Remote CDS access portal upgraded

[Jonathan, Dave, Erik]

The portal for remote access to CDS, cdsssh, received an OS upgrade.  Remote access to CDS was down during the upgrade and is now restored.

Ops Day Shift Start

TITLE: 02/02 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: USEISM
    Wind: 5mph Gusts, 4mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.71 μm/s
QUICK SUMMARY:

- HAM 3 work is completed, doors is slated to go back on later today

- HAM 7 beam spot work continues

- CDS/DMs ok

Damping of MC baffles completed, beam spot photos taken, unplanned baffle installed

Mitchell, Betsy, Corey, Robert

Today I damped the MC baffles and took beamspot photos. More on this later.  For now, I want to give some details about the unplanned baffle I installed.

While taking beam spot pictures I noticed an extremely bright retro-reflection seen by MC3. I had noticed this before (and also a similar glint for PRM). But this was the first time I was using the IR Illumintor and camera at this location. I use bracketing so that I could attempt to avoid saturation since the idea is to be quantitative. I had not previously realized how bright this reflection was – it completely saturated the pixels even with short exposures (see Fig. 1).

So, with creative help form Mitchell, Betsy and Corey, we baffled the glint. Figure 2 shows that the baffle is clamped to a HAM2 wall fixture and projects out about 2 cm from the wall to hide the glint surface from the MC3 beamspot.

Checked SQZ beam alignment in HAM7 after ZM4 PSAMs offloading.

Julian, Sheila, Vicky, Camilla. After today's alog 75677 ZM4 PSAMs offloading. WP11666

Started with ZM4 sliders at Pit  -362, Yaw -273. Our beam off the OPOS was good, centered on both HAM7 QPDs with nsum 150 to 160.

The beam was off mainly in yaw, centered on irises by moving sliders to Pit -521, Yaw -1213. This was with PSAMS at 200V. There is still loads of range on the sliders, DAC counts up to 27,000 out of 500,000.

We watched the beam and ramped PSAMS from 200V to 0V over 30s, the beam may have moved slightly higher. 

Leaving both ZM4 and ZM5 PSAMS at 0V for tomorrows work.

HAM6 electronics and ground check part 1: OMC DCPD/QPD/PZT chain has never been healthier. ASC-AS_C has a grounding issue.

Summary:

OMC DCPD/QPDs/PZTs are good without caveat for the first time in LHO history.

OM2 heater and thermistors are good.

ASC-AS_C has a grounding issue which should be fixed in chamber at some point.

Didn't check grounding of the beam diverter and picos (confirmed that picos move, didn't test BDV).

For flange layout, see D1002877 (but note that LHO uses D6-F4 for OMCR diode, not D6-F6).

For in-air wiring, see D2200215 (OMC DCPD), D1300589 (OMC PZTs), D1002283 (OMC QPDs, OMCR DCPD also uses one channel of the QPD interface), D2000212 (T-SAMS heater/thermistor).

New OMC seems to have eliminated the source of headaches in the past.

The new OMC (1st attachment left) has a PEEK connector bracket on top of the OMC breadboard instead of an aluminum bracket (1st attachment right). In the past this aluminum bracket caused many, many headaches. Now that it's gone, OMC DCPD/QPD/PZT chain makes sense w/o caveat.

D6-F1 (DCPD/Preamp)

At the feedthgough, I disconnected the D6-F1 DB25 (for OMC DCPD/Preamp) and used a breakoutboard on the feedthrough to check grounding. No pin including pin13 (that is used for shield) is connected to the chamber. Pin 13 is only connected to signal GND pins of the in-vac preamp (pin 10/15/16/19/20/23).

Inside the chamber on the in-vac preamp, the DB25 shell is connected to the preamp body (which is isolated from the ISI via PEEK spacer). At first DB25 shell and the preamp body was shorted to the ISI table, but this turns out to be via 3MHz cable ultimately connected to the in-air chassis. As soon as both of the 3MHz cables were discunnected from the in-air chassis, preamp body as well as the DB25 shell weren't conducting to the ISI table any more.

 D6-F1 and 3MHz connection.

