F. Clara, K. Kawabe, M. Pirello

We checked the following for ground loops:

CER:
Beam Diverter Cables - Both tested good.

From SUS R1:
JM1 is good
JM2 is good
JM3 is good
PM1 - Pin 2 is grounded, Shield is not connected to pin 13 (cable HAM1_311)
RM1 - Shield is not connected to pin 13 (cable HAM1_228)
RM2 is good

From ISC Racks:
ISC_222 (db9) pin 5 not tied to shield, signals good
ISC_221 (db9) pin 5 not tied to shield, signals good
ISC_226 (db9) pin 5 not tied to shield, signals good
ISC_356 (db25) pin 13 IS tied to shield, signals good
ISC_223 (db25) pin 13 not tied to shield, signals good (older cable)
ISC_224 (db25) pin 13 not tied to shield, signals good (older cable)
ISC_225 (db25) pin 13 tied to shield, signals good (new cable)
ISC_227 (db25) pin 13 tied to shield, signals good (new cable)

EOM RF Signals:
At Rack, all RF signals shields are tied to rack ground.
Cable runs are isolated from rack and chamber ground
At Chamber, all RF signal shields are tied together in chamber possibly at EOM.

IOT2 Table Enclosure:
Picomotor Cable - pin 13 tied to shield, signals good.

J. Freed, J. Kissel

We worried for the production, already class-A clean, SPI's single-element PD (SPD) assembly (D2600001) that the unused GAP5000 pins of the dual-purpose D1700116 ceramic circuit board may have shorts from FFD-200 SPD case to its anode and cathode if the case of the PD was not insulated from those GAP5000 pins -- as was found possible in the dirty test setup (see list item 2. in LHO:89247).

This morning, we opened up the cleaned assemblies (still serialized under the drawing for the cable, D2400341),
    - S2500514 :: HAM3 ISIK MEAS A and MEAS B
         --Pins 5-9 -> PD Box S2400197 -> DCPD 001
         --Pins 4-8 -> PD Box S2400198 -> DCPD 002
    - S2500515 :: HAM3 ISIK FBR PWR REF and FBR PWR MEAS
         --Pins 5-9 -> PD Box S2401094 -> DCPD 004
         --Pins 4-8 -> PD Box S2401093 -> DCPD 003
    - S2500516 :: HAM3 ISIK REF A and REF B
         --Pins 5-9 -> PD Box S2401096 -> DCPD 005
         --Pins 4-8 -> PD Box S2401095 -> DCPD 006

And found that for every assembly,
    - Per D2400341, only pins 1,4,5,8, and 9 exist. See example picture of S2500514
    - All the anode (5 or 4) or cathode (9 or 8) pins are isolated from the case pin (Pin 1)
    - The anode pins for the two diodes (5 and 4) are isolated from each other
    - The cathode pins for the two diodes (9 and 8) are isolated from each other
    - Each diode's cathode to anode resistance (5 to 9 and 4 to 8) is in the ~2e6+/-1 [Ohm] = ~few [MOhm] as expected for the reverse bias operation we'll use the system.

The production PD assembly will function as designed without any shorts :: the negative reverse bias topology of the transimpedance amplifier and cable readout system will work!

I also attach pictures of the bags that aide assignment of serial numbers to assemblies.

Wed Feb 25 10:02:04 2026 INFO: Fill completed in 2min 3secs

A messy fill, CP1 has been dribbling since the dewer fill yesterday so it was close to full, resulting in a quick fill or sorts.

The JAC steps finally completed to a point where we are ready to hand over to Jim to finish the cabling pinning and ISI balancing.  This morning the LVEA has been transitioned to full laser safe and the IOT1 JAC table has been moved out of the way of the chamber.  The viewport fixture still needs to be removed, will get a crew on that soon.

Adding CHETA slow controls channels to DAQ EDC

Jonathan, Erik, Dave:

Following the installation of the CHETA Beckhoff chassis in the Vacuum Prep Lab we added the 724 AWC channels for itm[x,y] to H1EPICS_ECATTCSCS.ini for inclusion into the EDC.

at 12:22 I did a DAQ 1-leg and EDC restart. The EDC would not run, its systemd service was in a continual respawn state.

