aLIGO LHO Logbook

H1 CAL - PCAL EY End Station Measurement

anthony.sanchez@ligo.org — Tue, 04 Aug 2026 17:08:19 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91393

Ibrahim and I went to End Y with the PS4 Working Standard to do a PCAL End Station measurement. We followed T1500062-V21 to complete the measurment suite with out any issues.
Here are the obligitory Before Beam spot pics.
Martel plots for ADC conversion.

Working standard at TX module with only One beam.

Working standard at the RX module with only One beam.

Working standard at RX module with Both beams.

Post measurement beam spots!

anthony.sanchez@cdsws25: python generate_measurement_data.py --WS PS4 --date 2026-07-16
Reading in config file from python file in scripts
../../../Common/O4PSparams.yaml
PS4 rho, kappa, u_rel on 2026-07-16 corrected to ES temperature 299.6 K :
-4.698647654693516 -0.0002694340454223 0.000750622815531554
Copying the scripts into tD directory...
Connected to h1daqnds1
martel run
reading data at start_time: 1469911700
reading data at start_time: 1469912270
reading data at start_time: 1469912670
reading data at start_time: 1469913100
reading data at start_time: 1469913500
reading data at start_time: 1469913900
reading data at start_time: 1469914560
reading data at start_time: 1469915320
reading data at start_time: 1469915650
Ratios: -0.5339859682199335 -0.543765733929218
writing nds2 data to files
finishing writing
Background Values:
bg1 = 18.671164; Background of TX when WS is at TX
bg2 = 5.156755; Background of WS when WS is at TX
bg3 = 18.605483; Background of TX when WS is at RX
bg4 = 5.281252; Background of WS when WS is at RX
bg5 = 18.674174; Background of TX
bg6 = -1.117857; Background of RX

The uncertainty reported below are Relative Standard Deviation in percent

Intermediate Ratios
RatioWS_TX_it = -0.533986;
RatioWS_TX_ot = -0.543766;
RatioWS_TX_ir = -0.526609;
RatioWS_TX_or = -0.535095;
RatioWS_TX_it_unc = 0.059001;
RatioWS_TX_ot_unc = 0.057064;
RatioWS_TX_ir_unc = 0.061781;
RatioWS_TX_or_unc = 0.063032;
Optical Efficiency
OE_Inner_beam = 0.985936;
OE_Outer_beam = 0.983757;
Weighted_Optical_Efficiency = 0.984846;

OE_Inner_beam_unc = 0.046465;
OE_Outer_beam_unc = 0.047412;
Weighted_Optical_Efficiency_unc = 0.066385;

Martel Voltage fit:
Gradient = 1637.889101;
Intercept = 0.085727;

Power Imbalance = 0.982015;

Endstation Power sensors to WS ratios::
Ratio_WS_TX = -0.927858;
Ratio_WS_RX = -1.383422;

Ratio_WS_TX_unc = 0.047658;
Ratio_WS_RX_unc = 0.041564;

=============================================================
============= Values for Force Coefficients =================
=============================================================

Key Pcal Values :
GS = -5.135100; Gold Standard Value in (V/W)
WS = -4.698648; Working Standard Value

costheta = 0.988362; Angle of incidence
c = 299792458.000000; Speed of Light

End Station Values :
TXWS = -0.927858; Tx to WS Rel responsivity (V/V)
sigma_TXWS = 0.000442; Uncertainity of Tx to WS Rel responsivity (V/V)
RXWS = -1.383422; Rx to WS Rel responsivity (V/V)
sigma_RXWS = 0.000575; Uncertainity of Rx to WS Rel responsivity (V/V)

e = 0.984846; Optical Efficiency
sigma_e = 0.000654; Uncertainity in Optical Efficiency

Martel Voltage fit :
Martel_gradient = 1637.889101; Martel to output channel (C/V)
Martel_intercept = 0.085727; Intercept of fit of Martel to output (C/V)

Power Loss Apportion :
beta = 0.998844; Ratio between input and output (Beta)
E_T = 0.991820; TX Optical efficiency
sigma_E_T = 0.000329; Uncertainity in TX Optical efficiency
E_R = 0.992968; RX Optical Efficiency
sigma_E_R = 0.000330; Uncertainity in RX Optical efficiency

Force Coefficients :
FC_TxPD = 9.158396e-13; TxPD Force Coefficient
FC_RxPD = 6.237025e-13; RxPD Force Coefficient
sigma_FC_TxPD = 4.417816e-24; TxPD Force Coefficient
sigma_FC_RxPD = 2.847865e-24; RxPD Force Coefficient
data written to ../../measurements/LHO_EndY/tD20260804/

Images attached to this report

Non-image files attached to this report

LHO_EndY_PD_ReportV6.pdf

H1 CDS - Replace Adnaco with bad slot h1seiey

david.barker@ligo.org — Tue, 04 Aug 2026 17:00:47 -0700

Author: david.barker@ligo.org

Report ID: 91394

WP13482

Jim, Erik, Dave:

h1seiey was powered down: computer, IO Chassis and AI chassis.

The IO Chassis A2 Adnaco backplane was replaced with a spare. The original backplane's slot3 failed during O4 (Oct 2025) and back then we shifted the cards left by one slot to avoid it.

old backplane with broken slot3 (removed)	C8610513
spare backplane (installed)	C8610832

I was then able to put the cards back into their original slots, making h1seiey identical to h1seiex. This meant A3 now had no cards installed, so I disconnected the A3 fibers from the rear of h1seiey.

For backplane testing we stopped the models from running to verify all the cards are seen. Auto start was turned back on, the system was powered up, the models started and lastly I powered the AI chassis back on.

LHO General - Comment to OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 16:43:23 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91392

It is also worth nothing that as of 16:30 PT, there are no active fires in Benton or Franklin county per Watch Duty.

H1 AOS - JAC ASC Loops Closed

khanh.vu@ligo.org — Tue, 04 Aug 2026 16:41:19 -0700

Author: khanh.vu@ligo.org

Report ID: 91391

Masayuki Nakano, Khanh Vu We successfully closed all of the JAC ASC loops. Attached below are the outputs from the two wavefront sensors. All of the signals converge to zero within approximately 30 seconds, indicating that the loops are working beautifully. More details will be reported tomorrow.

Images attached to this report

LHO General - OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 16:33:07 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91389

TITLE: 08/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

Slow day due to ongoing FAC water and outdoor air quality issues but the following was done:

HAM7 Power measurements
JAC Beam profiling at IOT1 and power measurements and IOT2L
Scissor lift work
Gate phone work
PCAL EY Measurement
Seismic work (Jim) on HAM2 electronics and ITMX

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:45	FAC	Kim	LVEA	Local	Technical Cleaning	15:18
15:21	SQZ	Camilla	LVEA	Local	Taking Viewport covers off HAM5	16:13
15:31	FAC	Kim	LVEA	Local	Technical Cleaning	16:15
16:11	ISC	Jennie	Optics Lab	Local	Looking for parts	16:13
16:17	JAC	Jennie, Masayuki	LVEA	YES	IOT1 beam profiling, then IOT2L beam pwr meas.	19:17
16:21	FAC	Chris	LVEA	YES	FAMIS Tasks	17:21
16:31	JAC	Khanh	LVEA	YES	Joining JAC Team	20:02
16:37	SEI	Jim	LVEA HAM2	yes	Chcking signal paths	17:58
17:16	VAC	Jordan	LVEA GV6	y	Getting parts.	17:25
18:30	CDS	Dave	EY	N	SEI Chassis work	20:02
18:40	SQZ	Camilla	LVEA	YES	HAM7 power measurements	19:34
18:42	SQZ	Ryan S	LVEA	YES	HAM7 Power measurements	19:34
19:33	PCAL	Tony	PCAL Lab	Local	Staging parts	19:53
19:39	FAC	Randy	LVEA	Y	Scissor Lift Work	20:39
19:54	CAL	Tony, Ibrahim	EY & Lab\\	Y	PCal measurement	22:18
20:50	SQZ	Camilla	LVEA	-	Covering HAM5/7 viewport	21:16
21:44	SQZ	Camilla	LVEA	Y	HAM7 power budget	00:44
22:01	SQZ	Ryan S	LVEA	Y	HAM7 power budget	23:13
23:31	SQZ	Sheila	LVEA	Y	HAM7 power budget	01:31
23:31	CDS	Dave	EY	N	Chassis work	23:32

H1 SQZ - Comment to SQZ OMC Scans and M^2 Measurements with new ZM4 ZM5 PSAMS Preloadings

eric.oelker@ligo.org — Tue, 04 Aug 2026 16:27:21 -0700

Author: eric.oelker@ligo.org

Report ID: 91390

Below I calculate the astigmatism based Ryan's grid of M^2 measurements.

