The handler of this valve was torqued, and the pressure in the X-manifold fell to 8.14E-8 Torr, and it is seemingly stabilized. Before poking with this valve, the pressure was 1.04E-7 Torr (and still rising), so there was indeed a leak from this valve to the system, as this torquing means ~20% reduce in gas load.
We do a comprehensive leak check on the X-manifold during the rest of the week, so this valve with all adjacent flanges will be bagged and leak checked.
We are also considering putting an adapter on the valve instead of a blank, and pump it down, so the lower pressure in the outer side of the valve could help, if there is still some communication between the valve and the system - but of course, it depends on the result of the leak check.

Finally, the handler of this valve was LOTO-d - it was simply taken off, so there will be no accidental moving of this valve anymore.

This install has completed.  Passed a few quick tests, so looks successful to me.

SR3 Measurements:

• all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
• The coil driver filter in state 1
• SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

I had a hard time trying to take data at first (no matter the excitation amplitude we were seeing no movement on the ISI sensors), and we figured out that it was because the SUSPOINT matrix for HAM5 ISI had never been populated! We found the correct matrix values in $(USERAPPS)/isc/common/projections/ISI2SUS_projection_file.mat as ISI2SUSprojections.h1.sr3.EUL2CART, and used /ligo/svncommon/SeiSVN/seismic/Common/MatlabTools/fill_matrix_values.m to fill them in. Then I was able to run the transfer functions.

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/Common/Data/2025-04-15_2100_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{L,T,V}_0p02to50Hz.xml, and have been committed to svn as r12227.

This morning we decided to do the rest of the DOFs for the SUSPOINT to M1 measurements of PR3 and SR3.

For SR3:

Same setup as before:

• all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
• The coil driver filter in state 1
• SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/Common/Data/2025-04-15_2100_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{R,P,Y}_0p02to50Hz.xml, and have been committed to svn as r12232.
 

For PR3:

Same setup as before:

• all of the M1 damping loops at a gain of -0.2 (instead of the nominal -0.5)
• The coil driver filter in state 1
• SEI state was ISOLATED, but HEPI is locked, so we circumvented guardian by sliding off the Isolation Gain on HEPI

Data files can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/Common/Data/2025-04-15_1431_H1ISIHAM5_ST1_WhiteNoise_SR3SusPoint_{R,P,Y}_0p02to50Hz.xml, and have been committed to svn as r12249.

Linking analysis pdf showing cross coupling between all DOFs

Also adding a comparison between this measurement and the last time that we took damped transfer functions since those previous measurements would have been taken with a different set of damping gains.

The last time a damped measurement was taken was back in 2015, and those transfer functions look a lot different than the model and this recent measurement, so I also looked at the next previous damped measurement, from 2014. This one was in phase 2b, so not in chamber, but here at least we see that these damped measurements match up pretty well both with the model and with the recent measurement.

This PDF along with a zoomed in version of some of the plots can be found at /ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/Data/ as

     allhltss_DampingOnComparison_H1SUSSR3_M1_Apr25vsFeb15vsMar14_ALL_TFs.pdf

     allhltss_DampingOnComparison_H1SUSSR3_M1_Apr25vsFeb15vsMar14_ALL_ZOOMED_TFs.pdf

and have been committed as r12251.

Months of build and testing, weeks-days of prep, 1 min 41sec to slide into chamber.  In like Flynn.

Movie is too large so on One Drive:

https://caltech.box.com/s/5p1eysbye8tmq2177x40tera254ezpl4

Good job Jim, Mitchell, TJ, Tyler, and the illusive Randy on the forklift (not shown)!

Woo Woo!  Awesome job!  Tagging EPO for photos.

Among the first things we did was measure the power at various places along the ALS beam path to get a good starting point. 

For the ~2W beams we used an Ophir 20C-SH (datasheet says accuracy of +/- 3%) and for ~100 mW beams we used a S401C, (datasheet says accuracy of +/- 7%). 

For laser safety, we would unlock the PMC and shutter the laser while we were placing these power meters, so I also kept track of the PMC TRANS to scale our measurements by input power appropriately.
We did NOT turn on the PMC's intensity stabilization servo (ISS), for no particular reason other than we forgot to turn it on for the first measurement, and then wanted to stay consistent. 
This meant that the PMC TRANS itself was slowly noise at that +0.5 [w] level, so my reported values below are "eyeball averages."

