Camilla, Rahul
SUS ZM2 in HAM7 chamber needed a pitch offload since it was using up a lot of DAC output. This morning we went to HAM7 chamber and at first confirmed the beam alignment and its position on the irises. Then I entered in HAM7 chamber and locked the suspension and unlocked the pitch adjuster screw. At first I gave it a full 1 turn anti-clockwise making ZM2 pitch down (and then unlocked the suspension) and Camilla confirmed that the alignment looked better but perhaps we overshot by a small amount. I retracted by 1/4 turn (thus making 3/4 turn anti-clockwise in total) and then the beam looked good on the iris. Before exiting the chamber I locked the screw for pitch adjuster and checked if all EQ stops were set free from the suspension chain.
Finally Camilla adjusted the alignment sliders on ZM2 for fine tuning it.
I took a quick chamber side transfer function measurements and the suspension was found to be healthy.
Took ZM4,5,6 to SAFE.
Accepted some TCS HWS settings, turned the EY enclosure lights off via medm (already off on table) , unmonitored the CHETA flipper. Attached.
Stil have more SQZ and CO2 to do....
CS_AUX Disabled then reverted picomotor settings, attached. Accepted ISCT6 AS Beam shutter (SHUTTER_M_THRESHOLD) from 1.2V to 2V as it's been this since ~February. Fast shutter (SHUTTER_G) offset accepted.
TITLE: 07/27 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: 3mph Gusts, 0mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
Quick scan for the week looks like HAM7 may get closed up this week, CDS has a list of items, Y-Beam Manifold's GV work, cleanroom moves.
IMC guardian is set to DOWN (ISC lock is in MANUAL & at IDLE.
As a test, HAM3 Ry loop was switched to SUPERSENS6 blend, which includes a newly designed 30mHz CRS blend. It has been running stably for the last 20 minutes.
start_gps = 1468138518
note - to avoid confusing results I also turned off the CPS-DIFF loop
| UTC | Jul 15, 2026 | 08:15:00 | UTC |
As suggested by Huyen, attached in pdf1 is the comparison with all hams remade, including HAM1, which is the only chamber in the vicinity of HAM3 that also has the fine CPS upgrade.
Jim asked to plot a comparison of the CPS Ry channe before/after, which is attached in the 2nd pdf.
Finally, there is a typo in all plots and figure names from the other comments - the blends between the CRS and the GS13 is at 800mHz, not 80mHz (thanks Michael for the catch), so the blend plots and noise budget plots were regenerated, and are attached below as reference.
The loops stayed stable overnight and have been running for ~12 hours.
The overnight data was analyzed (first pdf) and spectra of the GS13 and CRS Ry were compared with the data from last week wtih the CPS/GS13 400mHz blend on the Ry loop. The in-loop CRS shows a factor of 100 improvement in the 0.2-0.5Hz band between the two times (purple vs pink), and the GS13 is now self noise limited up to ~0.8Hz (compare dark blue vs light blue).
A comparison of the Ry dof between all HAMs is also attached in the second pdf as a reference.
A tilt noise estimate used to design the blends is shown in the third pdf. This estimate uses the 3 sensor noises (CPS, GS13 and the updated CRS noise model), as well as (estimated) tilt input, and the 3 way blend. The total platform tilt noise for the new blend is shown in the dark blue dash lines and compared with the in-loop CRS measured spectrum. The dash green line shows the estimate for the 400mHz previous blend, compared with out-of-loop CRS spectrum.
Note the 1-20mHz noise in the measured spectra is from windowing leakage (2582) rather than real tilt. I kept using the same Hanning window to be consistent with the reference data saved in dtt from last week. Eventually we should remake those plots in matlab (or dtt) with bmh windowing.
The blends were designed using Brian's script attached to T2200393 as a starter point. The CRS sensor response is inverted in the blend filter (the same way we do with the GS13). The installed blend filters (including sensor response, as opposed to the plot shown in the main alog above) are shown on the last pdf.