I compute the 1D overlap between the x and y directions using the q values from the M^2 measurements

eta_1D = 4*zRx*zRy / ( (z0x - z0y)^2 + (zRx + zRy)^2 ) where z0 is the waist position and zR is the rayliegh length = pi * w /(M^2*lambda)

The astigmatism, which i express as 1 - eta_1D is tabulated below in %

ZM5 \ ZM4	-3.2	-1	1.2	3.4
-8	0.52	0.52	0.55	0.59
-6.75	0.51	0.48	0.60	0.64
-5.5	0.56	0.55	0.62	0.50
-4.5	0.57	0.56	0.55	0.36
-3.3	0.52	0.50	0.40	0.29
-2	0.42	0.50
-1	0.56	0.78	0.62	0.15

The dependance is pretty weak over much of the grid, but things get a bit squirly in the lower right corner near the positive end of the range for both PSAMS. We're not as sensitive to the strain gauge setting as ZM2 (91185), but there's clearly a noticible dependence.

Non-image files attached to this report

Aug03_2026.zip

H1 AOS - Comment to IOT1 Table Work

masayuki.nakano@ligo.org — Tue, 04 Aug 2026 14:56:43 -0700

Author: masayuki.nakano@ligo.org

Report ID: 91388

The beam profile between the beamsplitter and the JAC WFS was measured. Here I fit a Gaussian beam to those measured beam sizes and convert the WFS locations into Gouy phase.

Fit

The measured beam diameters were fit independently in x and y with the standard Gaussian beam model, w(z) = w0 * sqrt(1 + ((z - z0)/zR)^2) with zR = pi * w0^2 / lambda and lambda = 1064 nm:

	w0 [um]	z0 [m from JACR_BS4]	zR [cm]
x	141.2	0.377	5.89
y	151.9	0.370	6.81

The beam is slightly astigmatic, so x and y are treated separately throughout.

WFS positions and Gouy phase

The positions of WFS A and WFS B were measured with a ruler from the same reference as the profile scan: WFS A at z = 0.325 m, WFS B at z = 0.410 m. The corresponding Gouy phases, psi(z) = arctan((z - z0)/zR), are:

	WFS A [deg]	WFS B [deg]	Separation [deg]
x	-41.3	+29.5	70.8
y	-33.5	+30.4	63.9

Assessment

The separation is 71 deg in x and 64 deg in y, not the optimal 90 deg. This is not optimal, but it is not terrible either: the two WFS remain well separated in Gouy phase and the sensing matrix would not be close to degenerate. Given the time available we did not optimize the layout.

If we want to optimize it later, the fix is straightforward: moving WFS A upstream (toward the BS) by about 5 cm in x / 7 cm in y, i.e. from z = 0.325 m to roughly z = 0.27 m, brings the separation to 90 deg. WFS B does not need to move.

Images attached to this report

H1 IOO - IOT1 Table Work

khanh.vu@ligo.org — Tue, 04 Aug 2026 14:32:40 -0700

Author: khanh.vu@ligo.org

Report ID: 91386

Jennie Wright, Masayuki Nakano, Khanh Vu This morning we worked on several tasks on the IOT1 table, including installing the camera and shutter, profiling the beam, and calibrating the DC power. We identified a new location for the camera using the beam transmitted through JACR_M5. During this process, Masayuki noticed that the beam was being clipped by the shutter. We suspect that the beam may have been clipped for some time. We then installed the camera in its new location, and Masayuki aligned the shutter on the table. Next, we profiled the beam for the wavefront sensors. We found that the Gouy phase separation between the two WFSs is approximately 70 degrees. We decided to leave the current configuration as it is since the separation is good enough. Masayuki will make a plot and perform a more detailed calculation later. We also maximized the laser power in the REFL path by optimizing the waveplate angle. When JAC is unlocked, the measured power on the RFPD is 5.1 mW, and the trigger PD voltage is 0.28 V. When JAC is locked, the measured power decreases to 0.4 mW, and the trigger PD voltage is 0.02 V. Since the beam is split evenly, each WFS receives approximately 2.55 mW of optical power. Finally, we calibrated the DC readout of RFPD by converting counts to mW. Before performing the calibration, Masayuki checked the alignment and recentered the RFPD. He then recorded two sets of measurements, each averaged over 10 seconds: Measurement #1 * JAC_REFL_A_LF_INMON: 1072.3966186523437 counts * DC power: 4.4 mW Measurement #2 * JAC_REFL_A_LF_INMON: 1073.5228637 counts * DC power: 4.5 mW After the calibration, we updated filter number 10 with the new coefficients. IOO

H1 ISC - Comment to SRY locked with different BS alignment

elenna.capote@ligo.org — Tue, 04 Aug 2026 13:34:59 -0700

Author: elenna.capote@ligo.org

Report ID: 91387

After discussion this morning, I put the ITMX sliders back to the O4 alignment position: pitch = -113 and yaw = 104.6

H1 SEI - Comment to BS ISI health check

jim.warner@ligo.org — Tue, 04 Aug 2026 10:36:57 -0700

Author: jim.warner@ligo.org

Report ID: 91384

Finally had a chance to repeat the test swapping st2 h1 v1 cps. Still no change, as I have seen when I did this test before. The excess low freq noise follows the in-air to feedthru and in-vac cables, so the problem is not from the satellite chassis or the CER rack. I can try to swap the cable from the feedthru to the satellite rack, but the work platform, crossbeam and feedthru protection make access to that difficult from pretty much any direction.

Attached spectra compare the nominal H1 V1 asds and the asds with the white in-air cables at satellite rack for st2 H1&V1 swapped. Dashed is nominal, solid is the swapped configuration. Red is the H1 channel, blue is the V1 channel.

Images attached to this report

H1 ISC - Comment to SRY locked with different BS alignment

keita.kawabe@ligo.org — Tue, 04 Aug 2026 10:33:35 -0700

Author: keita.kawabe@ligo.org

Report ID: 91383

Attached is a not-to-scale, super-simplified cartoon so people understand what happened. As of now, ITMY is unchanged (because I reverted the changes temporarily made to ITMY), BS is angled in PIT, ITMX was angled mostly in PIT to follow the BS motion.

Initial state is in the top cartoon. The symptom that the two beams (single bounce and reflection of SRM reflected back by ITMY) didn't interfere well only meant that the beam was not retro-reflecting on ITMY.

This could be remedied by many different ways. At first I moved ITMY just to confirm that something like this was going on, and we did confirm that (because we were able to make the SRY fringe deeper).

Once we confirmed this was actually the case, I reverted the ITMY back, moved BS, and refined SRM using SRY fringe. The bottom cartoon represents this final state.

Though it's not captured in the cartoon, this of course made the MICH fringe wrong, so we moved ITMX, too.

Using BS or ITMY (or a combination of them) is not the only way though, you can change the angle of the beam from PR3 hitting the BS and refine SRM alignment to recover a good SRY fringe depth. As long as the beam is still on ITMs it will work. I haven't done that bacause it was late and I wanted to see the beam on POP_A or B, but we should.

Note that, ultimately, the good alignment of the ITMs, BS and PR3 won't be known until we open the arms. There's no magic in the current alignment we have (or even after using PR3 instead of BS to regain SRY fringes).

The main purpose of this excercise is just to confirm that nothing terrible is going on in the SRC chain. Because of the things described in Elenna's alog above, we already know that nothing terrible is going on. The rest is just an effort to gradually, maybe, approach the good alignment (on a belief that we already know the good angles for ITMs).

Images attached to this report

LHO General - OPS Day Shift Start

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 07:41:34 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91382

TITLE: 08/04 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, 1mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Today, we anticipate some Ion Pump work from Vacuum and some comissioning work after Tues Maintenance

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 04 Aug 2026 06:01:13 -0700

Author: erik.vonreis@ligo.org

Report ID: 91381

Workstattions were updaed and rebooted. This was an OS packages update. Conda packages were not updated.

LHO VE - Comment to Seal Replacement on GV6 Air Cylinder

jordan.vanosky@ligo.org — Mon, 03 Aug 2026 17:45:39 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91378

8/3/2026

Travis, Gerardo, Jordan

Today we again disassembled the GV6 air cylinder with the valve soft closed to try and see what may have been causing the air blow-by which prevented us from fully opening the valve last week.