D6-F2 (PZT)

Disconnected D6-F2 (PZTs) at the feedthrough, used a breakout board. Discharged the PZTs. Measured capacitance: HZ PZT (pin1-14) was 373nF, LV PZT (pin2-15) 392nF, these include in-chamber cables. Nominally these are 380nF and the measured numbers are good.

Pin 13 is not connected to any pins nor the chamber. No short circuiting between LV and HV path.

Restored D6-F2 connection.

D6-F3 (QPDs)

Disconnected D6-F3 (OMC QPDs) at the feedthrough, used a breakout board.

Pin 13 is not connected to any pins nor chamber. Diode connection from QPD1 anode 1/2/3/4 (pin 15/2/14/1) to QPD1 cathode (pin 16). Diode connection from QPD2 anode 1/2/3/4 (pin 18/5/17/4) to QPD cathode (pin 19). No connection from QPD1 to QPD2 and vice versa.

Restored D6-F3.

OMCR diode is good

Disconnected D6-F4 to check. Pin 13 is not connected to chamber nor any pins. Restored D6-F4.

ASC-AS_C has a grounding issue

Disconnected D6-F5 to check. Pin 13 is connected to the chamber. Restored D6-F5.

T-SAMS heater/thermistors are good

Disconnected D6-F9 to check.

Pin 13 is not connected to chamber nor any pins.

Pin 1-14 (heater) is 104 Ohm, which is good.

Pin 11-24 (thermistor 2) and pin 12-25 were both 11.7kOhm, sounds about right. No cross-connection between thermistor 1 and 2.

Things that weren't checked

Will check grounding:

Pico (checked that both WFSA and B pico moved).

WFS (DC).

Suspensions. Will leave it to Fil.

Won't recheck grounding:

Beam diverter (will check that it moves). Known in-chamber grounding, this was dealt with in air in the past, no reason it changed.

WFS (RF, interface). Coax, no reason to worry.

DCPD 3MHz. Coax, no reason to worry.

HAM3 ISI TFs look ok after baffle work

Purge was pretty high for my first couple horizontal tfs, but I didn't see any of the normal symptoms of rubbing while doing the measurement. The tf's themselves look a little rough below my .5-5hz passband excitation probably because of the high purge, but otherwise I think everything is okay to put the door back on.

Thursday Ops Day Shift End

TITLE: 02/02 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:

Engineering Run Work Update:
HAM3 is Almost complete, Waiting on Jims TF. before the HAM3 Doors go back on.

HAM6 & 7 teams are still in the LVEA and just transitioned the LVEA to LASER HAZARD (work permit 11666) and Camilla is expected to transition the LVEA Back to LASER SAFE before she leaves.

VAC team did some leak down tests on EndX.
 

Alarms:
16:43 UTC Restart of Dust monitors.
Dust Mon in PSL alarm went off at 17:41 UTC

18:06 : UTC Dust mon alert again

HAM7 Watch dog tripped 18:08 UTC
Dust Mon 10 Alarm are at 140 for 300nm & 89 for 500nm

19:31 UTC Dust mon 102 in Anteroom  Vacuum  H0:VAC-EX_X4_PT525_MOD1_PRESS_TRR Alarm went off twice while Jordan and Gerardo were down at EX.

