Sheila, Sophie, Camilla
The HAM7 PSAMS (ZM2,4,5) were railed last week, we noticed that the ZM2 alignment changed Friday after the FC gatevalue was closed which led us to noticing this. Reset the ZM4 and ZM5 PSAMS, following 84639 and adjusted sliders to bring osem values back. ZM2 was not railed, something on Friday afternoon (maybe the GV being closed) stopped ZM2 PSAMS being railed.
Once the FC GV was opened, we could see a beam on FC-IR camera. We went to the FCES and after mis-aligning FC1 and FC2 while moving ZM3 would could see a green beam on the green camera. After temporarily tuning up the exposure and adjusting FC1 and FC2 we could see beams on both IR and green cameras and the best flashes we've had so far, 20 on FC_TRANS_C (green) with 6.5mW in and 1.35 on FC_TRANS_D (red) with 75mW SEED. Sheila adjusted the IR camera steering mirror in Pitch as she had last week to bring the beam more central on the camera.
Looking back to November, typical flashes when we have the OPO locked and FC aligned with 7.8mW into FC green are 60 on FC_TRANS_C (green), 0.8 on FC_TRANS_D (red) and 0.002 on OPO_IR_PD, see attached.
During the Y-manifold vacuum work today we have had three occasions where the control room and EDC had lost connection to h0vely IOC for several seconds. The times are: 11:02, 14:39 and 16:26 PDT.
TITLE: 03/23 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
Lots of activities & new visitors on site today. Main activities were the VAC team working on swapping a pneumatic actuator for GV7, squeezer alignment checks (cont.), SPI & BHD work in the optics lab. (Also had Girl Scout cookies arrive!)
LOG:
Sheila, Tony
On Friday we continued trying to get flashes in the filter cavity for 1064nm, 532nm, and IR light onto the SQZT7 diode which we are using to establish that we are going through the VIP without clipping.
At the start of the day we saw IR flashes of at max 0.04 counts on SQZ-FC_TRANS_D_LF with the OPO locked with CLF (with 21mW on CLF trig PD) 1.7 counts on FC_TRANS_C_LF with 5mW into the green fiber, and 36e-6 counts on OPO IR PD. We saw that the green was clearly misaligned in yaw in the filter cavity, and we were able to improve the IR flashes and IR on SQZT7 with some yaw moves, but that made the green flashes nearly disappear. We pio'd MOTOR 3 (H:M2) -710 counts, which improved the green flashes to 6 counts.
Then we could see that the IR flashes and on SQZT7 were easiesr to improve with pitch moves, and that we no longer loose the green by improving them, so we spent some time trying to walk ZM1/2/3 for slow improvements, to get IR flashes of 0.1 counts, 83e-6 on SQZT7, and green flashes of 5. (22:30 UTC March 20th)
This was slow going, so we decided to go back to FCES with cameras to see if we could get some photos or see flashes. We will continue from the FCES this afternoon.
Betsy wanted a look at the last few months of dust trends for BSC2.
(This is Dust Monitor LVEA10 which was moved to BSC2 in Feb [alog89137].)
One of the flashlight arrays we used during the vent had a bunch of battery corrosion in each battery compartment.
I used isoprop and water on long q tips to clean these out in the optics lab. It is now drying on the bench next to the fume hood. See first pic.
Unfortunately I didn't realise the sink hadn't been used in while and turning this on splashed water on some nearvby electtronics, second pic.
The pipes attached to the taps also leak.
I dried off the silver box and the extension block after powering off the extrension block, it was just some water spraying on it so should be fine.
Erik, Marc, Dave:
I've updated the CDS Overview to show the timing card firmware as a color block in the RGC version section of the IOP model.
For each IOP model, the top part of this block shows the RCG version, GREEN=5.5, BLUE=5.5.2. The lower part shows the Timing Card version, GREY=old, DARK-BLUE=new.
For user models this block just shows the RCG version as before.
FAMIS 31130
Not much to report this week. Noisy FSS TPD times line up with the IMC naturally flashing through resonance, and looks like there were some temperature spikes for a few days last week, but these appear to have stopped.
Hepi Pump Trends (Monthly) Famis 39954:
On Jan 26th the HPI-PUMP_EX_PRESS1_PSI started rising in maximum pressure. and on maybe feb 2nd it started getting worse. Seems like it has plateau-ed on Feb 16th, but the Pressure still remains elevated.
That channel back in Oct was between 92.4-92.6 PSI.
And now it's between 91.9 - 93.5 PSI. I'm not sure if this is out of bounds for HEPI.
X-Arm electronics:
All chassis have been tested mounted in the rack. All that is left is to replace the variable power supplies currently being used for the visible laser, fan and flipper with 5V, 12V and 15V DIN mounted power supplies respectively.
X-Arm beam profiling:
X-arm is not behaving as predicted by the model especially in the horizontal axis.
