4-22 (Tuesday) activities:

- After reaching ~1.3E-6 Torr at the corner, GV2 was opened (the corner was valved together with the X-manifold), that brought down the pressure to ~9E-7 Torr in ~2 hours
- The aux carts from GV5, BSC8, and HAM4 have been detached, 2 of them have been staged at HAM1/HAM2 as a preparation for the pumpdown of the annulus volume

4-23 (Wednesday) activities:

- The stiffening frame for the 1000 amu RGA is being built
- The filter elements were replaced in the EX clean air supply, and it is now running for 24 hours, with a vent valve open in the VEA

TITLE: 04/23 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Productive day in which the following tasks were done:

• HAM 1
  • IAS alignment checks - DONE
  • Actuation reattachment work, ISI prep - DONE
  • SEI, IAS cabling - DONE
  • More cabling - Almost done
  • Cable straightening and cable tray
• RANDY - Crane 3IFO flange crate over BT - DONE
• MARC - Post install measurement of RF cables (contd.) - DONE

LOG:

Jonathan, Dave,

We replaced the hardware that is running h2daqfw2 today.  This was done to put in a system that had more memory.  We pulled a spare daq unit out of the test stand (most recently named x6dc0).  While doing that we swapped the memory with a broken daqd system, so that the new h2daqfw2 now has 256GB of ram.  The system is up and running again, I'm tracking the setup in puppet so that we have a low rebuild time.

This was done to support investigating differences between the frames generated on h1daqfw[01] and hqdaqfw2.  I need to be able to run modified versions of daqd to see some of the internal state that is not exposed to be able to understand and fix differences in encoding of the frames.  When I ran daqd on the old hardware, it ran out of memory, even after reducing buffer sizes.

After finishing initial alignment this morning, Mitch and I wrapped up the upgrade of the ISI to A+ spec. The last parts to go on were the vertical stops for the new .25mm vertical CPS and the vertical St0 L4Cs. All the sensors look live now, I will take some more detailed data later. Last pieces to be installed will be some spring tuned mass dampers that have been waiting for me to measure in the staging building for a couple weeks now. 

Tomorrow, I'll help with the cable routing up the ISI, and ISC can start re-installing the optics.

Marc Fil Daniel

We finished the cabling work for the ISC cables between HAM1, ISCT1, and ISC-R1/2/4. This includes re-labeling of all cables that had no or misleading labels.

Preeti, Gaby, Tabata, Debasmita

Summary:

We calculated the duty-cycle of L1 and H1 in O3, O4a and O4b winters (Nov, Dec, and Jan) on each day and plotted with the median of microseismic ground motion in 0.1-0.3 Hz and 0.3-1.0 Hz. The duty-cycle was modified by removing earthquake times (ground motion in the 0.03-0.1 Hz band above 150 nm/sec) from lock duration and day duration.

Conclusion:

• We found the evidence of linear correlation between microseismic ground motion and duty-cycle; except for Hanford O3 and O4a (2023) winters. For Hanford, useismic ground motion affected the duty-cycle in O4b winter (2024-25) only (see figure).
• In L1 O4a winter (2023-24) plot, zero duty-cycles at lower ground motion disappeared in the next winter, which seems to be resolved with the changes in ETM and CRYO BAFFLE during Jan 2024 commissioning break (LIGO-G2400537).
• Negative value of the Pearson coefficients indicate negative linear correlation between them (see the attached table and plots).

After the ITMY transfer functions I posted Monday(84031), there was some discussion by Edgard and Brian about an extra zero on M0 between L and P ~0.27Hz that maybe seems like it's there when the ISI is isolated and now there when the ISI is in Damped (although he later decided that maybe that didn't make much sense 84068). I took some ITMY M0 transfer functions yesterday afternoon with the ISI in Isolated, to check out any possible correlations there.

Looking at the comparison between Monday and yesterday's measurements(pg 13-14), where the only difference was the ISI in Damped vs Fully Isolated, respectively, that difference alone doesn't seem to account for the disappearence of the extra zero. This further backs up the conclusion Edgard came to this morning.

Data (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Data/)
2025-04-22_2300_H1SUSITMY_M0_Mono_WhiteNoise_{L,T,V,R,P,Y}_0p01to50Hz.xml
In SVN as r12271

Results (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Results/)
2025-04-22_2300_H1SUSITMY_M0_ALL_TFs.pdf
In SVN as r12272

Comparison (/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Data/)
allquads_2025-04-23_ISI-DampedvFullyIso_Apr212025vApr222025_ALLM0_TFs.pdf
allquads_2025-04-23_ISI-DampedvFullyIso_Apr212025vApr222025_ALLM0_ZOOMED_TFs.pdf
In SVN as r12274

Wed Apr 23 10:08:22 2025 INFO: Fill completed in 8min 19secs

J. Warner, R. Crouch, J. Oberling

Took another look at WHAM1 ISI alignment this morning after the HEPI actuators were attached yesterday.