The number of EDC channels had increased from 59894 to 60618, and I remembered that there is a channel limit in the EDC code, which Erik verified was 60k.

Erik quickly built a new EDC with a 70k limit and installed this on h1susauxh56.

In the mean time I had put the H1EDC.ini file back and restarted 1-leg and EDC to get everything stable again.

At 13:22 we did a second round of DAQ+EDC restarts with the expanded channel list which was successful.

Installing h1sush6 IO Chassis

Fil, Dave, Erik:

I relocated the old h1sush2b IO Chassis from the CER to the MER. It is in the bottom of the SUS-HAM6 rack, at the same height as the neigboring h1sush7 and h1seih7.

I pulled a new MTP fiber from the IO Chassis to the MER patch panel, using the third port.

This IO Chassis currently has the cards left over after the h1sush2[a,b] consolidation in Dec 2025, we will populate it with the correct cards later.

Current layout:

No work was done on the front end computer in the MSR.

Later this week when the IO Chassis is powered up we will make the following changes in the MSR to the old h1susb2b computer:

1. disconnect the Dolphin cable from its IX card and verify the Dolphin switch port is fenced

2. move the MTP from the CER patch over to the 3rd port on the MER patch

3. run puppet to reconfigure the boot server to boot this computer as h1sush6 sans-Dolphin and only running h1iopsush5 model

4. boot the computer and verify the IO Chassis can be seen, the IOP runs and that the timing is good.

h1susb123 accumulated 4 DAQ CRC errors on the 1-leg overnight as reported by DC1, but none on the 0-leg.

All 4 models on h1susb13 increment their CRC counters at the same time. Normally we have zero CRC errors for weeks/months across the board.

I have cleared the CRCs and we will see if this trend continues.

TITLE: 02/25 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 6mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.19 μm/s 
QUICK SUMMARY:

More JAC work today

The annulus ion pump body for the BSC1 annulus system was replaced.  We then hooked up and started the turbo/aux. cart.  Pressure at the cart was dropping nicely as pumping commenced.  

There will be a pump cart running on the south side of the Y-arm beamtube, near the TCSY table, until the ion pump transition pressure.

S. Muusse, C. Compton, G. Vajente

We are still in the process of testing the CHETA electronics integration and have began fixing the optical setup on the ITMY Table to test the sensor in situ.
The optical system was realigned with the lenses, waveplate and polariser repositioned to ensure lower 4.65um intensity on the pickoff to prevent burning after the issues in post. All core optics for the 4.65um beam have been placed and we are in the process of adding the sensor paths and laser dumps. 

Electronics:
We tested all the laser diode and TEC controller ports on the chassis which were working. It is worth noting when connected to the Laser Enable control the diode will not turn on unless this is enabled and can be used to shut off the laser power.
The thermal power meter input was also working and power changes can be seen on ndscope
I've put in a table the status of all the CDS I/O we've tested so far:

Some notes are that:
PD_C is the thermal powermeter 
PD_A and PD_B are the PDs

We aim to installl the PD setup tomorrow and test its electronics. 

Medm
Adjacently, there was continued progress on the medm, a flipper control was installed using SQZT7 code, the slow PD was added using LSC_CUST_DCPD.adl and QPD using QPD.adl. Both will be tested in the coming days on the actual system and the rest of the controls added.

J. Freed (with help from Marc and Fil)

I tested the real wiring chain described in D2400111 from PD through the 3 variants of the TIA and it does follow exactly what is described in the link. There were 4 things of note that were found during this test. 

1. All the whitening filters were switched "on" inside the TIA, however our final design document states that only the QPDs need whitening. As such the SPD boards S2500647 and S2500645 whitening switches were set to bypass. I logged this change in the E-Traveler.

