Displaying reports 1-20 of 87659.Go to page 1 2 3 4 5 6 7 8 9 10 End
Reports until 15:20, Thursday 14 May 2026
H1 SUS
ibrahim.abouelfettouh@LIGO.ORG - posted 15:20, Thursday 14 May 2026 (90249)
BBS01 Installed into BBSS

Ibrahim, Betsy, Oli

Today, we installed BBS01 into the BBSS successfully. 

BBS01 was on a table. BBSS was on the aluma lift. We picked BBS01 using the ERGO arm and slowly came into the optic. In this process, we:

On top of pictures below, 2 videos:

Images attached to this report
H1 CAL
michael.ross@LIGO.ORG - posted 10:58, Thursday 14 May 2026 (90246)
iNCal Low Speed Accelerometer Tests

I spun the iNCal (currently installed version) at a low speeds to see if low speed operation shows the same vibrations that high speed operation does (see 67207). Even rotating at 1 Hz shows a large increase in signal in the accelerometer (H1:PEM-EX_ACC_BSC9_ETMX_Z) around 200 Hz. 7 Hz shows an order of magnitude increase between 100-300 Hz. The 0 Hz spectrum is with the iNCal powered but a set speed of 0 Hz. 

The lesson is that the iNCal will inject broad band noise in the strain readout even at very low speed operation.

Non-image files attached to this report
H1 SUS (SUS)
ryan.crouch@LIGO.ORG - posted 10:42, Thursday 14 May 2026 (90245)
OPLEV charge measurements, ETMX, ETMY

I ran the oplev charge measurements this morning for both of the ETMs, previously checked in alog89906.

ETMY's charge remains largely unchanged, the values across the quadrants remain below 100 on all quadrants/DOF and I don't see any appreciable trends. As a reminder we switched off the HV digitally for EY.

ETMX's charge is decreasing across all quadrants/DOF after the sign flip we inposed back in April. Over the past 4 weeks the average decrease for P was ~ -14 [V], and ~ -18.25 [V] for Y. UL saw the greatest decrease, a drop of over 30 [V] for both P & Y, UR saw the smallest decrease, around ~ 5 [V] for both P & Y. The charge is now at or below 50 [V] on all quadrants/DOF except UR_P and LR_P.

Images attached to this report
LHO General
corey.gray@LIGO.ORG - posted 07:34, Thursday 14 May 2026 (90241)
Thurs DAY Ops Transition

TITLE: 05/14 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: 5mph Gusts, 3mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.23 μm/s 
QUICK SUMMARY:

New ISS Array alignment will continue as well as work with the new Bigger BeamSplitter. 

No alarms overnight. Clearer & calmer weather this morning.

With the better weather, perhaps the DGR subcontractors will start pouring concrete for the CEBEX walls today (this will require the main gate to be left open for the cement trucks to roll through.  (WP# 13250)

H1 IOO (INS, IOO, ISC)
keita.kawabe@LIGO.ORG - posted 23:19, Wednesday 13 May 2026 - last comment - 11:50, Thursday 14 May 2026(90237)
Swapped the ISS array. Alignment into the new unit started. (Rahul, Elenna, Keita)

Following yesterday's alog 90219:

At this point I and Rahul checked the beam positions in HAM2. Some things to note:

We proceeded to swap the ISS array unit.

At this point we saw flashes on QPDs as well as array PDs right away. INNER as well as OUTER SUM flashes were both about 0.06 (in the old unit it was 0.03 for OUTER but INNER was much smaller).

We started trying to center the QPD using the first pico mirror. Since pico driver is temporary unavailable (IOT2L is moved away) Rahul turned the pico manually while Elena looked at the laptop screen to monitor flashes in the individual segments. We managed an OK job (arrayqpd_centered.jpg) and checked the beam spots again.

The baffle height might not be the same as the lens height and/or the ISS array input hole height, but otherwise it seems that we're shooting down the beam from the 1" lens to the ISS array. We'll check if the lens, baffle and the array are all at the same height or not, and decide how to proceed.

Images attached to this report
Non-image files attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 23:40, Wednesday 13 May 2026 (90239)

1st: Rahul is disconnecting the QPD cable.

2nd, 3rd (photo by Betsy): Rahul in chamber (me outside).

