Sat Mar 21 10:09:41 2026 INFO: Fill completed in 9min 38secs

(Jordan V., Gerardo M.)

Yesterday we tried to hand over the pumping of HAM1 to the ion pump only, it did not go good, the ion pump started having issues maintaining pressure for HAM1 volume, this ion pump showed a very unusual behavior, the pressure was going up and the output of the controller kept going down.  We tried a second controller with similar results.  The controllers just quit and turned the high voltage off themselves, self protection/preservation.  Today, we went up to the ion pump and ohmed out its feedthrough fischer connector, and to our surprised no short was found, we were convinced that the pump had shorted.  So, we took a controller chamber side and connected it with a "short" cable to the ion pump, and the pump turned on without issues.  These findings lead us to believe that the cable may be faulty/shorted/broken/no good.

The temporary setup will be used to maintain the ion pump under vacuum, and the setup will remain until another suitable cable (working one) can be acquired and installed.

Attached are a couple of photos of the temporary setup and trend of the controller/pressure at HAM1 behavior during the last couple of days.

(Jordan V., Gerardo M.)

We hard closed GV5 with no issues, the gate valve hard closed at 30 psi.  Something to note is the loud clank the gate valve made, and when the valve hard closed it shook the cameras housing, probably the alignment is not what it used to be.

We tried to hard close GV7 but no luck, it soft closed only.  We slowly increased the pressure up to 35 psi, and the gate valve remained unchanged.  For the activities planed for Monday soft close is good, we will visit the GV7 on Monday.

Then, we moved to close the filter cavity tube isolation valves, we closed FCV-1, FCV-2, FCV-3, FCV-4 and FCV-5.  We also isolated the relay tube by closing RV-1 and RV-2, the filter cavity volume will likely go up in pressure.

Today we swapped the 75 l/s ion pump used for the annulus volume on the Y-Beam Manifold (YBM) . Annulus volume was isolated and the pump swapped, no issues encountered during the swap.

An aux cart was used to pump out the ion pump body before switching the IP on. After a couple hours of pumping with both the aux cart and the IP, the aux cart was isolated and the IP was able to maintain the pressure.

Closing WP 13107

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

TITLE: 03/20 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: n/a
SHIFT SUMMARY:

No Locking Today.  There was some Squeezer alignment checks by sheila & tony.  Gerardo & Jordan CLOSED GV5 & 7 as well as Filter Cavity mini-gate valves.
LOG:

• 1448-1520 Moving spreader bar over Y-Beam Manifold in West Bay in prep for cleanroom moves next week---canceled this since it was 510lbs.  So Randy rolled a scissor lift into the lvea instead.
• 1450-1536 MY Technical cleaning (nellie)
  • 1552 LVEA Technical cleaning (nellie)
• 1532-1550 Turning on laser for SPI work (jeffK)
• 1603-1615 grabbing laptop in CER (tony)
• 1642 HAM8 FCES work (sheila,tony)
  • 1930 Lunch break
• 1710 SPI optics (jeff,bram)
  • 1943 lunch break
  • 2057-2313 Afternoon work continues.
  • Laser is OFF for the weekend
• 1756 Ion pump replacement @Y-beam manifold (gerardo,jordan)
  • 1925 lunch break
  • 2134 Afternoon work continues with checks of Ion Pump along YBM & then looking at an Ion pump on top of HAM1
• 1827 Pallet from Apollo for Jim received by Randy
• 2225 Starting to close GVs (5 & 7?)....then after coordinating with SQZ team (sheila,tony), VAC team will close GVs for Filter Cavity (gerardo,jordan)
  • 22:40:17 GV5 Hard Closed (red on medm);  Definitely heard this in the Control Room!
  • 22:51:20 GV7 Soft Closed (yellow on medm); Did not hear this in the Control Room
• 2225 Tony grabbing IR viewer and then...
  • 2230 Sheila joining and they will be looking at beams at ham shack
• 2226 EX grounding work 1hr(robert)

Also, CP1 PT114 tripped during the close of GV5, it has been disabled in VACSTAT and bypassed in ALARMS.

At 10:19:54 PDT both h1seib3 and h1seib1 had CRC errors on DAC leg zero.  These errors probably represent missing data blocks and not data corruption.

Fri Mar 20 10:19:50 2026 INFO: Fill completed in 19min 46secs

This is for FAMIS #39756.
Laser Status:
    NPRO output power is 1.839W
    AMP1 output power is 70.43W
    AMP2 output power is 139.3W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 13 days, 15 hr 44 minutes
    Reflected power = 27.02W
    Transmitted power = 104.2W
    PowerSum = 131.2W

FSS:
    It has been locked for 0 days 3 hr and 56 min
    TPD[V] = 0.4857V

ISS:
    The diffracted power is around 4.3%
    Last saturation event was 0 days 20 hours and 40 minutes ago

Possible Issues:
    PMC reflected power is high

TITLE: 03/20 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: 32mph Gusts, 27mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.14 μm/s 
QUICK SUMMARY:

Moves starting in the lvea and in the schedule there is the possibility of closing Gate Valves today.  IMC_LOCK is DOWN and ISC_LOCK is in IDLE.  Had Lab dust alarm at 609am (due to cleaning?).

TITLE: 03/20 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Beam hunting at SQZT8 wrapped up and the FCES is back to Laser SAFE. Ground noise measurements and work in the optics lab finished as well.