2. The D1700116 silicone circuit board for the FFD-200 causes shorts. The main issue is the GAP 5000 pinholes on the PD side of the board. If the PD is flush with the board those pins touch the case of the FFD. Since the GAP pins are also connected to the cathode and anode, this causes the circuit to short. This is simple enough to test without taking out any PDs from the case. If there is "no" resistance between the case (ground) pin and the anode/cathode pins on the DB9 connector coming from the PD, then it is shorting and the system should not be turned on. There are 2 options suggested to fix this, either put insolation between the GAP pins and the FFD case or cut the GAP pins connection to the FFD anode/cathode. For this specific test, the issue was bypassed by putting in a tissue between the FFD and the silicone board.

3. I tried to take transfer functions from all the PDs through the TIA, however the laser I used (the MIT ISC AM Laser) AM modulation was designed for 5 - 200 MHz, not the 4096Hz we are trying to use. As such, I suspect the harsh attenuation (~70dB at 4096Hz AOM_Attinuation.png) I measured was caused by the laser. So I decided it would be better to put off the transfer functions through the TIA until after SPI is built, then use our own laser AOM system to run the test. The laser was just left at DC and was used as the light source to see if signals on the PDs follow the correct wiring chain.

4. I used the laser to check that the signals on the PDs follow the expected wiring chain through the output of the TIA. Ex. Laser on Quadrent 1 of the QPD outputs a voltage on the expected pin on the output of the TIA. All pins were found to be correct.

Jason, Jennie, Betsy

After working for a bit to try to beam dump the second Septum refl beam dump which also is coming off the IMC septum window, we finally came to a solution.  It involved stealing one of the SPI D1800140-07 smallest beam dump panels and also putting it into the same mount as the first panel.  These 2 beams are pretty close to the main beam at this location, but with the beams otherwise hitting the internal metal of the output periscope we could not come up with anything better.  It took us quite a few small adjustments and many pictures to convince ourselves we are not clipping, but the attached picture is the best visual of the situation.  Commissioners agree that this is what we will live with.

TITLE: 02/25 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: N/A
SHIFT SUMMARY: Another productive day working towards closing out HAM1.
LOG:

Alignment into HAM2

Locked JAC with RF at 1W. IMC WFS was centered in IOT2L and IMC started working. As we steered JM3 MC2 TRANS responded as expected (i.e. JM3 PIT -> MC2 YAW and vice versa though there's a significant cross coupling). Sheila had to recenter the WFS once again at some point as the WFS started to get off-centered as we turned JM3, but as far as the WFSs were centered, things worked.

In the end, MC2 TRANS was centered reasonably well (right before the cursor in the attached), JM3 DAC output was O(1e7) while a 28 bit DAC's range is +-134e6.

Apparently we made the last step of JM3 PIT adjustment in the wrong direction at the time (we didn't notice because the WFS is very slow) and overshot. I steered it back later, now H1:SUS-JM3_M1_OPTICALIGN_P_OFFSET is -39 instead of -19 (second screen shot).

Anyway, this means that the alignment into HAM2 is good with more than a comfortable range left for JM3. No need to further refine.

One caveat is that the IM4 trans is totally off in PIT. But that's a downstream problem which we'll have to deal with later in HAM2. That should not prevent us from moving forward to close down the chamber.

The tasks listed below are described in different alogs.

JAC TRANS PD calibration

Last beam dump (alog 89249)

ALS beam path check

It seems that whitening gains of some corner station QPDs were somehow set to zero on Friday Feb/20 17:22 UTC (09:22 PST).

Not sure why this happened, this seems to be earlier than the failed effort to update h1imcasc model (alog 89208). ALS QPDs, end station QPDs and all WFS RFs are good. Was something done to Beckhoff that day? 

I first noticed this for MC2 trans yesterday because it was interfering with IMC locking and WFS triggering. I checked all QPDs and WFS today and found that the following channels were affected. I restored them all to the value right before it was set to zero. 

Today, Gerardo replaced the annulus ion pump body for the GV6 annulus system.  He then handed off to me to hook up the turbo/aux. cart.  The pressure at the cart was ~3e-5 after 4 hours of pumping.  

There will be a pump cart running at GV6, at the Y-arm termination slab, until the ion pump transition pressure.