We did not find anything immediately obvious such as a seal that had jumped out of the groove, so we measured the ID of the original air cylinder, which was re-used, and found that it was ~0.01" larger than the ID of the spare cylinder (original ID ~8.015", spare ID ~8.005"). We then elected to use the spare cylinder instead to make sure there is good sealing contact with the cylinder wall, so we re-distributed the grease on the new cylinder and attempted to install over the piston, but the tube seemed to be slightly out of round and would not fit over the piston. So we flipped the tube 180 degrees and measured that side of the tube and found it was better. We again added grease to that side of the cylinder and installed it over the piston, ensuring the seals and wear band stayed in place, Then we re-installed the threaded rods, torqued the nuts, installed the reed switches and installed the air lines.

To verify all the new joints/connections were ok, we put ~10 psi to the top of the cylinder and then to the bottom to see if there were any leaks. There were none so we started to open the valve by increasing air pressure at the regulator, once we got to ~25 psi we could hear and feel air coming out of the bottom plate/adapter flange below the cylinder assembly, see picture below the area where air is coming out of is circled in red, at which point we stopped trying to open the valve and closed the quarter turn isolation valve to the air line.

We spoke with a GNB rep who advised we try to to open at a higher pressure and see if the bottom seals, so we then tried to open the valve again. This time we started at 20 psi and followed our normal opening procedure with the exception of increasing by 5 psi instead of 10 and waiting 3 minutes between increases. At ~35 psi, air stopped leaking out of the bottom flange, there was no air blow-by in the cylinder and we could hear the carriage starting to move. The gate fully opened at ~48 psi and Gerardo was able to take a video where you can hear the piston incrementally move up the cylinder. We increased the holding pressure to 58 psi and verified the MEDM screen showed the valve status as green.

Images attached to this report

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 03 Aug 2026 17:25:49 -0700

Author: ryan.short@ligo.org

Report ID: 91377

FAMIS 63910

Last Tuesday's interlock work and brief time in the enclosure are clearly seen on many trends, and essentially everything came back as expected. One item of note is the PMC, which relocked at a slightly higher temperature, which seems to have caused the transmitted power to be a bit lower while the reflected power is a bit higher.

Images attached to this report

H1 ISC - SRY locked with different BS alignment

elenna.capote@ligo.org — Mon, 03 Aug 2026 16:58:30 -0700

Author: elenna.capote@ligo.org

Report ID: 91376

[Keita, Elenna]

Sheila and I struggled to lock SRY last Friday, 91360. Keita and I revisited today.

To start, I ran the usual SR2 alignment, which centers the beam on AS_C, and the AS centering which centers OM1,2 on AS A and B.

Then, we could see a large beam at the center of the AS AIR camera, and a strange fringing beam at the top edge of the camera. We swept SRM in both pitch and yaw to both edges and saw the beam disappear. This convinced us that we were seeing the two beams we needed to overlap in SRY, however, there was not an SRM alignment that could overlap the two beams.

Keita first moved ITMY 10 urad in pitch, and was able to overlap the two beams. He then undid that alignment and moved the beamsplitter instead. We were able to achieve the SRY fringing and then lock SRY with the guardian. The resulting beam ended up on the top edge of th AS AIR camera view.

Using that beamsplitter alignment, we then relocked MICH dark, which required a large movement of ITMX, since we had decided to maintain the beamsplitter and ITMY alignment. ITMX is now at P: -135 and Y: 113.1 on the sliders. This means it has been moved relative to where it should be according to a previous arm alignment we achieved.

We can still see the MICH fringes on the ISCT1 refl camera with this alignment.

We can also lock PRX, with a movement of PRM. We still see no beam on POP A or B, so Keita is scanning the input alignment.

The attached screenshot shows the alignment sliders after we locked SRY, MICH, and PRX.

I'm not sure if we are happy with this alignment overall, since we're not sure if this is where we want the ITMs.

Images attached to this report

H1 DAQ - Comment to WP 13472 - new frame writer software on h1daqfw0 + OS upgrade

jonathan.hanks@ligo.org — Mon, 03 Aug 2026 16:46:53 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91375

As the new framewriter is a different piece of software, we track different metrics. So we will need an updated edc capture list and a daqd restart.

A note about what this system brings in.

* It automatically changes its configuration when there is a channel list. It is a step towards not having daqd restarts (those don't go away while we have the daqd in other places).

* When we restart the daqd we usually have a gap of several frames. We hide this from the outside world by having two frame writers and only restarting one at a time. This reconfigures the channel list and does not have gaps unless you actually restart the program.

* It is also being used in the ngdd work to write derived frame data, so that we have a common frame writer (we just change the input type).

H1 DAQ - WP 13472 - new frame writer software on h1daqfw0 + OS upgrade

jonathan.hanks@ligo.org — Mon, 03 Aug 2026 16:37:37 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91374

Per WP 13472 updated h1daqfw0 to use the new auto-reconfiguring frame writer. This is the same code has been running on h1daqfw2 for months in a test mode.

I also did an inplace upgrade of h1daqfw0 to Debian 12, which is what h1daqfw2 is running and what we have tested as.

Erik helped with package wrangling for Debian 12. I had been running h1daqfw2 from the experimental repository (which is a snapshot of the continous integration system). We were able to move this from using the experimental repository to the unstable repository. We will move it up to production later. We don't have a full Debian 12 release of advligorts as we are not planning on supporting the rcg and real time code on Debian 12.

Dave and I will be watching the timings and checksums to make sure everything looks good. The IO setup is a bit different between h1daqfw2 and h1daqfw0 (fw2 writes to local disk, fw0 to a NAS).

H1 General - Ops Monday report

anthony.sanchez@ligo.org — Mon, 03 Aug 2026 16:35:47 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91373

TITLE: 08/03 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: 11mph Gusts, 7mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:
The well pump was not working today due to some electrical issue. Last I heard FAC had a contractor on site to check on the well. So there is limited amounts of water here. Many folks were asked to work from home if they can.

GRB-Short E644098 @ 17:29 UTC

Jonathan started working on the FrameWrite0 today, installing Deb12 OS.

End stations were misaligned today to some tests that Camilla was doing.

ITMX ISI Stage 1 & 2 WD tripped twice today. Jim went out to the CER today to fix this.

Vac Team did some work on the GV6 Gate Valve today and GV6 is currently Open on the Y arm, But GV5 is still closed so the corner volume is still not open to the Arms yet.

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:10	FAC	Kim	LVEA	y	Technical cleaning & resupply	17:00
15:41	CDS	EJ	Remote	N	Test on OAF	15:42
15:43	FAC	Tyler, Eric, & contractors	EY	N	Working on the well	20:39
15:48	SQZ	Camilla	LVEA HAM5	YES	Opening ViewPort on HAM5	15:55
16:10	FAC	Kim	Mid X	N	Tecnical Clkeaning & resupply	17:01
16:11	SEI	Jim	LVEA	n	working on SEI near BSC2	18:08
16:41	VAC	Jordan & Travis	LVEA GV6	N	Working on the Gate Valve	18:39
17:20	SEI	Jim	remote CER	N	Tests on HAM2 & looking at Wiring	18:22
17:25	VAC	Gerardo	LVEA	N	Checking on GV6 work	19:25
17:45	CDS	Partick	MSR	N	CDS work?	18:06
18:39	FAC	Kim	HAM Shaq	N	technical Cleaning & Resupply	19:07
19:05	CDS	Jonathon	Remote	N	Re-imaging FW0	22:04
19:59	SEI	Jim	Remote	N	Tests on HAM3	21:25
20:03	VAC	Jordan	LVEA	N	Getting pics of GV6	20:07
20:51	VAC	Travis & Gerardo	End Y	N	Using the pump cart for Anulus work.	21:28
21:10	SQZ	Camilla & Ryan S	LVEA HAM7	YES	Beam Profiling with M2**2 profiler. Ryan Out early	23:10
21:12	SEI	Jim	CER	N	troubleshooting ITMX ISI WD trips.	21:24
21:43	VAC	Jordan	LVEA GV6	N	Checking on GV6 status	22:28
22:41	VAC	Jordan & Gerardo	LVEA GV6	N	Opening GV6	00:11
22:46	SQZ	Sheila	LVEA HAM7	YES	Working on the Power budget	00:16

H1 ISC - Dark offsets run

elenna.capote@ligo.org — Mon, 03 Aug 2026 16:15:01 -0700

Author: elenna.capote@ligo.org

Report ID: 91372

Keita and I took an opportunity while JAC was offline to run all the dark offsets. I ran the usual dark_offsets_exe.py from userapps isc/h1/scripts/dark_offsets

I did not visually check all of them but the ones I compared before and after in SDF looked reasonable.