The total station occupied monument LV25 and we used LV26 as the backsight.  The autolevel was placed sighting 171.9 mm on the scale we attached to height mark 600, placing it +100.0 mm above the ISI target z-axis position.  Measurements and calculations done as detailed in alog 84057.

We initially found the ISI a little off level, it was high on the -X side, so Jim did a small correction for that (it has to be small since there is much less range in HEPI with the actuators attached).  Final positional deviations from the ISI target of [-22726.7, 0.0, -201.9] mm are:

• X axis: +0.8 mm
• Y axis: +1.9 mm
• Z axis: +0.15 mm
• Yaw: 96 µrad CCW
• Level to within 0.38 mm

Tolerances for position are +/- 3.0 mm in all axes (reusing tolerances from aLIGO install); I don't find a yaw tolerance in my aLIGO install notes so we tried to minimize it while making other adjustments, I'd say <100 µrad is pretty good.  Jim says the level is good, so this ends IAS for the WHAM1 ISI for now.  IAS equipment has been taken down, although we still have it in the general area should there be a need to take another look at the ISI before the chamber is closed.

Based on the above deviations, the WHAM1 ISI coordinates in the LHO global coordinate frame are [-22725.9, +1.9, -201.75] mm.

Data and Calculations

Data and calculations for the above results.

X-axis Position and Yaw:

• +Y scale: +0.7 mm
• -Y scale: +0.9 mm
• X axis deviation: (0.9 + 0.7) / 2 = +0.8 mm
• Yaw: (0.9 - 0.7) / 2082.8 = +96 µrad -> 96 µrad CCW

Y-axis Position:

• Total Station EDM: 2011.2 mm
• Target: 2009.3 mm
• Deviation: +1.9 mm

Z-axis Position and Level:

• -X/+Y: 3.925"
• -X/-Y: 3.93"
• +X/+Y: 3.94"
• +X/-Y: 3.94"
• Average: 3.934"
• Scale target: 3.94"
• Z axis deviation: 3.94 - 3.934 = 0.006" -> +0.15 mm
• Level: 3.94 - 3.925 = 0.015" -> 0.38 mm

Morning dry air skid checks, water pump, kobelco, drying towers all nominal.

Dew point measurement at HAM1 , approx. -42C

We noticed following the power outage a couple weeks ago that we set the pump diode currents 0.1A lower than they should have been, so this morning I bumped them up from 8.7A to 8.8A each (with the ISS off). This caused a ~1W increase of power out of both amplifiers, and a ~0.5W increase in both PMC transmitted and reflected power. Trends attached.

M. Todd, C. Compton, S. Dwyer

This is a continuation of the last alog discussing how we can estimate thermal actuator contributions to the surface curvature to the test masses. In this I tried to layout the problem with a little more detail.

Essentially, with a few different ring heater powers and their corresponding HOM spacing measurements from OMC data, we can estimate the coupling factor of ring heater power to test mass surface defocus [D/W]. The assumption is that the cavity g-factor is linear with this ring-heater power dependence, and higher order terms are assumed to be small enough to ignore.

This fit to a premlinary dataset (one HOM data point per ring-heater power_) yields a ring-heater coupling value of 0.6483 uD/W -- note: the HOM spacing has been observed to change during the same ring heater powers over time, and these should be included in the dataset.

This value is about 65% of what we think it to be, from TCS - SIM.

We can also constrain the HOM spacing shift from self-heating alone using the intercept of this curve -- this is estimated to be about 153 Hz (from 5166Hz to 5319Hz), compared to the predicted 411Hz change.

The plots and derivations are attached in the notes pdf

There is a ladder section along the X-arm access road between the mid- and end-stations.

The second attached photo was taken looking toward the mid-station from the direction of the end-station.

Marc Daniel

One of the coax cables shows a discontinuity at the feedthrough, ISC_RF25-B/3. This is the coax for ASC-REFL_B 9MHz chn 4 (Q4 RF Low). This is feedthrough D1-1D1. We can see the signal going though the pig-tail but terminating at the feedthrough. This could be an issue of the in-air pig-tail or the in-vac cable at the  feedthrough side.

Typical In-vacuum RFPD ASC Wiring Chain for aLIGO: https://dcc.ligo.org/LIGO-D1300467
O5 ISC/SQZ Wiring Diagram: https://dcc.ligo.org/LIGO-D1900511

Edgard, Brian.

Following up on the fits for the SR3 estimator. I ran the plotall scripts on the transfer functions we took last Friday [see 84003]. Then ran the attached code to fit the transfer functions.

Figure 1 shows the ISI-M1 fitted transfer function. The Q-factors for the fit were tweaked by hand so I could get a decent fit. The exported M1 to M1 transfer function is shown in the second attachment. I decided it should have the same poles as the ISI one, and the gain was fit so the estimator matches the high-frequency behavior of the measured transfer function. The choice to share poles is because the math indicates that it will lead to some potential modeling errors cancelling out.