4th: Old unit was extracted. This is S1202971.

5th: New unit (S1202965) to the left, old one to the right.

6th: Rahul after successfully connecting up the new unit in chamber.

7th (photo by Betsy): Elenna (front) is checking the QPD centering, Rahul (a shadow in the back in this photo) is manually moving the pico mirror from -Y door, and I'm somewhere inbetween just observing the two doing a good job.

Images attached to this comment
corey.gray@LIGO.ORG - 08:45, Thursday 14 May 2026 (90243)EPO

epo tagging for photos!

rahul.kumar@LIGO.ORG - 09:39, Thursday 14 May 2026 (90244)

Attaching two pictures in reference to Keita's comment above - "The beam was very high on the left hole of the two-hole baffle (Rahul has a good pic), high on the right hole (right_hole_after_new_array_QPD_centered.mp4)"

Images attached to this comment
keita.kawabe@LIGO.ORG - 11:50, Thursday 14 May 2026 (90248)

We concluded that the height of the baffle and the array unit are both correct, the beam is really too high on the 1" lens and we're shooting down from there to the QPD. (This should have been the case for a long time with the old unit. Right after the new unit was installed the beam was on QPD and the beam stayed on the QPD, the diameter of the QPD is 3mm, i.e. we haven't made any huge change on the height of the beam at the left baffle hole.)

  • Rahul found in solidworks that the design beam height for LHO is 6.132"=155.75mm.
  • Looking at the pictures we took in the chamber, the center height of the two-hole baffle is about 156mm so that's fine.
  • The height of the spacer we have, which is supposed to be D1101074 specifically made for LHO,  has 4.94"~125.5mm nominal height and our measurement shows somewhat larger than 125.5mm, excellent agreement. We didn't measure the thickness of the thin part of the array base plate (https://dcc.ligo.org/LIGO-D1300323, detailed dimensions are only available in solidworks) nor the distance from the bottom to the beam center of the elevator plate D1400140 (again only available in solidoworks) but Rahul's number makes sense, the height of the actual array unit seems to be according to the design.

With this information, what we'll do next is to gradually bring down the height of the beam on the left baffle hole using the first pico mirror, and use the second pico mirror to bring the beam back on the QPD, until the beam line into the array becomes level-ish with the ISI surface. It doesn't have to be perfect but we don't want to be this much tilted.

Images attached to this comment
H1 SEI
jim.warner@LIGO.ORG - posted 18:38, Wednesday 13 May 2026 (90238)
CRS progress today

Shoshana, Michael, Jim

Today we went into the PSL and started putting together the 2 complete CRS assemblies we have cleaned and ready to go. This went pretty smoothly and we now have to mostly done CRS, sans HOQI readout. We don't have flexures we can use, so we can't suspend or do any mechanical tuning, but proof masses are installed in the frames, mass adjustment hardware and picos are mounted. Tomorrow, we will probably look at what prep we can do on the other 2 CRS, but fasteners are still working through c&b for those, so I don't know there is much to do until those come out.

Images attached to this report
H1 SUS (EPO, SUS)
ibrahim.abouelfettouh@LIGO.ORG - posted 16:36, Wednesday 13 May 2026 (90236)
BBSS Taken out of Can and Prepped for Install

Ibrahim, Betsy, Randy

Today, we:

Particle counts were checked periodically and were under 75 consistently during acitvity

See pictures.

Images attached to this report
LHO General
corey.gray@LIGO.ORG - posted 16:30, Wednesday 13 May 2026 (90222)
Wed DAY Ops Summary

TITLE: 05/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

ISS PD Array and BBSS work continues.  Had a couple of big school field trip visits.

Odd weather day with fairly high winds and rain for most of the day.
LOG:

H1 COC (EPO)
ibrahim.abouelfettouh@LIGO.ORG - posted 16:29, Wednesday 13 May 2026 (90235)
BBS01: First Contact on HR Side (and flipping BBS post-gluing)

Ibrahim, Betsy, Oli

BBS01 AOSEM flag standoffs were removed, concluding gluing.

BBS01 was flipped to the HR Side via the inspection fixture.

Betsy and I then first contacted the HR Side (S1) and peeled an hour or so later.

