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Reports until 10:55, Friday 09 February 2024
H1 AOS
jason.oberling@LIGO.ORG - posted 10:55, Friday 09 February 2024 - last comment - 14:48, Friday 09 February 2024(75771)
FARO Update

J. Oberling, R. Crouch

Update on FARO progress so far.

Monday, 2/5/2024

On Monday we tried adding a monument to the existing alignment routine, primarily to see how it worked; we used the same alignment from alog 75706, the one where we had changed PSI-1 and PSI-2 to points but kept BTVE-1 and PSI-6 as spheres (the final 2 pictures from the alog).  We used the magnetic nest that we had placed in line with height mark 903 and checked with an autolevel that it was still in line with the height mark (done before the LVEA went Laser Hazard for HAM6 work, nest alignment to height mark was good as found).  The FARO gave us X and Y coordinates for the nest, and we used those to convert the local Z coordinate for 903 into a global Z as described in alog 75706.  The listed local Z for 903 is -79.9mm (from T1100187), which translates to a global Z for the nest of -79.7mm using the following:

ZG = ZL + (XL * 0.0006195) + (YL * -0.0000125) = -79.9 + (1082.3 * 0.0006195) + (37455.6 * -0.0000125) = -79.7mm               [1]

Including the mark in the alignment routine was very straightforward: Open the alignment routine, right click in the window listing the objects used in the alignment and select Add Object, and select the desired point from the drop-down menu.  The results of adding this point to the existing alignment routine are shown in the first 2 pictures.  As can be seen some got worse and some got better.  While it's tempting to say the Build/Inspect results are great, there is one caveat.  We checked PSI-6 in the same way we performed the differential height survey between BTVE-1 and PSI-6 in alog 75669 (SMR on the CPN ~1 foot in front of the monument on the vinyl floor, but in line with the X coordinate; we know this isn't exact, but it gives a ballpark) and that found PSI-6 to be -1.1mm from its nominal Z axis coordinate.  Another interesting note, notice the measured Z for 903 in the first picture (2nd column on the annotation).  When incorporating 903 into the alignment routine, the best the FARO can do is get within 3.5mm of the nominal Z axis coordinate; when 903 is out of the alignment routine, the FARO thinks it's ~4.2mm above its nominal Z axis coordinate.  That's... not so good, and an indication of maybe a larger discrepancy in Z coordinates than we initially thought.

Wednesday, 2/7/2024

We did the alignment test noted at the end of alog 75706; use a sphere for BTVE-1 and points for PSI-1, PSI-2, and PSI-6.  We used BTVE-1, PSI-1, and PSI-2 to perform an initial alignment, then moved the FARO to a spot with direct line of sight to PSI-6.  We then probed PSI-6 as a point instead of a sphere and added it to the alignment routine.  The third picture shows the results of the alignment routine.  We did a Build/Inspect to PSI-6, since we were in a location with direct line of sight, and then moved the FARO back out to the West Bay to do Build/Inspect for PSI-1 and PSI-2; we wanted a line of sight to height mark 902, but this put us out of line of sight to BTVE-1 so we did not do a Build/Inspect to it.  The Build/Inspect results are shown in the fourth picture.  That is also not so great, and one of the worse Z axis alignments we've seen.  This was unexpected given the variations we've seen when using the sphere fit rod.

Since we had line of sight to height marks 902 and 903 we used the magnetic nests that we had placed on them to probe them against their nominal coordinates (global Z for 902 was calculated in the same way as we did 903); at this time the LVEA was in Laser Hazard so we were unable to use an autolevel to confirm the magentic nests were still in line with the height marks (903 had been checked on Monday so was likely still good; 902 was last checked roughly a week ago so could have shifted, will check it now that the LVEA is Laser Safe).  The results are shown in the fifth picture.  There is something fishy here, as the FARO thinks both height marks are higher than our listed coordinates would indicate, by 3 to 4 mm, again indicating that we have some discrepancy between the BTVE/PSI Z axis coordinates and those of the height marks.  This was also apparent when we attempted to include both height marks in our Z axis alignment routine.  The sixth picture shows the Build/Inspect results if the height marks are included into the Z axis alignment routine with the BTVE/PSI monuments, and the seventh picture shows the Build/Inspect results with the alignment routine considering only the height marks (the check marks next to Use X and Use Y make no difference here, as this portion of the alignment routine has been constrained to only align the Z axis).  Including the height marks with the BTVE/PSI monuments results in a bad alignment, especially for PSI-6; the FARO still cannot get a good alignment to 902 and 903.  Using only the height marks gets a good alignment to the height marks, but drags the PSI monument way out.  This is a further indication of some discrepancy between our BTVE/PSI monuments and our height marks.