So, not exactly a NIST-level precision/accuracy setup, but good enough for sanity checks. As such, I'm not going to bother report uncertainty in the numbers below.

Here're the results (again, this is prior to doing anything to the path).
Times of measurements are all for 2025-04-15, and in UTC, such that trends of other PDs may be captured if need be.
    Location                               Power Meter [mW]         PMC Trans [W]       Time [UTC]
    (1) Going in to ALS-HWP2                   2060                    103.2              21:39     # expected: 2000 [mW]; good!
       (between ALS-L1 and ALS-HWP2)      

    (2) p-pol in trans of ALS-PBS01            1970                    102.8              22:17     # expected: 1950 [mW]; good!
        (between ALS-M2 and ALS-L2)          
    
    (3) s-pol in refl of ALS-PBS01               49.4                  103.2              21:44     # expected: 50 [mW]; good!
        (between ALS-L1 and ALS-M9)            
    
    (4) s-pol in refl of ALS-M9                  47.7                  103.0              21:48     # 44.9 [mW] reported by ALS-C_FIBR_EXTERNAL_DC_POWERMON, which is in trans of ALS-M9 at this time; good!
       (between ALS-M9 and ALS-FC2) 

All of these powers match expectation quite exquisitely. My guess for the inconsistency of (4) with the EXTERNAL monitor PD is that the beam splitter ratio of ALS-M9 programmed into the beckhoff calibration of the PD's channel is a bit off, but this can be cross-checked later.

We then installed SPI-BS1 (the 80R/20T BS), and cross-checked the reflectivity reported in LH0:83863.
    Location                               Power Meter [mW]         PMC Trans [W]       Time [UTC]
    (5) s-pol in refl of SPI-BS1                 37.7                  102.4              22:22

The PMC power is lower between (3) and (5), the input to the SPI-BS1 is different, so we need to scale the measurement a bit,
    Input Power to SPI-BS1 = 49.4 [mW] * (103.2 / 102.4) = 48.81 [mW]
    REFL power from SPI-BS1 = 37.7 [mW]
    
    Fractional reflection = 37.7 [mW] /  48.81 [mW] =  0.772 = 77%
    (from LHO:83863) = 77%.
Thus, our results today are consistent with what Josh and Keita measured in the optics lab.

Pictures from the work on 2025-04-15.

The first three attachments are without labels, just in case the pics are needed for something else in the future.

The diagram we were working with (from the SPI ECR) is also attached here for convenience.

The second three attachments *are* labeled, so I'll describe what happened using those.
20250415_some_optics_removed_labeled.jpg
- This is (mostly) the how the team started the day: with the area where the SPI pick-off path is intended to go full of un-diagrammed spare/unused stuff. I highlight red circles everything that was removed in this first attachment. Additionally, before the picture was taken, ALS-M8 and ALS-FC1 were removed and the temporary large vertical beam block was installed.

20259415_all_optics_removed_labeled.jpg
- This is the "after" all components cleared picture, and the table layout during the power measurements. As you can imagine, because of the lens tube on the SM1PD1A, there was no room between the PD and ALS-M9 to insert a power meter to measure the transmitted light  thru ALS-M9. As such, we can't validate the beam-splitting ratio of that optic. Ah well.

20250415_end_day_1_labeled.jpg
- This is how we left yesterday: We SPI-BS1 installed in its permanent location. Downstream, we sent the reflected beam into a WinCam head such that we could profile the beam incoming to the SPI path -- and assess whether we need lenses in order to adjust the beam size to match our fiber collimator. While we definitely saw the expected change in power and alignment at ALS-FC2, we elected to restore the power and alignment later.

CP1 RGA Bakeout - Ramped up to 100C. Will continue ramp up tomorrow. Please avoid this area inside of the caution tape

Just ensured the noise budget runs in an operator machine. It needs access to the SusSVN, to the matlabtools folder of the SeiSVN, and access to the ISI2SUS projection matrices saved in /opt/rtcds/userapps/release/isc/common/projections/

The changes are current as of SusSVN revision 12226.

Alarms has been reconfigured to expect GV7 to be soft closed.