PSL 10-Day Trends

FAMIS 31082

Generally, things are stable following the three days of work in the enclosure for the SPI pick-off path install last week, which show clearly on several trends. Most notable is the decline in PMC and RefCav transmission, which have significant misalignments as seen by the beam spot cameras. Fil and I plan to switch the connection of the picomotors to their new driver tomorrow, so after that they'll be usable again and I'll touch up the alignments.

Also, we have still not increased the pump currents for AMP1 as we noticed last week following the power outage. This should bring the power out of both amplifiers and the PMC closer to their levels pre-outage.

Mon CP1 Fill

Mon Apr 21 10:08:36 2025 INFO: Fill completed in 8min 32secs

 

PSL Weekly Checks

FAMIS 26393

Laser Status:
    NPRO output power is 1.843W
    AMP1 output power is 69.23W
    AMP2 output power is 139.7W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 3 days, 15 hr 20 minutes
    Reflected power = 23.37W
    Transmitted power = 104.4W
    PowerSum = 127.8W

FSS:
    It has been locked for 3 days 15 hr and 20 min
    TPD[V] = 0.6888V

ISS:
    The diffracted power is around 4.0%
    Last saturation event was 3 days 15 hours and 20 minutes ago

Possible Issues:
    PMC reflected power is high
    FSS TPD is low

Morning Purge Air Checks 4-21-25

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

Dew point measurement at HAM1 , approx. -42C

Monday Ops Morning Shift Start

TITLE: 04/21 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: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.14 μm/s
QUICK SUMMARY:

VAC Team reports that the corner's pressure is currently 2e-6 Torr 

• Trello tasks that may be worked on today:
• Corner Pump Down Continued or Lifted, STANDOWN OF HAM1 IN-CHAMBER WORK - check pressure
• 8:30am MEETING - check with VAC on lift of Stand down due to corner pumping
• Check on & Continue work from last week
• HAM1 ISI Sensor health checks, cabling
• HAM1 - ISI Payloading of center masses
• HAM1 - IAS alignment

45 degree annular beam from BS reproduced in-chamber with flashlight; reminders of potential H1 scattering sites in H2 chambers

I made a couple of ancilliary investigations while I was in-chamber helping adjust CPY. First, I shined a flashlight through the ITMY elliptical baffle towards the BS. Figure 1 shows that this produced a 45 degree annular beam, similar to the one observed during lock that I noted here ( 83050 ) , consistent with the hypothesis that it is a reflection from the BS cage (see linked alog).

Second, our entry through BSC8 also reminded me that LHO has some unique potential scattering sites that LLO does not have.  Figure 2 shows that several of the blanked off nozzles in BSC8 act as corner retroreflectors visible to the beam spot on ITMY, and there is a reflection from the chamber, just below the beam.  A look at my compilation of beam spot photos from several years ago ( 41142-Figure3 ) also shows these issues at ITMX (second page of Fig. 2). We should probably put in nozzle baffles next time we are in-chamber near BSC8 and 7.

BS HEPI injection at 0.2 Hz increases noise in DARM

I recently reported on multiple potential stray light issues in the vertex area, including a 45 degree conical annular beam from the beamsplitter, and a reflection of the halo of the beam passing through the ITMX elliptical baffle that is roughly directed at ITMY (83050). In a first attempt to study potential scattered light noise problems from these beams, before the break I injected 0.2 Hz X and Y motion onto the BS HEPI, with motion amplitudes of about 1e-6 m at stages, 0 and 2 (see figure).  The figure demonstrates with spectrograms and spectra (second page), that there is a slight increase in DARM noise for both X and Y injections,  mainly below 60 Hz. I turned the injections on and off multiple times because the noise is pretty subtle. I think we should further study these potential scattering issues after the break.

Sun CP1 Fill

Sun Apr 20 10:09:17 2025 INFO: Fill completed in 9min 14secs

 

OSEM estimator summary

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

Sat CP1 Fill

Sat Apr 19 10:08:32 2025 INFO: Fill completed in 8min 29secs

 

h1susauxh2 crash Fri 18 April 2025 23:43:02 PDT

h1susauxh2 models stopped running 23:43:02 Fri 18apr2025 PDT with an ADC timing error.

I am able to ssh onto the machine and first scans suggest we have lost an ADC in this system (only 7 of 8 are seen with lspci). We will need to power cycle the IO Chassis before deciding if an ADC replacement is needed.

This is an auxiliary SUS frontend for HAM2 meaning ADCs only and no control function has been lost.