Thursday, 2/8/2024

Seeing this potential discrepancy between our BTVE/PSI Z coordinates and our height marks, we set out to try to see where this comes from.  Recall, per T1100187 the height marks were laid out in the local LVEA coordinate system, all relative to WBSC2 [0,0,0] (which is the origin of the site coordinate system, both the site global and the LVEA local).  The first set of height marks were set using the chamber-side door flange scribe lines; there are 2 scribes on each door flange (one at the 9 o'clock and one at 3 o'clock), for a total of 8 scribe lines per chamber.  The 8 scribe lines for WBSC2 were averaged together to produce the Z axis origin, and the height marks were set relative to this.  The initial chamber placement was done using the BTVE/PSI monuments, thereby linking them to the height marks.  Knowing this, we again used the FARO as an autolevel to perform a differential height measurement between BTVE-1 and height marks 902 and 903.  We set the FARO in a location with line of sight to BTVE-1, PSI-1, PSI-2, and both height marks.  It was oriented to local gravity and we used the Hubbs CPN (with its 2" vertical offset) to measure a Z coordinate for BTVE-1, PSI-1, and PSI-2, corrected in the -Z direction by 50.8mm to account for the vertical offset of the CPN.  These Z coordinates are relative to FARO's initial coordinate system, but since we're doing a differential height survey this doesn't matter.  We then did the same measurement with the height marks, and calculated a measured deltaZ between our height marks (and a repeat of PSI-1 and PSI-2) and BTVE-1.  Results, all units in millimeters:

Interesting here is that our deltaZ for PSI-1 and PSI-2 is different than our last measurement in alog 75669, both by +0.2mm.  This is a very small difference so not very worrying, and is likely caused by how the CPN sits in the BTVE punch (since the punch is not directly on the top of the domed monument, the CPN does have a slight wiggle to it; we tested this by wiggling the CPN and watching the measured Z coordinate, it does move but by only a couple tenths of a mm).  The deltaZ between marks 902 and 903 comes out at +16.9 mm w.r.t. 902; the theoretical difference is +17.2mm w.r.t. 902, so pretty close.

Moving on, we can convert our global Z for BTVE-1 into a local Z using the opposite direction cosines used above in [1] (from Section 2 of T0900340 XL = XG and YL = YG).  This looks like:

ZL = ZG + (XG * -0.0006195) + (YG * 0.0000125) = -1057.2 + (0.0 * -0.0006195) + (46000.0 * 0.0000125) = -1056.6 mm               [2]

With a local Z for BTVE-1 we can then calculate the theoretical deltaZ to height marks 902 and 903 and compare to our measured (all units in millimeters):

  Theoretical Measured Difference
deltaZ902 +993.9 +997.4 +3.5
deltaZ903 +976.7 +980.5 +3.8

So according to the FARO these 2 height marks are several mm higher than our listed coordinates indicate, at least w.r.t. BTVE-1.  As a quick and dirty test we have line of sight to height mark 504, which sits on the north wall of the West Bay, near the main crane parking spot.  We do not have a nest on this mark (would need to glue one, the walls aren't magnetic), but roughly holding the SMR center on the height mark we were able to get a ballpark Z and compare it to BTVE-1.  This indicated that mark 504 is very approximately +2.9mm from where T1100187 says it is.  Combined with the discrepancies measured for 902 and 903, this is worrying.  Where is this coming from?  Several possibilities come immediately to mind:

Our next step is to try to figure out the source of this discrepancy.  The obvious way is to check WBSC2 Z=0 against the existing height marks to see how they register to each other using the 8 door flange scribe lines on WBSC2.  This is much easier said than done, however.  There is a lot of infrastructure blocking lines of sight, including beam tubes and other BSC chambers, electronics racks, TCS/HWS tables, HEPI piers, and cabling that was not present when WBSC2 Z=0 was established during site construction.  So in reality our next step is to figure out how to figure out the source of this discrepancy.  Stay tuned, more to come.