Some of the whitening gain settings have been set strangely for the vent, so this should help fix that now that we have reset the proper settings.

SDFed, see screenshots.

After we ran, Keita and I realized the whitening settings for POP B were still wrong, so I corrected them and reran the offset for the POP B segments. Added screenshot.

Images attached to this report

H1 SQZ - SQZ OMC Scans and M^2 Measurements with new ZM4 ZM5 PSAMS Preloadings

camilla.compton@ligo.org — Mon, 03 Aug 2026 15:44:46 -0700

Author: camilla.compton@ligo.org

Report ID: 91371

Sheila, Ryan S, Camilla

We spent the morning repeating 90783, now that ZM4 preloading has been adjusted (90951) and ZM5 has been swapped and now has a different preloading than our O4 ZM5 (91292):

Using SQZ ASC with ZM4 and ZM5 to get ASC_A and ASC_B centered, we needed to move SRM to stop saturating ZM4/5,
then locking OMC on 00 touching up OMC and OM3 alignment to maximize 00 peak,
then putting these ASC-OMC offsets into H1:OMC-ASC_QPD_A/B_PIT/YAW_OFFSET so that the OMC ASC will put us in this good location.

Sheila then used her script to run OMC scans at a grid (below) of PSAMS locations. These initially look great, showing sqz to omc mode mismatch is as good as 1%. with some alignment fluctuations. Ndscope of data taking attached.

PSAM_VALUES_V5 = [-8, -5.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

Ryan then took M^2 measurements on SQZT7 of a slightly different grid:

PSAM_VALUES_V5 = [-8, -6.75, -5.5, -4.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

Images attached to this report

H1 ISC - BBSS model with MICH ASC

elenna.capote@ligo.org — Mon, 03 Aug 2026 10:44:11 -0700

Author: elenna.capote@ligo.org

Report ID: 91368

Following a similar process for the length control as in 91028, I used both the BSFM and BBSS model to construct a model of the MICH ASC and check the crossover frequencies.

The most recent ASC OLG measurements of MICH P and Y are in userapps asc/h1/templates/MICH. MICH P UGF is roughly 2 Hz, MICH Y is roughly 0.7 Hz. Using the BSFM model and this information, I once again assumed the optical gain of the MICH ASC would be the same and calculated a rad/ct calibration factor to use with the BBSS model. Note that these UGFs are from full power lock, so I'm not certain what the MICH ASC OLGs look like in DRMI lock.

The BSFM model also says that both P and Y have a 22 mHz crossover between M1 and M2.

Using these calibration factors show that we might have some trouble running with the exact same MICH ASC design with BBSS. I think this is because the MICH ASC design contains a pretty extreme BSFM plant inversion. We could replace it with a BBSS inversion, or use this opportunity to move to a slightly different design principle that doesn't require precise plant inversion.

The model also suggests that the yaw crossover from M1 to M2 will be about 22 mHz as before, but shows the pitch crossover would now be 8.5 mHz. I need to confirm I am using the correct lever arms for the calibration to make sure I haven't made a mistake there. Either way, we can confirm the crossover with an injection.

Just as with length, we would need to slightly adjust the locking filter design if we want to move to M1 and M3 actuation, but in principle I don't see any issue with driving from M3 instead of M2 for ASC as well. This would be in line with how we drive all other triple sus for ASC.

First attachment shows the MICH ASC in the BSFM model, second in the BBSS model.

SUS

Images attached to this report

H1 CDS - Greened up h1iopomc0 timing card status on CDS Overview

david.barker@ligo.org — Mon, 03 Aug 2026 10:42:38 -0700

Author: david.barker@ligo.org

Report ID: 91370

Post upgrade the CDS Overview was showing an issue with h1iopomc0's timing card. On further investigation we found that this timing card is a very early rollout of the V5 firmware, upgraded back in Feb 2025 for DT-frequency changes. The actual issue is that RCG5.65 is more accurately calculating the duotone crossing for h1omc0's low-noise ADCs. This value was +0.1uS pre-upgrade and now is -5.625uS with only nano-second variation. The CDS overview was using the DT crossing time as an indicator of timing card firmware version. V3 had DTs between +7uS and +8uS, V5's are in the -1uS to +1uS range.

I've changed the CDS Overview to extend the lower limit of acceptible DT timings to -6uS. No further action is required.

H1 CAL - O4b DARM Loop Design Comparisons and Critiques

rachel.langgin@ligo.org — Mon, 03 Aug 2026 10:16:40 -0700

Author: rachel.langgin@ligo.org

Report ID: 91369

Rachel and Elenna:

The goal of this project is to better understand the DARM loop design that was used during O4b and evaluate how well it performed. By identifying where the design worked well and where we observe limitations, we can gain insight into potential improvements for future DARM loop designs.

To do this, I recreated the pydarm.plot.critique() function using valid O4b calibration reports (H1: 20250111T193645Z and L1: 20250102T163026Z). I then broke the DARM loop down into its individual components to understand how each stage contributes to the overall control performance.

The analysis includes comparisons of the open-loop gain (OLG, (G)), the suppression function (1/(1+G)), the digital_out_to_displacement actuation transfer functions, the lock_in_to_displacement actuation transfer functions, annotated crossover frequencies, and the frequency ranges over which each actuation stage dominates.

Several notable differences emerge between the H1 and L1 DARM loops. H1 has a lower unity gain frequency (72.2 Hz vs. 86.0 Hz), a lower low-frequency OLG magnitude, and substantially less phase margin (22.5º vs. 34.3º). The reduced phase margin is also reflected in the larger gain peaking observed in the suppression function. Regardless of how future DARM loops are offloaded, increasing the available phase margin should be a primary design objective.

The actuator comparisons show that the overall stage hierarchy is similar between the detectors, with the UIM dominating at low frequencies before the TST becomes dominant above approximately 17 Hz. However, the lock_in_to_displacement transfer functions reveal more complicated interactions between the UIM, PUM, and TST at low frequencies than are apparent from the digital_out_to_displacement transfer functions alone.

See: LIGO-G2601606 for slides.

CAL

H1 IOO - Comment to JAC heater and HAM1 pressure

keita.kawabe@ligo.org — Mon, 03 Aug 2026 10:15:31 -0700

Author: keita.kawabe@ligo.org

Report ID: 91366

Actually I turned the heater back on shortly after I turned it off on Friday because the pressure rise that some were worried about looked like diurnal change to us and it was already peaking at the time.

I monitored the pressure on Friday evening and it was good, it was good on Saturday too so I kept the heater ON over the weekend. No need to turn it off from this point on.

Images attached to this report

H1 General - Monday Ops Morning report

anthony.sanchez@ligo.org — Mon, 03 Aug 2026 08:09:34 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91365

IFO status: Currently Unlocked. Both GV5 and GV7 are shut..... for now.
Corner pump down continues.
Spool cameras work to reinstall IR cameras.
More Distributed acoustic sensing DAS system.

H1 CDS - Comment to no h1sush12 IPC errors since fiber/SFP swap

david.barker@ligo.org — Sat, 01 Aug 2026 09:59:05 -0700

Author: david.barker@ligo.org

Report ID: 91364

h1syscsauxsdf had gotten stuck, I restarted it on h1ecatmon0.

H1 CDS - no h1sush12 IPC errors since fiber/SFP swap

david.barker@ligo.org — Sat, 01 Aug 2026 08:12:15 -0700

Author: david.barker@ligo.org

Report ID: 91363

Following yesterday's swap of h1sush12's IPC fiber and switch-SFP (port3) 23 hours ago there have been no IPC errors from this frontend. Also the 25GE switch (sw-msr-ipc0 port3) shows zero packet errors.

H1 SQZ - Comment to HAM7 Squeezer beam alingment work, power budget estimation and beam injected into HAM5.

sheila.dwyer@ligo.org — Fri, 31 Jul 2026 17:39:09 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91360

Power budget: We measured 1.35mW out of the OPO, and 1.2mW on SQZT7. we struggled as usual with the reliablity of the power meter measurements, but it seems like the return beam through SFI1 has higher loss than it should, and there also seems to be power missing between the beam leaving the VIP and the beam arriving on SQZT7. If we believe this measurement we have too much loss, with 12% measured loss in HAM7 where we should have 4-5%.

