Madi, TJ

This week, TJ and I went down to EX to re-measure the location of all components within the EX HWS path. The updated measurements are in the attached file. 

We each measured the distances, to give some indication of the uncertainty on each measurement. 

Shoshana, Arnaud

We cleaned up the SensInv filters in the CRS filter bank. Those invert the CRS sensor response so the signal is still calibrated in urad below 50mHz. 

* fm9 is the reference filter (based on a fit of this measurement)
* fm1 is the running filter, which is a modified version of fm9 with lower Qs, to reduce ring down time during a filter reload or a step in the signal (see step response in fig2, red is fm1, blue is fm9). 

Before the JAC PZT problem, I did get an hour or so of alignment time in.  Summary: we now have light on LSC POP and POP X for the same PM1 alignment, and ITMX is back to the alignment that should point down the arm.

These screenshots show MICH fringes with 10W input power, where I started and where I ended.  The idea was to move to the ITMX alignment that Jenne Driggers found using the arm beam here: 89738.  I watched the mich fringes and AS camera while moving the ITM, moved the beam splitter to keep the michelson fringes, and as Keita suggested moved PR3 to keep the beams on the ISCT1 refl camera.  This did cause the michelson fringes on the LSC pop diode to get smaller, when that happened I paused, went to the PR2 spot move guardian state, and adjusted PR3 to bring the fringes back on LSC POP.  After bringing the ITMX yaw alignment back I could see that there is now light on POPX and LSC POP A for the same PM1 alignment.  

When I walked ITMX pitch, I had to also adjust yaw several times as I went along to keep the mich fringes.  I also adjusted PRM to keep PRX alignment good as I moved along. Looking at this screenshot of the brief time when PRMI was flashing, the POP A LF flash was about the O4 power level (91211), as was reflair A, but popair has too little power.   The result of this was that PR3 started the day 56urad away from the O4 slider, but is not -15urad.  PR3 yaw started the day close to the O4 slider but is now -47urad.

I also adjusted the POP X dark offsets so that this QPD will be less confusing to read, SDF screenshot attached. 

Summary:

JAC PZT outputs were turned off, this lead to hours of confusion.  It shows up in HAM1 suspensions because light was sparying all over HAM1.

I'm followed the pydarm deployment instructions here, to update the LHO pydarm install.  However, the deploy script is slightly out of date, and currently owned by Jamie, so used a modified version to point at environment-py39.py (a change in the setup allows for different python version installs).  I need to get this fixed longer term.

This is the 20260724.0 tag for pydarm, which pulls in fixes from the last year or so, aimed at allowing for an up to date test of calibration export functionality on Monday.

This is not the default cds conda environment, but the default you get when typing pydarm at a command line, or specifically invoking by running "conda activate /ligo/groups/cal/conda/pydarm"

Tony, Dave:

At 10:33 FW went unstable, restarting itself after writing a new frames.

I restarted the daqd process at 10:44 (systemctl restart rts-daqd) which so far appears to have fixed it.

J. Kissel

Seeing the "first light," calibrated SPI Optical Lever amplitude spectral densities in  and , and thinking about ADC noise limitations and the calibration models assumption that the spots are centered on the QPDs drove me to re-check the spot positions on the QPDs. 

Timeline of centering:
    2026-07-17 17:00 UTC (LHO:91124) -- Jennie turned on the SPI laser for the first time since doors went on and the ISIs were isolated, and re-centered *only* QPDB with M_C1 (and thought she had adjusted QPDA centering with M_M1, thought she had mistakenly moved M_M2, but confirmed later she did not; LHO:91219).
    2026-07-23 14:00 UTC (LHO:91218) -- Jim unlocks and restores function of HAM2 HEPI, such that now both HAM2 and HAM3 are fully functional, and remain ISOLATED with corner station sensor correction ON as their nominal condition.
    2026-07-23 20:30 UTC (LHO:91221) -- Jennie re-centered (only) QPDB again using M_C1.
    2026-07-24 16:05 UTC (this aLOG) -- Not knowing that Jennie had yet recentered any QPDs, and finding QPDA PIT's normalized beam displacement at +0.23 [rad], I recentered *both* QPDA and QPDB.

I attach a similar trend of relevant channels including both Jennie's centering work from 2026-07-23 and mine this morning. Similar to Jennie's plots but with thick lines, light mode, and with the y-axes labeled.
I saved this template to 
    /opt/rtcds/userapps/release/spi/h1/ndscope/QPD_Centering.yaml  (rev 35598).