Next, we will assess how this improvement can help reducing the blend frequency in the horizontal loop.
The dtt template, blend script and blend filters are saved under :
/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/HAM3/CRS/Templates/dtt/2026-07-25_CRS_Spectra.xml
/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/HAM3/CRS/Scripts/make_crs_blends.m
/ligo/svncommon/SeiSVN/seismic/HAM-ISI/H1/HAM3/CRS/Filters/CRS_BLNDS_30mHZ.mat
The SEI_ENV automation guardian transitioned back HAM3-ISI Ry loop to the nominal blend (SUPERSENS4) before an earthquake on July 26 at 01:51 UTC
Analysis time for the CRS in-loop is between July 25 08:15 UTC and July 26 08:51 UTC
I was excited, so I made a comparison of PR2 suspoint motion in pitch and length during Arnaud's test time, which encompasses both the CRS change made here and the CPS improvement made in 91113.
For a comparison time I went back roughly a year ago to August, to a time when we were in observing. Hopefully the seismic environment is fairly similar.
The attached plot shows pitch on the left, length on the right, along with the RMS. The channels are calibrated into rad and m respectively.
Overall, the pitch is the most straightforward: between 0.1 to 1 Hz there is up to a factor of 25 reduction in the motion, and between 1 and 10 Hz roughly a factor of 4 reduction. These plots purposefully don't show anything above 10 Hz because we don't expect improvement there, and we're still returning from the vent so there's lots of ambient noise which could be confusing.
Length has some weird features, which I'm not sure are attributable to the changes in the sensors and blends, but also shows improvement between 0.1-10 Hz.
As a reminder, PR2 is used to control the PRC alignment.
Edit to add: Arnaud reminded me that the suspoint channels use the GS13s to project the noise, and when the CRS is in loop, the resulting noise is lower than the GS13 noise. It is likely that the suspoint noise is reduced further than is visible in these plots.
Jennie Wright, Khanh Vu This morning, we entered the calculated values into the sensing matrices on the JAC menu. We encountered a few points of confusion that are worth mentioning: 1. The calculated matrix contains 16 values because it is a 4x4 matrix, with four possible angular actuator offsets and pitch and yaw readout channels from two wavefront sensors. However, the matrices on the JAC panel contain only eight inputs. This design assumes that, ideally, a yaw actuation produces only a yaw signal and a pitch actuation produces only a pitch signal. In practice, the system is not perfectly decoupled, so we observe cross-coupling between pitch and yaw, leaving us with more than eight matrix entries. 2. For the PZT actuator, the relationship between pitch and yaw is reversed. A pitch offset produces a signal in the yaw channel, while a yaw offset produces a signal in the pitch channel. This is due to the configuration of the optical components, and this convention has been maintained in the control system. We will continue working on the sensing matrix on Monday to determine how to account for these issues.
Jennie W
I edited the file /opt/rtcds/userapps/release/ioo/h1/medm/jac_macro.txt that changes the gifs on the JAC_OVERVIEW_NEW screen so that the screen displays the picture of the beam transmitting through the JAC and also reflecting off the front surface of JAC and hitting the WFS.
I have set these to work if we are putting in 200 mW or above into HAM1.
These values might need further tuned.
I used the values recorded during a 2W lock of JAC today and divided the REFL, WFS and TRANS power by 10 so these thresholds still make sense at 200mW.
The trigger PD on the REFL signal has such a small power on it that it will sometimes go negative so I left this value at -10.
If anyone notices that the this screen doesn't show a beam reaching the PDs when it actually is based on the epics values, please let me know so i can fix it.
TITLE: 07/24 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
Comissioners got in today and we started trying to lock PRMI and align the input arm.
After a short while.... something happened. and there were some suggestions that a power outage had happened.
Which also coincided with FW0 connection issue. ( The control room was running on FW1 and otherwise the CDS "one leg" as opposed to the zero leg which is good, cause FW0 is not connected.)
So we all started trying to gather data of all the things that would have been tripped or otherwise upset by a power glitch.