We did not see any features or defects as we did with S2.

Images attached to this report
H1 TCS
thomas.shaffer@LIGO.ORG - posted 16:00, Wednesday 13 May 2026 (90234)
TCSY table chiller lines all replaced and tested

Camilla C, Madi S., TJ S

Just as we did with the TCSX table a few weeks ago (alog90078), we swapped all of the flex lines on the table. Most of this was done last week, but today Madi and I fisnished the last two lines today. We then used the same vacuum trick to suck water into the table lines to "test" the lines over lunch, and then plugged the table back into the full system and slowly turned on the chiller. We had one leak at the laser driver, but cutting and reseating the 1/8"OD tube seemed to fix it. 

While trying to removed the old 3/4"OD return tube from the tee, I managed to bump the iris next to the bottom periscope mirror. We'll have to recheck this when we have beam again and can some HWS tests.

The chiller is running, I'll check on things in the morning.

Images attached to this report
H1 SEI
anthony.sanchez@LIGO.ORG - posted 15:51, Wednesday 13 May 2026 (90233)
H1 ISI CPS Noise Spectra Check - Weekly

H1 ISI CPS Sensor Noise Spectra Check - Weekly FAMIS 39336

For some context, most of the Corner station is vented and the BS cartridge is not in the chamber which explains what is shown on the BS plots here..

Non-image files attached to this report
H1 SPI
joshua.freed@LIGO.ORG - posted 12:38, Wednesday 13 May 2026 (90231)
SPI Pathfinder, RF Install Pt 1, ISIK 80MHz

J Freed, M Pirello,

We continued the progress to install the SPI RF chain as well as measured the 80MHz RF power along key points along the chain. 

SPI_RACK_LAYOUT_SUS-R2.png Shows the schematic of the rack layout for SPI in HAM 3 as well as measured power along that chain. We currently have the entire chain installed to just before the 2W amp. The main thing of note is that we have more power than even our most optimistic estimate. (We were expecting about 5dBm, MAX 8dBm, but we have 9.5dBm). The Heliax cables are much more efficient than we expected. As such next on the list is to install attenuators such that we get the power we expect. 

IMG_0627.jpg Shows the current Balun/Spitter set up. There is not really a good place to put the splitter on the SUS-R2 rack as the Patch Panel "walls" prevent using zip-ties or velcro to attach the Splitter on the sides of the SUS-R2 rack. Above the patch panel is the top of the rack; and below cables are in the way. As such, the least intrusive way is to attach the splitter to the balun (The transformer that converts the balanced Heliax cable to the unbalanced coax N-type cable), and add some strain relief on it. Not sure how effective this strain relief is but its better than nothing.

Marc also set up the 18V and 24V DC that powers the Double Mixer and other chassis that will eventually be installed. 

Next steps: 

1. Add attenuators such that the power going into the 2W amp would be correct.

2. Do phase noise measurements on the output power of the Double Mixer and see if anything has changed since 90179 

3. Test if instead of Attenuators we can attenuate the power output of the double mixer by adjusting the input voltage of the 4096Hz signal from the CDS that goes to the Double Mixer

Images attached to this report
H1 SPI
jeffrey.kissel@LIGO.ORG - posted 11:20, Wednesday 13 May 2026 - last comment - 11:20, Wednesday 13 May 2026(90228)
SPI Pathfinder ISIK Transceiver In-vac PD cable routing vs. PD / Cable Serial Numbers
J. Kissel 

SPI Wiring Diagram: D2400111-v6
In-chamber in-vac cable routing: In-vac Cable Routing Plan from G2401479-v3

I never aLOGged our choice of cable-table bracket floor assignment down when we originally assembled and signal-checked the D2400107-v4, so during disassembly in prep for upgrade to D2400107-v5 (LHO:90225) I took the time to write down the cable routing, cable serial number assignment, and cable table bracket (CBT) floor assignment:

Path       PD Name         PD SN          Duopus      D9 CBT Name / Floor     Quadrapus    D25 CBT Name / Floor 
                      |----------D2600001--------|  
                      D1600083 Type 2     D2400341    D2000492                D2400343     D2000492 
    
