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Reports until 00:22, Wednesday 24 June 2026
H1 SUS
thomas.roocke@LIGO.ORG - posted 00:22, Wednesday 24 June 2026 (90729)
QOSEM Readout Sign Convention Checks

To verify that the QOSEM readout has the expected sign convention, as detailed in D2500284, I injected a longtidual offset into the BBSS M1, via the QOSEM coils, and monitored M1, M2, M3 OSEMs. The QOSEM readout sign should be consistent with the BOSEMs and AOSEMs.

Figure 1 plots M1 F1x, M2 LL, M3 UR and the test L injection into M1. Due to the location of these OSEMs they should all readout with the same sign. Here we see that the sign is consistent between the QOSEM, BOSEM and AOSEM for this given longitudal offset, verifying that the QOSEM sign convention is indeed as documented.

 

Images attached to this report
H1 SEI (SEI)
shoshana.apple@LIGO.ORG - posted 18:25, Tuesday 23 June 2026 - last comment - 18:34, Tuesday 23 June 2026(90715)
CRS Chamber Side Testing Continues

[Arnaud, Michael, Jim, Fil, Shoshana]

As mentioned in 90702, one of the readouts for the CRS HoQI amplifier wasn't working, after investigating we figured out that it was an issue with a broken op-amp in a transimpedance amplifier (HoQI B, channel E/COS). Fil switched out the op-amp so we now have a working chassis. Our best guess is that the op-amp failed after plugging it into the rack.

The HoQI on the left side of the CRS (SN01-005, currently HoQI2) had much lower fringe visibility than the other one (SN02-007) since yesterday. We figured out that the laser collimator was positioned in a way where the beam wasn't hitting the center of the photodiodes. The laser collimator was re-aligned and we were able to greatly increase the fringe visibility so the HoQIs now match.

HoQI 1 (SN02-007), SIN: 86.7%, COS: 79.4%, MCOS: 84.9%

HoQI 2 (SN01-005), SIN: 81.4%, COS: 82.7%, MCOS: 80.1%

CRS was balanced, currently has a estimated resonance frequency of 15.7mHz, but we will re-check it in the morning. We are leaving the laser on over night hoping to get some noise measurements, both due to the air currents in the clean room, and the fact that we didn't ground the damping capacitors, it looks unlikely that it will damp down overnight.

Arnaud got the ellipse fitting working, the python script is in /opt/rtcds/userapps/trunk/isi/h1/scripts/write_ellipse_values3.py

We added a gain 0.0847 um/cnt (1064 nm/4pi) to the HoQI Dist filter banks to calibrate the HoQIs into distance. We also changed the CRSRY_PHI_SUM matrix elements to 2.75 to put the RY channels into urad.

 

An unrelated mystery: HoQI1 and HoQI2 are switched, we aren't sure where in the chain they get flipped, but right now we are guessing it's at one of the cables to the chassis

 

Comments related to this report
michael.ross@LIGO.ORG - 18:34, Tuesday 23 June 2026 (90727)

We took a quick spectrum to check the HoQI performance. The CRS is very rung up so this noise floor is not indicative of the final performance. Yet the noise floor already looks good.

Images attached to this comment
H1 SUS
oli.patane@LIGO.ORG - posted 18:12, Tuesday 23 June 2026 - last comment - 00:43, Wednesday 24 June 2026(90725)
BS Sign Convention fixed throughout signal path

Previously (90441), Tom, Ibrahim, and I had found out that the QOSEM coil drivers were wired opposite as compared to other OSEMs. To compensate for this at the time (since we were attempting to use damping), we had swapped the signs of the damping gains. But we had only swapped those gains, meaning that other actuation coming through the TEST or OPTICALIGN filter banks was still pushing the coil drivers the opposite way from expected. Today we finally decided to fix it to reduce confusion wrt the direction the BS was moving when offsets were put in (offsets were moving the BS in the opposite direction than expected). 

To do this all I did was put the M1 DAMP filter gains back (before, after) to being negative and then swapped the signs of the gains in M1 COILOUTF (before, after). To put the beamsplitter back with the OPTICALIGN offsets that it had before, I then swapped the sign of each offset. 