Here're the DC values of the QPDs after this morning's centering (done with the precision one can achieve with a picomotor STEP SIZE of 1 [ct]):
$ gpstime now;z avg -30 H1:SPI-H23_OL_QPD_A_PIT_OUT_DQ H1:SPI-H23_OL_QPD_A_YAW_OUT_DQ H1:SPI-H23_OL_QPD_B_PIT_OUT_DQ H1:SPI-H23_OL_QPD_B_YAW_OUT_DQ -s

t = 
PDT: 2026-07-24 09:27:44.113664 PDT
UTC: 2026-07-24 16:27:44.113664 UTC
GPS: 1468945682.113664

Channel                        t-30 sec average       t-30 standard deviation
H1:SPI-H23_OL_QPD_A_PIT_OUT_DQ -0.0024822048842906954 4.722167842008142e-06
H1:SPI-H23_OL_QPD_A_YAW_OUT_DQ  0.0030039884615689514 5.884913671432033e-06
H1:SPI-H23_OL_QPD_B_PIT_OUT_DQ -0.0022898733150213957 8.094109742945136e-05
H1:SPI-H23_OL_QPD_B_YAW_OUT_DQ  0.008859152471025783  4.6337990240392655e-05

$ gpstime now;z avg -30 -s H1:SPI-H23_OL_QPD_A_PIT_OUT_DQ H1:SPI-H23_OL_QPD_A_YAW_OUT_DQ H1:SPI-H23_OL_QPD_B_PIT_OUT_DQ H1:SPI-H23_OL_QPD_B_YAW_OUT_DQ H1:SPI-H23_OL_QPD_A_SUM_OUT16 H1:SPI-H23_OL_QPD_B_SUM_OUT16

t0 = 
PDT: 2026-07-24 09:54:54.983607 PDT
UTC: 2026-07-24 16:54:54.983607 UTC
GPS: 1468947312.983607

Channel                        (t0-30 sec) average       (t0-30 sec) standard deviation
H1:SPI-H23_OL_QPD_A_PIT_OUT_DQ  -0.002713  3.4e-05
H1:SPI-H23_OL_QPD_A_YAW_OUT_DQ   0.003265  4.2e-05
H1:SPI-H23_OL_QPD_B_PIT_OUT_DQ  -0.002033 10.0e-05
H1:SPI-H23_OL_QPD_B_YAW_OUT_DQ   0.009682 5.3e-05
H1:SPI-H23_OL_QPD_A_SUM_OUT16   25.846691 0.003820814636259141
H1:SPI-H23_OL_QPD_B_SUM_OUT16   29.265472 0.004081774857250754

WP13433 TW1 offload

As Tony mentioned, I did a quick NDS1 restart at 07:57 to get it to serve the past 6 months of minute trends from the archive following this week's copy.

At 08:09 I started the deletion of the old data from TW1's SSD-RAID. This typically takes a few hours. At the start of deletion disk usage was 93%.

TITLE: 07/24 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: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.10 μm/s 
QUICK SUMMARY:
 

The Vacuum pressure is still being pumped down.

CDS team needed to reboot the NDS server again so the NDScope screen shots may stop beifly.

SUS: First stage of PRM seems to be pushing a bit harder than I'd expect given that it's misaligned.

Jeff, Sheila, Fil, Elenna, Oli

The feedthrough cables (air side) for MC2 M2 and M3 have been swapped and now MC2 is back to behaving how we expect it to. Transfer functions for M1 to M1, M2 to M2, and M3 to M3 are correct (red traces) and crossover plots for MCL and M2/M3 are looking good.
Current correct cable numbering for MC2 at the HAM3 D6 feedthrough port is:
D6-F1 -> MC2 M3 (HAM3_020)
D6-F2 -> MC2 M1 (HAM3_001)
D6-F3 -> MC2 M2 (HAM3_019)
This should be updated in the flange layout D1002874, which I don't see the altium file for. Next time we open up HAM3, we should fix this lineup so F1/F2/F3 line up with MC2 M1/M2/M3.

Full troubleshooting:
After lots of troubleshooting and my MC2 M2 and M3 measurements from yesterday, Jeff noted that the M2 to M2 TFs looked a lot like the M3 to M3 Tfs, and vice versa. This was also very suspicious because back in May (90185) there had been a feedthrough swap for the feedthrough that MC2's M1 (T1/T2/T3/LF), M2, and M3 were all connected to, and M1 and (we thought) M2 had been found to be plugged in incorrectly on the vac side. After the plugs going into F1 and F2 had been swapped, we had measured only M1 to confirm that the swap was successful.

A (silly) mistake:
Fil and I went out to HAM3 D6 flange and meant to swap the M2 and M3 cables, but since the flange layout was still listing F1 -> M1, F2 -> M2, F3 -> M3, we swapped the cables connected to F2 and F3, which were actually M1 and M3, respectively. We determined that this was wrong because M1 to M1 and M3 to M3 looked horrible but M2 to M2 looked the same as before (wrong but not different), which means that M2 must have been in the F1 port and so hadn't actually been swapped with M3. We noticed later that this lineup was written in the May 8th MC2 'fix' alog(90185).

Actual fix:
We plugged M3 (HAM3_020) into F1, M1 (HAM3_001) into F2, and M2 (HAM3_019) into F3. Here's a diagram/timeline of this mistake and fixing it.
Everything is looking good for MC2 and it seems like we've been able to go back to using MC2 to lock the IMC normally.