I did walk the alignment of ZM1/2/3 a little bit, we could try this more to see if we can fix clipping that way. Screenshot of where I left the sliders is attached.

Elenna and I put SR3 back to where it was in O3, aligned SR2 to center on AS_C, and ran the AS centering + offloaded. We then tried to align SRY, but could not get the fringes as high as they should be. We paused on SRY alignment to inject sqz into HAM6.

The sqz beam was on the HAM6 QPDs, we ran the AS WFS to ZM4+5 loops descirbed in 90742. This is close to saturating ZM4 + 5 but is within the range. (We would like to increase the range on these as was done at LLO to make things easier).

We set the OMC PZT offset to 0, decided to scan the psams through strain gauge values of

PSAM_VALUES_V5 = [-8, -5.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

and engaged the strain gauge servos. I did not tune the OMC ASC offsets carefully as described in 90783, perhaps that needs to be done to get a good estimation of the mode matching.

A set of OMC scans for different psams is running now.

Images attached to this report

H1 IOO - JAC heater and HAM1 pressure

sheila.dwyer@ligo.org — Fri, 31 Jul 2026 17:36:36 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91361

Keita turned on the JAC heater this afternoon. Attached plot has the first cursor at the time of 91296, the second cursor at the time when Keita turned on the heater, they both happened at the same point in the diurnal pattern where the termperature rises.

Keita has now turned the heater off before people leave for the weekend, because we can't say it's not causing the pressure to rise. Let's repeat this earlier in the day on Monday.

Images attached to this report

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 16:31:59 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91359

TITLE: 07/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
SHIFT SUMMARY: The final bits of the CDS upgrade continued today, as well as some SQZ and michelson commissioning. The LVEA is currently in Operations SAFE.

The corner station continues to be pumped down, pressures are around 4e-7torr. The HAM1 pressure has been a concern when using the JAC heater this week, but I think we may have been scaring ourselves. The HAM1 pressure changes diurnally regardless of whether the heater is on or off. We have seen a pressure response from turning on the heater, but this diurnal effect might be the dominating factor. Looking at LVEA temps around HAM1 it tracks well with the local temperature.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
13:33	DAS	Jenne, Wanda, Shoshana, Gizem	Yarm, Xarm inside	N	Hitting things with hammer	17:09
16:05	CDS	Jonathan	MSR	n	Troubleshooting iopsush12	16:13
16:12	FAC	Kim	LVEA	n	Tech clean	17:13
16:21	SUS	Ryan C	CR (Ends)	n	EX & EY sus charge meas.	18:03
16:38	SQZ	Sheila, Rahul	LVEA	LOCAL	SQZ alignment with refurb ZM5	19:38
17:37	VAC	Gerardo, Travis	EY	n	BSC6 annulus work	18:25
17:39	VAC	Gerardo	LVEA	n	Grabbing lifting hardware for EY	17:49
17:57	ENG	Betsy	Opt Lab	n	Parts	18:03
18:01	SAF	Ryan C	LVEA	N -> n	Transition LVEA from Upgrade laser safe to Operations lasre safe, open light pipe	18:31
18:08	DAS	Wanda	EX, vertex	n	Looking for glasses	18:31
18:20	SQZ	Daniel	LVEA	LOCAL	Look at ZM4 electronics	18:49
19:31	FAC	Randy	LVEA	n	Measuring around BSC1	19:58
19:37	SEI	Shoshana	LVEA	n	Turning on CRS laser	19:41
20:43	VAC	Gerardo, Travis	LVEA	n	Checking on HAM2 pumps, disconnecting	20:56
20:45	SQZ	Sheila, Rahul	LVEA	LOCAL	Open HAM7 to HAM5, check alignment	21:45
20:52	CDS	Dave	CER, CUR	n	iopsush34 troubleshooting	21:50
21:34	CDS	Richard	CER	n	Checking in on iopsush34 work	21:35

Images attached to this report

H1 SQZ - HAM7 Squeezer beam alingment work, power budget estimation and beam injected into HAM5.

rahul.kumar@ligo.org — Fri, 31 Jul 2026 15:51:44 -0700

Author: rahul.kumar@ligo.org

Report ID: 91358

Sheila, Rahul

We got back into HAM7 for beam alignment work after ZM5 was repaired and, up & running. Listed below are the things we did to check and improve the alignment in HAM7 chamber and also on the SQZT7 irises.

1. Checked the incoming beam on ZM5 from ZM4, found it to be off in yaw by few mm - hence we translated ZM5 (pushing it in the direction towards SQZT7 table) to center the beam on the PSAMS.

2. Checked the reflected beam from ZM5 on the iris (which Camilla had set last week) - it was off in Yaw and was too high as well. Hence, I mechanically adjusted the pitch and yawed the suspension cage to center the beam on the iris. Sheila then checked the beam on the two irises in SQZT7. Using sliders we were able to center it nicely on the two irises, however several times while doing so we were eating up on DAC output. Hence iteratively we were using sliders and mechanically offloading Pitch/Yaw by adjusting the pitch adjuster or yawing the suspension cage.

3. Sheila also used ZM4 sliders to fine tune the alignment on the irises on the table.

Current status - we have centered the beam on the two irises in SQZT7 but we might have to mechanically offload ZM5 or perhaps ZM4 as well. ZM5 has all four dog clamps attached and baffle installed as well.

We removed the yellow viewport cover (and guillotine) from HAM5, removed the foil and opened the gate valve on HAM7 viewport (going towards HAM5) and then confirmed that the beam is injected into HAM5.

Sheila, is fine tuning the IFO alignment before aligning the two beams (IFO and squeezer) in HAM6 photodiode.

We also did some power measurements in HAM7 chamber, mainly on the OPO and then compared it against SQZT7 table. Sheila will posting the numbers later on.

SUS

H1 CDS - fix h1susb2h34 DAC MEDM and verify correct drive of DACs

david.barker@ligo.org — Fri, 31 Jul 2026 15:16:11 -0700

Author: david.barker@ligo.org

Report ID: 91357

WP13479 Move last ADC in h1susb2h34 in front of the LIGO-DACs

Erik, Jonathan, EJ, TJ, Dave:

The 3rd ADC, which was after the LIGO-DACs on the PCI bus, was moved to be before the LIGO-DACs. EJ found that if a General Standards card followed the LIGO DACs, and there are other General Standard DACs in the chassis, then the DAC mapping became ambiguous. This was first discovered by TJ when he noticed that the LIGO-DAC card temperatures was being reported as -1C (not being read). We then found that model's LIGO-DAC drive counts were being reported by h1iopsusb2h34 on the wrong DAC MEDM.

A quick fix as to move the ADC inside the IO Chassis from after to before the LIGO-DACs

The original card layout (BIO not shown):

empty

***ADC2***

LIGO-DAC1

LIGO-DAC0

20bit-DAC1

ADC1

20bit-DAC0

ADC0

empty

Timing

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

The new card layout (BIO not shown):

empty

LIGO_DAC1

LIGO-DAC0

empty

***ADC2***

20bit-DAC1

ADC1

20bit-DAC0

ADC0

empty

Timing

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

I was able to shuffle the cards without disconnecting any rear cables except ADC2 (SUS_HAM_209) and the MTP. The cables had enough slack to pull the chassis out to access the card screws. At the rear I was able to push the h1susauxb2h34 chassis forward to access the interface cards.

Internally only ADC2's ribbon cable needed to be disconnected.

TJ methodically started driving the top stages for MC2, PR2 and BS. We verified the model's and IOP's MEDM reported the correct channels being driven.

I trended the ADC2 channels from before and after its move to verify it is connected correctly.

H1 ISC - DIAG_MAIN whitening checks updated

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 15:08:29 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91355

Keita pointed out that the normal DIAG_MAIN whitening check doesn't currently cover the OMC DCPD external analog whitening (state of which can be seen on H1:OMC-DCPD_{A,B}_GAINVAL, 0=high 1=low), and the corresponding digital antiwhitening for it at FM2 on H1:OMC-DCPD_{A,B}0. This is now in DIAG_MAIN's whitening test.

While I was looking at this test, I noticed it was quite out of date with the whitening overview screen. I pull all of the names from that screen and made a new list for the DAIG_MAIN test. There were only additions from the old list, so I don't think we dropped any sensors. I commented out some BHD sensors until they are fully ready.

