J. Oberling, R. Crouch

In talking with Calum about the upcoming pre-deintall BS measurements, I realized that in the middle of JAC install I completely forgot to write an alog about the WBSC2 support tube FARO survey Ryan and I did at the beginning of February.  So, here it is.

Following the same procedure we used to survey the support tubes for WBSC3 and the +X ends of WBSC2 (alog 88620), we surveyed the -X WBSC2 support tube ends.  The results are shown in the 3 attachments; the first 2 are in the LHO Global Coordinate system and are the images I will be discussing.  The 3rd attachment contains all info from the first 2, but in the Corner Station building Local Coordinate system (included for completeness; for more on LIGO coordinate systems, see T0900340).  The first attachment shows the surveyed locations of the support tube ends, while the 2nd shows information regarding the midpoint location of the support tubes and their angles w.r.t. the IFO axes (the line shown represents the centerline of the support tube created from one end point to the other; the Nominal column (Nom) comes directly from the CAD model, while the Measured column (Meas) is our measured data.  Some interesting things to note here:

• Both support tubes are shifted in the -X direction, with the +Y support tube shifted 2.3mm more than the -Y support tube.  This is seen in the Midpoint X row in the centerlines image (2nd attachment).
  • This implies a CCW yaw of the WBSC2 cartridge assembly, in addition to the -X position shift
  • Averaging out the shift, this implies a -2.6 mm shift in the X axis position, and a 1.36 mrad CCW yaw
• My expectation was to find the support tubes too low in their Z axis position by ~2.5mm, but that is clearly not the case.
  • The BS SUS is the same length as the QUAD SUSs, but the BS sits lower in the coordinate system than the QUADs do (-82.9mm vs -80.0mm); this difference was to be made up with HEPI (i.e. shifting the support tubes lower), since physically making the BS SUS longer isn't exactly practical
  • The support tube end survey in the 1st attachment show the ends are not lower by ~2.5mm as expected, but rather fairly close to the nominal Z axis position
• No real comments re: Y axis position, this looks good

Now keep in mind that the support tube locations may not be indicative of a misalignment of the BS optic itself.  When we installed this we only cared about putting the BS where it needed to be, and HEPI (and by extension the support tube ends) was wherever it (they) needed to be to support that.  We will be taking measurements of the BS SUS cage and the optic itself once the corner is vented (likely to be one of the 1st activities after the vent), and we'll know more about the location of the BS optic once we have done so.

(Travis S., Jordan V., Richard M., Gerardo M.)

Last Friday we tried to "hard close" GV7, but we only achieved a "soft close" status.  After looking at the system that uses instrument air at the gate valve, we did noticed that the solenoid valve to "open" and "close" the gate valve was "leaking" air, lots of instrument air, to fix the air leak we decided to replace the solenoid valve with a new one.
Then when it was time to "hard close" GV7, its pressure regulator broke, we were not able to open the regulator.  We ordered a couple of new regulators and should be here on Wednesday.  Meanwhile we are going to "hard close" the gate valve using a bottle of nitrogen.
Attached is a photo of the broken regulator, yes the knob is off, but the metal piece within is free floating and not able to do its job.

We previously reported that the wiring to ground on the OMCA DCPD dsub9 cables seemed odd, see 89562. There appears to be two conflicting diagrams of the pin wiring, D2200276 and D2300119. Neither of these diagrams follow the correct pin naming practice either.

Today, Oli and I checked the ground connectivity for the OMCB DCPD dsub9. The case ground is wired to what is labeled pins 6 and 9, according to both of the diagrams above and also proper convention. However, this is different from OMCA, where the case ground is wired to pins 2 and 5 (following the incorrect naming of the diagrams above), or pins 1 and 4 (following correct naming conventions).

So either way, we have two different wiring set ups for OMCA and OMCB. We have only checked the ground pins so far, and it seems like we should confirm the cathode and anode wiring as well.

To summarize:

- we have two different diagrams for pin wiring

- OMCA and OMCB are wired differently from each other

- the diagrams are not following proper pin naming convention which is making this more confusing

Tue Mar 24 10:06:11 2026 INFO: Fill completed in 6min 7secs

Elenna, Oli

Summary: OMCB has its DCPDs installed and most of its stoppers (barring one that needs to be retapped + helicoiled). OMCA has been aligned according to the OMCA / OMCB install template and is ready for laser alignment. Cabling for both OMCs should be good to go.