The pole information for the two filters is:

         Pole              Damping       Frequency      Time Constant  
                                       (rad/seconds)      (seconds)    
                                                                       
 -4.38e-02 + 6.38e+00i     6.86e-03       6.38e+00         2.28e+01    
 -4.38e-02 - 6.38e+00i     6.86e-03       6.38e+00         2.28e+01    
 -7.64e-02 + 1.44e+01i     5.30e-03       1.44e+01         1.31e+01    
 -7.64e-02 - 1.44e+01i     5.30e-03       1.44e+01         1.31e+01    
 -2.97e-02 + 2.13e+01i     1.39e-03       2.13e+01         3.37e+01    
 -2.97e-02 - 2.13e+01i     1.39e-03       2.13e+01         3.37e+01

And the zpk strings (in MATLAB format) are:

ISI to M1:

zpk([-0.068+20.398i,-0.068-20.398i,-0.099+11.454i,-0.099-11.454i,0,0],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],-0.75)'

M1 to M1:

zpk([4745.079,-0.089+8.28i,-0.089-8.28i,-0.113+19.058i,-0.113-19.058i],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],-0.015)

I did the fits by using the spectrumest function in MATLAB (which is sadly not available in 2019a). The long term plan is to switch to one of the many python fitting tools that people like for the fits. The code is attached to this logpost for bookkeeping

Took transfer functions for ITMY M0 and R0 now that we are in a good enough vacuum. The ones I had taken in air before doors were put on are here: 83876.

M0
Data (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Data/)
2025-04-21_1700_H1SUSITMY_M0_Mono_WhiteNoise_{L,T,V,R,P,Y}_0p01to50Hz.xml
Results (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGM0/Results/)
2025-04-21_1700_H1SUSITMY_M0_ALL_TFs.pdf
2025-04-21_1700_H1SUSITMY_M0_DTTTF.mat
Committed to svn as r12261 for both Data and Results

R0
Data (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGR0/Data/)
2025-04-21_1800_H1SUSITMY_R0_WhiteNoise_{L,T,V,R,P,Y}_0p01to50Hz.xml
Committed to svn as r12259
Results (/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGR0/Results/)
2025-04-21_1800_H1SUSITMY_R0_ALL_TFs.pdf
2025-04-21_1800_H1SUSITMY_R0_DTTTF.mat
Committed to svn as r12260

I wanted to compare these measurements with old ones, and on the first try I tried comparing these measurements to the last time that ITMY measurements in vac were taken, which was a measurements set from 2018-05-22_2119 and 2018-06-08_1608 for M0 and R0 respectively. However, comparing these two measurements to the ones I just took, there are multiple differences in some of the cross-coupling traces, so I then decided to also compare my measurements to the last full set that was taken (which was in air), 2021-08-10_2115 and 2021-08-11_2242 for M0 and R0. These measurements line up well with the current measurements, so ITMY is looking good!

Comparison between May/June 2018 In-Vac vs Aug 2021 In-Air vs April 2025 In-Vac (/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Data/)
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALLM0_TFs.pdf
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALLM0_ZOOMED_TFs.pdf
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALLR0_TFs.pdf
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALLR0_ZOOMED_TFs.pdf
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALL_TFs.pdf
allquads_InVacComparison_MayJun2018vAug2021vApr2025_ALL_ZOOMED_TFs.pdf
Committed to svn as r12263

Here's a quick summary of the Estimator installation from this week (Edgard, Oli, Jeff K, Brian L)

slides with basic info: T2500082 
FRS ticket 32526

Installation alogs
Infrastructure installed on HAM2/PR3 and HAM5/SR3, style updates to model, MEDM linked to sitemap - alog 83906

Tools installed in Estimator folder in the SUS SVN alog 83922

We updated the OSEM 10:0.4 calibration filters, but only on SR3 and PR3. alog 83913

Damping filters installed - alog 83926

Tested the fader switch - alog 83982

Designed and installed a blend for SR3 Yaw (DBL_notch in the first filter bank) - alog 84004

Created a new OSEM calibration script - alog 84005
(Edgard is thinking about a general version of this using Python, that is still TBD)

Fitting is well underway, but isn't done yet.

We made much more progress than we expected - thanks Oli and Jeff for all the help. It's not quite ready to go, we need to install the TF fits for the model.

We might have actually been able to test, except the temperature changes from the pumpdown were causing the SR3 optic to move, and the TFs were not very stable. Edgard is working on a log to document this. We have good fits for SR3 yaw taken Friday morning, and we might just try these remotely with Oli's help. We do plan to get a clean set of TFs in a few days when things have stabilized.

-- notes for next steps, thanks to Sheila for this --

We plan to leave the SR3 overall yaw damping gain at -0.5. This means we'll set the 'light damping' to -0.1  and the gain in the estimator to -0.4. Edgard used -0.1 for the fitting, but he notes that the Q's are pretty high so we may need to revisit this.

SR3 oplev channels are : H1:SUS-SR3_M3_OPLEV_{PIT,YAW}_OUT_DQ

Some interesting alogs about the impact of changes to SR damping: alog 72106 and 72130  

Elenna's PR3 coherence plots: alog 65495