Images attached to this report
Comments related to this report
jason.oberling@LIGO.ORG - 14:48, Friday 09 February 2024 (75806)

Ryan and I took a walk around WBSC2 this morning, and given the amount of items blocking line of sight we are currently looking into setting up a water tube level as suggested by Mike here.  This would give us a way to register door flange scribes on opposite sides of the beam tubes.  The thinking is we could use an autolevel, water tube level(s), and some scales to average the door flange scribes together and recreate the original Z=0; we could then use this to start checking the height marks in the LVEA (specifically the West Bay to start, I think, since that's where we're currently working and finding these apparent discrepancies).

Forgot to add to the above alog, on Thursday afternoon we also used the FARO in the last used alignment routine (BTVE-1 as a sphere, PSI-1, PSI-2, and PSI-6 as points) to probe the old brass floor monuments for Test Stand #2 as a possible means to test our alignment to the X and Y axes (yes, we don't like the Z axis alignment of this routine, but we're not testing Z here).  Our X and Y alignment has looked very good in every iteration of this routine we have done, but to date we have only tested against the monuments we use to set the alignment; we would expect these to have a good alignment (hence our continued puzzlement with Z).  But how well does this aligment work when tested against monuments not used to set the alignment?  Enter the Test Stand monuments.  D1100291 includes monument layouts for the mechanical test stands used during initial aLIGO install (used to pre-build and align the ISI+SUS "cartridges" before installation into a BSC chamber).  These monuments are only registered to the test stand they are associated with, but we do have a monument representing [0,0].  The thinking here is we can probe the [0,0] monument (monument TS2-10, in this case), which then allows us to put the rest of the test stand monuments into our LVEA coordinate space.  This gives us a theoretical X/Y location for the rest of the test stand monuments that we can then compare to where the FARO thinks they are.  Data has been collected and is currently being processed, will post results once complete.

H1 SEI
arnaud.pele@LIGO.ORG - posted 10:24, Friday 09 February 2024 (75800)
ISI CPS BLRMS noise monitoring- status check

Similarly as in llo (ref llo alog 69495), a comparison of the cps blrms channels vs spectra is attached for the bsc and hams. This is to confirm we can use those channels for automated cps noise monitoring in guardian.

Same observations as for LLO :

1- the blrms channels are all working
2- the threshold of 30nm rms seems like a good number to start with for guardian monitoring
3- some odd behavior on some channels - eg itmy stage 1 - 65_100Hz (p5) where, looking at the spectra, we would expect the v2/green channel to be the highest in the blrms signal. Nathan has some ideas of how to verify this, see alog 69603.

Next step : copy the CPS_NOISEMON state from the LLO DIAG_MAIN to the corresponding LHO guardian

Non-image files attached to this report
LHO General
corey.gray@LIGO.ORG - posted 08:06, Friday 09 February 2024 (75797)
Fri Ops Day Transition

TITLE: 02/09 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 3mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.20 μm/s
QUICK SUMMARY:

With HAM6 work finishing up last night, this morning will focus on HAM6 buttoning up.  EY wind fence will continue weather permitting.  EX pump down + rga wor + BRS work continues.  More FOM work. 

LVEA is laser SAFE.

H1 SUS
oli.patane@LIGO.ORG - posted 18:35, Thursday 08 February 2024 (75795)
HAM6 Suspensions Healthy!

Rahul, Austin, Oli

Transfer functions for OM1, OM2, OM3, and OMC were taken today following the rebalancing of the HAM6 ISI. At first we were having trouble getting good data due to the purge air flow entering the chamber, even with the purge air on a low setting, but once turning down the air flow further we were able to get decent TFs.

All four suspensions are looking healthy and HAM6 is ready to be closed up!