After last week's issue of the OMCB DCPD A (TRANS) missing a diode hole (89583), we were able to clear up the issue and fix it (89606). Elenna then installed the DCPD B (REFL) diode. Note that once again there were tiny metal shavings below where the DCPD's were installed, which we picked up with a qtip that we wet with iso. Once we had both installed (pic), we installed the rest of the stoppers around OMCB. The only one we didn't install is one of the vertical stops. This is because there was an issue with the helicoil last week, and we ended up having to remove it. We think this might be due to an issue with the threads, so we are waiting on a 3/8"-24 tap to retap the hole before installing a new helicoil. Because we don't have this stop yet, it doesn't really make sense to fasten on the butter dish, but we might just sit it on today to hinder dust accumulation.

We also realized that the PZT cables were going to be way too short to reach the cable pylons for both OMCA and OMCB, so we very carefully opened the peak cable wraps on the OMCs and took out what we think should be enough. On OMCB we noticed that the little copper wrap for one of the PZTs was not right above the PZT as it should be, but instead was on the other side of the peak cable wrap and was only wrapped loosly around one of the cables. Because of this we just removed the wrap. The cables right above the PZT are looking fine and don't look like they need anything to hold them together.

I had been confused about the OMCA / OMCB install template for the past few days, since installing it was putting OMCB further back in its slot than OMCA, but I was able to confirm yesterday in eDrawings that OMCB is actually supposed to be an extra 1 mm away from the front of its slot as compared to OMCA, so we moved OMCA into position and bolted it down.

I also went in and installed the magnet mounts for the OSEM magnets (without the magnets), as well as the big mass on the back of the BHSS.

Installed serial numbers:

OMCB (SN 105)

• DCPD A (TRANS)
  • DCPD: 1C-14
  • Housing: SN 002
• DCPD B (REFL)
  • DCPD: 1C-10
  • Housing: SN 008

Yesterday during the cleanroom move, CO2Y tripped off, this is a known issue when people get near the TCS racks, FRS 6639. I turned it back on this morning by pressing the "GATE" button on the chassis. 

Corey, Fil, Erik, Jonathan, Dave:

Last night's earthquake caused SWWD trips for ETMY, ITMY, ITMX. It also caused a HWWD trip of ITMY (BSC1) which was concerning.

We were able to untrip the SWWDs, but we kept ITMY DACKILLED while we work on its HWWD.

Jonathan went into the CER and pressed the RESET button on the ITMY HWWD chassis, this did not untrip the power to the ISI coil drivers. We tried a second time, again no restoration of power.

The front panel and the readback by h1susitmy both agree that the only red led is SEI-trip, the input conditions PD=osem-photodiode-rms and LED=osem-led-current are both GOOD, which should have permitted the reset.

But when the reset button was pressed, the PD led went RED and the unit did not reset the SEI trip.

Fil is heading out to reboot the unit and possibly replace with a spare if it is not working correcty.

TITLE: 03/24 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: CALM
    Wind: 14mph Gusts, 10mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.19 μm/s 
QUICK SUMMARY:

Arrived to see lots of tripped Watchdogs.  This was due to a M7.5 Tonga earthquake from last night just before 10pm local time (5utc).  Dave contacted me to give me the heads up on this and noted that ITMy actually had the Hardware Watchdog trip---this requires someone to go out to the CER to push a button to restore coil drivers.  We were hesitant on addressing this without Jim's guidance--not sure how powering things back on would affect the system.  Will message Jim with a heads up for BSC1's ITMy/BSC1-ISI/BSC1-HEPI.  Will continue bringing everything else back.

Other than that, today is Maintenance Day.  The Filter Cavity Tube has light flashing and so its small gate valves must still be open (I had thought the discussion was to close these gate valves to allow craning over the FC Tube, but not certain on this.

Day1 of 2-day CEBEX workshop begins today.

Workstations updated and rebooted.

Sheila, Sophie, Camilla 

The HAM7 PSAMS (ZM2,4,5) were railed last week, we noticed that the ZM2 alignment changed Friday after the FC gatevalue was closed which led us to noticing this. Reset the ZM4 and ZM5 PSAMS, following 84639 and adjusted sliders to bring osem values back. ZM2 was not railed, something on Friday afternoon (maybe the GV being closed) stopped ZM2 PSAMS being railed.

Once the FC GV was opened, we could see a beam on FC-IR camera. We went to the FCES and after mis-aligning FC1 and FC2 while moving ZM3 would could see a green beam on the green camera. After temporarily tuning up the exposure and adjusting FC1 and FC2 we could see beams on both IR and green cameras and the best flashes we've had so far, 20 on FC_TRANS_C (green) with 6.5mW in and 1.35 on FC_TRANS_D (red) with 75mW SEED. Sheila adjusted the IR camera steering mirror in Pitch as she had last week to bring the beam more central on the camera. 