                                                                              S2500512
IFO REF    A/B        S2401096/S2401095   S2500516    CBT 2 / 2nd of 2        cable E      CBT 1 / 1st of 2   
IFO MEAS   A/B        S2401097/S2401098   S2500514    CBT 2 / 1st of 2        cable D      CBT 1 / 1st of 2
FBR PWR    REF/MEAS   S2401094/S2401093   S2500515    CBT 3 / 2nd of 2        cable C      CBT 1 / 1st of 2

                           PD SN          Monopus 
                      |----------D2600002--------|
                      D1600083 Type 3     D2400340

OL ISIK    QPD B      S2401091            S2500518    CBT 3 / 1st of 2        cable B      CBT 1 / 1st of 2

First and Second of the attached pictures are of the CBT 2 cable routing. I needed two pictures because the D9 end's two-part backshell of IFO REF cable was assembled with its serial number stamped on one side of one part, and the other side of the other part. C'est la vie.

Third picture is of CBT 3's cable routing.

The 2x D9 CBT assemblies (since the "type" we've assembled is not explicitly drawn in D2000492) are 
    - QTY 1x D2000519 baseplate
    - QTY 1x D2000520 "Type 2" two-floor uprights, with
    - QTY 2x D2200443 D9 adapters,
    - QTY 2x 1/4"-20 x 0.625" L captive SHCS (95966A512) for securing to the HAM table (rather than the 3/8"-16 captive SHCS that are used to secure to the BSC tables)
    - QTY 2x #6-32 x 0.375"L SHCS (92200A146) for securing the baseplate to the upright
    - QTY 2x per D9 adapter (4x total) #4-40 x 0.224"L ("2D"; 1185-04EN224) nitronic 60 helicoils for each of the upright holes
    - QTY 2x per D9 adapter (4x total) #4-40 x 0.5"L captive SHCS (95966A140) for securing the adapters to the upright

For the single D25 2-floor CBT that holds the D25 ends of the PD and picomotor quadrapuses, we used the standard D2000492 Type 2 configuration.
Images attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 11:02, Wednesday 13 May 2026 (90229)
Pictures of the D1600083 Generic PD enclosure ends of the D2600001 Assemblies

In order of their appearance in D2400111-v6 page 3:
    - IFO_REFA
    - IFO_REFB
    - IFO_MEASA
    - IFO_MEASB
    - FBRPWRIN_REF
    - FBRPWRIN_MEAS
    - QPD_B
Images attached to this comment
H1 IOO (INS, IOO, ISC)
keita.kawabe@LIGO.ORG - posted 10:07, Wednesday 13 May 2026 - last comment - 13:46, Wednesday 13 May 2026(90226)
ISS work restarts

Restored the alignment sliders for IM2 and IM3 back to Monday values ([IM2P, Y] =[765, -187.7], [IM3P, Y]=[-560.7, 320]).

Measured the flashes. Chose the flash that gave the MC2 trans sum maximum power, which in general agreed with IM4 trans sum max but didn't with ISS QPD nor array PD inner sum nor outer sum. 

Anyway, 

PIT and YAW numbers were after normalization divided by (seg1+2+3+4), not by SUM, so there's a small difference but that doesn't matter at this point.

IM4 TRANS and ISS QPD PIT and YAW are broadly in agreement with Jenne's alog 90206 i.e.

I haven't compared the ISS Outer SUM with March 2026 when IMC was locked with 2W. Somebody check please. We'll go into chamber and start checking the beam path.

Comments related to this report
elenna.capote@LIGO.ORG - 13:46, Wednesday 13 May 2026 (90232)

On March 11 when we locked the IMC at 2 W, the outersum was 0.062. Today, I measured the outersum flashes (relative to the dark noise) to be 0.031, with 0.18 W input. This means our alignment into the ISS has improved relative to March.

LHO VE (VE)
gerardo.moreno@LIGO.ORG - posted 08:34, Thursday 07 May 2026 - last comment - 04:03, Thursday 14 May 2026(90152)
CP1 Soft Regeneration Update

(Jordan V., Dave B., Gerardo M.)

The internal pressure to CP1 turned around overnight signaling that the process of emptying the trap is complete, now we'll continue to monitor and pump on the cryotrap volume.until good pressure is achieved.