LOG:                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:54	FAC	Kim & Karen	LVEA	No	Technical Cleaning	17:01
16:35	VAC	Jordan	LVEA	No	Vaccum work	17:07
16:37	TCS	TJ	LVEA	No	Chasing TCS leaks	18:31
16:47	PEM	Robert & Mitchel	LVEA HAM3	No	HAM3 Baffle Work	19:19
17:01	FAC	Kim, Karen, Emma	HAM SHAQ	No	Technical Cleaning.	19:02
17:07	VAC	Jordan	END X	N	Checking End X Pump Down	17:44
17:38	VAC	Travis	LVEA +Y	N	Removing Feedthrough on BSC8	20:02
17:44	SUS	Rahul , Austin, Camille	HAM7	No	ZM4 in HAM7 work + HAM6 OMC Recentering	20:15
17:45	VAC	Jordan	LVEA +Y	N	BSC8 feedthrough work	20:02
17:58	FAC	Eric	MidX	No	checking Air Handler	18:30
18:28	VAC	Betsy	Mech Rm	No	Checking Equipment & looking for parts	18:55
18:56	EE	Mark	PEM Rack CER	N	workin on PEM Accelerometers	19:08
19:10	OMC	Keita	LVEA HAM6	No	Electronics check	00:37
19:18	VAC	Gerardo	LVEA BSC8	No	Feed through removal	20:02
20:18	PEM	Robert & Mitchel	LVEA HAM3	No	HAM3 Baffle work	00:17
21:13	IAS	Jason & RyanC	LVEA West	No	Surveying the LVEA	22:47
21:23	FAC	Tyler	LVEA	N	Crane inspection	23:21
21:27	VAC	Jordan & Gerardo	LVEA BSC8	N	Working on  removing feedthroughs	21:59
21:30	SUS	Corey	LVEA HAM3	N	Taking in chamber pictures	23:10
21:59	VAC	Gerardo & Jordan	EndX	N	Leek Checking	00:18
22:00	VAC	Betsy	LVEA HAM3	N	Pestering HAM3 Workers.	00:13
22:36	SQZ	Sheila Julian	OPTIC Lab	N	Gathering equipment	23:48
22:52	SQZ	Camilla	LVEA	N	Talking to Betsy, and helping Camille.	23:21
23:15	FAC	Richard	LVEA HAM3	N	Pestering Betsy & HAM3 crew.	23:55
23:38	VAC	Travis	HAM SHAQ	N	Dropping off equipment	23:58
00:01	SEI	Jim	LVEA	N	Tripping Watchdogs in HAM3	00:18
00:12	SAFE	Camilla	LVEA	yes	LASER SAFE TRANSITION	00:18
00:20	SQZ	Camilla, Sheila, Julian, Vicki	HAM6	yes	HAM7 & SQZ work	02:20
00:21	LASER	SITE	LVEA	YES	LVEA IS LASER HAZARD	00:21
00:31	VAC	Gerardo	LVEA	YES	Twittling Some Valves	01:31

LVEA Transiton to LASER HAZARD

LVEA and just transitioned the LVEA to LASER HAZARD (work permit 11666) for a few hours and Camilla is expected to transition the LVEA Back to LASER SAFE before she leaves tonight.

2-1 vent vacuum diary

Today's activities:
- EX pumpdown continues. The pressure is in the mid-E-7s already, after ~37 hours of pumping.
- EX was also leak checked: the newly installed 12" blank on BSC5; the new RGA angle valve; and the dismounted and re-mounted 3 viewports were leak-checked, and all passed nicely: see it more in-detail in the comments
- At EX the last thing to do is the RGA bakeout, which will be started on next Monday
- From BSC8 all the 12" 3IFO feedthroughs were removed, and they were replaced with blanks (5 pcs. of them). The removal of the particularly awkwardly placed 16.5" feedthroughs has been started (there are 3 of them).
- The purge air dew point was measured in the LVEA, and found satisfactory (~-42 deg C) - see more in-detail in the comments

HAM3 Close-Out Photos (with +Y HAM door removed--for IMC Mode Cleaner Baffle Rotation)

Not a complete & thorough photo close out since we only had one door removed for HAM3, but tried to take as many photos as possible (last photos I have were from 2017 for HAM3!).  Here's the link on Box:

https://caltech.box.com/s/hds72npwsrhzwe01h79drkrdnytow3t4

ZM4 (P-SAMS in HAM7) preload adjusted to change the radius of curvature of the mirror

Camille (CIT), Austin , Rahul

This morning we went to HAM7 chamber and changed the preload on ZM4 (P-SAMS) suspension as per the document E2300463_V1. This changed the RoC of ZM4 mirror without the PZT actuation. Given below are the details of our work - Camille will add pictures later on.

- After setting ZM4 into SAFE state we locked all three stages of the suspension. We had already taken healthy TF measurements before starting our work.

- The bottom mass cable was disconnected and carefully re-routed so that it stays away from the fixture plate.

