -- because the same part is used in both actuator interfaces, the ball of the pitch actuator (be it manual- or pico- driven) will sit "deeper" in longitudinal than the yaw actuator. The yaw actuators' stopper nuts all easily clear the movable mounting plate, but the pitch actuators do not.
   - The manually driven IXM100s show there's no issue, given that the cupped 8-100 alignment screw clears the carbide plate holes in the moveable optic-mounting plate.

ACTIONS FOR NEXT WEEK
We're at our wits end, and considering just ax'ing the picomotor actuation on M_B4 and M_M2. In fact, we've already replaced the mount of M_M2 with a manually driven IXM100, and may do so for M_B4 if we find enough clean IXM100 mounts.

However, we've got some ideas to fix the problem and still have remote actuation:
    - Place a washer between the carbide plate and the front plate.
    - Remove the stopper nut.
    - Mill away parts of the front plate.
    - Get a thicker carbide plate.
    - Use only one pico-motor per holder.

Pictures and further commentary to come in due time.

Jordan, Randy

HAM7 and the relay tube were vented this morning following venting procedures E2300169 and M1300464. RV1 remained closed along with FCV1 and FCV2, FC-A section remains under vacuum. 

Purge air particle counts were zeros, and the measured dewpoint at the HAM7 point of entry was -41.7C. Chamber was vented in ~2 hours to 780 torr, then the chamber was blown down to atmosphere ~762 torr.

Annulus ion pump was isolated, powered off and the annulus volume was vented using dry nitrogen.

After the chamber and annulus were vented, I wiped down the door flanges with IPA wipes, then Randy and I removed all but four bolts from the -Y door, +X door, and the 2x 12"CF blanks on the +Y door to be used for ISI access.

Will close WP 13283 once doors are removed next week.

Madi, Camilla, TJ. Repeating work at EX: 90370

Ingoing ALS beam measured between L6 and L7. Beam shape is better than at EX but still has strange astigmatic artefact.

Return beam arguably worse than at EX. Demonstrating the same lobed behaviour, with an overall 'peanut' shape.

Nanoscan head was tilted 45deg at each measurement point, to get comprehensive view of the beam. Both sets of measurements attached.

Pellicle beamsplitter has been left on table at EY.

Madi, Camilla, TJ

Recently been taking measurements of the ALS beam at EX, initially to observe the beam as it returns from vacuum. This was done using a Pellicle beamsplitter placed in the path of the ALS beam between the PBS and the LPM, which picked off the return beam for observation. Images from this measurement are attached. It was observed that the return beam was elliptical in shape, with two intensity peaks.
The input beam was also re-measured (previous measurements recorded here). It was seen that even the input ALS beam is elliptical in shape, and as it gets closer to the PBS, a lobed intensity pattern begins to appear. Considering the return beam is also elliptical with two lobes in the intensity pattern, the effects of the in-vacuum system are unable to be separated from the input beam characteristics, and limits our ability to use the ALS beam as a diagnostic tool for the in-vacuum path.

Also concerned for the performance of the ALS, that that the ALS beam is elliptical before going into the vacuum system. Potential future task will be to find out where the beam gains this ellipticity and correct it.

TITLE: 05/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 17mph Gusts, 13mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.29 μm/s 
QUICK SUMMARY: High winds last night that trigered some dust alarms that have since cleared. More HAM2 alignment work today in Laser HAZARD.

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=90343

As per the plan in the above alog, we did the following for IMC and IM alignment.

• Rotated JM3 in negative PIT to center the beam on MC2 in YAW (i.e. the input beam comes close enough to the nominal MC2-MC1 line measured at the location we chose in HAM3). The beam height was good.
• Rotated MC2 to bring the beam back to the center on MC3 (i.e. MC2-MC3 line comes close enough to the nominal line measured at the location we chose in HAM2). The height was good.
• The beam was already flashing, MC2_TRANS_SUM was already good enough according to Elenna so we didn't bother to turn MC1 and MC3, even though we could have refined further.
• The beam spot on the IFI output baffle was very low, so we made a big change to IM2 in PIT. It looked good in YAW but we steered IM2 in YAW to make the beam slightly move to +X direction on the IFI output baffle because so we don't have to do too much YAW for IM3.
• We started moving IM3 but didn't finish.

As for clipping, before making IM changes, I installed an iris between IM3 and IM4 to see if the beam from PRM was retroreflecting.

• It was not that useful for the intended purpose as I couldn't tell if the IFO refl beam is actually retroreflecting. If anything it looked off in PIT.but it was very hard to tell any difference for YAW even when we made +-300urad changes in PRM in YAW.
• However, I noticed that -100urad on PRM YAW makes the IFO refl beam clipping better on IFI input baffle, and -300urad made it disappear.  +X side of the IFI input baffle. However, this also resulted in a clipping of the IFO refl beam on the IFO refl baffle in +Y edge. We'll see how this goes after we're done with the IM2 alignment we did today.
• Clipping of the IFO refl beam on the IFI input baffle doesn't look like a ghost beam. I used an IR sensitive camera and it was a bright beam.

Numbers and pictures will follow.

Will continue doing the IM3 and IM4 alignment tomorrow.

Just noticed DM 10 has been steadly going up for last 6 hours. So has the wind - could be an unpropped door? Just adding it here for log. Screenshot attached.

Ibrahim, Oli, Betsy

Today, we confirmed the BBSS Pointing with an oplev set-up using the M2 BOSEMs while the M1 BOSEMs were still on.

Then, we switched to cabling to prep for the QOSEM install. We installed the QOSEM flags and checked using the M2 BOSEMs and the OPLEV set-up that the pointing was unchanged. Thankfully, it remained the same.

Finally, we installed the QOSEMs onto the flags and began centering. We followed the procedure Oli and I wrote with Thomas' guidance on how to center QOSEMs - E2600219.

Before the end of the day, we were able to center:

• the QOSEM about SUM counts, confirming that the LED is totally on the lens. 
• The QOSEM in the X direction, confirming that the light is hitting the center of the lens along the axis of the flag (in-out).

We will return to it on Monday to finish centering. 

The QOSEMs were placed as followed (by SN):

F1 - S2600012 

F2 - S2600009 

F3 - S2600013

LF - S2600008

RT - S2600011

SD - S2600010

Attached is a sketch confirmation of our electronics for reference.

(Jordan V., Dave B., Gerardo M.)

The internal pressure to CP1 turned around overnight signaling that the process of emptying the trap is complete, now we'll continue to monitor and pump on the cryotrap volume.until good pressure is achieved.

A side note, I manually turned off the CC for PT114B last night at 9:44 pm (local time) as the pressure was rising a bit high, then turned it back on this morning at 5:33 am local time.

Attached is a snapshot of one day trend data of pressure behavior regarding the soft regeneration for CP1.

Process started here.