A side note, I manually turned off the CC for PT114B last night at 9:44 pm (local time) as the pressure was rising a bit high, then turned it back on this morning at 5:33 am local time.

Attached is a snapshot of one day trend data of pressure behavior regarding the soft regeneration for CP1.

Process started here.

Images attached to this report
Non-image files attached to this report
Comments related to this report
gerardo.moreno@LIGO.ORG - 00:44, Wednesday 13 May 2026 (90220)VE

(Jordan, Travis, Gerardo)

CP1 soft regeneration update, CP1 pumpdown continues, system is currently pumped down by the SS500 cart, one turbo pump and one scroll pump.  Yesterday we visited the sensing line and we injected high purity nitrogen gas, we removed the lower sensing line near the Rosemount sensor to be able to inject the nitrogen gas, no issue introducing the gas, lower sensing line appears clear.

To be done, leak check CP1.

Attached is a plot of the pressure internal to CP1, the plot is for the total ongoing soft regeneration.

Images attached to this comment
gerardo.moreno@LIGO.ORG - 04:03, Thursday 14 May 2026 (90240)VE

(Jordan, Gerardo)

We leak checked CP1, specifically the bi-braze joints, we introduced He to both sensing lines (we disconnected the lines before the 3 way valve -X marks the spot - , this is less disruption to the shape of the metal tubing lines), we started with the bottom or low sensing line, we introduced 1 psi of flow into the line for about 35 seconds, no signal was detected by the leak detector attached to the exhaust of the turbo pump.  We did the same test with the high sensing line, no signal was detected.  Since we had the setup on hand we also decided to spray all the bellows, given that now they are free of ice, sprayed helium for about 35+ seconds, no signal was detected by the leak detector at any of the points sprayed.

During all the tests performed the He background at the leak detector was 1.0X10-10 Torr*L/Sec.

Images attached to this comment
H1 SPI (CDS, ISC, SEI, SPI)
jeffrey.kissel@LIGO.ORG - posted 14:50, Wednesday 06 May 2026 - last comment - 11:22, Wednesday 13 May 2026(90139)
First In-vac Components for SPI Pathfinder Installed!! ISI HAM2 (ISIJ) Reflector Assembly Installed and Cabled up to Feedthrus
J. Kissel, J. Warner
ECR: E2400026
WPs: 13237, LHO:13238
Final Design Doc: T2400145
Relevant Systems Level Drawings:
    . Mechanical Assemblies
        :: ISIJ Reflector D2400102
        :: HAM Table Baffles D1700335
        :: HAM2 Systems Layout D0901083 (not yet-inclusive-of-SPI)
    . Electronics Wiring Diagram 
    . Cable Routing In-vac Cable Routing Plan from G2401479 (pages )
    . Flange Layout D1002873-v11

Executive summary:
    - Removed ISIJ +X-side, center, HAM2 ISI table baffle from D1700265-v4 Type 2 
        :: Bracket mounting bolts left screwed into ISI optical table for this will eventually become a D1700265-v4 Type 3 and remounted.
    - Installed ISIJ Reflector + QPD Assembly D2400102 on +X ISI side wall (D071057-v2), with its shroud (D2500030) in place
        :: We didn't weigh it, but the SW Assembly predicts a mass of 1.96 [kg], which we can likely round up to 2.0 [kg] with the shroud installed.
    - Routed and connected QPD read-out cable system to D3 flange, F10 spigot.
    - Routed and connected picomotor cable system to existing D1101515 quadrupus leg Cable #3, J4 
        :: Cable #4, J5 is connected to IO PM5 mirror, Cables #2 J3 and #1 J2 were reset in neat coil with connectors floating to avoid electrical grounding as before.
    - Nudged make-shift baffle system using D1700261 ballast mass baffle mounted vertically on the +X / +Y / Beam Height corner of the chamber wall upon entry into beamtube.
        :: the will DEFINITELY need a technically-minded reset.

In at 10:30a PT and out by 12:30a PT. It's so lovely when everything goes to plan!

Pictures and further info to follow in the comments below.
Images attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 14:56, Wednesday 06 May 2026 (90140)
Removing Center ISI Table Baffle

Not much to say more here -- removal was easy. We tried "just" removing the panel using the the coated/capped screws, but these didn't budget upon several attempts with Jim's fingers and grunts. So, elected to fight that battle outside the chamber and removed the whole assembly at the table mounting point.