Non-image files attached to this report
LHO VE
janos.csizmazia@LIGO.ORG - posted 17:26, Thursday 08 February 2024 (75794)
2-8 vent vacuum diary
Today's activities:
- EX pumpdown status: ~7.2E-8 Torr
- EX BRS: it is pumping: the roughing was already done, the small aux cart has been already disconnected, now it is only pumping on its own Ion pump
- On BSC8, the last 16.5" feedthru was replaced by a blank. In sum, 5 pcs. of 12" and 3 pcs. of 16.5" 3IFO feedthrus were replaced
- After a leaky calibrated leak was found on HAM8 RGA, it is still pumped now with an aux cart (which also needed some troubleshooting), and a pre-vent scan will be taken next week
H1 General
betsy.weaver@LIGO.ORG - posted 17:05, Thursday 08 February 2024 - last comment - 11:52, Friday 09 February 2024(75791)
HAM6 closeout

(Betsy, Keita, Rahul, Sheila

We finished installing the new square-hole OMC glass shround end panels this morning after a good round of cleaning.

Then we spent most of the day hunting for the OMC Trans Cam beam - we finally found it, aligned it to the viewport door simultor, and were able to launch Jim and Rahul for final SUS/SEI closeout.

We transitioned to Laser Safe (thanks TJ), Closed HAM6, 7 and the HAM5 mini port gatevalve.

A new contam control wafer was laid near the center of the table and cables, tools, interferences, were all checked.  Most signoffs have been complete - Jim and SUS crew checking TFs now and expect to be cleared this eve.  Jim has signed off, Rahul on now.  He'll txt me any issues, so otherwise all good, doors to proceed.

Doors on HAM6 tomorrow morning followed by corner pump down ~Monday hopefully.

Images attached to this report
Comments related to this report
corey.gray@LIGO.ORG - 11:52, Friday 09 February 2024 (75803)EPO

Tagging EPO for HAM6/OMC photos

H1 SEI
jim.warner@LIGO.ORG - posted 17:00, Thursday 08 February 2024 (75792)
HAM6 ISI tfs look ok

Unlocked and did some rebalancing of HAM6 ISI after ISC crew finished. ISI tfs look ok. On attached tfs, red, blue and green tfs are actually HAM3 tfs from last week, brown pink, light blue are all HAM6 tfs from today. Purge was a bit lower today, so there's less tilt, and the whitening states aren't the same between the chambers, so the 10hz + part of these tf shouldn't look the same. HAM6 is good to close.

Images attached to this report
H1 CDS
jonathan.hanks@LIGO.ORG - posted 16:12, Thursday 08 February 2024 (75790)
WP 11669 upgrade the link between sw-msr-core and sw-gc-sysadmin to 10G
As per WP 11669 I upgraded the link between sw-msr-core and sw-gc-sysadmin to a 10G link.

This is done to simplify the configuration of the new core switch when it gets put in later this month, by moving everything to 10G everywhere.
LHO General
corey.gray@LIGO.ORG - posted 16:01, Thursday 08 February 2024 (75780)
Thurs DAY Ops Summary

TITLE: 02/08 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Today's main activity was closing out HAM6 (more specifically--being able to steer the OMC trans beams out of the chamber (after the installation of the modified OMC shroud plate)---the beam they worked with was very faint and hard to see (most of the LVEA lights needed to be off for this work!).  LVEA was then transitioned to SAFE, and then HAM6 ISI was unlocked and balanced for SUS transfer functions.

There was wind fence work and lots of VAC team work as well.
LOG:

 

H1 PEM
ryan.crouch@LIGO.ORG - posted 12:32, Thursday 08 February 2024 - last comment - 17:00, Thursday 08 February 2024(75788)
PEM accelerometer cable being crushed

While Jason and I were doing some FARO surveying we noticed a cable being crushed under a computer rack leg in the bier-garten. Following the cable led to an accelerometer by GV6 on the Y-arm beamtube.

Images attached to this report
Comments related to this report
david.barker@LIGO.ORG - 17:00, Thursday 08 February 2024 (75793)

I think this accelerometer is H1:PEM-CS_ACC_BEAMTUBE_YMAN_X, in which case its signal went very noisy around 9am Tue 16th Jan (first day of the break).

