Sheila, Camilla, Jim, EJ, Dave:

At 16:29:25 we had a timing glitch on h1iopsush7 which stopped it from running. 

Sheila and Camilla checked the SDF settings for h1susfc1 and h1sussqzin models before the restarts.

I verified all the IO Chassis cards were present and correct, and then restarted all the models.

I untripped the HAM7 SWWD, but accidentally also untripped HAM1. I returned HAM1 back to PM1 bypassed, SEI-HAM1 tripped.

Dave has to restart SUS SQZ in and SUS FC1.  Camilla and I went through the SDF files and accepted all the current sliders.  
We also saw that the OPO T damp gain was changed, we did not accept that.  

TITLE: 02/09 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

HAM7 had viewports inspected and steps initiated for pumping down.  JAC team spent a good part of the day inspecting the in-vac EOM output beam.  The ACCESS SYSTEM computer had its network issues fixed (for Access System & cameras).
LOG:

• 1531-1547 Optics lab clean (kim)
  • 1703-1803 Return for main cleaning in lvea (kim)
  • 1803-1859 Picking up garb at Receiving and cleaning our buggy MidY (kim)
  • 1900-1931 MX cleaning (kim)
• 1733-1756  Looking for ground seismometer at end stations (jim)
• 1825-1945 HAM7 Annulus Ion Pump (AIP) pumping begins (gerardo)
  • 1941-1945 Jordan joining
• 1837-2050 JAC EOM checks (jennie, jason)
  • 1843-2044 Keita joining
• 1847-1913 HAM3 taken to ISI_DAMPED_HEPI_OFFLINE (from ISOLATED) to allow crawling around the chamber to look at feedthrus (jim, betsy)
  • Jim out and HAM3 returned to ISOLATED.  Betsy working with Travis.
• 1851 HAM3 + HAM7 AIP pumpdown checks (travis)
• 2000-2008 increasing PSL power for JAC (ryanS)
  • 2019 another adjustment (RyanS)
• 2117 VAC team return to work on HAM7 for AIP pumpdown, viewport inspection, chamber pumpdown (travis, gerardo, jordan)
  • 2342 Travis out
• 2139 Out to HAM7 (betsy,richard)
• 2203--0025 Back to HAM1 for JAC EOM checks (keita, jason, jennie)
  • They mentioned issues with one of the platforms at HAM1 to Richard.
• 2207-2315 Checking VAC cable at EX (marc)
• 2250 Organizing parts in optics lab (camilla)
• 2233 swapping spheres in PCal Lab (tony)
• 2353 Dropping parts off at MY (travis)
• 2357-0012 Maggie giving a tour to intern applicant
• 0012-0019 Rack photos (oli)
• 0025 VAC team (gerardo,jordan) preparing for roughing pump at HAM7.  
  • I confirmed that the picomotor "Squeezer Things" are DISABLED via picomotor medms.

Per WP13021

I have scanned the disabled SHV cable from EX Ion Pump X-8.  Using a 10' launch cable, on DTF setting, with bandpass set from 10MHz to 50MHz.

The attached plot is from the scan., the following aberations appeared on the cable run:
73m = 1st interface/reflection
130m = 2nd interface/reflection
361m = 3rd interface/reflection
456m = 4th interface/reflection

There were no other reflections beyond 456m.  All scans were done at C=1.

M. Pirello, G. Moreno

Jennie W, Jason O, Keita K.

As reported in this alog (#89073) from Masayuki and Keita, after we turned the power in HAM1 up to 1W we found a series of vertically spread ghost beams aroubnd the main beam after the EOM and before JM3.

These could not be removed by translating, yawing or pitching the EOM position relative to the beam. It was decided in a larger meeting with EOM design personnel that we would first check if the crystal was cracked or damaged anywhere in case this is the cause.

First photo shows the EOM from above, using a green torch to illuminate the beam path. I can't see any scatter from defects or cracks in the crystal.

Second photo shows possibly a chip at the corner, but this should not affect the beam as its right at the edge.

Third and fourth show side view with illumination from the top at an angle.

In summary we did not see any 'smoking gun' to cause these ghost beams.

Randy, Ibrahim

Randy and I put the BBSS in the can today, as shown by pictures.

Following LLO's advice from their experiences in alog 79950, we were able to use the aluma lift to can the BBSS. What we did in order:

1. Strip locked-mass BBSS of all cables, check for looseness, bring alum-a-lift into position to lift BBSS from lifitng bars

2. Undo dog clamps to let lift take suspension load, ensure suspension is secured on the lift. Move BBSS out of test stand - as LLO said, very small clearance.

3. Prepare temporary platform for lift fork adjustment

4. Set BBSS on temporary platform - this part was successful but needed extra blocks to avoid interference with Y-bracks on the Lower Structure.

5. Adjust forks to be allow for canning without bottoming out, relift.

6. Put into wiped-down can and check for looseness. Rewipe, check for particulate and ensure secure fit

7. Close doors.

See pictures below.

FAMIS 31124

FSS has been on and off over the past week and the PZT has been swept several times for JAC install work, but otherwise not much to report this week.