Dmesg:

[Fri Apr 18 23:43:12 2025] rts_cpu_isolator: LIGO code is done, calling regular shutdown code
[Fri Apr 18 23:43:12 2025] h1iopsusauxh2: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[Fri Apr 18 23:43:12 2025] h1susauxh2: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
 

2025 April vent - VAC diary

4-18 (Friday) activities:

- The corner pumpdown continued: the roughing pump was restarted at ~8:15
- After reaching 5E-1 Torr, the OMC turbo was started up (~15:10). The updated temperature control worked well again, neither the turbo pump, nor the controller did not heat up above 40 deg C during the whole process.
- After reaching 1E-4 Torr, the already spun up HAM6 and X-manifold turbos have been valved in to the volume (16:50)
- The 2 so far problematic annulus IPs are now doing well: at HAM4 and BSC8, the aux carts are ready to be taken off. The one at GV5 can now be switched on with good chances.
- The leak check continued at the X-manifold beamtube: ~80% of it was wrapped - this will be finished on Monday, and so the leak check itself will be also done

Now, as the pressure is <5.5E-5 Torr, WP12439 is closed, so the in-chamber HAM1 work is now possible again. HOWEVER, NOTE THAT HEAVY LIFTING IS STILL FORBIDDEN - and hopefully is not needed anymore.

Added the ISI to HLTS M1 OSEM calibration scripts to the SVN

Edgard

I added two matlab scripts to find the multiplicative correction factors for the OSEM calibrations by using the ISI Suspoint drives, as described in 83605. The script is still a work in progress, but it should be compatible with lightly damped ISI-to-M1 measurements like the ones in 83940 and 80863.

The scripts live in

/ligo/svncommon/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/

and they are

extract_HLTS_ISI_dtttfs_for_OSEM_calibration.m
HLTS__ISI_to_OSEM_calibration.m

I will post the calibration comparisons with in air calibrations later.

 

Estimator progress/ SR3 model status

We've had an excellent week of progress on the estimator - thanks to everyone on site for the great hospitality!

Status of things as we go

1. The estimator is OFF. We set the damping of M1 Yaw back to -0.5.

2  There are new YAW estimator blends in the SR3 model. These were put into foton with autoquack. The foton file in userapps was committed to the SVN

3. We updated the safe.snap SDF file with a decent version of the OFF estimator. We HAVE NOT updated the observing.snap file. At this point, all the estimator settings should be the same in safe and observing. (I'm not sure how to update the observing.snap file)

4. All the work on the estimator design is all committed to the {SUS_SVN}/sus/trunk/HLTS/Common/FilterDesign/Estimator/  

 

-- some detailed notes on the blend design and svn commits follow --

Design new blend filters, load them into the model, commit the updated foton file

seems like a 2% error in the peak finding makes a bunch of noise in the estimator with the agressive blend, and is not a reasonable error (judgement call by Brian and Edgard)
 
>> print -dpng fig_2pcnt_error.png
>> print -dpng fig_2pcnt_error_result.png

Check noise again with 2% error in model/actual using the robust blend (EB blend) - we see the peaks are not any better.

I can't get a broad notch for notch 3 without causing the OSEM filter to be larger than 1. Issue seems to be the freq of the notches going past 60 deg. Could be tuned further.
Instead - use a simple notch.  This means we'll need to be quite accurate with the 3 peak - probably withing 0.5% of the actual frequency

figures
gain error - no performance hit
2% freq error - clear perf hit
1% freq error - acceptable perf hit - top mode clearly worse, but only a little
0.5% freq error - tiny perf hit at top mode only

print -dpng fig_perf1_gainerror.png
>> print -dpng fig_perf2_0p5freqerror.png
>> print -dpng fig_perf3_1p0freqerror.png
>> print -dpng fig_perf4_perfectmatch.png

turn the script into a blend design script - Estimator_blend_doublenotch_SR3yaw.m

update the yaw frequencies to 1.016, 2.297, 3.385
can we use autoquack? - yes!
Real foton file is: /opt/rtcds/userapps/release/sus/h1/filterfiles/H1SUSSR3.txt

(make a backup copy): /opt/rtcds/userapps/release/sus/h1/filterfiles$ cp H1SUSSR3.txt H1SUSSR3backup.txt

the file make_SR3_yaw_blend.m uses autoquack to put the new filters into the SR3 foton file.

(log notes)
please review the recent foton -c log file at
/opt/rtcds/lho/h1/log/h1sussr3/autoquack_foton_log_recent.log
   Checking foton file to see if filters got implemented correctly
BAD - Filter SR3_M1_YAW_EST_MEAS_BP has issues in sect. 1 : DBL_notch
at least one filter got messed up, please follow up...
Autoquack process complete
initial foton call succeeded
foton file ready for updating
starting foton cleanup process
final foton call succeeded
log file updated
please review the recent foton -c log file at
/opt/rtcds/lho/h1/log/h1sussr3/autoquack_foton_log_recent.log
   Checking foton file to see if filters got implemented correctly
BAD - Filter SR3_M1_YAW_EST_MODL_BP has issues in sect. 1 : DBL_notch
at least one filter got messed up, please follow up...
Autoquack process complete
>>

Check the foton file - it looks good - I checked the TFs by eye, and they look correct. the matlab error checker is irritated, but the matlab plots it makes look fine. I think it's OK.