I will update the SUS Sign Conventions document to mention that the QOSEMs require the opposite COILOUTF signs from nominal.

So now EVERY BBSS OPTICALIGN slider offset from before 2026/06/24 00:50 UTC requires the opposite sign to be recreated.

Images attached to this report
Comments related to this report
arnaud.pele@LIGO.ORG - 00:43, Wednesday 24 June 2026 (90728)

Following this sign change, we verified the following conventions for the M1 actuation : 

Positive offset on the coil ouptut filterbanks corresponds to positive qosem signal on M1(figure 1)
Positive offset on the cartesian basis (test filterbanks) corresponds to positive cartesian signal on M1 (figure 3)

Figure 2 and Figure 4  show the dc cross couplings for the local and cartesian basis drive, as as reference for the on-going xcoupling investigation.

The two scripts to make those plots were saved in the svn under /opt/rtcds/userapps/trunk/sus/h1/scripts

push_pull_bs.py
push_pull_bs_cartesian.py
 

Images attached to this comment
H1 CDS
erik.vonreis@LIGO.ORG - posted 17:27, Tuesday 23 June 2026 (90722)
new trace color system for ndscope

Ndscope has a new system for picking trace colors that tries to maintain a high contrast between the trace and the background.

You can test the new system by running "ndscope-test" instead of ndscope on any workstation, laptop, or login portal.  Give it a try and let me know what you think.

H1 SUS
oli.patane@LIGO.ORG - posted 17:24, Tuesday 23 June 2026 (90720)
BBSS Model M1 to M3 TFs and DC values

Arnaud, Oli

As part of our BBSS alignment and investigation, I used /ligo/svncommon/SusSVN/sus/trunk/BBSScomparetripleparams.m to look at the DC values of our current model when actuating at M1 and reading out at M3. 

I made a few edits to comparetripleparams.m in order to allow me to do this easily, and I've committed those changes as r13039.

The plots (P, Y) show that the DC value for M1 P to M3 P is 0.029 rad/Nm and M1 Y to M3 Y is 0.129 rad/Nm. These plots can be found in /ligo/svncommon/SusSVN/sus/trunk/BBSS/Common/Results/comparetripleparams/comparetripleparams/2026-06-23_M1toM3Model/triplemodelcomp_2026-06-23_M1toM3Model_M1toM3.pdf r13040.

We then converted into cts/N using (1e-6)*(1/DACdrive)*(1/coilDriver)*(1/forceCoeff).

For this we used DACDrive = 20/2^16 cts/V, forceCoefficient = 1.694 N/A, and coilDriverTransconductance = 0.011919 A/V. The reason why DACDrive = 20/2^16 cts/V and not 20/2^28 is because we already compensate for the difference between a 16-bit DAC and a 28-bit DAC in the COILOUTF filter bank so we don't need to put that into our calibration.

This gives us:

   Calibration factor [cts/N] = (1e-6)*(1/(20/2^16[cts/V]))*(1/0.011919 [A/V])*(1/1.694 [N/A])

     = 1.623e5 [cts/N]

Then multiplying this calibration factor by our earlier fractional values for P and Y gives us:

   Pitch slider calibration : 4.7e-3 cts[M1]/urad[M3]

   Yaw slider calibration: 20.9e-3 cts [M1]/urad[M3]

Images attached to this report
H1 SUS (ISC)
ryan.short@LIGO.ORG - posted 17:14, Tuesday 23 June 2026 - last comment - 17:46, Tuesday 23 June 2026(90719)
BS Pitch Pointing Offloaded

B. Weaver, C. Compton, R. Short

Carrying on from alog90708 posted at lunch, Betsy, Camilla, and I offloaded the BS pitch sliders mechanically at the suspension.  This was a tad tricky since we were looking at the beam(s) at HAM3 in front of PR2, so we had to work out blocking 1 ITM beam in order to not be confused by both beams crossing each other after the long PR chain of optics.  In the end, we worked out the process to bring the BS PIT slider from +1000 to 0 which meant pitching the BS optic HR "up" (PUM roll bar "in").  Unblocking the other ITM, we got both beams overlapping onto each other with a little more slider to see how much better we could get them and see flashes in the AS_AIR camera (PIT = -300, YAW +1560).