OpsInfo

LHO VE - Comment to HAM2 Annulus Ion Pump Work

gerardo.moreno@ligo.org — Fri, 31 Jul 2026 14:46:20 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91356

(Travis S., Jordan V., Gerardo M.)
HAM2 annulus system pumpdown is done, Jordan Isolated the system earlier on the week from the aux-cart, ion pump took over the pumping with no issues. Today, taking advantage of a computer reboot, Travis and I removed the flex hoses and can turbo from the annulus system. Aux-cart and components were moved away and stored away from the chambers. BTW, this time we only used one aux-cart for the pumpdown process. HAM2 annulus system is back to nominal.

Images attached to this report

H1 SEI - DAS system, tap testing to calibrate distances along fiber

jenne.driggers@ligo.org — Fri, 31 Jul 2026 13:30:53 -0700

Author: jenne.driggers@ligo.org

Report ID: 91353

Jenne, Wanda, Shoshana, Gizem

We started very early this morning to beat the heat, and performed 'tap tests' at various points along the length of the arms to identify positions along the length of the fiber (according to DAS) with GPS positions (according to Wanda's phone).

Spreadsheet attachment is information about where along the fiber Shoshana and Gizem identified our tapping in the data, and associated time stamps. I've also copied the spreadsheet data to a google sheet, so that we can add to it.

We tried to do more dense taps on the 'inside of the vertex' side of the arms, where the fiber actually is. This required some walking out in the sand along the arms, so we had sun hats and knee-high boots and plenty of water. We also did a few taps along the road during our drive back, to get some more coarse information along the length of the arms. At the Xend station, there were too many tumbleweeds for us to walk along the inside-vertex side of the arm, so there at EX we did our more dense taps along the road side, with the exception of the EX vault location.

In the attached photos, you can see some examples of our tap test method. Gerardo provided us with a scrap piece of steel that we used as a strike plate. We also borrowed a sledgehammer from the mechanical / vacuum parts lab. For most of the Yarm, we only did 3 heavy strikes and Gizem and Shoshana chose the strongest signal from that as our time. Once we were on the road-side of Yarm, and then for all of Xarm, we added some light tapping that seems to have helped identify which distance bin (called a "channel" in DAS terminology) we were closest to. The photos are also labeled with X/Yarm, and position number, which corresponds to the position numbers in the google sheet - I tried to capture features in the photo to help identify where exactly the strike plate was.

Wanda has added to the google sheet the GPS locations that she identified while we were at each tap point.

The last photo shows our used (but can be used again in the future!) strike plate.

Images attached to this report

Non-image files attached to this report

DAS_Fiber_Test_July_31_2026.xlsx

H1 SUS - OPLEV charge measurement, ETMX & ETMY

ryan.crouch@ligo.org — Fri, 31 Jul 2026 12:22:47 -0700

Author: ryan.crouch@ligo.org

Report ID: 91350

I ran the charge measurements for both ETMs this morning. Unfortunately a medium (5.2 from Mexico) earthquake rumbled through from 16:38 to 16:58 UTC, but it didn't seem to effect the errors and coherences noticeably enough for me to restart the measurement.

For ETMX:

I was consistently getting low coherence for LL in Yaw, the charge appears to have plateaued or seen small increases (the error bars from the last measurement overlap with this one on all DOF/quadrants) on most DOFs/quadrants. The charge is above +\-50[V] on UR_P and LR_P, LR is still slowly trending to zero. ETMX is also quite misaligned as seen by its OPLEV.

For ETMY:

I was also seeing the worst coherence and largest errors on LL, both P and Y. The charge appears stable, there's not much difference from this measurement to the second to last (most recent one has large errors so it's not as valuable of a comparison). The charge is above +\-50[V] on LL P and Y, and UL_Y, there were some small increase of charge on LL as well.

SUS

Images attached to this report

H1 SEI - Distributed acoustic sensing (DAS) setup, day 4

jenne.driggers@ligo.org — Fri, 31 Jul 2026 10:44:54 -0700

Author: jenne.driggers@ligo.org

Report ID: 91351

Late post for DAS setup work on Thursday yesterday. Jenne, Wanda, Gizem, with Jonathan and Nyath helping get our remote access set up.

* EX, Fil connected a patch cable between fiber chassis and our termination fiber. This patch cable was FC-APC on the end that was connected to the fiber chassis, and FC-UPC connected to the FC-UPC termination cable. We were trying this mismatch between the FC-UPC of the chassis to a patch cable, in hopes that that would reduce any etalon effect between the UPC-UPC connectors. It didn't seem to help much.

* Xarm, Did a test for a while where Fil connected both our DAS channels to 2 fibers (#23 and #24) on the Xarm, to see if that made any difference in the noise; no impact, so eventually went back to just using #24 on X and #24 on Y.

Eventually we realized that the reason the data looked noisier is that we had changed some acquisition settings (effectively, changing our averaging). So, nothing actually changed in the overall performance of the system, which is good (we had thought that somehow we made it much worse between Mon and Wed).

We started an overnight data set using 500 Hz sample rate, to see that hopefully this is an okay balance between big file sizes and going up to high enough frequency to be useful. Xarm was connected to the Febus instrument, and Yarm to the Sintela instrument.

Also in the afternoon we got the remote connectivity working for both the Sintela and the Febus instruments.

Febus is the IP adress that ends in xxx.xxx.xxx.xx3
Sintela is the IP address that ends in xxx.xxx.xxx.xx4

H1 CDS - Comment to h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:16:30 -0700

Author: david.barker@ligo.org

Report ID: 91348

Replacement completed. I have unbypassed the SWWD for SEI HAM1 and HAM2.

Jonathan replaced the original fiber FMM-02M-1120 and installed FMM-02M-1111. sw-msr-ipc0 port3 SFP was replaced.

H1 CDS - Comment to h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:12:40 -0700

Author: david.barker@ligo.org

Report ID: 91347

Here is the CDS overview while h1sush12's fiber/SFP are being swapped out.

Images attached to this report

H1 CDS - h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:04:35 -0700

Author: david.barker@ligo.org

Report ID: 91346

Jonathan, EJ, Erik, Dave:

The first step in fixing h1sush12's IPC errors is to replace the fiber and switch SFP. I've put SEI SWWD for HAM1 and HAM2 into bypass mode in preparation for this.

Jonathan will perform the swap in the MSR.

This will be a hot-swap, no models need to be fenced, stopped or computers rebooted. Very different from the "Dolphin crash" days.

H1 CDS - Comment to extremely large coil output in the user model will flip the DAC output from positive to negative rail

keita.kawabe@ligo.org — Fri, 31 Jul 2026 08:55:35 -0700

Author: keita.kawabe@ligo.org

Report ID: 91345

Erik made a new git issue here: https://git.ligo.org/cds/software/advligorts/-/work_items/748

H1 CDS - Comment to h1sush12 low level send errors following the link restart Thursday 16:55

david.barker@ligo.org — Fri, 31 Jul 2026 08:53:01 -0700

Author: david.barker@ligo.org

Report ID: 91344

h1sush12 is connected to port 3 of sw-msr-ipc0. Looking at the port stats shows errors on port3 which are not seen on any other port (port2 shown for comparison).

h1susb2h34 Port2:

sw-msr-ipc0#show interfaces ethernet2
Ethernet2 is up, line protocol is up (connected)
Hardware is Ethernet, address is 4c09.9737.14bb (bia 4c09.9737.14bb)
Description: "h1susb2h34 | FMM-02M-1122"
Ethernet MTU 9214 bytes, BW 25000000 kbit
Full-duplex, 25Gb/s, auto negotiation: off, uni-link: n/a
Up 2 days, 16 hours, 31 minutes, 54 seconds
Loopback Mode : None
6 link status changes since last clear
Last clearing of "show interface" counters 2 days, 19:10:45 ago
5 minutes input rate 44.4 Mbps (0.2% with framing overhead), 34811 packets/sec
5 minutes output rate 937 Mbps (4.1% with framing overhead), 534449 packets/sec
6036140558 packets input, 962213865558 bytes
Received 84764 broadcasts, 6036055766 multicast
0 runts, 0 giants
0 input errors, 0 CRC, 0 alignment, 0 symbol, 0 input discards
0 PAUSE input
90864581964 packets output, 19842295883609 bytes
Sent 1569974 broadcasts, 90863012607 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output

h1sush12 port3:

sw-msr-ipc0#show interfaces ethernet3
Ethernet3 is up, line protocol is up (connected)
Hardware is Ethernet, address is 4c09.9737.14bc (bia 4c09.9737.14bc)
Description: "h1sush12 | FMM-02M-1120"
Ethernet MTU 9214 bytes, BW 25000000 kbit
Full-duplex, 25Gb/s, auto negotiation: off, uni-link: n/a
Up 15 hours, 49 minutes, 3 seconds
Loopback Mode : None
6 link status changes since last clear
Last clearing of "show interface" counters 2 days, 19:10:47 ago
5 minutes input rate 19.4 Mbps (0.1% with framing overhead), 18429 packets/sec
5 minutes output rate 962 Mbps (4.2% with framing overhead), 550830 packets/sec
3187368940 packets input, 418602501888 bytes
Received 96260 broadcasts, 3187272674 multicast
50 runts, 0 giants
57 input errors, 7 CRC, 0 alignment, 38 symbol, 0 input discards
0 PAUSE input
93703371906 packets output, 20383690243959 bytes
Sent 1558417 broadcasts, 93701815262 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output