We even made a list!:
[Sheila] 10:20 PDT JAC REFL power drops -- i.e. we lost the beam out the JAC into the IFO.
[Sheila] 10:20 PDT JM1 OSEMs show sharp change in behaviour " exponential droop" at the ~few [urad] level (JM1 is upstream of JAC)
[Sheila] 10:20 PDT IMC PWR IN PD also shows a (faster) "exponential droop" from 2 [W] to 0.8 [W]
[Sheila] 10:27 PDT Started making changes to laser power guardian (requesting 10 [W]) to get back to 2 [W]. This turns the IO rotation stage. OSEMs on JMs, RM1, seem to witness this
[Dave] 10:20 PDT h1sush12 DAC2, channel 20 (the JM1 UL channel) shows a spike glitch, at the 0.01e6 [ct] ~= 1.5 [mV] output voltage level (28-bit DAC, so [DAC V] = [DAC ct] * 20/2^28 [DAC V/DAC ct])
[Dave] 10:20 PDT ADC3 channels 0-3 (JM1's OSEM PDs) change mean behavior, similar "exponential" but up,
[Dave] 10:29 PDT another sharp "glitch" feature change in the ADC3 CH 0-3 (JM1 OSEMs)
[Dave] 10:29 PDT Reported "glitch" in the corner station power
[Dave] 10:33 Frame writer went unstable
So I started looking for the MAINS channels to document the voltage change.
H0:FMC-EX_MAINS_CHAN_1_VOLTAGE looked very strange, so did 2, and 3. They haven't reported Voltage correctly since JUN 18th! Perhaps from a Hardware Swap or a Beckhoff change?
Thankfully dave has these channels in an ndscope template that still work to determine power glitches:
H1:PEM-CS_MAINSMON_EBAY_1_DQ , and ebay 2 and 3.
Turns out there was a button pusher and an alog about how that button no longer exists which you can read about here: alog 91246 .
M6.0 Earthquake from Vanuatu Shook up End X so much I had to go down to EX and tickle the H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_OUTPUT control loop until it worked again.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 14:47 | FAC | Kim, Dawn | H2, MY, EY, MX, EX, HAM SHAQ | N | Tour of VEA areas and resupplies. | 16:13 |
| 15:41 | VAC | Jordan | MY | N | Setting up outside pump | 16:59 |
| 15:51 | PEM | Robert Shrey | LVEA | y | Setting up shaker and accelerometers | 16:18 |
| 16:27 | FAC | Kim | LVEA | y | Technical Cleaning & resupply | 16:55 |
| 16:31 | PEM | Robert , Carlos, Shrey | LVEA | y | Debugging Shaker issues | 17:25 |
| 17:00 | VAC | Mitchell & Jordan | LVEA | y | Taking pump cart Down from platform | 17:14 |
| 17:26 | PEM | Robert, Carols, Shrey | Just over the over pass | N | Seismometer testing | 19:37 |
| 18:14 | CDS | Dave | Remote | N | Restarting the Entire \ | 18:44 |
| 18:17 | ISC | Jennie | LVEA | yes | Opening IOT1 to check beams | 18:40 |
| 18:59 | EE | Jennie W & Marc | CER | N | Checking on the SAT AMP JM1 | 19:44 |
| 19:37 | CDS | Jonathan | Remote | N | Restarting 0 leg | 19:44 |
| 20:24 | JAC | Sheila, Jennie, Keita | LVEA | yes | Working on the JAC Table | 21:09 |
| 20:27 | PEM | Carlos & Miranda | Overpass | N | Setting up seismometers | 22:08 |
| 20:31 | vac | Jordan | LVEA | N | Corner RGA work | 22:08 |
| 22:06 | Tour | Robert, Shrey & Co | LVEA & Roof | y | Giving a tour of the LVEA | 23:48 |
| 23:01 | ISC | Sheila & Jennie | LVEA | yes | Working in ISCT1 | 23:17 |
| 23:35 | VAC | Jordan | Mid Y | N | Shutting down Pump | 23:54 |
| 00:40 | SEI | Tony | EX | N | restarting the HEPI Pump controller. | 00:42 |
Keita, Sheila, Tony, Jennie W
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. We have the expected power in LSC POP path, but a factor of 20 too small in both DC and RF signals in the popair path.