- four add-on masses (basically 1/4-20 screws with washers) attached to the bottom mass was then removed.

- bottom mass Fixture plate (D2100121) was attached to the structure using six 8-32 screws.

- The bottom mass (already locked using EQ stops) was then further clamped using four 1/4-20 screws through the fixture plate. We had to adjust the height of the bottom mass to the align the threads with the holes on the fixture plate.

- Once the bottom mass was securely clamped, we removed the three set screws on the preloader.

- Using a torque wrench we increased the preload on the bottom mass by ~29 in.lb. (Total preload from torque after increase was 75 in.lb).

- We then followed all the above steps backwards (i.e set screws, add on mass put back, fixture plate removed, cable re-connected and the suspension set free).

- Once all done, we started damping the suspension and checked for any BOSEM flag changes - looked all fine.

- We took the transfer function measurements and ZM4 looked healthy.

Hence we took all the tools out and put the curtains back on HAM7 chamber.

Next, we will go into laser hazard with SQZ team and check for any changes in beam alignment and make adjustments as required.

1st image: PSAMS locked in place with EQ stops.
2nd image: PSAMS locked with bottom mass fixture plate.
3rd image: Removal of set screws.
4th image: Preload adjustment with torque wrench.
5th image: Preload adjustment with torque wrench.
6th image: Torque wrench dial with the blue needle showing the total torque on the preloader (75 in lbs.)

FARO Progress So Far

J. Oberling, R. Crouch, T. Guidry

Update on FARO progress so far.  Warning, incoming wall of text.

There have been issues accurately aligning to the LHO global coordinate system to the accuracy necessary for IAS work, specifically in getting good alignment to the global Z axis.  This is somewhat of a repeat of the struggles when prepping the FARO for the FCT (Filter Cavity Tube) install work; while we were able to get an alignment good enough to be well within the FCT installation tolerances, the tolerances for optic alignment are more stringent (+/-1.0 mm positional tolerance) so we have to get a better alignment to our global coordinate system.  To date we have worked in 2 areas: aligning to the global coordinate system, and accurately moving the FARO around the West Bay.  For reference, monument name and coordinate information can be found on the DCC at D1100291.

Global Coordinate System Alignment

To start, we began by following our WIP procedure for global coordinate alignment.  Part of this is to refine said procedure, since I quickly threw this document together (almost 2 years ago now) after a phone call with PolyWorks tech support; we now have a red lined copy that I will use to update the WIP procedure.  Due to line of sight issues and monument shape (BTVE monuments are domes, not flat; direct line of sight to PSI-6 is blocked) we use a sphere fit rod to probe the monuments (place the point of the rod in the monument punch and trace out a sphere as best we can while keeping the rod point firmly in the punch (the monument punch limits how much of a sphere we can trace, and therefore the accuracy of Polyworks' sphere fit); the Polyworks software then fits the data to a sphere).  In this way we can enter the coordinates of our alignment monuments as the center point of a sphere, then use the sphere fit rod to probe the monument (useful for ones that are out of direct line of sight, like PSI-6, or ones that are not flat, like BTVE-1).  We have 2 sizes of sphere fit rod, a 3" and a 5".  We first used the 5" rod, as it's the same we used for FCT install setup, and the results of that alignment are shown in the 1st picture.  As can be seen, not very good (one can ignore the diameter measurement on this picture and all the ones that follow, the error there is a result of the limited sphere shape we can trace with the sphere fit rod; PolyWorks told us back in 2022 that the alignment algorithms do no consider this data, only X, Y, and Z).  We then used the 3" rod and repeated the alignment procedure, results shown in the 2nd picture.  This is seemingly a good bit better, but the issues arise when we then try to measure a known monument.  Unfortunately, due to a lack of known monuments in the LVEA West Bay, we don't have any independent monuments we can measure against that have an associated Z axis coordinate, so we have to use the same monuments we use to perform the alignment (i.e. BTVE-1, PSI-1, PSI-2, and PSI-6).  In addition, we can't use PSI-6 (located in the biergarten), because the SUS electronics rack closest to WBSC2 sits directly over it and blocks direct line of sight (we can see it when using a sphere fit rod, but not with a regular SMR nest).  When looking at the 3 available monuments we have, the FARO reports their coordinates as ~1.5mm higher than our documentation says they are; this is consistent across all 3 monuments, indicating a systemic error somewhere (or maybe the documentation is wrong?).  X and Y are accurate to <0.1 mm across all monuments measured.