Do a diff on the updated file and my backup - the only diffs I see are the new lines I added (that's good)

save the foton file, delete my backup.

press 'coef load' to get the new filters
(the CFC light goes green)

commit the updated foton file in userapps R31301

Save the work in the estimator folder

Estimator$ svn1.6 add fig*
A  (bin)  fig_2pcnt_error.png
A  (bin)  fig_2pcnt_error_result_EBblend.png
A  (bin)  fig_2pcnt_error_result.png
A  (bin)  fig_blend.png
A  (bin)  fig_perf1_gainerror.png
A  (bin)  fig_perf2_0p5freqerror.png
A  (bin)  fig_perf3_1p0freqerror.png
A  (bin)  fig_perf4_perfectmatch.png

$ svn1.6 add Estimator_blend_doublenotch_SR3yaw.m make_SR3_yaw_blend.m
A         Estimator_blend_doublenotch_SR3yaw.m
A         make_SR3_yaw_blend.m

committed in R12257

Set the model to a good state:

final switch = OFF.
gain of the normal yaw damping set back to -0.5

OSEM_Damper  = populated, but off (in=off, out=off, gain=0)
Estim_Damper = populated, but off (in=off, out=off, gain=0)

OSEM bandpass = populated and set to running state (on, gain=1)
MODEM bandpass =  populated and set to running state (on, gain=1)

 

accept SDF changes in H1:SUS-SR3_M1_
YAW_EST_MODL_BP
YAW_EST_OSEM_BP
YAW_DAMP_EST
YAW_DAMP_OSEM
save this to the safe file - I have not changed the observing file!

the SDF shows 0 differences

 

notes on Diff of foton file:

brian.lantz@cdsws44:/opt/rtcds/userapps/release/sus/h1/filterfiles$ diff H1SUSSR3.txt H1SUSSR3backup.txt
1025,1030d1024
< # DESIGN   SR3_M1_YAW_EST_MEAS_BP 0 sos(0.00026333867650529759, [0.99999999999999867; 0; -0.9999616512111712; 0; -1.999953052714962; \
< #                                   0.99995343154104388; -1.9997062783494941; 0.99970796324744837; -1.9998957078482871; \
< #                                   0.99989686159668212; -1.9999090565491939; 0.99990984807473893; -1.9999426937932141; \
< #                                   0.99994346902553977; -1.9999108726927539; 0.99991163318180731; -1.9999774146135141; \
< #                                   0.99997744772231478; -1.9999375279667919; 0.99993768590749621; -1.999963134023643; \
< #                                   0.99996328560740799; -1.9999399837273171; 0.9999401295235868])
1032,1037d1025
< SR3_M1_YAW_EST_MEAS_BP 0 21 6      0      0 DBL_notch  2.633386765052975870236851e-04  -0.9999616512111712   0.0000000000000000   0.9999999999999987   0.0000000000000000
<                                                                  -1.9997062783494941   0.9997079632474484  -1.9999530527149620   0.9999534315410439
<                                                                  -1.9999090565491939   0.9999098480747389  -1.9998957078482871   0.9998968615966821
<                                                                  -1.9999108726927539   0.9999116331818073  -1.9999426937932141   0.9999434690255398
<                                                                  -1.9999375279667919   0.9999376859074962  -1.9999774146135141   0.9999774477223148
<                                                                  -1.9999399837273171   0.9999401295235868  -1.9999631340236430   0.9999632856074080
1042,1047d1029
< # DESIGN   SR3_M1_YAW_EST_MODL_BP 0 sos(0.99973666135688777, [-1.000000000000002; 0; -0.9999616512111712; 0; -1.999965862142562; \
< #                                   0.99996754725922932; -1.9997062783494941; 0.99970796324744837; -1.9999754834715859; \
< #                                   0.99997627502341802; -1.9999090565491939; 0.99990984807473893; -1.999975984305477; \
< #                                   0.99997674481928778; -1.9999108726927539; 0.99991163318180731; -1.9999871245769849; \
< #                                   0.99998728252160574; -1.9999375279667919; 0.99993768590749621; -1.9999876354434321; \
< #                                   0.99998778124317389; -1.9999399837273171; 0.9999401295235868])
1049,1054d1030
< SR3_M1_YAW_EST_MODL_BP 0 21 6      0      0 DBL_notch  9.997366613568877680151559e-01  -0.9999616512111712   0.0000000000000000  -1.0000000000000020   0.0000000000000000
<                                                                  -1.9997062783494941   0.9997079632474484  -1.9999658621425620   0.9999675472592293
<                                                                  -1.9999090565491939   0.9999098480747389  -1.9999754834715859   0.9999762750234180
<                                                                  -1.9999108726927539   0.9999116331818073  -1.9999759843054770   0.9999767448192878
<                                                                  -1.9999375279667919   0.9999376859074962  -1.9999871245769849   0.9999872825216057
<                                                                  -1.9999399837273171   0.9999401295235868  -1.9999876354434321   0.9999877812431739

SPI Pick-off Path Install Day Three: Complete!

