It has been a difficult relock acquisition following our last lockloss due to a few reasons all related to the inability to lock DRMI:

1. Small local EQ showing up on both primary and secondary microseism.

2. ALSX PLL Crystal Beatnote insufficient for ALSX lock - this comes on and off and was happening largely in the first hour of lock aquisition. There were 9 locklosses at this state in IR, PRMI, DRMI and of course, LOCKING_ALS. I attempted to cycle through "enable/disable" for the ALSX FIBR LOCK on the ALSX PLL page, but this did not help. The issue seems to have largely went away on its own 45 minutes into trying.

3. DRMI/PRMI general alignment. The flashes are good, and I've seen DRMI lock in worse conditions. I touched the BS, PRM, PR2, SRM, SR2 in order to optimize the alignment further but this proved useless.

The first thing I did after the lockloss was to do a full initial alignment, since I heard that the PRMI ASC was fixed. Before my shift, we were having 45 minutes of issues locking DRMI but the initial alignment did not seem to fix this. After 2 hours of trying to touch suspensions, I have decided to do a step-through of initial alignment. I still allowed PRMI ASC to happen automatically (though will do manually if this lock attempt fails). This has just finished and I'm relocking now..

TITLE: 06/27 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

Currently relocking and stuck not being able to get past DRMI due to it not wanting to lock and some previous ALSX crystal frequency issues. Ibrahim is working on trying to fix that.

When we went back into Observing after Commissioning today at 21:20 UTC, we had accidentally left the beam diverters open, and didn't notice for 20 minutes, so between 21:20 and 21:41 UTC the beam diverter was open. Once we noticed, we went out of Observing, closed it, and then went back ito Observing. tagging detchar

LOG:

14:30 Observing and have been Locked for 7.5 hours
14:38 Lockloss
15:40 NOMINAL_LOW_NOISE
    21:20 Observing after commissioning end
        - We had accidentally left the beam diverter open so this data may not be very good
    21:41 Out of Observing to close the beam diverter
    21:44 Back into Observing with everything looking good
22:29 Lockloss

In preparation for the SatAmp swap (ECR E2400330), I've written a script that allows us to easily compare the noise performance between satellite amplifier swaps. It takes in a suspension name, ifo, and two gpstimes, grabs the DAMP IN data for all dofs, regresses out the ISI GS13 noise, and then compares the leftover noise between the two gps times.

We wanted to have the script divide out the loop suppression, and Jeff looked into which suspensions we've taken valid open loop TFs for (85289). Some suspensions have valid OLTF measurements, so from those we were able to export the loop suppression to divide out (and are saved in the suspension's Data folders), but others don't have valid measurements, so I made it so if there is a valid measurement, it will divide it out from the regressed sensor noise data, otherwise it'll just show the regressed.

Here is an example of the suspension noise before and after a satellite amplifier swap for SR3 that was done at LLO last summer (72417). There was no loop suppression for us to divide out here, so the plots just show the DAMP IN and the leftover sensor noise.

Here is another example for LHO PR3. This one is only meant to be an example of the plots with the loop suppression removed, as the sat amp is the same for both gps times. There is some weirdness around where the peaks were supposed to be removed by the loop suppression - some dofs still show thin peaks. The loop suppression didn't remove them correctly, and we think this might be because the loop suppression assumes a SISO loop, but we might have cross coupling that then is not accounted for when we are dividing by the loop suppression.

The script is located in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/damp_regression_compare.m, and is a function so it can be called from somewhere else. It has been committed as r12362.

The data that's pulled for the gps time and timespan for the sus dofs and chamber GS13s takes a while to grab the first tme, so I had it save the data in the respective suspension Data folders (ex. /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Data/dampRegress_H1PR3_M1_1405123218_1200.mat). Then if you need to run that gps time + span again it'll get the data right away.

The results get saved in the suspension's Results folder (ex. /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Results/allDampRegressCompare_H1SUSPR3_M1_NoiseComparison_1405123218vs1433376018-1200.pdf).
 

