Thu Apr 09 10:07:34 2026 INFO: Fill completed in 7min 31secs

WP 13154
a-Plus O5 SUS HAM5 (sush5) System Wiring Diagrams - D2300380
aLIGO SUS HAM 5-6 System Wiring Diagrams - D1002740

SUS-C7/ SUS-C8
Two HAM-A coil drivers were installed in the SUS-C7 rack, part of LO3. We decided to use the existing OMC cables for the new OFI. Cables are going to correct CER and field rack. OMC is being moved to the MER. Once HAM6 is vented the OM1/OM2/OM3 electronics and cabling will be removed.

SEI-C1
Started clean-up of the SEI racks. Removed a HAM ISI Interface Chassis from SEI-C1. This was part of the HAM1 L4C testing back in 2018. Plan is to remove the STS distribution electronics. See alog 89835 for testing of sending signals over IPC.

ISC-C3
The Heliax cable for SPI was landed in ISC-C3 (Patch Panel U37/U38, port 4) 

LVEA Work
Finished routing the ±18V power cable for CHETA Y around BSC8 and BSC1. Cable was landed in the TCS-R2 rack. We spent some time cleaning cabling in the TCS rack and the space between the TCSY enclosure and BSC1.

F. Clara, C. Gray

Wed Apr 08 10:07:42 2026 INFO: Fill completed in 7min 39secs

Late entry for yesterday's fill.

TITLE: 04/09 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: 3mph Gusts, 2mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.16 μm/s 
QUICK SUMMARY:
Work today is Likely going to be removing bolts from chambers HAM3, BSC1, And BSC2's Dome.
 

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

To get ahead on door removal, we vented a couple of anuli systems, and we used nitrogen to vent BSC1, BSC2 and HAM3.  No issues to report for any of the vents.

Also, we removed most of the bolts from HAM3 chamber doors.

Elenna, Madi, Oli

Today we started tackling the alignment of all the REFL optics that go on the BHSS.

A Path
The A path went relatively smoothly. We had an issue with A-R1 where we had the left side alignment template D2400130 correct and placed A-R1 in it correctly, but the angle of A-R1 was off and sent the beam into the side of the OMCA butter dish. This was possibly due to an error with the clocking tool, but since Elenna had roughly placed the downstream optics last week, we were able to easily fix it by rotating A-R1's mount until it was shooting down the right way. We then were able to get the rest of the REFL A path worked out pretty well, just not the beamdumps.

B Path
The B path caused a few more issues. First, trying to place 36-R1 using the left side template, we realized that we couldn't actually use the tooling since 36-R1 has a J-holder for the black glass, and the screw that holds the J-holder in place doesn't screw in all the way - there are a couple of threads that stick out. Those couple of threads mean that the screw is in the way of the optic sitting in place in the template. To work around this, we ended up installing B-R1 using the right side template, and once we had that we used that as a reference to get 36-R1 reflecting OMCB REFL towards it. Later, we had some trouble getting the beam to B-R3 while also keeping B-R3 at the correct screwhole. We ended up moving it over one screwhole to the left, from L8 / T13 to L9 / T13. At this point we just roughly aligned it to go towards the QPD and left it for now since we might need to move it back over. We might end up needing to shift all the optics in that line over ?
UNFORTUNATELY, we also made a mistake. We aligned B-R2 to hit the B-2 QPD, and B-R3 to hit the B-1 QPD, but it's supposed to be the other way around. We will have to correct this next time!

TITLE: 04/09 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
Vacuum team has been Venting the corner station still. 

OMC's were taken to SAFE for a model reboot then taken back to aligned.

Dave and Marc  swapped some cables and restarted the following IOP's & models today. Please check your SDF's haven't been reverted.

H1IOPOMC0 
H1IOPOAF0 
H1IOPASC0
Tagging teams that may have SDF issues in the future.

SRM taken to aligned. (I have no idea Why it was misaligned.)

IMC Input Power Channel is no longer "Cray Cray" and is now reading correclty as of Jennie D's alog.