Mon Feb 09 10:10:47 2026 INFO: Fill completed in 10min 44secs

FAMIS Link:  39337

Only CPS channels which look higher at high frequencies (see attached) would be the following:

1. ETMx_ST1 H1
2. ETMx_ST1 H2
3. ETMy_ST1 H2
4. ETMy_ST2 H1

In the bash window we get this note:

"HAM high freq noise is elevated for these sensor(s)!!!:       HAM1_CPSINF_V2  &  V3 "

The GC UPS reported a brief switch to battery power this morning due to a minor glitch in power on all three phases. The MSR UPS did not report.

TITLE: 02/09 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: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.34 μm/s 
QUICK SUMMARY:

HAM7 not pumped down.  HAM1 JAC work continues. LVEA is in the Bifurcated Laser SAFE state. And Seahawks are Super Bowl Champs!

(Jordan V., Gerardo M.)

-Late entry

On Friday we removed and replaced the ion pump for HAM3.  We replaced the copper gasket twice, the first gasket seal had a bad leak, it was hard to see the mating surfaces due to visibility issues (laser safety goggles and not enough light).
After installing a second gasket, we started pumping down the annulus system and pressure went down fast.  Last pressure reading at the aux-cart was 4.63x10^-05 Torr.
BTW, we have other 4 (four) ion pumps to replace.

Sun Feb 08 10:11:56 2026 INFO: Fill completed in 11min 52secs

Summary of investigation into the vertically split beam from the EOM

• First, we confirmed that the vertical beam splitting observed yesterday originates from the EOM itself. To check the possibility of multiple reflections from lenses, we inspected the back-reflection port of the JAC output mirror. Two reflected beams were observed, most likely originating from the planar and curved surfaces of the lens, and they were mainly separated in yaw. Since the space between the EOM and the lens was blocked during this test, these reflections were conclusively identified as lens reflections. No vertically split beams were observed from this source.

• A knife-edge–like test was performed by slowly lowering a metal ruler from the top at both the EOM input and output. At the EOM input, the entire beam disappeared simultaneously, whereas at the output the beam disappeared gradually from the top. This behavior confirmed that the vertical splitting is generated inside the EOM.

• To accurately determine the beam positions at the EOM input and output, beam positions were measured from photographs. Taking refraction and geometry into account, it was found that the beam is slightly displaced in the horizontal direction. Details of this analysis will be documented in Keita’s alog.

• Based on this result, the EOM was rotated in yaw. Dog clamps were placed at the ±y projection points of the EOM input and output, in contact with the base plate. One 0.5-mm shim was inserted between the base plate and each dog clamp to rotate the EOM counterclockwise. However, the beam pattern did not change. Additional shims were tested, but no significant change was observed. The EOM was fixed with one 0.5-mm shim at each position.

• Next, pitch adjustments were explored. The original shim configuration (two shims on the +y side and one on the −y side) was changed by moving shims to the +x side (one location at center) and the −x side (two locations, upper and lower). Each location initially had two shims, and by adding or removing shims, it was observed that the vertical positions of the split beams changed. When the +x (downstream) side was raised, the vertically split beams appeared in the upper part of the beam profile (approximately 5–7 beams; Keita will upload photos). Conversely, when shims were added to raise the −x side, the split beams moved toward the lower part of the beam. With the downstream side lowered by approximately 0.25 mm, about two beams were observed in the upper part and one in the lower part.

• 1W input power shows 6 or more beams, but 2-3 beams can be observed even with 100mW.

• With the last configuration, we proceeded the IMC scan measurement after alignment. The 2nd order mode peak was the same level as we observed when we sim up the EOM first time.

• In summary, the EOM shows highly questionable and nontrivial behavior. Possible causes include diffraction due to crystal defects or multiple reflections at the AR-coated surfaces. However, identifying the exact mechanism is challenging at this stage.

[Sheila, Eric, Jim, Kar Meng, Daniel D.]

When we started working this morning, the particle counts were 20/10/10 per cubic foot

It looked like the old cable for the PZT that needs to be replaced was routed to back into the chamber to a cable bracket which was far from reach. Before we can remove it, we need to find the cable harness plan for HAM7.

In the mean time, we were able to re-route the TEC cable using photos from this alog. 

### Broke for lunch ###

Over lunch, we determined the correct connector for the PZT/translation stage was on CB5 in HAM7. It's labeled cable #4 according to the wiring diagram. We also verified the correct operation of the TEC controller and the oven from CDS

After we returned, the particle counts were 0/0/0 per cubic foot and we uncovered the chamber to finish replacing the cables.

Unfortunately, cable #4 between CB5 (see image) and the OPO is terminated in a male molded connector, which is screwed into the connector bracket. This meant that we needed to remove the female cable (from the flange) from the rear of the connector and then remove the male connector (to OPO) from the cable bracket. Jim came in to help us reach the connector and he decided that it would be easier to remove the top and second-from-top connectors (3rd and 4th on CB5 in the wiring plan) from the bracket to make it easier to reach the ones for cable #4. Jim was able to remove the old cable and replace it with the new one in the bracket.

After Jim left, we were able to continue reinstalling the new cable. The longest DB-9 tentacle on the new cable is for the VOPO PZTs, the DB-15 is for the stage control, and the short DB-9 is a spare which was coiled to the side. We were then able to connect the piezo and stage control connectors to the OPO and roughly re-route the cabling on the ISI table. Final routing and securing of these new cables/checking for mistakes is still required.