This launched us on trying to find this 1.5mm error.  The first thing we tried is reading up on PolyWorks' alignment algorithms to see if there's something in the setup we're missing (PolyWorks' included reference guide is a wealth of information on the software).  From this we learned that the alignment algorithms are updateable after the fact (including adding and removing alignment features/monuments), and the software will then apply that update across all alignments in the project.  This includes adding and removing alignment targets on the fly, and changing how the routine considers the available data (weighting different monuments over others, which axes to use, etc.).  Part of our alignment procedure is to first align to X, Y, and axis tilt, then perform another alignment routine to align to the Z axis.  We noticed that the portion of the alignment routine that aligns to X, Y, and tilt was also considering Z, when it shouldn't be; the portion that aligned to Z was considering X and Y when it shouldn't be.  We can make these corrections on the fly, without having to re-measure anything, so we did.  The update changed the X and Y axis deviations, but caused no change in the Z axis deviations; the results of this correction are shown in the 3rd picture.  The X deviation for PSI-2 got a little worse but improved for the other 3 monuments, Y is practically the same across all 4, and Z was unchanged as expected.  But we still see the +1.5mm Z axis error when directly measuring these monuments (X and Y remain accurate to <0.1mm).

The next thing we considered is the difference between the monument surface and the monument punch.  The sphere fit rod measures to the point of the rod, which sits at the bottom of the punch while we use it to probe the monument location.  However, the Z axis coordinate for these monuments is registered to the surface of the monument, not the bottom of the punch.  Therefore in this setup the FARO is actually measuring the bottom of the punch, which then adds error to the coordinate system alignment.  Using our Center Punch Nest (an SMR nest with an included punch for marking monuments, abbreviated CPN from here on out) and a depth gauge we measured the difference between the monument surface and the bottom of the punch for each of our 4 alignment monuments (the punch portion of the nest only depresses as far as the punch can go, so we can measure the difference between the surface and the monument punch based on how far the nest punch can travel).  The results, assuming the surface of the monument is 0:

• BTVE-1: -0.8 mm
• PSI-1: -1.1 mm
• PSI-2: -0.7 mm
• PSI-6: -0.6 mm

This means that when we use a sphere fit rod to probe these monuments we have to correct the global coordinate by the above amounts so we're measuring the correct point on the monument.  For example, the global Z axis coordiante for BTVE-1 is -1057.2mm, but when using a sphere fit rod we need to enter the corrected coordinate of -1058.0mm (-1057.2 - 0.8) into PolyWorks.

Tyler suggested we also check the local difference in the Z axis between our alignment monuments, using BTVE-1 as the origin.  We have a local coordinate survey from the late 90s for the PSI and BTVE monuments in the LVEA (the last time this was done); this data is available at D970210 in the file Rogers_LHO_PSIMonumentsAs-Built.pdf on page 2, and again in D1100291 in the file LHO_PSI_Monument_Z_Corr_MEZ220406a.xlsx, in Column C.  We used the FARO to check this, using a blank project so the FARO was not aligned to our global coordinate system.  Setup again in the West Bay in the same position we've been using to probe our alignment monuments, we oriented the FARO to local gravity (the FARO levels and then orients itself to the local gravity at its current location), then used an SMR with our CPN set over each monument punch to measure the difference in Z for each monument (deltaZ_PSI-X = Z_BTVE - Z_PSI-X); we're essentially using the FARO as an autolevel to perform a differential height survey.  Since we don't have direct line of sight to PSI-6 we set the CPN roughly inline with PSI-6 in X but set against the SUS rack so the FARO can see it (roughly 300mm +Y from the monument); this put the SMR on the vinyl floor, which we measured to be ~2mm thick using a set of calipers.  This could add some error, as we're not directly over PSI-6 and therefore cannot account for any height difference between our location and the monument (such as variations in the surface height of the concrete), but it's the best we have given our line of sight restrictions (the West Bay is crowded, but it's the only place where we have a collection of monuments with a registered Z axis coordinate).  Results and deltaZ from the old Rogers survey, all units in mm:

• Heights as measured with FARO
  • BTVE-1: -539.9mm
  • PSI-1: -1365.0mm
  • PSI-2: -1366.3mm
  • PSI-2: -1360.9mm

	Rogers As-Built Survey, 1997	FARO, 2024	Difference between Rogers/FARO
deltaZPSI-1	-826.3	-825.1	+1.2
deltaZPSI-2	-827.5	-826.4	+1.1
deltaZPSI-6	-822.4	-821.0	+1.4

So the FARO indicates that the Rogers As-Built survey from 1997 was not correct, so we adjusted the global Z axis coordinates for our 3 PSI monuments using the above FARO data.  We then further adjusted the Z axis coordinates using the difference between the punch depth and the monument surface.  This gives us the following global Z axis coordinates for our alignment monuments, all units in mm:

	New global Z using FARO height	Global Z for bottom of monument punch
BTVE-1	-1057.2 (unchanged)	-1058.0
PSI-1	-1880.8	-1881.9
PSI-2	-1877.7	-1878.4
PSI-6	-1876.2	-1876.8

We then used these new global Z axis coordinates for the bottom of the monument punch to align the FARO to our global coordinate system, results shown in the 4th picture.  We created points based on the global Z of the monuments themselves, and performed a Build/Inspect operation to get our deviations in X, Y, and Z (again using the CPN to place the SMR over the monument punch; the CPN registers to the monument surface); these results are shown in the final picture.  As can be seen, the reported X and Y axis measurements are good to better than 0.05mm, but we still have some significant error in Z.  It's much better than the ~1.5mm we were seeing previously, but nowhere near as good as X and Y.

We also noticed from the FARO's position that we could see height monument 903 (information in T1100187); this height mark is registered to the local LVEA coordinate system, and is on a metal post.  Using a autolevel we placed a temporary magnetic SMR nest in line with the height mark.  From this we could get X and Y coordinates for a spot very close, but not exactly on, the height mark (X is right on it, but Y is roughly 1" +Y).  With these X and Y coordinates we can transform the registered local Z coordinate to a global one (see T0900340) and compare to what the FARO says (the ~1" offset in Y is not an issue, as the Y axis tilt is very small at 12.5µrad, which causes a 0.3µm error in the global Z (yes, that's micrometers)).  We did this very quickly with a cell phone calculator, and did not get a screenshot or picture of the results (my fault), but the FARO thinks that height mark 903 is ~4.2mm higher than we would expect after converting its local Z to a global Z.  We have no other height marks we can place a nest by to do this same measurement, so we currently have no way to know if this error is in the height mark itself or something with the FARO (or a combo of the 2).  Will have to move the FARO around (which we can do accurately, see next section) to find something else to look at.

What's causing this error?  At this point in time we are not sure.  Some thoughts:

• It could be due to an issue with the alignment routine; as can be seen from the collection of 3" sphere fit rod alignment results, we aren't able to get much consistency.  This could be due to differences in probing technique with the sphere fit rod, so we want to repeat this with someone else probing the monuments (Ryan probed the monuments while I ran the software, we want to swap and repeat).
• It could be due to the sphere fit rod itself.  Since we're limited in how much of a sphere we can trace, it's possible the internal sphere fit that PolyWorks does is not able to accurately locate the center of the sphere as it relates to the position of the tip of the rod, thereby causing error in the alignment.
• The coordinates we have could be wrong.  We're trusting 25 year old survey data, because we have nothing else.  Any errors in those initial surveys would cause errors in our FARO alignment.