Images attached to this comment
X1 SUS
oli.patane@LIGO.ORG - posted 11:30, Thursday 08 February 2024 (75787)
BBSS M1 Transfer Function Comparisons to Model

Oli P,  Ibrahim A, Betsy W

The first transfer functions were taken for the top stage of the BBSS a couple of weeks ago (75211), and we have been working on plotting these transfer functions against their models. We have finally been able to do this (pdf), and what we see is a pretty good match to what we expected to see. Plots 1 - 6 of the pdf (also attached as pngs) are the transfer functions for each individual degree of freedom compared against the model's result for that degree of freedom. Plots 7 - 12 compare the measured and model TFs between dof's that tend to couple into each other. Pages 13 - 18 compare each measured and modeled dof to the OSEMs that make up that dof.
Here are the plots for M1 L to L, M1 T to T, M1 V to V, M1 R to R, M1 P to P, and M1 Y to Y. The results are similar to what we noticed when manually comparing the location of the peaks.

Scripts Used
The original BBSS model is a Mathematica notebook found at $(sussvn)/Common/MathematicaModels/TripleLite2/mark.barton/20211212bbss/production/stdcalc/ASUS3L2ModelCalcPlots.nb.

The default model parameters in Matlab can be found at $(sussvn)/Common/MatlabTools/TripleModel_Production/bbssopt.m. Then, $(sussvn)/BBSS/Common/MatlabTools/plotBBSS_dtttfs_M1.m was run to grab the data from the transfer functions we ran and plot them against the theoretical models.

The results are found in $(sussvn)/BBSS/X1/BS/SAGM1/Results/2024-01-05_1000_X1SUSBS/.

Questions we have:
- Why are the measured magnitudes higher than the model magnitudes?
    After looking over it for around 4 hours and getting some help from Jim and Rahul, we could not figure out whether the discrepency was due to:
    - an incorrect calibration factor (the 1.5404 is a calibration factor that was a remenant from the BSFM script who's values seem to make sense)
    - an issue with the filter units on the test stand or dtt
    - an issue with the model
    - turbulance from cleanrooms
    - something else??
- What's up with Pitch?
    Seems coupled to "V", which should have expected coupling but not in this peak (according to model). Ideas are:
    - issue with model? Were "new wire lengths" added to model params?
    - issue with how we built it? Pitch being off can sometimes indicate an issue with the location of the center of mass
    - something else?
- What's with noisy P to "any other DoF" coupling traces?
    There is terrible coherence.
    - Some mechanical issue? No rubbing from inspection ~month ago
    - Some DTT issue? There are no GDS overflows/railing (which is what caused the problem last time) when running TFs
    - Something else?

Next steps:
- Take many measurements of different parts of the BBSS and make sure they are within their build tolerance, as well as double checking that all updates to the build have been included in the model parameters.
- Make any adjustments to the build or model that are needed.
- Rerun TFs and see if the new results make sense.

Images attached to this report
Non-image files attached to this report
LHO VE
david.barker@LIGO.ORG - posted 10:26, Thursday 08 February 2024 (75786)
Thu CP1 Fill

Thu Feb 08 10:09:10 2024 INFO: Fill completed in 9min 6secs

Gerardo confirmed a good fill curbside.

Images attached to this report
H1 SEI
shoshana.apple@LIGO.ORG - posted 10:02, Thursday 08 February 2024 - last comment - 08:31, Tuesday 13 February 2024(75785)
BRS Remote Mass Adjuster Install
[Michael, Jim, Tony, Shoshana, Neil]

We've spent the week working on installing a remote mass adjusting/balancing system for the End-X BRS. Upon opening the End-X BRS we discovered that it is slightly different than the other BRSs (most likely because it was the first one built, photo 1 below) so we had to get a couple extra parts machined for the parts we brought from UW to fit properly. The hardware has finished being installed (photo 2), and we've run a quick test of the picomotor (Newport  8341-UHV) to make sure it has full range of motion. We've finished closing the BRS up and are now waiting for it to pump down before doing some additional in-vacuum tests. 

We are writing up some installation and balancing instructions as well as leaving another set of parts, so a remote balancing system can be installed on the other BRS. We assume the End-Y BRS should fit the drawings on the dcc (D1800045), so no additional parts should need to be machined. We are also leaving 16 flexures here with Jim.