H1 CDS - h1sush12 low level send errors following the link restart Thursday 16:55

david.barker@ligo.org — Fri, 31 Jul 2026 07:37:43 -0700

Author: david.barker@ligo.org

Report ID: 91343

At 16:55 the IPC-ETH link on h1sush12 went offline for about 5 seconds, stopping all IPC traffic into and out of this front end. Since that time we have had a low rate of send errors from models running on h1sush12, but no receive errors.

Two models on h1sush12 send IPCs to remote models:

chan	send model	rate	receive model
H1:IOP-SUS_H12_RM1RM2PM1_WDIPC	h1iopsush12	2k	h1iopseih16
H1:IOP-SUS_H12_MC1MC3PRMPR3_WDIPC	h1iopsush12	2k	h1iopseih23
H1:SUS-PRM_M1_LOCK_L	h1susprm	16k	h1seiproc

Note that the SWWD IPC send at 2k even though the models run at 64k.

The receivers on h1iopseih16, h1iopseih23 and h1seiproc reported a low level of receive errors overnight. Each time these were one error in the second. Most of the time the IOP error times were not the same as the PRM times, except for the last one (see trend)

In the past 14 hours, IOP had 5 errors and PRM 9 errors.

EJ recommends as a first step to replace h1sush12's ethernet fiber and the switch SFP (not replacing h12 Mellanox SFP at this time).

Images attached to this report

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 07:33:18 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91342

TITLE: 07/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 2mph Gusts, 0mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY: SEI BS is in ISI_DAMPED_HEPI_OFFLINE, CDS overview is Green, Temps and dust look good.

H1 CDS - h1sush12 IPC ethernet link reset itself

david.barker@ligo.org — Thu, 30 Jul 2026 22:07:15 -0700

Author: david.barker@ligo.org

Report ID: 91341

At 16:55 h1sush12's IPC ethernet port reset itself, taking all IPC to and from h1sush12 down for 5 seconds.

No in rack work was ongoing in the MSR at the time.

H1 General - Thurs Ops Eve report.

anthony.sanchez@ligo.org — Thu, 30 Jul 2026 19:02:54 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91340

TITLE: 07/31 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
ITMX ISI stage 1 & 2 WD tripped and there seems to be some ground motion there that may have tripped them.

But The BS HEPI and ISI seems to be fine as of writing!

H1 CDS - Comment to Testing WFS on JAC table

keita.kawabe@ligo.org — Thu, 30 Jul 2026 18:28:39 -0700

Author: keita.kawabe@ligo.org

Report ID: 91339

JAC WFS analog whitening was in a weird state where it didn't match digital anti-whitening. Fixed it by pressing "ON" for the first and the second whitening filter.

Images attached to this report

H1 CDS - Comment to Testing WFS on JAC table

keita.kawabe@ligo.org — Thu, 30 Jul 2026 18:16:57 -0700

Author: keita.kawabe@ligo.org

Report ID: 91338

There's no reason to suspect that DC connection is somehow wrong, the issue was RF cross-wiring (which we "fixed" by making another cross-wiring) and we already knew that.

FYI, this is what happened on Monday:

We were able to move the JAC refl beam spot on the WFS using JM1 as well as picos and nothing weird was observed. PIT was PIT, YAW was YAW, you can move from e.g. segment 1 to segment 2 by YAW motion, then from 2 to 3 by big PIT etc. If segment 2 and 3 were swapped in DC, the beam would have hopped from segment 1 to segment 3, not to 2, after YAW motion, but that was never the case. So QPD connections seemed good.

We confirmed (by pico-ing the beam on WFS while using DC signals to guide us) that DC segment 2 corresponded to RF segment 3, and DC segment 3 to RF segment 2, both for WFS A and B. Clearly the RF chain was somehow cross-wired. When we disconnected the segment 2 RF cable connecting IOT1 and the field rack on IOT1 feedthrough, segment 3 signals in digital world (e.g. H1:JAC-WFS_A_I3_OUT etc.) showed big jumps in the dark offset, and vice versa, if I remember correctly. As a quick "fix" we made another cross-wiring to undo whatever cross-wiring that existed by swapping the RF connection of segment 2 and segment 3 on the feedthrough on IOT1 (alog 91272). This caused an inconsistency between the cable labels and the feedthrough marking, i.e. somethingsomething_A2 cable is now connected to WFSA segment 3 TNC on the feedthrough, A3 cable to segment 2, and the same thing for WFSB.

Considering the above, it's unlikely that the RF cross-wiring is in IOT1. It should be downstream somewhere.

H1 General - Comment to Thursday Ops Eve* report.

anthony.sanchez@ligo.org — Thu, 30 Jul 2026 17:44:27 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91337

Revived BS's Hepi and ISI. Lets see if it's more stable now.

CDS, SEI

H1 CDS - WP 13415 migrate IOCs to newer hosts

jonathan.hanks@ligo.org — Thu, 30 Jul 2026 17:37:27 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91336

WP 13415. I migrated the EX, EY, and Mid Y weather station from h0epics to the new container system. This just gets us closer to turning off h0epics.

H1 General - Thursday Ops Eve* report.

anthony.sanchez@ligo.org — Thu, 30 Jul 2026 17:01:06 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91335

TITLE: 07/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 15mph Gusts, 9mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
Not much going on today as the CDS team was working on the file system today.

H1 General - Ops DAY Shift End

oli.patane@ligo.org — Thu, 30 Jul 2026 16:39:28 -0700

Author: oli.patane@ligo.org

Report ID: 91334

TITLE: 07/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Mostly more CDS work and some gate valve 6 work today. There are still a few lingering issues that are being worked on. The LVEA is currently in Laser Safe but Laser Hazard in the bifurcated HAM7 area.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:02	FAC	Kim, Dawn	LVEA	n	Tech clean	16:59
15:52	SUS	RyanC	CR	N	ZM5 health check TF	16:18
16:19	SEI	Jim	Remote	n	HAM2 and HAM3 measurements	18:04
16:39	FAC	Randy	LVEA	n	Cleanroom move	18:01
16:54	FAC	Eric	LVEA	n	Ceanroom move	18:01
16:57	FAC	Travis	LVEA	n	Cleanroom move	17:55
16:58	EE	Fil	EX	n	More cabling for DAS (in 16:20)	16:58
16:58	FAC	Jordan	LVEA	n	Cleanroom move	18:01
17:34		Betsy	LVEA	n	Checking on cleanroom move	17:40
17:48	JAC	Jennie, Khanh	LVEA	n	Looking at JAC table with a laser pointer, SUS-R2	19:12
18:09		Madi, Shoshana, Millie	LVEA	n	Tour	18:32
18:33	VAC	Gerardo, Travis, Jordan	LVEA	n	GV6 opening and closing	19:57
18:39	SQZ	Sheila	LVEA	y(local)	Putting up HAM7 bifurcation curtains and maybe turning SQZ laser on	18:50
19:53	CDS	Dave	EX, EY	n	Labeling cables and cleaning up	21:19
20:01	FAC	Randy	LVEA	n	BSC2 measurements	20:19
20:48	HWS	Madi, Camilla, TJ	EX	y(local)	HWS measurements	23:07
20:50	SUS	Ibrahim	CER	n	Grabbing bag	20:53
20:58	SEI	Jim, Randy, Fil	LVEA	n	Look at relocating ITMY electronics	21:40
21:01		Betsy, Travis	LVEA	n	Looking at GV6	21:56
21:26	FAC	Tyler	LVEA	n	Checking on Randy and others	21:29
21:41	SEI	Jim	Remote	n	HAM2 and HAM3 measurements	22:41
23:02		Sheila	LVEA	n	Cleaning up near JAC table and HAM3	23:18
23:15	VAC	Jordan	EY	n	Checking on pump	23:33

LHO VE - Comment to Seal Replacement on GV6 Air Cylinder

jordan.vanosky@ligo.org — Thu, 30 Jul 2026 16:04:08 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91333

We were unable to fully open GV6 today after the cylinder repair. We heard the clunk of the gate camming over at 45 psi, but it did not start to raise until 55 psi, at which point we could hear air blow-by at the solenoid manifold, and up at the cylinder itself.