Moving FARO

We were able to move the FARO into the biergarten area using a collection of glued nests (set during FCT install) and magnetic nests.  This was done independently of our gloabl coordinate alignment work.  We were aligned to our global coordinate system (although we're still questioning the accuracy), but only looking at how accurately we could move the FARO (device target deviations between moves and device positional uncertainty at each location), which does not depend on being accurately aligned to any set coordinate system.  When doing a move you want a minimum of 3 targets, but PolyWorks support has repeatedly told us that you really want at least 6.  While the software will use 3, using 6 or more greatly increases the accuracy of the move.  We were able to use roughly 8 targets to move into the biergarten area and back out near the Test Stand.  In total we did 3 device moves for a total of 4 device positions: position 1 at our intial setup point, position 2 closer to the FCT to have better line of sight into the biergarten, position 3 in the biergarten area but outside of the cleanroom, and position 4 back in the West Bay near the test stand.  The largest target deviation we saw between device positions was ~0.2mm.  In addition, PolyWorks has a routine to calculate the positional uncertainty of the FARO.  This routine reported a positional uncertainty of <0.05mm for each device position, indicating that we can accuratly move the FARO around.  This was good to confirm, as we're going to have to move the FARO around the LVEA to find other monuments with known global Z axis coordinates to test our global coordinate system alignment.

Next Steps

• Have someone else probe the monuments, to check if probing technique has a measurable affect.  Maybe we need to refine our technique here.
• Move the FARO around to find other monuments with known global Z axis cooordinates to test our alignment.
  • Our main option here is other PSI monuments, but I question how useful this will be.  The FARO indicates that the old local Z coordinate survey from 1997 was incorrect, which now brings into question the Z axis coordinate for every PSI monument in the LVEA.  It would be great if we could perform the same differential height survey with other PSI monuments, but to do so we need line of sight to BTVE-1.  There's too much stuff in the way, including existing unused H2 infrastructure, to make this practical.  Need to think of something else.
• Assuming we're happy with the global coordinate system alignment, begin mapping existing LVEA monuments.

Added ndscope trends to track EX pumpdown

The EX pumpdown trends were added to the CDS Ndscope Trends:

https://lhocds.ligo-wa.caltech.edu/exports/dave/vac_ex_press_1_day.png

1 day

Quiet HAM6 day (Rahul, Betsy, Keita)

We put the OMCS baffles back on except the -Y side vertical panel, which had a non-standard screw/washer/O-ring configuration. It turns out that that was done intentionally back in Aug/2016 because otherwise the OMC trans beam won't come out of the shroud hole (alog 28944).

The shroud panels had finger marks from gloves as well as spots that look like dust particulates (1st attachment). We wiped using IPA and wipes, which reduced the finger marks (2nd attachment). Though they look much better in the picture, in reality we might have been just spreading it over the larger surface. Some spots didn't move at all. Anyway, we cleaned the panels using ionized nitrogen gun (for particulates) immediately followed by alcohol-wipe.

There was one particularly bad spot, see Betsy's picture.

3rd and 4th pictures show Rahul and Betsy working on a small horizontal top panel. 5th picture shows the OMC surrounded by the shroud panels.

After attaching the shroud panels (except for the -Y side vertical one), we found that one of the white DCPD cables interfered with the top glass panel, so Betsy pulled the cable up higher in the cable retainer attached to the suspension cage. PZT cable was really close to the other DCPD cable, but the PZT cable doesn't have a retainer, so I bent that cable to form a large arc to avoid interference. On -X side, Rahul found that one of the QPD cables is very close to a BOSEM cable, so he worked on that.

These resulted in some change in the OMCS alignment, and top osem numbers shifted according to Rahul. My hope is that this is benign enough we can take care of that using mostly OM2 and OMC.

Rahul measured the TF for OMCS and they're OK.

Tomorrow we'll attach the remaining panel, recenter BOSEMs for OMC and OM2,  and I'll start the electronics check.

CER Accelerometer Chassis Installed

Replaced the Endevco Accelerometer Power Conditioners with LIGO Accelerometer Power Conditioners. WP11653

Order in the rack:

U19 - Accelerometer Power Conditioner S2300062

U16-U17 AA Chassis S1300101

U14 - Accelerometer Power Conditioner S2300063

U13 - Accelerometer Power Conditioner S2300065

U12 - Accelerometer Power Conditioner S2300069

U11 - Accelerometer Power Conditioner S2300064

Still have EX, EY, MX, MY, FCES to complete.