The pico motor controller chassis was not working, so we are leaving our UW picomotor driver (Newport 8742) here so that the End-X BRS can be adjusted until the chassis is fixed. Once it is fixed the in-air wiring will need to be re-connected to get the motor to the chassis. For now adjusting will have to be done with a laptop at the End-X station, but once hooked up to the chassis, adjustments can be made from the control room.
Images attached to this report
Comments related to this report
brian.lantz@LIGO.ORG - 08:35, Friday 09 February 2024 (75799)

Yeah! Jim's back will be grateful.

Notes about the design and additional details on the installation are in SEI log 1886 and attachments.

corey.gray@LIGO.ORG - 08:31, Tuesday 13 February 2024 (75837)EPO

Tagging EPO for these new BRS innards photos.

H1 PEM (PEM)
corey.gray@LIGO.ORG - posted 09:28, Thursday 08 February 2024 (75784)
HVAC Fan Vibrometers FAMIS Check (FAMIS 26266)

For FAMIS #26281:  All looks mostly well for the last week for all site HVAC fans (see attached), EXCEPT a TINY increase for the (lvea) MR FAN3 almost 5-days ago.

Images attached to this report
H1 PSL (PSL)
corey.gray@LIGO.ORG - posted 09:16, Thursday 08 February 2024 (75783)
PSL Status Report (FAMIS #26230)

For FAMIS 26230:
Laser Status:
    NPRO output power is 1.81W (nominal ~2W)
    AMP1 output power is 67.75W (nominal ~70W)
    AMP2 output power is 136.8W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN

PMC:
    It has been locked 5 days, 20 hr 2 minutes
    Reflected power = 18.46W
    Transmitted power = 108.3W
    PowerSum = 126.8W

FSS:
    It has been locked for 23 days 0 hr and 30 min
    TPD[V] = 0.6882V

ISS:
    The diffracted power is around 1.8%
    Last saturation event was 23 days 1 hours and 2 minutes ago
Possible Issues:
    PMC reflected power is high
    FSS TPD is low
    ISS diffracted power is low

H1 SEI (OpsInfo)
jim.warner@LIGO.ORG - posted 17:57, Wednesday 07 February 2024 - last comment - 20:26, Thursday 08 February 2024(75776)
ITMX cps glitching, forgot to reconnect CPS, temp bypass, need to fix tomorrow

The ITMX cps had started glitching this week, I tried reseating the cards to fix the glitching, but I guess I forgot to reconnect one of the sensors. The St1 h1 sensor is railed, so the watchdogs nominally can't be reset. I've temporarily bypass the st1 cps in the wd (via an epics variable that raises saturation threshold above the adc range), but the bypass will reset, eventually. I'll reconnect the st1 h1 sensor tomorrow morning.

Comments related to this report
jim.warner@LIGO.ORG - 20:26, Thursday 08 February 2024 (75796)

I plugged the sensor back in this afternoon. Bypass not needed now.

H1 SQZ
sheila.dwyer@LIGO.ORG - posted 15:30, Tuesday 06 February 2024 - last comment - 17:52, Wednesday 21 February 2024(75749)
SQZ beam profile measurements after PSAMs offloading

Naoki, Camille, Julian, Rahul

Summary: We measured beam profiles in HAM7 and HAM6 using the SQZ beam, after the PSAMs offloading work from 75677 75709 and the alignment work from 75732. We noticed that there is a lot of astigmatism on the beam in HAM6, but not in the HAM7 location that we were able to reach with the profiler. 

Details:

In HAM6 we measured at three locations marked by the letters a,b,c in the sketch that Julian will attach. The red lines in the sketch show the irises. 

Location 6A is 1.75 inches from the iris, Location 6B is 2 inches from the iris (closer to OM1).  At location 6C we measured the beam in reflection off OM1, 23.25 inches after OM1.  (The fast shutter is further in the -Y direction in chamber than what is shown in the CAD drawing).  We also would like to measure at position 6D, once the second iris is removed. 

We also measured beam profiles on the -X side of the HAM7 table, location 7A is 6.25" in the +X direction (closer to ZM5) from the iris, 7B is 8.25" from the iris in the + X direction, and location 7C is 12" from the iris in the +X direction.  We weren't able to move the profiler further into the chamber without blocking the beam heading towards FC1.