Looking back to November, typical flashes when we have the OPO locked and FC aligned with 7.8mW into FC green are 60 on FC_TRANS_C (green), 0.8 on FC_TRANS_D (red) and 0.002 on OPO_IR_PD, see attached. 

During the Y-manifold vacuum work today we have had three occasions where the control room and EDC had lost connection to h0vely IOC for several seconds. The times are: 11:02, 14:39 and 16:26 PDT.

TITLE: 03/23 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Lots of activities & new visitors on site today.  Main activities were the VAC team working on swapping a pneumatic actuator for GV7, squeezer alignment checks (cont.), SPI & BHD work in the optics lab.  (Also had Girl Scout cookies arrive!)

LOG:

• 1444-1541 technical cleaning in LVEA (nellie)
  • 1456-1543 kim joining 
  • 1541-1623 EY technical cleaning (nellie)
  • 1543-1613 EX technical cleaning (kim)
  • 1623-1723 FCES technical cleaning (nellie)
  • 1752-1812 quick clean around ham3 post cleanroom move(kim)
• 1450-1500 Grabbing stuff in LVEA supply area (betsy)
• 1505-1620 Move + retrofit legs for HAM3 cleanroom (chris, eric, jordan, randy, tyler))
• 1507 h1lsc0 models restarted (dave)
• 1542-1602 LVEA walkthru (betsy, calum, dennis, albert)
• 1554 TCSy Laser OFF (guessing due to HAM3 cleanroom activities, camilla was in CR when Verbal gave notification).
• 1628-1632 checking clearrances on feedthrus at HAM3 (jim)
• 1629-1630 quick garb room trip (oli)
• 1633-1650 taking BHD photos (elenna)
• 1641 lvea craning...spreader bar, plates, etc. and (randy)
• 1704-1850 grounding checks at EX (robert)
• 1736-1829 Hard Close GV7 (jordan,gerardo)
  • leak w/ instrument air, so will need a part replaced.  NO vent until this is fixed! 
• 1757-1829 CHETA lab work (sophie.camilla)
• 1851-1912 Installing new sphere in PCal Lab (tony)
  • 1851-1912 escorting kim into the PCal lab for round of technical cleaning
• 1900-1930 cleaning equipment in Optics lab (jennie)
• 1855-2018 BHSS dcpd fix  (elenna, oli)
• 1930 Craning spacer plates in lvea (randy)
• 2001-2010 Looking for cable around HAM6 (ryanC)
  • 2020 Looking in cer (ryanC)
• 2016 SPI work in optics table (bram,jim)
  • 2027 Jeff joins them
• 2039-2059 Taking group inside the beamtube enclosure (tyler & others)
• 2046 GV7 work  (travis)
  • 2103 jordan & gerardo joining for GV7 work  
• 2047 BSC2 checks (richard,betsy)
  • 2109 betsy out
  • 2127 richard out
• 2052 Asking VAC team to OPEN FC gate valves (sheila)
• 2125-2150 BHD work (elenna)
• 2128-2138 Seattle Pacific U tour (maggie)
• 2144-2154 Looking for laptop charger in lvea (camilla)
• 2157-2245 HAM8 sqz work (camilla,sheila)
  • FCES transitioned to HAZARD.
• 2145 BHSS work in optics lab (oli)
• 2152-2200 Lifting bars (for BBSS) to lvea (ibrahim)
• 2152-2159 Putting clean items away (betsy)
• 2200-2225 Checking up on VAC crew (richard) 
• 2218 BHD work continues (elenna)
• 2239 Optics Lab check (tyler)
• 2252-2255 Elec feedthru checks at BSC2 (jim)
• 2255-2259 pump for ergo arm being taken to test stand (ibrahim)

Sheila, Tony

On Friday we continued trying to get flashes in the filter cavity for 1064nm, 532nm, and IR light onto the SQZT7 diode which we are using to establish that we are going through the VIP without clipping.  

At the start of the day we saw IR flashes of at max 0.04 counts on SQZ-FC_TRANS_D_LF with the OPO locked with CLF (with 21mW on CLF trig PD) 1.7 counts on FC_TRANS_C_LF with 5mW into the green fiber, and 36e-6 counts on OPO IR PD.  We saw that the green was clearly misaligned in yaw in the filter cavity, and we were able to improve the IR flashes and IR on SQZT7 with some yaw moves, but that made the green flashes nearly disappear.  We pio'd MOTOR 3 (H:M2) -710 counts, which improved the green flashes to 6 counts.  