So we stopped trying to open the valve any further and slowly reduced the regulator output in order to bleed out the accumulated pressure on the bottom side of the piston. This lowered the gate back down and we heard the gate touch down indicating it is soft closed.

We will have to disassemble to air cylinder again and see what may be the issue. We still have 4 sets of replacement seals and one brand new air cylinder on hand if needed.

The valve remains soft closed until we are able to troubleshoot and repair the cylinder.

H1 CDS - Testing WFS on JAC table

jennifer.wright@ligo.org — Thu, 30 Jul 2026 14:33:31 -0700

Author: jennifer.wright@ligo.org

Report ID: 91330

Jennie W, Khanh V,

Since Keita and I realised that the WFS A and B quadrants 2 and 3 are swapped between the RF channels and the DC channels, I have been trying to trace down where the error is. Last week we fixed the problem by swapping the cables for WFSA segment 2 and 3 and WFS B segment 2 and 3 cables at the IOT1 feedthrough panel.

I don't think it is in the RF signal chain as when we unplugged WFS HF segment 2 from the outside of the feedthrough, the channel that corresponds to WFS segment 2 went dark in EPICS.

Since we are still laser SAFE in the corner, Khanh and I took a laser pointer onto the JAC table and tried to see if we could only shine it on one quadrant of the QPD. Since the QPD is as large as the beam this was not really practical. We instead moved a beam card in front of the PD and slowly drew it downwards.

Since quadrants 2 and 3 are the two we suspect are swapped, we looked at which of these showed some light first.

We used the response to the table lights being blocked with the card to see if there was a difference in the readout from each QPD segment. Using the laser point for this did not work as the beam reflects off the card and the QPD casing.

Segment 3 showed light before segment 2 when moving the card down from the top of the diode.This implies the readout channels for 2 and 3 are swapped. The step in power was not as obvious as with a laser beam so I would like to recheck this once we go laser hazard.

Khanh and I also took the side panel off the table and traced the individual WFS cables from the QPD boxes to the feedthrough. These cable are all plugged in correctly on the inside of the feedthrough.

Next step is to get Fil's help to either check the DC pin outs on the WFS boxes or check the channels on the RF PD chassis at ISC-R1.

Summary: We think the JAC WFS QPDs have two segments wired incorrectly but only on the DC readouts, not the RF readouts.

IOO

H1 CDS - h1isibs model crashed again

david.barker@ligo.org — Thu, 30 Jul 2026 14:30:38 -0700

Author: david.barker@ligo.org

Report ID: 91332

h1isibs crashed again following the power cycled of h1seib2 at 09:07 this morning. EJ took a closer look and found that the problem was most probably with Adnaco A4, which has two BIO cards. h1isibs uses both cards and h1hpibs has no binary IO, which explains why only the ISI model is crashing.

While keeping the IO Chassis powered up, we tried a reboot then a power cycle of h1seib2. No A4 was detected and the adapter card link was red. We then powered the computer down and Erik cleaned the A1 fiber pair. This time the adapter went green and the binary cards were seen again.

We started the models at 15:01 and will run like this overnight. At time of writing, 22:00, it has been running for 7 hours.

WP13475 was opened to move the BIO cards from A4 over to the empty A3 if we need to disconnect A4 from the computer (as has been found for h1lsc0).

H1 AOS - Comment to updated laser safety interlock PLC code

patrick.thomas@ligo.org — Thu, 30 Jul 2026 14:19:14 -0700

Author: patrick.thomas@ligo.org

Report ID: 91331

The branch labeled 'scripted' has been merged and deleted. The link still works however (https://git.ligo.org/cds/ifo/beckhoff/lho-laser-safety/-/commit/86f4fb088fbed6ce3c0e47afcdfc756547e70416).

H1 SPI - SPI Picomotor Channel Names Updated

ryan.short@ligo.org — Thu, 30 Jul 2026 14:01:49 -0700

Author: ryan.short@ligo.org

Report ID: 91329

D. Sigg, R. Short

At the request of the SPI team, I've updated the names of the picomotor driver channels that correlate to new picos added with the SPI install. I also removed the names of old HAM2 and 3 oplev picomotors, as these have not been installed and are not going to be installed. This involved a Beckhoff software restart at approximately 19:00 UTC.

Controller	Channel	Old Name	New Name
Controller 5 pico B "HAM 2"	5	HAM2 oplev	None
	6	HAM3 oplev	None
	7	None	SPI ISIJ M_C1 HAM2
Controller 10 pico G "TCS Y CO2 + SPI HAM 3"	5	None	SPI ISIK M_M1 HAM3
	6	None	SPI ISIK M_B4 HAM3
	7	None	SPI ISIK M_M2 HAM3
	8	None	SPI ISIK Spare HAM3

H1 SUS - Comment to HAM7 ZM5 update - PSAMS replaced (2nd time) and suspension re-installed in the chamber.

ryan.crouch@ligo.org — Thu, 30 Jul 2026 10:08:14 -0700

Author: ryan.crouch@ligo.org

Report ID: 91327

I ran a health check transfer function on ZM5 this morning, then compared it against ZM4 from earlier this year, and it looks good.

Non-image files attached to this report

allhxdss_2026-07-30_H1_ZM5_ZM4_ALL_ZOOMED_TFs.pdf

allhxdss_2026-07-30_H1_ZM5_ZM4_ALL_TFs.pdf

H1 CDS - Power cycle h1seib2 system

david.barker@ligo.org — Thu, 30 Jul 2026 09:33:20 -0700

Author: david.barker@ligo.org

Report ID: 91326

Jim, Jonathan, EJ, Oli, Fil, Dave:

h1seib2 has had several problems over the past 24 hours; missing BIO adnaco, overheating Mellanox IPC, user model ADC timeout, ISI L4C switching not working, DAQ CRCs.

We decided a clean power cycle of the front end and IO Chassis is a good first step.

09:07 h1seib2 stop all models and powerdown. Fil went into CER and powered down IO Chassis and AI Chassis

09:09 IO Chassis power up, CPU power up, AI chassis power up.

Once the models got going again, Jim reported the binary switching problem was resolved.

H1 PSL - PSL Back Online After Interlock & CDS Work

jason.oberling@ligo.org — Thu, 30 Jul 2026 09:28:36 -0700

Author: jason.oberling@ligo.org

Report ID: 91325

The PSL is now back on after the CDS and interlock work over the last couple of days. We turned the PSL back on yesterday and locked the PMC at the end of the day so both could warm up overnight. This morning I tweaked beam alignment into both the PMC and RefCav. With the ISS ON, PMC Trans is ~104.8 W and PMC Refl is ~28.6 W, while the FSS RefCav TPD is ~0.527 V. PMC Trans and Refl have not quite returned to their pre-interlock work levels, but in the past we've seen that it can take up to 24 hours for this to occur. To that end, I have left the ISS OFF while the PMC continues to warm up, but it can be turned on whenever it is needed.

H1 General - Comment to Wednesday Ops Eve* Shift Coverage.

oli.patane@ligo.org — Thu, 30 Jul 2026 08:37:03 -0700

Author: oli.patane@ligo.org

Report ID: 91324

Misaligned MC2, PRM, and SRM

H1 General - Comment to Ops DAY Shift Start

david.barker@ligo.org — Thu, 30 Jul 2026 08:19:31 -0700

Author: david.barker@ligo.org

Report ID: 91323

DAQ was restarted between 07:45 and 07:55 to green up the EDC:

Remove h1cdsrfm CDSMON channels

Remove h1cdsrfm long-range-dolphin IOC channels

Add CRS laser safety channel

H1 General - Ops DAY Shift Start

oli.patane@ligo.org — Thu, 30 Jul 2026 07:38:40 -0700

Author: oli.patane@ligo.org

Report ID: 91322

TITLE: 07/30 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: 4mph Gusts, 3mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:

Looks like everything is almost back to nominal after the rcg upgrade yesterday!