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 

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:                     

• A wildfire sparked up to our southwest by Benton City around 19:00 UTC, the smoke could easily be seen to the left of Rattlesnake. Multiple helicopters, and a plane were out fighting it. As of the end of shift it looks like they've mostly put it out based on the smoke or the lack of.

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.

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.

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:

• The setup was replicated and the distance was remeasured on a different day and this is why the distances are different.
• The QOSEM as-it-is is inversed in its actuator sign convention and you can see this in the attached diagram. One of our action items is to rectify this. So right now, +P = Pitching up instead of down with respect to the HR. In general, we will abide by T1200015, the SUS/Actuator Sign Convention.

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.

Conclusion:

• For a QOSEM Drive:
  • Pitch at M3 read +-475urad (1/2 the total sweep of 949.72 shown above), which is equivalent to 3.16 Opticalign Cts per urad.
  • Yaw at M3 read +-3365urad (1/2 the total sweep of 6730.64 shown above), which is equivalent to 1.19 Opticalign Cts per urad.
• BOSEM and QOSEM ranges are comprable
• No cross coupling was observed. Remember that this was done on the test stand a few weeks ago, before we found P:Y and Y:P coupling in chamber.

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.

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!

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.

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:

• ITMX and ITMY at March DRMI top mass OSEM sensors
• ZM4 and ZM5 to get SQZ beam on SQZT7 irises
• ZM6 to O4 sliders.
• SR3 at the Oplev/slider positions of March DRMI/O4 (all similar)
• SR2 Yaw slider back to O4, Pitch to get SQZ ITMY beam on AS_AIR (+440urad PIT sliders different from O4).
• SRM aligned to improve SRY fringes (+200urad PIT sliders, +400urad YAW sliders different from O4).

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.

Workstations were updated and rebooted.  This was an os packages update.  Conda packages were not updated.

TITLE: 06/23 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: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.08 μm/s 
QUICK SUMMARY:

• Continuation of CRS, and aligment today
• DetChar FF in the MPR, try to use the kitchen door

Pictures of as-built balance mass of ITMs taken today to compare with drawings in anticipation of rebalancing both ITMs with the added baffle weight

ITMY:

table: pic1, pic2, pic3
corner 1 side wall: pic4
corner 2 side wall:  pic5
corner 3 side wall: pic6 and pic7

ITMX: 

table: pic8, pic9, pic10
corner 1 side wall: pic11
corner 2 side wall: pic12, pic13
corner 3 side wall: pic14, pic15

Shohana, Michael, Fil, Jim, Arnaud

wp 13344 

Following up from 90652. The CRS chamber side testing started: 

• The CRS electronics (HOQI amplfier, Laser Driver and TEC controller) and laser were installed in the TCS-R2 rack, where the permanent cables are installed (see pic1)
• The E-stop was mounted on the TCS-R2 rack with label 'CRS local E STOP' (see pic1)
• The db25 in the CER was plugged to the HAM AA chassis going to ADC
• db25 and fiber patch cables were ran on the floor from the rack to the 'CRS' cleanroom (see pic2) 
• The laser was turned on to verify HOQI signals and HOQI alignment. The 2nd channel on HOQI B from the TIA is saturating (it was working last week) so we pulled the board out and will inspect in the EE shop tomorrow. In terms of algnment we are getting >70% fringe visibility and will continue to tune it tomorrow.

Ibrahim, Oli

Today, Oli and I installed and centered the M2 BOSEMs and centered and attached the cables for the M3 AOSEMs. AOSEM and BOSEM cams were also inspected and centered.

A few notes:

• One of the M3 lower cables was not taut enough (LL) so after centering it was removed and stowed securely. We'll think more on how to fix this to the structure safely from the optic. LLO attached theirs around the LS figure 8 so we will likely do the same. See a picture.
• M3 OSEM values haven't been normalized via the OLG adjustment so they "look" uncentered but they are centered. This will be applied tomorrow so they should look even on the spedometers.
• As a side-quest, we were also checking for rubbing (for the 3rd time) to see if there's a reason behind P:Y (and Y:P) coupling in OSEM slider readouts - alog 90697. We found no evidence of rubbing or touching, which is frustrating. We will return to it tomorrow.

Next:

• We are now able to take BRD measurements in-chamber so we'll do that tomorrow. Hopefully, the P:Y coupling issue is resolved. We'll see.
• Re-attach lower M3 cable (LL) and fix them to their final resting place.
• Take TFs.

[Tom, Ibrahim, Oli]

Summary: The yaw / pitch coupling seen on the BBSS is not due to the the coil driver chain.

As noted in LHO alog 90665, we are seeing strong pitch yaw coupling on the BBS, when actuating via the top stage QOSEM coils. When we try and adjust the optic yaw we see a 1:5 response in pitch and vice versa. This is seen in both the QOSEM readouts, and visually using an IR beamcard on the PSL beam bouncing off the optic. 

To investigate whether the cause was electronic in nature, we went into chamber to ensure that only the F2 and F3 QOSEM coils are being driven when requesting yaw drive. We used a multimeter to measure the voltage drop across the coils, to determine whether theyre being driven or not. As we expected, only the F2 and F3 coils are being driven, with equal and opposite magnitude, when trying to drive yaw. This suggests that this coupling is not coming from the coil electronics chain, or an issue in CDS.

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:

• reseated the M_M5 mount in its holder. We had troubles with this stick-slipping when we tried to move it. Jeff replaced the 45 deg adaptor part D2400336-v4 S/N 001 type 1 with S/N 002. This seats better in the holder.
• realigned beam to QPD A and B using picomotors M_C1 and M_M1.
• Confirmed other two picomotors M_B4 and M_M2 work and their pitch DOF (in breadboard basis) matches left/right on picomotor controls.
• We had some weirdness in the meas IFO which Josh has solved and will discuss in other alog from Josh (LHO alog #90680).
• During this debugging we used the oscilloscope to plug into analog outputs for meas and ref IFO and a commercial RF source.
• We used the breadboard steering mirrors to get 85.9 % heterodyne efficiency on the reference IFO PD A and 88.9% efficiency on reference IFO B.
• With no adjustment the measurement interferometer PD A had 86% efficiency and PD B had 93.4% efficiency so we will take this (ch4 on scope is PD A, ch2 is PD B).
• This afternoon we installed the shroud around the ISIK breadboard.
• We had to move the fiber spools to avoid the bottom shroud bracket and these are now close to the edge of the beam tube where it meets HAM3 in the -x direction.
• After installing the shroud panels both QPDs had dropped in power by ~2V, will investigate on Monday as the beam does not appear to clip the shroud when we check with the card.
• There is also a stray beam from the FBR_PWRIN_REF PD that hits the upper shroud stand-off on the lower panel on the -y side and then hits the door cover, this will need dumped somehow.
• After moving the fiber spools I checked the FBR PWRIN channel for meas and ref and these both drifted after we rerouted the fibre spools but the level seems to have been dirfting more than this since we got into chamber this afternoon at 14:20. The first cursor in the photo is when we started moving the spools and the second is when I shuttered the laser.

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.

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