Once back in the control room, Keita scanned BS alignment to find the SQZ beam reflected by ITMX as well as ITMY in AS camera as well as ISCT1 camera, ending with BS PIT = -520, YAW = 1677. With this alignment, IMC flashes reflected by ITMX as well as ITMY were visible in both of the cameras. Though SQZ beam and IMC flashes are not coaligned,  the corner alignment is already pretty good as of now.

At this point we want to:

1) Recenter the OPLEV

2) Go in and physically calibrate which way the sliders go as seen on the oplev and at the HAM3 PR Beams since there is confusion around the sliders (direction, calibration, cross coupling)

3) Based on 2) Potentially make a request for HEPI YAW correction tomorrow when they resume HEPI "fine" alignment and actuator reattachment (TBD convo with SEI/IAS)

4) Get on with landing HEPI/actuator attachment, etc.

5) Final round of BS PIT SUS mechanical Offloading 

Comments related to this report
jason.oberling@LIGO.ORG - 17:21, Tuesday 23 June 2026 (90721)

The BBS OpLev has been recentered.  I had to yaw the beam onto the QPD, as it was not on it.  Once recentered, the SUM counts were around 2400, which is much lower than for the old BS, which was up around 20k.  I checked the Output Configuration Switch on the BBS OpLev chassis in the biergarten and it has not changed, the amount of gain is still 0 dB.  The other explanations are the coating on the BBS (OpLev beam is at 635 nm, which is not a design wavelength for the coating, so the %R at 635 nm for the BBS could be very different than the old BS) and a failing OpLev laser.  I'll check the power output from the laser to see how it's doing (likely tomorrow).

ryan.short@LIGO.ORG - 17:46, Tuesday 23 June 2026 (90723)

Keita's note: After Jason recentered BS oplev, we changed the BS sliders to see the sign of the sliders (we knew that they were flipped) and how bad the pit to yaw coupling was.

Sign of the H1:SUS-BS_M1_OPTICALIGN_P_OFFSET and H1:SUS-BS_M1_OPTICALIGN_P_OFFSET are systematically wrong.

Positive PIT (right column top) in the slider consistently makes negative PIT on oplev, M2 OSEM and M1 OSEM, i.e. positive PIT tilts the BS up when positive offset is added to the pit slider.

Same story for YAW, negative PIT (left column top) in the slider consistently makes positive YAW for all sensors available, i.e. positive YAW rotates the BS clockwise when viewed from the top.

Arnaud and the gang will fix the sign issue.

PIT to YAW coupling is about 2 YAW per 1 PIT (i.e. PIT actuation make BS move more in YAW). YAW to PIT is not bad.

Positive PIT of 50 counts (uncalibrated) made negative 10urad in PIT and negative 20urad in YAW according to oplev. This agrees with our experience of observing how the beam spot moved in chamber as well as on the AS and ICST1 cameras when trying to move BS in PIT using the slider.

Interestingly, P2Y coupling seems to be OK for M1 (1:0.17 if we trust the QOSEMs), bad (about 1:0.7) for M2 and absolutely terrible (1:2) for M3 oplev.

Negative YAW of 20 counts made positive YAW of about 30urad and almost unmeasurable amount of PIT according to oplev.

Images attached to this comment
H1 General
ryan.crouch@LIGO.ORG - posted 16:33, Tuesday 23 June 2026 (90710)
OPS Tuesday Day shift summary

TITLE: 06/23 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: SPI in-chamber installation was finished yesterday, CRS work, and alignment work continued ending with Jason recentering the BBS OPLEV as of 23:30 UTC.
LOG:                     

