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

Sat Feb 07 10:09:46 2026 INFO: Fill completed in 9min 42secs

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.

TITLE: 02/06 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
Super Bowl Weekend SHIFT SUMMARY:

JAC team continued with JAC alignment work in HAM1.  HAM3 AIP was swapped & started pumping over the weekend. 

(Go Seahawks!)

LOG:

• 1611-1725 Optics lab & LVEA technical cleaning (kim)
• 1612-1622 eMod retrofits/checks (randy)
  • 1636-1920 heading back out & will use crane for handrail moves (randy)
• 1836-1845 Opening lightpipe & increasing power via rotation stage for HAM1 team (ryanS)
• 1837-2014 HAM1 ghost beam search for JAC (keita, masayuki)
  • 2241 HAM1 work continues (keita, masayuki)
  • 2300 Jennie joins JAC team
• 1838-1851 power cycle volt meters (tony)
• 1906-2123 swapping out Annulus Ion Pump (AIP) at HAM3 (gerardo, jordan)
  • 2249 start pumping down HAM3 AIP (gerardo, jordan)
• 1925 Taking laser power from 1.0 to 0.100 W (ryanS)
• 2040 Had issues with the Ops Camera/Access system computer, named ACCESSCONTROL (it's not ZOTPSL2). Problem was with OpenEye (camera app) not working (Refresh would do nothing).  I restarted the app a few times, and also restarted the computer as well.  Access System (Intelli-Site) app was fine.  Thinking it was a network issue because it said there was no access to the internet, I clicked Network Reset.  But after this also lost Intelli-Site.  Tony and Dave did a few checks and also phoned Richard with no luck.  As workaround, using the OpenEye webpage on the Operator CDS computer and if someone is at the gate, we can open it via the ops phone.
• 2051 nds1 restart (dave)---this required a restart to FOM ndscopes.
• 2118-2220 Checking eMod rail parts at EY & EX. (randy)
• 2230-2301 HAM1/IOT2 checks (jennie, sheila)
• 2334 Timing checks at both EX & EY CERs (Dave)
• 0008 Input power raised to 1W for JAC (ryanS)
• 0033 HAM3 AIP is pumping over the weekend Aux-Cart near HAM3 & gerardo/jordan are done for the day.

FAMIS 28229

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

From the previous alog post, Sheila measured a power drop across BL2 lens.

Here I modeled the loss of the 700um beam waist across the 2.5mm BL2 lens aperture.

The expression for the transmitted power obtained by modifying the Gaussian beam equation to include a displacement d² = d_x² + d_y² is shown here.

And here's the contour plot for the loss (1-T) across the lens aperture for a beam transversing across various spots on the lens.

WP13007

The rawminute trend copy to permanent archive completed 04feb2026. Today I reconfigured NDS1 to serve these data from their permanent archival location and started the deletion of the files from TW1.

NDS1 was restarted at 12:51 for the new configuration.

[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.