WP12637 Install HWS Camera Controls

TJ, Camilla, Dave:

I made a slight change to my original Dec 2023 hws_camera_control.py code to use the python epics module to do the cagets directly, and to also use this to add caputs which will try, in a non-blocking way, to send the camera's status to a central EPICS IOC.

The central IOC code is hws_camera_status_ioc.py which runs on cdsioc1 under puppet control.

The camera control code runs every minute in an infinite loop. Each loop it checks the status of H1 using Guardian ISC_LOCK (greater or equal to 600 denotes H1 LOCK). If H1 is locked and the camera is on, it turns the camera off. If H1 is not locked and the camera is off, it turns the camera on.

A mini-overview of the 4 HWS cameras (ITMX, ITMY, ETMX, ETMY) is available on the CDS Overview screen. The block is divided into 4 segments, each camera is shown either in SKYBLUE (camera is enabled, images are being taken) or GREEN (camera is disabled, no noise being created).

Note that the color scheme relates to what is nominal for OBSERVE. Green indicates the cameras have power, but their frame acquisition has been disabled.

Clicking on the HWS block on the CDS Overview opens a detailed screen (see attachment). For each camera this shows if the camera is powered (ETMY is the only one powered down) and if the camera is enabled. The control code also reports its current time, its uptime, its start time and details of where and how it is running.

Second attachment shows the four tmux sessions running the control code, and the arguments used.

J. Kissel, F. Clara
ECR E2400330

Fil modified the UK SatAmp (D0900900 / D0901284) per ECR E2400330, which means "rev'ing" up the D0901284 circuit board inside from -v4 to -v5 (thanks Michael Laxen for the updated drawing!). 

This mod changes the whitening stage frequency response by adjusting the (R180, R181, R182) values from (750,20e3,20e3) to (1.5e3,80.6e3,80.6e3) Ohm, causing the zero:pole pair to move from z:p = (0.384 : 10.6) Hz to z:p = (0.0969 : 5.31) Hz.

I then measured the frequency response with the nearly*** identical procedure as described in LHO:85349. 

The measured results agree with the expected model of z:p = (0.0969 : 5.31) Hz (and a ~7 kHz high-frequency pole) to within +/-1.5% and +/-1.0 [deg], as was the case for the measured results when this same board was at -v4.

I think we're good to go for rev'ing up many of these satamps, and can have excellent confidence in compensating every channel of every satamp with a z:p = (5.31 : 0.0969) Hz digital filter.

***The only difference is that I needed to drop the source voltage from 0.3 V_SRC to 0.2 V_SRC in order to prevent the differential output stage opamps from saturating. Note -- the saturated response was only ~7% different from expectation and only above the frequency-dependent output of the whitening stage exceeded the ~14V that the differential output opamps can push; I got clued in to this subtlety and have a quantitative answer because the ratio between saturated model and measurement sharply kinked up at 6.39 Hz, and rose up to 7% -- consistent across all four channels -- in a non-linear way that couldn't be explained by adding more zeros and poles. #ThreeHoursWasted

TITLE: 06/26 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 20mph Gusts, 8mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is LOCKING at ACQUIRE_DRMI_1F

Planning on going straight to observing once locked.

Lockloss during comissioning (not from calibration)

Lockloss at 2025-06-26 22:29 UTC after almost 7 hours

Sheila, Elenna

I adjusted the POP9 phase to see if it would improve the coherence of LSC REFL RIN with DARM. In the past, this has been an indication of poor POP9 phasing causing some offset in PRCL.

I tried checking the phase in two ways. First, I engaged the 88 Hz notches in LSC and injected an 88 Hz PRCL line. This result indicated that the POP9 phasing was actually pretty good, in that the signal appeared in I and not Q. The dotted lines in this attachment show this measurement.