Restart ISI models BSC 1,2, & 3 
FW1 Down 19:15 UTC
DC0 down 19:20 UTC 
DC0 Re-established at 20:36 UTC  

ISI BS Stage 1&2 watchdog tripped 20:36 Likely due to Vac activities. 
ISI HAM3 WD tripped 23:33

VAC team says BSC2 annulus is vented & Dome bolts ready to be broken. 
 

LOG:

Jeff and I started looking at HAM ISI signal chains to see if there were enough AA inputs for the planned upgrades during this install cycle. We realized that we still have all of the cabling for the original distribution of STS channels, where each STS is connected to one of the BSC front-ends, the signal goes through a distribution chassis that then sends copies of that STS to each of the other front-ends before sending signal to the source front-end AA, sort a physical ipc. This means each HAM rack has 3 db9 AA ports taken up by a signal distribution chain we no longer use, each BSC has 2.

Until today, ITMY sent its collection of 1 directly connected STS set of channels (the HAM2 (or A) STS) and 2 distributed sets (ITMY (or B) from BSC2 and HAM5 (or C) from BSC3) over IPC to SEIPROC, where it was calibrated, then used for a sensor correction signal that got sent back out to all of the corner seismic. This means we can free up AA ports by removing the rat-king STS distribution set up and just use the IPCs. Doing this required redistributing the IPCs for each STS to the front end model the ground sensor was directly connected to.

Arnaud is working on the ECR (with the helpful cartoon of what is being changed in p. 2 here), but I wanted to test the changes needed to do this today. I disconnected the extra connections for the shared STS signals between each BSC, leaving just the AA cable for each chambers directly connected STS. I then split out the 9 IPCs from ITMY to each chamber. Dave and EJ found a bug where I had mistakenly used an ADC selector instead or a bus, so I also fixed that in a couple places on the top level for each chamber. Somehow this had been before this point, but today meant the wrong channels got picked out for the BS STS IPCs. Dave also had to do some editing of some other files that had to do with the IPCs, because the sender models were changing, but not the names of the IPCs.  

As far as I can tell at the moment this seems to be working. Corner is vented, so testing sensor correction performance will be difficult, but I can at least check that the signals look like ground motion and do a couple other checks.

WP13110 IO Chassis Timing Card Firmware and Sync Ribbon Upgrade

Marc, Erik, Dave:

The timing card sync ribbon cable and the timing card firmware were upgraded on the following front ends

Corner Station BSC ISI GND STS shuffle

Jim, Erik, EJ, Dave:

The 9 GND STS channels (X,Y,Z for A,B,C) were being read by h1isiitmy and sent to seiproc via 9 PCIE IPC channels.

Today's change was to reduce those handled by h1isiitmy to the "A" set of three. Add the "B" set to h1isibs and the "C" set to h1isiitmx.

IPC senders have TX slow channels in the INI file, so a DAQ restart was required to remove the "BC" channels from itmy and add them to bs and itmx.

We chose to not change the name of the IPC channels, they remain H1:ISI-ITMY_[A,B,C]_GND_[X,Y,Z]_IPC_PCIE. Technically they are incorrect for those on BS and ITMX since they retain their ITMY designator.

Keeping the ITMY names meant we did not have to remove channels from the H1.ipc file. That being said, this file did need a hand edit to change the sending model/frontend for the channels which moved to bs, itmx. This was needed so these models could build without RCG reporting "channel already exists on another model".

After h1isi[itmy, bs, itmx] were restarted with the new code, the DAQ was restarted (no EDC restart).

Jim then found that the signals for the new IPC channels were not correct, for example h1isibs was sending the wrong ADC signals, the ADC channel numbers were offset by 3.

We tracked this down to a problem with the bus-creator -> goto-tag -> ADC-bus_selector chain between the ADC selector and the IPC parts. Jim cleaned this up by replacing all of this with 3 goto-tags for the X, Y and Z channels.

After a second round of model restarts I verified the correct ADC channels were being read and sent to h1seiproc.

F. Clara, M. Pirello, J. Kissel
D2400111
G2401479

Fil and Marc have been doing the bulk of the work installing the diversity of cabling for SPI, as governed by D2400111 (and aided by slides in G2401479). What they started in LHO:89641 they've continued to the point of "we're as ready as we can be before we get the last of the electronics from the optics lab."