Start Time System Name Location Lazer_Haz Task Time End
20:18 SAF LVEA IS LASER HAZARD LVEA YES LVEA IS LASER HAZARD 12:18
14:30 FAC Kim LVEA Y Tech clean 15:16
15:44 FAC Kim LVEA Y Tech clean 17:03
16:20 FAC Randy LVEA Y Moving scissor lift out of E bay 16:33
16:22 SAF Betsy LVEA Y Opening light pipe 16:24
16:44 FAC Chris Ends N End Station FAMIS checks 18:39
16:44 PEM Robert EndY N Grounding study 17:43
17:01 SEI Jim LVEA Y HAM3 CPS work 19:31
17:13 ISC Betsy LVEA Y HAM3 pictures 17:30
17:15 CDS Dave REMOTE N DAQ restart 17:30
17:47 SEI Mitch LVEA Y Join Jim 19:20
18:14 FAC Tyler+1 LVEA Y Walkthrough with vendor 18:31
18:15 ISC Camilla, Betsy LVEA Y Alignment checks 18:48
18:22 PEM Carlos, Shrey, Matilda Site, Xarm N Installing seismometers, overpass 23:03
18:57 CRS Michael, Shoshana, Corey LVEA Y CRS work by HAM3 20:05
19:22 ISC Betsy LVEA Y HAM3 checks 19:25
19:37 VAC Gerardo LVEA Y Viewport (1) removal by HAM5 23:05
19:40 PEM Robert+3 EndX N PEM checks, grounding study 21:40
20:06 VAC Jordan LVEA Y Join Gerardo @ HAM5 20:30
20:11 CDS Dave Roof N Looking at fire 20:21
20:12 ISC Betsy, RyanS LVEA Y HAM3 work, alignment, Betsy out 22:15 22:47
20:38 SEI Jim LVEA Y CPS work, SEI cabling around HAM3 00:11
20:59 ISC Camilla HAM3 Y Join team alignment 22:43
21:01 SEI Mitch LVEA Y CRS work, HAM3 21:17
21:04 VAC Jordan, Jake, Owen LVEA Y Remove RGA from CP1 23:15
21:35 CRS Michael, Shoshana LVEA Y CRS work Ongoing
22:44 SUS/IAS Jason LVEA Y Recenter BBS OPLEV and auto OFF/ON the FARO Ongoing
22:55 SPI SPI LASER IS ON LVEA Y SPI LASER is ON Ongoing
22:45 SPI Jeff LVEA Y Turn on SPI laser in @ 22:45 22:56
22:59 SEI Mitch LVEA Y Talk to  Jim 23:08
H1 SPI
jeffrey.kissel@LIGO.ORG - posted 16:11, Tuesday 23 June 2026 (90718)
SPI Pathfinder Analog LO Phase Rotators Set to 0.0 [deg] and 0.0 [deg]
J. Kissel, for J. Freed

At the last minute on 2026-06-18, Josh figured out that we had errantly been sending the SPI's double mixer two copies of a COS wave of 4096 Hz rather than a SIN and COS (LHO:90680). This was because someone had errantly put a 90 [deg] rotation in the SIN analog output path. He fixed it before he left, but didn't save it in the SDF system and it got lost during Monday's bootfest of h1seih23 (LHO:90689). I'm not sure if Josh (or anyone) tuned it to any specific value, but I've changed the SIN analog rotation phase to 0.0 and accepted it in SDF so we don't lose it.

Josh may add some more details in the comments below, in the comments to his LHO:90680.
H1 SPI (OpsInfo, SPI)
jeffrey.kissel@LIGO.ORG - posted 16:07, Tuesday 23 June 2026 (90717)
SPI Pathfinder Laser ON
J. Kissel

I'm looking to get some overnight data of the SPI pathfinder so start looking at science signals and debugging. Jennie has been turning OFF the laser via the external-to-PSL Uniblitz shutter controller (see LHO:90491) over this past long weekend, and each night this week because she was worried about the stray beam from the FBR_PWRIN PD, but again -- this is 0.2 [mW] and not an issue for humans or equipment as long as the LVEA is laser hazard. She didn't know the power was so low, and followed her good instincts.

But yeah, I want to get some over night data, so I've turned ON (unshuttered) the SPI laser input via the Uniblitz shutter controller box by the PSL.
I'd like to leave it ON as long as the LVEA is laser hazard.