I'll add plots next week comparing MC2 M2 to SRM M3 and vice versa

TITLE: 07/23 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Good progress today towards DRMI, see commissioning notes in alog91211. HEPI was unlocked for HAMs 1 & 2; see alog91218. Dust alarms throughout the day in the LVEA and optics lab. The LVEA remains Laser HAZARD and corner volumes are still pumping down.
LOG:

• found a bit of clipping on ISCT1 popair shutter, moved shutter, 2 inch lens and bs right after lens in -X direction
• Adjusted alignment onto POPAIR B using PRMI flashes at 10W, then MICH bright at 10W we were able to see a small signal to align this diode to. 
• Also checked alignment onto REFLAIR A using MICH bright. 

• Ran OMC scan to check modulation depth, comparing to 89497.  Modulation depth settings are 27dBm for both 9MHz and 45 MHz, as that alog says they should be.  Modulation depths are about the same as in that alog, (9MHz peak over carrier peak is 0.01, 45 MHz peak/carrier peak is 0.018).  However the carrier peak is about half as large as it should be.  AS_C sees 20mW, we have 8.5W at IM4 trans so we expect 18mW entering HAM6 in single bounce, so this seems OK.  
• With MICH dark locked, Elenna worked on centering POP X, while I went back to ISCT1 to check alignment onto the diodes.  I am sure that the beam is reasonably centered on REFLAIR A, POPAIR B, and POPAIR A (did not check REFLAIR B this time).

I tried the heater guardian today with a gain of 0.003 and a set point of 25 degrees seeing as it seems to have reached equilibrium around this value with no loop running and 1W input overnight. It looks like it overshot initially and is turning around and coming back to the set point of 25 degrees C now. Thermistor 1 is the loop sensor but I have marked the turning point on thermistor 2 in the attached picture. We still have some range on the PZT actuator (JAC-PZT_DRIVER_VOLTS is low rate channel from Beckhoff voltage driver and JAC-PZT_DRV_OUT_DQ is front-end PZT feedback channel for fast feedback) and the temperature actuator (JAC-HEATER_POWER_SET). I will get the operator to switch it off when they leave so we don't cause any pressure spikes overnight.

This is a late entry from last Friday.  We have removed the relay tube between HAM5 and HAM7 and replaced it with the adapter/viewport assembly on the HAM5 side.  The assembly is being pumped down independently by a small turbo/aux cart.  The GV should not be opened until the pressure in the viewport assembly is approximately the same as the corner pressure and the aux cart is valved out.

Shoshana, Jim, Arnaud

The x6 HAM3 new CPS boards have been set to the following configuration (as per E2200455): 

• Chassis ungrounded from PCB (P3 jumper removed) - To avoid ground loops (see p33 of the user manual)
• All boards set to slave (P26,27,28 jumpers removed) - This is because the LHO CPS are linked to an external timing chassis and don't need a master board (as per Jim)
• Phase set to 0 (P2 jumper on) - This setting is because the targets are now independant from each other (see point #1 in page 27 of the user manual)

There was some glitching noticed on the channels that were in range prior to this work, which was fixed after this setting change (see attached). Two of the cards were set to Master before and Jim is confident this would have created problems. 

Left to do : 

1- Label the cards at the front of the boards with module SN and corner #
2- Disconnect the grounding to the chamber of the crate on the +Y side 
3- Label the in-air lemo cables with H1, V1, H2 ...
4- Update ICS with the new boards SN
5- Gather the cards that were removed from WHAM3 to send back to microsense for recalibration with a new set of sensors (RMA)

The tracking spreadsheet for this ECR was updated here: E2500184 

Vicky, Austin, Camilla. Follows yesterdays alog 62089. Summary: aligned but weren't able to see any baffles and beam is smaller than ideal.

Austin and I measured distances between optics (all measurements attached and key ones below): 

We started with translation stages at: Collimating lens @ 1.44; HWS:L2 @ 12.39. Later Vicky and I moved the L2 on it's translation stage upstream ~ 1.5" (starting location attached). 

Vicky and I realigned the beam to remove the majority of the ITM reflection. Once we were finished and ETM was misaligned we could still see faint rings reflected off ITMX (that moved when ITMX adjusted) photo here. So more alignment could be done to get rid of those. We adjusted the CCD camera to try nd focus better but didn't see a difference so replaced in original position. 

We adjusted the collimating lens and L2 to try and get the retro-reflected beam at the iris after ALS-M11 D1800270 to be a similar size as the outgoing beam - it is ~ double the size which is the best we could get with the 40mm collimating lens. The waist of the beam is still just after L3. 

Adjusted wave plate to maximize beam to LPM from 270 to 292. This might have been the cause of reflected beam streaks we see on the camera. In the final image. 

Final beam after yesterday is attached. It still seems to small to me so maybe we need to go back to the 50mm lens. Once we are happy we need to dither the ETM to measure the magnification.