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.
We tried walking PR3 in PR2 spot move to allow us to centering POP X without saturating PM1, this alignment is shown in this screenshot, but when we then aligned PM1 to put the beam on LSC POP, we were missing power there.
| POP A LF | POPAIR B LF | REFLAIR A LF | MICH IN1 (REFLAIR A 45 Q) | PRCL IN1 (REFLAIR A 9I) | POPAIR B RF18 | POP X NSUM | |
| PRMI O4 | 200-400 | 200 | 2-10 | +/-6000 | +/-600 | 80-100 | |
| PRMI yesterday | 100 | 6 (10 today) | 2.5-4 | +/-20 | +/-100 | 5 | |
| PRX O4 | 0.5 | ||||||
| PRX now | 0.5 | ||||||
|
MICH dark O4 1468885440 |
7 | 1 | 0.01 | -0.5 (dark level -0.6) | |||
| MICH dark PM1 -265 P -2364 Y) | 0 | 1 | 0.01 | 3.1 (centered) | |||
| MICH dark PM1 0,0 | 4 | 1 | 0.01 | 0.2 (P and Y both close to -1) |
The MICH dark time that I labeled as O4 above was actually from July, a better time to use for O4 (chosen from a list that Tony generated of MICH dark times) would be 1457969940 which is May 28 2025 00:15:42 UTC.
MICH dark time from May 28th 2025, 00:15:42 UTC
Now MICH dark locked:
Sheila had me look back to all the time that ALIGN_IFO's channel H1:GRD-ALIGN_IFO_STATE_N was in in MICH_DARK_LOCKED [43].
I made a Statecounter query.
python3 statecounter.py -chan "H1:GRD-ALIGN_IFO_STATE_N" -operator "==" -value 43 -trend "m-trend" -gpsstart "1368975600" -gpsstop "1479398400"
Which returned the output.txt file that now contains all the times that H1:GRD-ALIGN_IFO_STATE_N was in Mich_Dark_Locked.
It was then easy to use those GPS times in an ndscope to check out the noise on other channels to compare them to today's Mich_Dark_Locked.
Comparing that to what we can see in May of 2025 the ASC-AS_A_DC_NSUM has larger fluctuations than todays Mich_Dark .
ASC-AS_B is roughly comparable.
BUT H1:ASC-AS_C_NSUM does seem to have less fluctuations a year ago.
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).
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.
After turning the PSL PZT back on with the same offsets before, JM1 was brought back to the position right before the problem started according to OSEM.
This didn't bring back the beam on JAC REFL diode so I steered PZT until JAC REFL see some light, and refined from there. In the end, JM1 didn't move that much
| before problem | after recovery | difference | |
| H1:SUS-JM1_M1_DAMP_P_INMON | -668 | -680 | -12 |
| H1:SUS-JM1_M1_DAMP_Y_INMON | -920 | -917 | +3 |
| H1:SUS-JM1_M1_OPTICALIGN_P_OFFSET | -537 | -634 | -97 |
| H1:SUS-JM1_M1_OPTICALIGN_Y_OFFSET | -1471 | -1434 | +37 |
JM1 OSEMs are drifting as I write this but it seems to be consistent with diurnal changes.
PZT output changed mostly in PIT, much larger than I expected from hysterisis. I don't know why but I leave it as is for now. Note that JAC-PZT_PIT_OFFSET and YAW_OFFSET move the beam in PIT and YAW in JAC basis, in the PSL room coordinate it is YAW and PIT.
| before problem | after recovery | difference | |
| H1:JAC-PZT_PIT_OFFSET | 6407.5 | 2546 | -3861.5 |
| H1:JAC-PZT_YAW_OFFSET | 26025 | 26605 | +580 |
I looked at the time we had to re-align PZT offsets after the power cut last Thursday and this was a much smaller change:
about + 500 counts on PZT YAW ( 1.9 % increase) and +100 counts on PZT PITCH (1.5% increase).