Sheila asked for some plots to compare positions of SRM, OM1, and OM2 to have an idea of their SQZ beam pointing. The first attached screenshot shows the last time DRMI was locked this morning with WFS centering on, so the OMs are in their final positions. The second attached screenshot is from this evening when I took H1 into single-bounce configuration at 10W input power where SRM is misaligned and used the AS_CENTERING states in the ALIGN_IFO Guardian to align the OMs, then offloaded their positions to sliders. One could see that there are slight discrepencies in the alignment of the OMs when comparing their positions between the two scenarios, some of only tens of microradians and others up to 130 microradians in OM1_P's case.

LOG:                                                                           

The USGS stream was switched to a new service on March 16.  Seismon is now using the new stream.

TITLE: 03/19 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 21mph Gusts, 16mph 3min avg
    Primary useism: 0.14 μm/s
    Secondary useism: 0.19 μm/s 
QUICK SUMMARY: SQZ recovery continues into the evening with beam hunting at SQZT8; no calls for any IFO locking attempts before arm gate valves are closed in the morning. A M5.2 EQ is rolling through from the Caribbean.

TITLE: 03/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is in IDLE for ENGINEERING

TLDR: Productive day. DRMI is locking easily (manual/by-hand locking). Main priority now is proving SQZ works, which Sheila and Camilla are working on.

After my initial alignment at the start of the day, we managed to lock DRMI by hand, tuning it as we got closer. DRMI to 3F still does not work. Elenna worked on fixing it by isolating the problem to a MICH loop. Details are in alog 89567. During this testing process, DRMI would automaticall relock over 10 times, which is good. 

Meanwhile, Sheila, Gabriele and Camilla were working on getting SQZ to work. Between the control room, FCES and SQZT7, they managed to find flashes and are now working on alignment. Alog 89569 documents their progress.

In the LVEA, VAC identified a faulty ion pump and closed HAM1 gate valves (a small pump one not the arm one since this is causing some confusion). EE continued cabling work.

Otherwise, Jim reports that SEIMON has not been working for 7 days and so EQ auto-detection may be faulty and should be monitored.  

LOG:

This update has been in for a little while, but I apparently didn't document it at the time.

I've updated the OPS Overview medm screen to reflect the addition of the JAC and JM suspensions in HAM1. There's a new JAC status box above HAM1, which like the IMC, will change color depending on the status of JAC for easy reference. I've also added another power readout below HAM1 to show JAC transmission; the channel used here is H1:JAC-TRANS_A_DC_POWERMON, roughly calibrated to Watts. The label for this readout is "IMC INPUT POWER," and the label for the monitor beneath the PSL now reads "JAC INPUT POWER" (even though that channel is still H1:IMC-PWR_IN_OUT16, which is a bit of a misleading channel name now).

Camilla, Gabriele, Sheila

This morning went to the FCES to look for the beams again.  We turned the light into the FCGS fiber up to 4.7mW, then we were able to spot a bit of green light on the FC2 baffle and coming out onto SQZT8 (photos with Keita's camera will be attached tomorow).  This beam was coming through the uncoated part of FC2, we were able to see this on the +X side of FC2 but not on the other side (probably clipped on the viewport).  We put the beam somewhere on the coated face of FC2, and then we see much less green light on SQZT8.  We moved FC1 + FC2 to see some kind of green flashes in the cavity, and also saw some IR flashes.  

We returned to the control room, and switched the IR back to CLF from seed.  We spent a good deal of time walking ZM2, ZM3, FC1, and FC2, and see some level of flashes in both IR and green, and a small transmission back through the VIP towards SQZT7.  We can see that the co-alignment of green and IR isn't perfect.  

Camilla is continuing this walking, but we will likely need some time tomorow to get all the beams going in the right places. 

Ibrahim, Ryan C, Gabriele and I did a bunch of work to help the locking effort of DRMI today. Here is a summary of some of the work I did.

We noticed that after being in DRMI locked for a while, we would see something ring up and cause a lockloss, close to 26 Hz in frequency. I checked the OLG of the PRCL loop and it has lost some phase at low frequency, with a zero crossing around 25 Hz. I doubled the PRCL gain and this averted the problem. Sheila mentioned offhand that this might be a phasing issue, but until that can be worked out, we need a factor of 2 gain in PRCL to remain stable in DRMI lock. Compare the blue trace on this plot (today before double gain) to the green trace (old reference) and the red trace (after the gain was doubled).

I then tried to work on the 3F transition. I tried driving a PRCL line at 88 Hz, and I phased REFLAIR RF27 to maximize the signal in I phase. I tried switching the signal over to PRCL 3F several times and this worked repeatedly, as long as the PRCL gain had the factor of 2 in the gain. I changed the phase by 90 degrees. This plot compares before (dotted) and after (solid). Here is the SDF.

I tried phasing REFLAIR RF135, and this is where I was not successful. I tried adjusting the phase to maximize the MICH signal in Q, driving a MICH line at 88 Hz. I went +90, which failed, and then I tried -90 which also failed. To see what I was getting wrong, I put the MICH 3F intrix values into the XARM input matrix on the LSC screen, and took a transfer function of MICH on 1F to the XARM 3 F signal. The phase was correct, but the gain was wrong by a factor of 2. I tried doubling the 3F intrix values and running the handoff again but this cause another lockloss. Therefore, I have reverted by changes to the RF135 phase to 115 deg, and I'll just give up on this for now, since I clearly don't understand what I'm getting wrong.

I'm not sure if we want to adjust the 1F phasing further or go with the double gain on PRCL, so I'm not going to make any guardian changes at this time.

The only permanent change I have made at this time is the updated REFLAIR RF27 phase, which has been SDFed. All other changes have been reverted.