The beam was profiled using the nano scan along a 55cm length after the second lens and a q-parameter was fit using this data.
This is compared to the model and a Jammt model using the measured QCL q and assuming a linear optical system with the lens at the same distances as in the physical set up.
For the fit q-parameter the w at the ITM was found by propagating the q at L2 to the ITM.
Additionally, during the trouble shooting process a wedge was found on the first telescope lens (L1) which isnt in the optical system and was compensating for some of the astigmatism of the QCL. The effect of this is that in the data below the beam size at the ITM is too large and astigmatic.
Discussion and solutions of this effect will be the subject of its own log.
Vertical
| Measurement/model | w0 [ µm] | z [mm] | w at ITM [mm] |
| Fit from data |
978.9±22.7 |
-1063.1±33.8 |
50.09 |
| Fintrace |
857.11 |
-500.64 | 61.38 |
| Jammt | 874.53 | -572 | 62.1 |
Horizontal
| Measurement/model | w0 [ µm] | z [mm] | w at ITM [mm] |
| Fit from data | 1280.3+/-54.9 |
-1813.3±83.5 |
38.01 |
| Fintrace |
979.42 |
-653.71 | 54.38 |
| Jammt | 1013 | -256 | 53.1 |
None of the values agree within the measurement uncertainty bounds, especially in the horizontal direction. We are also observing non-gaussian beam profiles on the nano-scan, plots attached, but this is predominately in the vertical direction. This structure isnt new and appeared when matt and I were initially profiling the lens and were able to see good agreement.
The fintrace and Jammt are close but not identical which would be expected as the Jammt does not include any additional optics outside the QCL and L1 and L2. We are currently working on determining the source of this discrepancy.
Mon Mar 23 10:06:23 2026 INFO: Fill completed in 6min 19secs
Only CPS channels which look higher by eye at high frequencies (see attached) would be the following:
TITLE: 03/23 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: CALM
Wind: 4mph Gusts, 2mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.22 μm/s
QUICK SUMMARY:
Arm (GV5/7), FC gate valves closed (GV7 is soft-closed, waiting to cam over). Cleanroom move this morning. Lots of activity around the Y-Beam Manifold begins!
As part of our investigation into h1ioplsc0 timing glitches since last week's h1lsc model change, I restarted all the models on h1lsc0 at 08:07 PDT this morning.
I've extended the alarm bypass on GV7 for another 24 hours.
Bypass will expire:
Tue Mar 24 09:17:05 AM PDT 2026
For channel(s):
H0:VAC-LX_GV7_ZSM179A_VALVE_ANIM
Sun Mar 22 10:03:10 2026 INFO: Fill completed in 3min 7secs
CP1 PT114 cold cathode gauge has come back to life, I've taken it out of the alarm bypass and enabled it in VACSTAT.
This is a belated report of work done by me, Oli and Keita on the OMC builds for the BHSS, done yesterday March 19.
Exciting summary: build for OMCA is complete, including DCPDs and butter dish. OMCA is installed onto the BHSS platform and ready for beam alignment!
Less exciting summary: build for OMCB is halted as tombstone for DPCD A (transmission) is missing a required PCB hole for the electronic connection.
OMCA build notes:
OMCB build notes:
[Elenna, Camille, Arnaud]
We had a quick zoom meeting to discuss this issue. Relevant drawing is https://dcc.ligo.org/D1201273
It is likely that the backshell+PCB assembly was assembled flipped 180 degrees (items 4,5,6 on the drawing). To fix, remove the two 2-56 screws (item 14), flip the assembly and reattach it to the housing. Camille suggest slightly pressing down on the housing while removing those screws to avoid torquing the base with the bond.
Tagging for EPO.
After consultation with Arnaud and Camille, Oli and I were able to correct the problem with the PCB assembly.
On the call with Camille and Arnaud, we referred to the diagram in D1201273 and determined that part #4 is rotated 180. I could also see from this diagram that part #5 is rotated, since there was no notch visible at the top. So, for future installation, make sure the notch in part #5 is oriented upwards! This indicated to us that all that needed to happen was to unscrew the #14 screws, flip the assembly, and screw it back in (we had some concern that we might have to take apart the "sandwich" of parts between #5 and #4).
Indeed, that's all that needed to happen. I carefully unscrewed the screws on the back, flipped the assembly, and screwed it back in. I was then able to install the DCPD. We can now see the notch along the top!
I went back into the lab today to try to get a better photo of the problem. I wasn't able to, but I did get an ok photo of the other tombstone (on reflection of the BS) which has the correct three holes. It's hard to see, but you can use it as a reference to compare with the photo I have attached to the original post which is missing a hole. I tried looking from many angles, and I don't see even a hint of the third hole, which is evidence in support of Keita's theory that the electronics assembly is flipped 180 degrees.