Here're some pictures of the status as of this afternoon. I'll attach them as comments to group them into a more digestible format.

A further step we can and will take in the coming days is to set up and power-budget the RF signal chain up to the point of the double mixer chassis, since this is not needed for the remaining optics-lab testing of the ISIK transceiver (which now must be redesigned; see E2600106).

FAMIS 28641

pH of PSL chiller water was measured to be between 10.0 and 10.5 according to the color of the test strip.

Jennie W, Ryan S, Sheila D

We changed the calibrated JAC trans power readout to be the front-end channel H1:JAC-TRANS_A_LF_OUTPUT. This is now the channel displayed on the OPS_OVERVIEW_CUSTOM screen labelled as 'IMC INPUT POWER'.

The calibration filter for 'H1:JAC-TRANS_A_LF' is in FM10 labelled W_in_HAM2.

This was previously set as the Beckhoff channel H1:JAC-TRANS_A_DC_POWERMON but this is too noisy and was also not calibrated correctly as it displays in mW and was on the ops screen as W.

I have changed the calibration for this channel so it is actual mW leaking out of the JAC towards JACT_BS1 beamsplitter, which reflects approximately 1% (alog #89251) of light that hits it towards the JAC-TRANS PD (see image).

After checking the calibration measurements we took in chamber, I have realised that the amount of power we get out of the JAC curved mirror (the beam of which goes to the JAC TRANS after reflecting off a laser window) is too high to match the input power we inferred. Looking at the power budget Masayuki and I took at CIT (see elog #863). This predicts a transmission through the curved mirror of 7.5e-5 and from our calibration measurements (alog #89251) we saw (2.7e-3W/1W) = 2.7e-3. The other measurements we took in that entry (BS1 reflectivity ~ 1%, JAC throughput ~ 96mW/115mW = 83 %) don't seem unrealistic.

I can use instead the 7.5e-5 transmission of the curved mirror to calculate that the HAM 2 input power for a certain value of W on the JAC-TRANS_A_LD PD is ~ 1.11e6.

As JAC-TRANS_A_LF has some high frequency noise multiplying by this large number causes it to show high values when there is no light on it. Therefore I propose adding another filter bank to the model where I can low-pass this noise so the display of the HAM2 input power makes sense.

Jenne has turned off FM10 in the JAC TRANS A LF filter bank (see image of the filter banmk with the filter still on here) so the value on the screen looks close to zero for the moment. See Jenne's alog #89823.

Per WP13110 we have upgraded the IO chassis listed below.
This link contains the asbuilt for all of the H1 IO Chassis: https://dcc.ligo.org/LIGO-D1301004
This link contains the ECR for the IO Chassis sync cable upgrade: https://dcc.ligo.org/LIGO-E2600069

This link is to the work in progress spreadsheet LHO Front Ends Upgrade Status

Corner:
SUSB2H34 has upgraded firmware and sync
SUSAUXB2H34 has upgraded firmware and sync
SEIH7 has upgraded firmware and sync
OMC0 has upgraded firmware and sync
OAF0 has upgraded firmware and sync
ASC0 has upgraded firmware and sync
LSC0 has upgraded firmware and sync

We started the venting process for the corner today, including the FCB1 section of the filter cavity attached to BSC3

GVs Closed:

GV2, GV5 (GV7 remains soft closed until repairs are done on the piston cylinder), RV1, FC1, 2, 4, 5.

Dry air dewpoint at vent port = -40.3C

We followed the venting procedure E2300169, until the small burp of dry air into the corner volume, during this "burp" we noticed a small pressure increase at PT114 (CP1 gauge on beamtube side of GV5). There was a clear pressure step from 2.02E-9 to 2.04E-9 Torr at the same time as the dry air burp, see attachment.

We waited for ~15 minutes and repeated the air burp into the corner, again we saw another pressure increase at PT114, though the pressure gauge on the opposite side of CP1 PT124 showed a small decrease at the same time as the pressure increases. 

We paused the vent to investigate, PT120, PT114 and PT124 are all pirani/CC gauge pairs and we are investigating if there is any potential crosstalk at the vacuum rack that could be causing this.

More to come.