If we need to go back to laser safe and I'm not around, one can easily shutter the laser by turning OFF the controller box: power it off with the rocker switch on the back, or unplugging the box from the wall, or both. With no power, the shutter defaults to CLOSED, which blocks the SPI pick-off path (only) from inside the PSL, thus making the entire SPI laser system laser safe anywhere outside the PSL.
H1 SUS (SUS)
ibrahim.abouelfettouh@LIGO.ORG - posted 15:08, Tuesday 23 June 2026 (90709)
BBSS Makeshift Test Stand Optical Lever Gross Pointing and Range Check

Ibrahim, Oli, Thomas, Betsy

Before we flew the BBS in, we did a sanity-check experiment to compare slider values with a laser-pointer optical lever. This experiment follows Jeff's G1200698 math for an optical lever (picture also attached).

Setup:

A laser pointer was pointed at the BBS HR side such that the HR and AR reflections could be seen on a paper near the laser pointer. The initial position was recorded on a paper, and then slider values were driven to their maximum range in P and Y. The distance between the laser source and the HR surface was recorded. The experiment was done with BOSEMs and then with QOSEMs.

Method:

When the laser pointer is incident on the BBS, there are two reflected beams (AR and HR). The average distance of these was taken along with the average distance from the BBS. This was done by calculating the distance to the BBS and adding the half-thickness of 30mm. This gives us "one beam" and "one distance' to go off for P and Y. See the attachment below for an image of the paper used during the experiment. This was done once for BOSEMs and then again with QOSEMs.

A few notes:

Results and Analysis

Pitch is in purple and Yaw is in Orange. The equation used was obtained from "G1200698, the Oplev Infamous Factor of Two", which is essentially the same outline as our experiment, a diagram of this is attached.

This equation is: DØ= DS/2L Where,

Ø is the angle in radians (adjusted to urad below), S is the displacement in the beam spot, L is the distance from the laser source to the optic.

For these data, the total range of the Opticalign sliders was considered (from lowest negative to highest positive). Thus, a half the range would apply if the sliders were zeroed.

  BOSEM QOSEM
Distance from HR surface (in) 130 118
Distance from HR surface (mm) 3302 2997.2
Average distance from optic 3332 3027.2
Pitch Displacement Total - +-1500 cts 5.5 5.75
Yaw Displacement Total +-4000 cts 46.75 40.75
Pitch Angle Swept (urad) 825.33 949.72
Yaw Angle Swept (urad) 7015.31 6730.64
Total Pitch Count Sweep (+-1500) 3000 3000
Total Yaw Count Sweep (+-4000) 8000 8000
Pitch urad/Ct 0.28 0.32
Yaw urad/Ct 0.88 0.84
Pitch Ct/urad 3.63 3.16
Yaw Ct/urad 1.14 1.19

Conclusion:

Next Steps:

Next, we're going to compare these results with the M3 AOSEM readouts once these are reliable. We will also compare these results with the model (which is used to corroborate slider calibration). Ultimately, this will help with the calibration of our slider values (both within the actuator slider actuation vs. sensing and from counts to real units).

Once we get a working OpLev (it's not on the BBS right now), we'll be able to get a more fine measurement of this kind.

Again, this is just a gross alignment check for information about our pointing and the capacity of our actuation.

Images attached to this report
Non-image files attached to this report
H1 SPI (SEI, SPI, SYS)
jeffrey.kissel@LIGO.ORG - posted 14:21, Tuesday 23 June 2026 (90716)
2026-06-22 SPI Pathfinder -- Installation Complete!
J. Kissel, J. Wright, T. Shaffer, J. Warner, J. Freed
(belated aLOG covering 2026-06-22 activity)

After enjoying a lovely long, Juneteeth Holiday weekend, TJ and I wrapped up the few loose ends that were left after the 2026-06-18 super push to get everything installed (see last update; LHO:90676). 
   - As a fall out of LHO:90667, Jim, Arnaud and I discussed the pros and cons of using the current, D1000907-v7, balance mass "Payload & Suspended Mass Assembly" arrangement in regards to the W9 corner. We concluded that leaving the D1000907-v4 configuration for this corner in place -- i.e. having 11.6 [kg] of mass in small, modular, optional components -- was better that having one "giant" 10 [kg] mass in "the same" location (on the table top, but in the same W9 corner). As such, we left the plates as re-installed on LHO:90713, with the acknowledgement that the final configuration to create a balanced ISI may be different even further than D1000907-v7.