S. Koehlenbeck, J. Freed, J. Kissel, J. Oberling, R. Short

The SPI pick-off path installation on the H1 PSL table is now complete. The beam in the new SPI path has been reduced to 20mW and is currently being dumped with a razor dump between SPI-L1 and SPI-L2. Pictures attached reflect the final installation and layout, which will be be reflected in the updated as-built layout at a later date.

Associated entries: 83925, 83933, 83956, 83961, 83978, 83983 (and more to come)

ECR E2400083
IIET 30642
WP 12453

Here's Ryan's birdseye view labeled with all the components.
For details of the components, see the SPI BOM, T2300363, exported from its google sheets to -v4 as of this entry.

Prep work for HAM1 SUS Tip Tilt (RM1, RM2 and PM1) installation

RyanC, Rahul

SUS Tip Tilt - RM1, RM2 and PM1 (picture attached) are now ready to be installed into HAM1, once the chamber is ready to accept them. The blade springs of all three suspensions have been un-muted and bosem connectors have kapton take inserted to prevent grounding issues. This morning we cleaned all three optics using First Contact - see picture for reference.

 

PM1 Beam Dump (rear)

Camilla, Betsy, RyanC, Rahul

SUS PM1 (Tip Tilt) has a new beam dump attached to it's rear - as shown in several pictures attached below. We had to design a new plate (D2500101_V1) to attach the beam dump. I can confirm that all the components integrates well with PM1 and there is some scope for adjustability as well.

Team SUS is now ready for HAM1 installation work.

SPi Pickoff Path Install Day Two

J. Kissel scribing for S. Koehlenbeck, J. Oberling, R. Short, J. Freed
ECR E2400083
IIET 30642
WP 12453

Another quick summary aLOG at the end of the day, with more details to come:
- With the power in the ALS/SQZ pick-off path to 10 [mW] for beam profiling,
- Installed a two lens system to handle the unexpectedly different beam profile of the ALS/SQZ pick-off path
- Remeasured the resulting mode after the two lens system, and we're happy enough. We're gunna call them SPI-L1 and SPI-L2.
- Installed steering mirrors SPI-M1 and SPI-M2.
- Rotated ALS-HWP2 to increase the s-pol light in the ALS/SQZ/SPI path to return the power transmitted through SPI-BS1 going to the ALS/SQZ fiber collimator back to 50.5 [mW]. This set the SPI path to 186 [mW] with the PMC TRANS measured at 103.5 [W]. The ALS_EXTERNAL PD in transmission of ALS-M9 measured 31 [mW] ***. 
- Installed SPI-HWP1 and SPI-PBS01
- Measured the power at each port of SPI-PBS01, with the intent to optimize the SPI-HWP1 position to yield maximum p-pol transmission through SPI-PBS01.

*** We expect this is lower than the goal of ~45 [mW] (from LHO:83927) because we've not yet re-aligned the ALS/SQZ fiber collimator path after the install of the SPI-BS1, which translates the beam a bit due to the thickness of the beam splitter. We intend to get back to this once we're happy with the SPI path.

Re-post of Ryan's picture at the end of day 2, labeled with the almost entirely complete SPI pick-off path.

Critically here, this shows the PSL row/column grid, confirming that this whole ECR E1900246 ALS pick-off path is 2 rows "higher" in +Y than is indicated on the current version of the as built PSL drawing D1300348-v8.

Ryan grabbed another picture I attach here. This shows the ALS pick-off path on this day in order to support the identification that the beamline between ALS-M1, through the faraday ALS-FI1 and ALS-L1, etc stopping at ALS-M2 (not pictured) is on row 25 of the PSL table *not* row 23 as drawn in D1300348-v8. I attach both the raw picture and my labeled version. So, ya, ALS-M1 should have its HR surface centered on Row 25, Col 117.

Note, the grid in the picture is labeling bolt holes. Because the optical elements are all ~4 inches above the table, the beams appear offset from the way they travel on along the grid given that the photo was taken at a bit of an angle from vertical. May the future updater of D1300348 bear this in mind.