Next, I tried a different method, injecting a frequency noise line at 700 Hz. That method showed that there was some signal in Q. I was able to reduce the signal in Q by adjusting the demod phase. The attachment shows the start in dotted blue and red lines, and the end result in solid lines. Overall, this was 2.9 degree change, so not significant.

After that adjustment, I remeasured with the 88 Hz PRCL line and saw a very small difference, shown in the solid lines.

After all that, I am not sure I see a difference in the REFL RIN coherence. Nonetheless, this does seem slightly better, so I SDFed in safe and observe.

I realized after we went to observing that I forgot to unplug the frequency excitation cable. Sorry!

Calibration suite was run after 5 hours of thermalization. Before the measurement was run, work had been done to update the SRCL offset (85362).

Broadband
Start: 2025-06-26 20:35:38 UTC
End: 2025-06-26 20:40:49 UTC
Data: /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250626T203538Z.xml

Simulines
Start: 2025-06-26 20:42:09 UTC
End: 2025-06-26 21:05:29 UTC
Data: /ligo/groups/cal/H1/measurements/DARMOLG_SS/DARMOLG_SS_20250626T204210Z.hdf5
          /ligo/groups/cal/H1/measurements/PCALY2DARM_SS/PCALY2DARM_SS_20250626T204210Z.hdf5
          /ligo/groups/cal/H1/measurements/SUSETMX_L1_SS/SUSETMX_L1_SS_20250626T204210Z.hdf5
          /ligo/groups/cal/H1/measurements/SUSETMX_L2_SS/SUSETMX_L2_SS_20250626T204210Z.hdf5
          /ligo/groups/cal/H1/measurements/SUSETMX_L3_SS/SUSETMX_L3_SS_20250626T204210Z.hdf5

Current version of the pydarm report can be found at /ligo/groups/cal/H1/reports/20250626T204210Z_prospring/H1_calibration_report_20250626T204210Z.pdf. We are investigating further into why the calibration is so different now.

• starting:  1435000693 (19:17:55 UTC) SRCL offset -455, no SRC ASC offsets.
• no squeezing: 1435001081 (19:24-19:32 UTC)

measured NLG with seed of 14.15, had to adjust temperature

• SRCL offset -200, no ASC offsets, 1435001999 (19:39 UTC)  angle scan: here
• SRCL offset 0, no ASC offsets 1435002482 (19:47:44 UTC) angle scan: here

Fitting to SRCL detuning guesses for these last two points would suggest we should update our SRCL offset to -382 counts (was previously -455).  We will do this now, as we are about to run a calibration measurement. 

While we were at 0 SRCL offset, Elenna looked at the impact of SRM alignment, she will alog this.  It does seem to have an impact of FIS, which is small compared to the impact of the SRC length offset. 

• -382, SRM alignment restored 1435004862 20:27:24 UTC

scan alignment using anti-squeeze: results final alignment sliders and sqz angle screenshot

scan alignment using squeezing: results final sliders screenshot

The biggest difference between these alignments is 30urad of ZM6 yaw, and almost 4 degrees of squeezing angle.  We've seen before that the demod phase we need to get the best squeezing angle depends on the ZM alignment, although we think this shouldn't be the case since we are using OMC trans RF3 to control the squeezing angle to reduce the impact of higher order modes on the squeezing angle.

The spectrum comparison shows slightly flatter squeezing after we ran the alignment using squeezing than anti-squeezing.  I've left it this way for now. 

After this Elenna and I looked at the SQZ to IFO ASC. We found that AS42 B was sensitive to ZM4 for both pitch and yaw, while AS42 A was sensitive to ZM6.  We set offsets in AS42 PIT and YAW filter banks to close the loops around the location that the SCAN_ALINGMENT guardian gave us, this worked with the settings shown in the two attachments.

I've set the SQZ ASC flag to true, we can see if this works during thermalization next time we relock.

Today I was able to drive a line on SRM pitch and yaw, aka SRC1 P and Y, in an attempt to understand how the SRM alignment signal appears in various sensors. Our current configuration has SRM alignment controlled via the AS RF72 signal, which is the beat of the 118 MHz and the 45 MHz.