   - Using a beam profiler, we measured the Beam Profile of the beam returning from M_C1 on the HAM23 ISIJ Reflector. This is to, at least roughly, confirm the radii of curvature of the M_C1 mirror. We expected a 2 [mm] diameter beam, and we got a 2 [mm] beam diameter. A more thorough aLOG to come.

   - We did NOT address the stray beam that Jennie mentions in her summary -- yet. I'll also write a separate aLOG on this, but in short -- it's a ~0.2 [mW] beam that's what ~18% reflection there is off of a silicon diode, and it hits the -X/-Z rim of the chamber of the +Y door, and the (splotchy) spot size is ~4-5 [mm] in diameter. The SPI team has been aware of this beam since testing in the optics lab (see mention of it, e.g. in LHO:90455), but hoped that it would land on some part of the SPI Shroud assembly, but it *just* misses it. 


With this last item, we consider the Installation and Integrated Test Plan COMPLETE (T2500024) ... to as good as possible with the HAM3 ISI still locked.

And that ... qualifier is a "just in case" qualifier, as it's a "we'll see what happens" when the ISI gets unlocked, and we've got an excellent amount of remote adjustability to be able to recover the MEAS IFO's alignment if HAM3 moves a lot between 
    - "locked," 
    - "re-balanced and damped" and 
    - "isolated with feedback and DC positioning engaged."
Essentially, we've launched the SPI pathfinder into space, and now its up to out built-in remote controlled actuators and sensors to take us home to achieve our scientific goals (see T2600019).

Super congrats to all, and similarly large thank you. We did a thing!
Images attached to this report
H1 CDS
david.barker@LIGO.ORG - posted 13:40, Tuesday 23 June 2026 - last comment - 13:44, Tuesday 23 June 2026(90711)
DAQ restart for new PWRCS Beckhoff Chiller channels

WP13303 Reimage PWRCS Beckhoff, update Corner HEPI Pump controller INI

Patrick, Erik, Jonathan, Dave:

Patrick created a new H0EPICS_PWRCS INI file. All of the EPICS channel names have changed since the first version of this system, and 40 of the new channels have old-channel equivalents. To preserve recent minute trends, the data acquired so far were transferred to the new names as part of the upgrade.

The sequence followed was:

 - Remove the old names from the edc_green_ioc IOC. 43 disconnects at this point (40 from H0EPICS_PWRCS and 3 from H1EPICS_HEPIPUMPL0)

 - Create the copy scripts to be ran on TW0,TW1 to copy the old files to the new, so that the new channels will "continue from where we left off"

 - Create the new H1EDC.ini and verify its changes.

 - Stop daqd on TW0 and TW1

 - Run the copy scripts on TW0 and TW1

 - Restart the 0-leg, followed quickly by restart of the EDC.

 - Wait till 0-leg was fully operational, including TW0

 - Restart the 1-leg

All went well except for the usual GDS1 needed a second restart, FW1 restarted itself after 5 minutes.

Comments related to this report
david.barker@LIGO.ORG - 13:44, Tuesday 23 June 2026 (90712)

Here is a random new channel which has non-zero data trended back one month to view its data back when it had its original name.

Images attached to this comment
H1 AOS
camilla.compton@LIGO.ORG - posted 12:50, Tuesday 23 June 2026 - last comment - 17:57, Tuesday 23 June 2026(90708)
BS Alignment with SQZ Beam, got MICH fringes with SQZ and IFO beam

Continued from 90691. Betsy, Keita, Sheila, Oli, Eric, Camilla, Ryan S, Jenne

First thing, we went back to alignment we had ITMX SQZ  the "flashes" and "fly-bys" yesterday, put the same size oscillation on the BS, but saw no flashes of fly bys. Betsy took a video of what the two SQZ beams looked like at PR2 at this alignment, they were crossing each other. 

We then rethought the alignments from yesterday, we are leaving:

Once we did this, we had SRY fringes, Betsy and I then adjusted the BS to bring the beams back on top of each other at PR2. This was a change in the BS sliders from (P 1000, Y 1290) to (P 1350, Y 1180).