We measured 13.5% widths, with A1 as the vertical axis and A2 as horizontal. 

location ZM4 PSAMs strain gauge [V] (PZT request [V]) ZM5 PSAMs [V] A1 Width [um] (standard deviation) A2 Width [um] (standard deviation)
6B 0.82 (0) -4.14 (0) 1392 (8.7) 1573 (9.9)
6B 4.38 (100) -4.14 (0) 1406 (7.3) 1584 (6.3)
7B 4.39 (100) -4.14 (0) 2001 (6.4) 2017 (6.1)
7B 1.0 (0) -4.14 (0) 1928 (5.6) 1924 (5.9)
7B 0.98 (0) -0.52 (100) 2200 (8.2) 2212 (9.4)
7B 4.31 (100) -0.52 (100) 2276 (9.5) 2303 (9.3)
7B 8.49 (200) * -0.52 (100) 2363 (11.0) 2412 (13.8)
7B 8.53 (200) 3.57 (200)* 2611 (9.0) 2691 (7.2)
7B 5.74 (100) * 3.59 (200) 2539 (13.7) 2603 (18.1)
7A 5.72 (100) * 0.64 (100) 2387 (13.5) 2446 (13.1)
7C 5.715 (100)* 0.63 (100) 2374 (11.0) 2415 (9.5)
6A 5.7 (100) * 0.625 (100) 2074 (9.9) 1611 (7.4)
6C 5.7 (100) 0.612 (100) 1670 (10.2) 1618 (7.0)
         

* strain guage still drifting

Stll left to do:

Useful distances from Don:

Don Griffith sent us some useful distances in HAM7 which are useful for interpreting these measurements, based on the CAD model that he updated in in March 2022 based on the as built photos of HAM7 (D1900365-v1). 

 

Comments related to this report
julian.gurs@LIGO.ORG - 16:00, Thursday 08 February 2024 (75789)

Attached are new and final sketches (these should be used for future analyses) of the beam profiler positions with distances.

Note: we measured a distance in HAM7 from the edge of the table to ZM5 of 1841.5mm, whereas Don Griffith CAD model shows a distance of 1822.7mm.

Images attached to this comment
camille.makarem@LIGO.ORG - 16:21, Tuesday 06 February 2024 (75753)AWC, SQZ
Attached are screenshots of the beam profile measurements. The screenshots are labeled to indicate position, ZM4 voltage, and ZM5 voltage.
Images attached to this comment
julian.gurs@LIGO.ORG - 16:12, Tuesday 06 February 2024 (75752)

Attached is the sketch of HAM6 and pictures of the beam profiler position.

Images attached to this comment
naoki.aritomi@LIGO.ORG - 16:22, Wednesday 07 February 2024 (75770)

Sheila, Naoki

We measured several distances as follows.

From first iris to OM1 in HAM6: 53.75'' 
From ZM5 to second iris in HAM7: 68.5'' 
From edge of table to second iris in HAM7: 4'' 

Then we removed the irises in HAM6 and measured the beam profile at the position of second iris, which is 13.5'' from OM1.

A1: 1285 (6.7)
A2: 1426 (9.2)

We also measured the seed power at several locations. The seed coming out of HAM7 is 1.05 mW and the seed in HAM6 is 0.71 mW, which makes sense since the SRM reflectivity is 68%. The seed reflected by OPO without dither lock in SQZT7 is 30.5 mW.

We tried to take a photo of the beam and the ruler in ZM5, but it was difficult to read the ruler by camera or our eyes so we roughly measured the beam position in the baffle of ZM5. The hole diameter of the baffle in ZM5 is ~3 cm and the beam is ~1 cm below the top of the hole so the beam in ZM5 is higher than the center of the hole of the baffle.

naoki.aritomi@LIGO.ORG - 17:52, Wednesday 21 February 2024 (75922)

The beam profile measurement in 75770 was done at 6D in this figure. The ZM4 and ZM5 PSAMs strain gauge [V] (PZT request [V]) are as follows.

ZM4: 5.68 (100)
ZM5: 0.52 (100)

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