M. Pirello, J. Jimerson. R. Schofield

PCAL EX End Station Measurements & Lab Measurements

X End Station Measurement:
During the Tuesday maintenace, the PCAL team(Rick Savage, Dana Jones, & Tony Sanchez) went to EndX with Working Standard Hanford aka WSH(PS4) and took an End station measurements.

The EndX Station Measurements were carried out according to the procedure outlined in Document LIGO-T1500062-v15, Pcal End Station Power Sensor Responsivity Ratio Measurements: Procedures and Log, and was completed by 11:45 am.
Note:
After the normal measurement, we did a few auxilary measurments.

LIGO-T1500062-v15 Measurement Log

First thing we did is take a picture of the beam spot before anything is touched! I then put the target apature cap on the RX sphere to see how far off from center the beam is.

Martel:
Martel Voltage sources voltage into the PCAL Chassis's Input 1 channel. We record the GPStimes that a -4.000V, -2.000V and a 0.000V voltage was applied to the Channel. This can be seen in Martel_Voltage_Test.png. We also did a measurement of the Martel's voltages in the PCAL lab to calculate the ADC conversion factor, which is included on the above document.

Plots while the Working Standard(PS4) is in the Transmitter Module during Inner beam being blocked, then the outer beam being block, followed by the background measurment: WS_at_TX.png.

The Inner, outer, and background measurement while WS in the Receiver Module: WS_at_RX.png.

The Inner, outer, and background measurement while RX Sphere is in the RX enclosure, which is our nominal set up without the WS in the beam path at all.:  TX_RX.png.

The last picture is of the Beam spot after we had finished the measurement. Note this beam spot is only ONE beam but the beam postitons were not adjusted during the measurement.

All of this data is then used to generate LHO_EndX_PD_ReportV2.pdf which is attached, and a work in progress in the form of a living document. This document was created with the PCALPARAMS['WHG'] = 0.916985 # PS4_PS5 as of 2023/04/18
And Not the latest number [PCALPARAMS['WHG'] = 0.91536 # 12/05/2023].
But I did run the report with the latest number just for my own curiosity and marked it down as a "Monday End Station measurement" performed on 2023-12-04 so it sits right behind the real measurement on the 5th and it doesn't vary by much: LHO_ENDX_PD_TEST_REPORT.pdf

All of this data and Analysis has been commited to the SVN :
https://svn.ligo.caltech.edu/svn/aligocalibration/trunk/Projects/PhotonCalibrator/measurements/LHO_EndX/

This is where the measurement normally ends, but instead we took a few more iteresting measurements.

Auxilary Measurements:
Rx Sphere is in it's nominal location and the WS was not in the beam path at all.  
Opened the Shutter GPStime 1385839530
RxPD = 0.2234 before moving the beam block.
Moved the beam block allowing both beams to hit RX sphere.
start time 1385839590
End time 1385839890

Shutter both beams for a background measurement.
Start time 1385839945
RxPD = 4.30966e-5
End time 1385840005

The OFSPD_OFFSET was set to 6.0. This should be the maximum power we reach while normally operating.
start time 1385840225
RXPD = 0.805388
TXPD = 0.813297
End time 1385840525

PCAL Lab Responsivity Ratio Measurement:
A WSH/GSHL (PS4/PS5)FrontBack Responsivity Ratio Measurement was ran, analyzed, and pushed to the SVN.
The analysis of this measurement produces 4 PDF files which we use to vet the data for problems.
raw_voltages.pdf
avg_voltages.pdf
raw_ratios.pdf
avg_ratios.pdf

Obligitory BackFront PS4/PS5 Responsivity Ratio:
A WSH/GSHL (PS4/PS5)BF Responsivity Ratio measurement was ran, analyzed, and pushed to the SVN.
The analysis of this measurement produces 4 PDF files which we use to vet the data for problems.
raw_voltages2.pdf
avg_voltages2.pdf
raw_ratios2.pdf
avg_ratios2.pdf

This adventure has been brought to you by Rick Savage, Dana Jones & Tony Sanchez.