Keita then wobbled ITMX and found the SQZ beam off ITMX! Aligned ITMX to get MICH flashes at AS_AIR, AS_A/B and ISCT1 REFL. He had to move ITMX from (P -96, Y 104) to (P -280, Y 94). 

He then got the PSL IX and IY reflection in the AS_AIR camera in this alignment. Sliders at this alignment attached

However as we are not sure we trust the ITMY alignment form top mass osems (from 90551), we want this Pitch change to be in ITMY, so ITMX is at it's known DRMI pointing. We could try to walk these, maybe along with SRC which might reduce some of our Pitch differences in SR2 and SRM. This change is so small that we will go ahead with mechanically offloading BS Pitch. The BS YAW will not mechanically changed. 

The OMs are also not currently in their O4 sliders/osems position, attached. We could verify the SQZ beam pointing by putting these back if we thought that was needed.

Images attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 17:57, Tuesday 23 June 2026 (90724)

Since IMTX was moved today, I had to move PR3 to compensate in order to regain IMC flashes in the AS camera as well as ISCT1 camera.

H1:SUS-PR3_M1_OPTICALIGN_P_OFFSET is now -247.0 (used to be -140).

H1:SUS-PR3_M1_OPTICALIGN_Y_OFFSET is now -245.0 (used to be -583).

H1 SPI (SEI)
jennifer.wright@LIGO.ORG - posted 18:39, Thursday 18 June 2026 - last comment - 13:47, Tuesday 23 June 2026(90676)
SPI install update - day 6

Jennie W, Jeff K, Josh F, TJ S,

Summary: SPI interferometers aligned, shroud installed successfully. One stray beam and possible clipping on shroud to investigate/deal with but otherwise all problems were solved. Obligatory success photo taken by Josh.

Today we:

 

Images attached to this report
Comments related to this report
thomas.shaffer@LIGO.ORG - 10:08, Monday 22 June 2026 (90690)

More details regarding the baffle installation:

When placing the below table baffle brackets, there was a ballast mass baffle (D1700262) that was blocking the angle bracket for the furthest -Y bracket. The bracket could not slide under the ballast mass baffle (bmb), so we decided to move the bmb in the +Y direction a few inches and I had to loosen the baffle panel within the feet to slide it up a few mm and then reclamp. This allowed the bracket to slide under the baffle just to the side of the feet, but the move partially exposed a corner of the shiny ballast mass stack.

The lower baffle shroud that covers the breadboard needed the fiber spools to be moved. We moved them over one set of bolt holes, but they are quite close to chamber edge, I'd guess around 1/2". Jeff then centered the two aperatures to the SPI beam, and we called it good. We still need to B&K the whole area.

Images attached to this comment
jennifer.wright@LIGO.ORG - 17:46, Monday 22 June 2026 (90699)

Just did an 8 hour trend of the fiber power monitor channels for REF and MEAS channels (left two plots) and the optical lever QPDs (right two plots) to check whether we expect variations on the order of ~2V on the QPDslike we saw on Thursday before and after baffle installation.

From this trend the power appears to drift more than this for two hours after unshuttering the laser (around 15:56 UTC), but once it reaches a steady state both QPDs were only drifting by 1V and the fiber power input monitor PDs by 1V or less.

Conclusion: I think we would have seen a dramatic power drop on Thursday when we installed the shroud, that I would expeact to have been much larger than the trends I saw today.

Images attached to this comment
jeffrey.kissel@LIGO.ORG - 13:47, Tuesday 23 June 2026 (90713)
Note mentioned in the summary of activities in the main entry -- per LHO:90667, we re-installed all the ballast or balance mass discussed during this 2026-06-18 day's session. See attached "after" picture.
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H1 SEI (SEI, SPI, SYS)
jeffrey.kissel@LIGO.ORG - posted 13:19, Thursday 18 June 2026 - last comment - 13:48, Tuesday 23 June 2026(90667)
ISI HAM3 Wide Wall Balance Masses vs. SPI
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.

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jeffrey.kissel@LIGO.ORG - 13:48, Tuesday 23 June 2026 (90714)SEI, SPI
Masses were re-installed as of 2026-06-18! See LHO:90713.
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