Then we could see that the IR flashes and on SQZT7 were easiesr to improve with pitch moves, and that we no longer loose the green by improving them, so we spent some time trying to walk ZM1/2/3 for slow improvements, to get IR flashes of 0.1 counts, 83e-6 on SQZT7, and green flashes of 5.  (22:30 UTC March 20th)

This was slow going, so we decided to go back to FCES with cameras to see if we could get some photos or see flashes.  We will continue from the FCES this afternoon. 

Betsy wanted a look at the last few months of dust trends for BSC2.

(This is Dust Monitor LVEA10 which was moved to BSC2 in Feb [alog89137].)

This is a belated report of work done by me, Oli and Keita on the OMC builds for the BHSS, done yesterday March 19.

Exciting summary: build for OMCA is complete, including DCPDs and butter dish. OMCA is installed onto the BHSS platform and ready for beam alignment!

Less exciting summary: build for OMCB is halted as tombstone for DPCD A (transmission) is missing a required PCB hole for the electronic connection.

OMCA build notes:

• We picked up where we left off to complete the OMCA build (see 89562)
• We noticed some dust and metal bits on the surface of OMC breadboard glass. Some of the dust appeared yesterday during DCPD install- we think the install drops small metal shaving onto the glass. We're not sure if the rest of the dust was already there or got on it during our install work. Keita took an alcohol soaked q-tip and tried to remove many of the particulates
• We had some confusion about the overhang of the OMC breadboard on the cradle. Turns out it was because we didn't realize the side posts (stops?) had two different sizes. One set is 16 mm in width, the other 20 mm. With the appropriate 20 mm side post, the OMC breadboard can be placed up against the viton stop as detailed in the instructions without any overhang
• We installed the remaining side horizontal and vertical posts, and adjusted the screws with viton tips to the required distance from the breadboard
• We took out the butter dish for install and noticed all the dishes were very dusty. We took the one we planned for install over to the top gun and dusted it off. We will have to do the same for the OMCB butter dish. Again, not sure if they were already dusty or got that way during storage and handling
• We routed the PZT and DCPD cables through the cable clamp.
  • We are a bit concerned one of the PZT cables could fall into the beam eventually, but there's nothing we can do about it, picture, you can see that the cable is routed off the PZT, and over the beam path to where it is wound and mounted
  • the routing of the PZT cables crosses an area where there is a vertical viton stop. We're concerned the cables could be caught between the viton stop and the breadboard at some point. We removed the vertical post so we could run the cables along the side of the breadboard instead. There is enough clearance for the cables here. picture1, picture2
  • here are two other pictures of the cable routing and cable clamp, picture1 and picture2
• We went to install the butter dish and realized that the supplied pins which are inserted for install and then removed later don't even fit the holes.
  • the purpose of the pins is to elevate the butter dish slightly as it is clamped on either side by the viton-covered "grabbers" (don't know the word for them). the pins are removed once the dish is clamped
  • we decided since we were three people, two could hold up the dish while a third screwed on the viton holders
  • we can confirm by eye that the holes we would align with the pins are aligned from this process
• We used the empty OMCB cradle to practice the placement of the cradle onto the BHSS a few times before I picked up the entire OMCA assembly and gently placed it on the platform. It's a bit tricky because the finger slots on the cradle are sized for what appears to be very small fingers and the OMC assembly is quite heavy.
• Oli started working out how to place the OMC alignment template tooling, so the OMC can be properly aligned to the platform and screwed down

OMCB build notes:

• We unpacked the second OMC, SN 105 from its box and placed it and aligned it on the cradle
• Keita once again macgyvered a grounding anklet for me, and I set out to install the DCPDs
• I cut the legs of the first DCPD down by eye remembering how much to remove from yesterday and set out to install it onto the transmission PD tombstone (DCPD A we think)
• I spent 15 minutes fiddling around trying to get the diode through the hole (I actually watched the clock) before I exasperatedly looked into the faceplate holes and realized that through the bottom hole, there is no corresponding PCB hole for the leg of the diode! see picture. There are three holes on the faceplate, and you can see that for two they lead to holes in a PCB where the diode legs are inserted. There is no hole on the bottom.
• How did this happen? We are very confused and not sure what to do. We confirmed that the reflection tombstone has the expected three PCB holes after the faceplate holes. We can't proceed on the rest of the build and install before this is resolved.
• Keita thinks it is possible that the mount is rotated, and we could unscrew the component from behind the tombstone and flip it, but I would want to confirm with an expert before I start fiddling with it, especially if it could mess up the alignment