The full assembly is wrapped in dry-wipes, foil, and ameristat bagged and in Mitch's office while it waits for the Type 03 version of the panel to come out of clean-n-bake.
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 15:01, Wednesday 06 May 2026 (90141)
Installation of ISIJ Reflector itself

Also not much to say, other than the great joy that the drawings of the D071057-v2 ISI Side Wall have the irregular positions of the 1/4-20 utility holes accurate enough that Bram's CAD-informed-only mounting holes for the ISIJ reflector's baseplate of the reflector lined up without issue. *phew*

Also -- the D2400102 drawing doesn't highlight which length 1/4-20 bolt should be used for mounting, so we used 1/4"-20 x 0.625"L (5/8"), which was "just enough."

Pictures from the main entry are the best "big picture" views, but here I attach a few more in case the need arises.
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 15:14, Wednesday 06 May 2026 (90142)
QPD Cable Routing

We didn't get dedicated pictures of this QPD cable routing but,
    - it follows the plan on page 22 of In-vac Cable Routing Plan posted to G2401479-v3,
    - You can see the ST1 portion of it well-enough in the above pictures,
    - Jim did the routing, so I trust that there's a healthy loop in the jump from ST1 to ST0, and
    - I attach a picture here of the record that we've connected it to D3-F10, and a copy of the "F-Type" (D2000225-v1) counting from page 18 of the above mentioned cable routing plan.
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 15:19, Wednesday 06 May 2026 (90143)
Picomotor Cable Routing BEFORE INSTALL

Just because we knew little about the details of this cable system ahead of time given how ancient the PM5 picomotor actuated mirror system, I got a lot of good "before" pictures. Mostly, I confirm that PM5 does use the Cable #4 J5 leg of the D1101515 quadrupus, and all the other legs were neatly cable-tied up and away.

 
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 15:27, Wednesday 06 May 2026 (90144)
Picomotor Cable Routing AFTER INSTALL

Here're photos of the routing of the two 72 [in] length D2400316 picomotor extension cables connected in series and routed to all the way around from the ISIJ reflector on the +X face to the -X / +Y corner of the table where CB-9 and the D1101515 quadrupus lives. 

I paid particular attention to the connectors and made sure they were left floating and not shorting to anything metal.

I also re-bundled up Cable #2 J3 and Cable #1 J2 in coil similar to the before pictures, again ensuring that the connectors are floating in both space and electrical connection.
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 15:29, Wednesday 06 May 2026 (90145)INJ, PEM
The Nudged Chamber Wall Baffle

Some pictures of the baffle that we nudged that will likely need re-alignment.
Images attached to this comment
corey.gray@LIGO.ORG - 10:28, Friday 08 May 2026 (90175)EPO

tagging for photos.

jeffrey.kissel@LIGO.ORG - 12:08, Tuesday 12 May 2026 (90212)
On the new channel assignment of HAM2's SPI ISIJ picomotor, and why I'm confident it's CH7:

Per D1000581-v13, page 13 and then D1900511-v12 page 17, I'm quite confident that the quadrupus cable and up in CH5-8 of the controller on IOT2L, called "PICOMOTOR 5" in D1900511, which I guess becomes "Picomotor B / Slot 2" on page 2 of the ECAT System Diagram D1100683-v11. 

This is corroborated with opening up the picomotor MEDM screen -- sitemap > LSC > picomotors > "HAM 2 + oplev" button (that has "controller 5" and "PICO B" next to it), and clicking through the channels and seeing that CH8 is called "PSL ISS QPD/PD (PM5)."

Here's a labeled picture that makes things more clear.
Images attached to this comment
jeffrey.kissel@LIGO.ORG - 11:22, Wednesday 13 May 2026 (90230)
Belated aLOG on in-vac cable routing of the ISIJ QPD A PD and serial number assignments:

Path       PD Name    PD SN          Monopus            D9-to-D25 Monopus
                      |----------D2600002--------|
                      D1600083 Type 3     D2400340      D2300128
OL ISIJ    QPD A      S2401092            S2500517      S2500511


Images attached to this comment
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