Jennie W
The offsets to the PZT were turned off because I turned off the ASC outputs on the JAC WFS screen and forgot that these were the buttons for the filter banks JAC-PZT_PIT_OFFSET and JAC_PZT_YAW_OFFSET that send static alignment offsets to the PZT mirror pre-periscope. It also is before the PD that the rotation stage uses for power adjustment and so that led to the rotation stage not taking us to the requested power.
I have now removed these output off/on buttons from the front of the JAC WFS MASTER screen. I have circled where they were in the medm screen. I left the buttons for the JM1 suspension as these do not control the DC alignment for the suspension, those are in the JM1 model itself.
In future I (and anyone else seeking to kill the JAC ASC outputs) should just turn the loop gain to 0 or turn the output from the JAC-DOF1_P, JAC_DOF1_Y, JAC-DOF2_P, JAC_DOF2_Y filter banks off.
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"
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.
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):
| INCHES | mm | |
| L3 to L2 | 41 | 1041 |
| L2 to L1 | 21 | 533 |
| L1 to LPM | 60 | 1524 |
| HWS to L3 | 58 | 1473 |
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.
From a controls tmux session on zotws24 I'm running a ETMX 0.5W ring heater test 2am-4am. Script will close ALS EX, EY shutters at the start. >> python3 /opt/rtcds/userapps/release/tcs/common/scripts/power_adj_scripts/ring_heater_schedule_shutterALS.py ETMX -s 1330941618 -d 2 -p 0.5" Robert will shutter ALS and when he turns the ring heaters back to thier nominal O3 values tonight.
This morning I replaced the Hartmann plate but didn't track down the source of the scattered light shown in alog 62121 photo yet.
The baffle is a 190mm circular aperture that should appear around 9.3mm in diameter on the HWS camera (assuming magnification of ~20.5X) - see aLOG 60937.
The aperture that appears in the HWS images looks plausible as the baffle shadow.
The ring heater test doesn't look like it's showing us anything much see attached. The spherical power is noisy and doesn't show any change. The TOTAL_PIXEL_VALUE does decrease.
Madi, TJ
These on-table distances were re-measured 22nd July 2026, and posted 91241
Here is Rahul inside HAM7, next to ZM5.
While I was fine tuning the alignment after this offload, I realized that the PSAMs setting was wrong. It appears that while this ZM2 work was happening that the ZM2 strain gauge reading has been shifted. We still have the same ΔV of 5V but the range used to be 1.2 to 6.2V plot and now is 4.6 to 9.6V plot. CIT has possibly seen this before in T2300426 but the effect was less.
Our nominal was 3.15V before, now I'm assume it should now be 6.55V (4.6V + (3.15V - 1.2V)). We will confirm this with beam scan measurements in chamber.
Ryan and I went to ZM2 PSAMS strain gauge at 6.55V and took data in 2 similar locations to in 91142. The beam size lis very similar to expected so we think ZM2 is fine, just the strain gauge now has an offset. Will look at the data in more detail tomorrow.
The data we took is attached. This plot shows the old data with SG at 3.15V in light/dark green and yesterday data at 6.55V in red/orange, It is very close. Also attached is the data taken 0.5V above and below the nominal SG values, both before when nominal was 3.15V (in blue/green colors) and now when it is 6.55V (in orange/purple/red colors). We conclude that the new nominal is << 0.5V from the old nominal. We are fine to stick with 6.55V as ZM2 PSAMS and can treat this as the old 3.15V.
Alignment sliders for the "new ZM2 position" are now P +300, Y -155.. Maybe we could do a little more fine tuning of the retrorefection and need to measure the power through the OPOS.