To do this measurement, I engaged the usual 8.125 Hz notches in the ASC loops, and drove at 8.125 Hz at the SRC1 SM exc point. I measured the signals in the I and Q phase on AS RF72, AS RF45, AS RF36 and POP X RF, which is a 45 MHz demod.

First, it is very hard to drive a large enough signal to even see the line in AS RF72 compared to other sensors. We are currently operating with 1 stage of whitening on RF72, for reference. The attachment shows how the signals appeared in the AS WFS as well as the POP WFS for pitch and yaw.

Once I took this measurement, I looked at the time series of the signals. POPX 45 Q pitch has an offset that corresponds to 1.5 urad of SRM pitch offset. I calculated this calibration factor from my injection: 7.37e-5 SRM pitch urad/POPX pit ct. The POPX Q yaw signal also had an offset, but it was much smaller, only 0.24 urad, calibration factor 3.25e-4  SRM yaw urad/ POPX yaw ct

On June 5, the SQZ team adjusted the SRCL digital offset, and when the SRCL digital offset was zero, the POPX Q offsets corresponded to about 0.09 urad of SRM pitch offset and 0.05 urad of SRM yaw offset (sqz alog).

In the past, we have operated with some SRC1 offset, however, that offset is remarkably small compared to even the dark offsets we have applied to the AS RF72 channels. SRC1 p offset was set to -0.042, SRC1 Y to 0.098, while the four segment dark offsets on RF72 Q are -17.8, 0.2, 2.2, 12.9 (medm screenshot).

Overall, I think we should consider a few things:

• do we need more whitening on AS RF72?
• should we commission POPX 45 Q as the SRC1 sensor instead?
• should we adjust the alignment offsets of SRC1 to offload some of the SRCL offset?

Sheila has suggested we open the SRC1 loop and try stepping the offset while monitoring the buildups, the effect of the SRCL offset on SQZ, and the overall offsets in AS RF72 and POPX Q.

Whatever effect alignment offsets in the SRC are having on the SRCL detuning seems to be much smaller in yaw than in pitch.

To calibrate the AS RF72 signals into SRM angle, we can use these factors:

0.274 SRM pit urad/ AS RF72 pit ct

0.173 SRM yaw urad/ AS RF72 yaw ct

(Jordan V., Gerardo M.)

Today we replaced the MKS gauge at FC-C-1, this is the first 6 way cross inside the filter cavity tube enclosure, we installed serial number 390F00490, twice, yes two times.  It turns out that the flange has some scratches on the knife edge, and it was not going to seal regardless of the effort that we put into it.  Once the gauge was removed the scratches transferred to the copper gasket.  We replaced it with serial number 390F00495, this one seems to be doing good.  New conflat was leak tested and no leak was detectable above 2.42e-10 torr*l/sec.

The old gauge serial number is 390F00406 with a date code of June 2021.

Ansel, Sheila, Camilla

Last week, Ansel noticed that there is a 2Hz comb in DARM since the break, similar to that that we've seen from the HWS camera sync frequency and power supplies and fixed in 75876.  The cabling has not been changed since, the camera sync frequency has been changed.

Our current camera sync frequencies are: ITMX = 2Hz, ITMY = 10Hz. We have typically seen these combs in H1:PEM-CS_MAG_LVEA_OUTPUTOPTICS_Y_DQ. With a 0.0005Hz BW on DTT I can't easily see these combs, see attached.

I have been running opportunistic noise budget injections:

• Pitch and yaw jitter injections on June 5
• MICH P and Y, DC6 P on June 18
• Frequency noise, CHARD P and Y, DHARD P and Y, PRC2 P and Y, and intensity noise on June 23

So far there seems to be no noise contribution from DC6 P and PRC2 P and Y. CHARD noise contributions are also down significantly with the ISI in place.