Jennie W, Jason O, Tony S, Olli P

Yesterday we put the viewport simulator on the -Y door of HAM1 to enable us to check the JAC REFL path, we had to move the in-vac mirrors for this path a couple weeks ago because the beam hit the side of a beam dump before hitting the second steering mirror after the JAC input coupler and so was mis-aligned.

The viewport simulator has tape marking the centre of the real viewport for this beam that was put in last time we had it up on this door.

We also rolled up the IOT1 table and plugged it in.

We had to move the table in -x direction from its ground markings as the periscope was too far right in the relative to the bellows hole and the viewport simulator, we also moved JACR-M1 as it was one row of holes too far in plus x direction.

The beam hit too high on the periscope, so it was missing the mirror by an inch, this will need to be corrected with pitch on the in-vac steering mirrors.

Closes FAMIS#39854, last checked alog88973.

For the CS:

MR_FAN4_170_1 had a slight noise increase a little over a day ago, MR_FAN2_170_{1,2} are both seeing lots of spikes.

For the OUT buildings.

The EX fans all increased in noise around 15:30 UTC this morning.

Today Randy T and I ran power for the Cross Flow HEPA fans on the platform around BSC2.  The fans are on and turned down to low at the moment.  We also moved the dust monitor from the floor to the platform to monitor dust counts to have a better understanding before pulling the dome.

Thu Feb 12 10:13:15 2026 INFO: Fill completed in 13min 11secs

Travis confirmed a good fill curbside. He removed an ice ball from the end of the discharge line pipe.

Dave, EJ, Ryan C.

Following the h1pemey install this morning I realized that this was the only model on h1iscey built against the latest RCG5.5.2 (all others were still at 5.5.0).

With Ryan's permission I rebuild h1iopiscey, h1iscey, h1caley, h1alsey with rev-lock to ensure identical software using RCG5.5.2 and restarted all the models at 09:41.

No DAQ restart was required.

WP13027, WP13029

Robert, Ryan C, Dave:

I installed new h1pem[cs, ex, ey] models this morning. Changes are:

 . OSC+NOISE_GEN signal-injection section for DAC drives

 . New AMON ground current monitor signals

 . Fix GDS_n indexing at end stations

Note that the temporary "ADC" channel names for the ground current monitor could not be removed because they are being sent by the DAQ Broadcaster to GDS. These should be either changed to the new names (and CS added), or they should be removed.

A DAQ restart was required. This generally went OK, but FW0 restarted itself after running about 8 minutes.

In the event MER in-rack work causes issues with h1sush7 SWWD, I have bypassed h1seih7 SWWD for the duration of the work.

The vane position of the fan inside air handler 1 at End X was changed from 100% to 70% in order to increase the airflow through the fan. This was changed to more closely match the settings at End Y. End Y temperature trending has been consistent while End X has had moderate variation in comparison. 

TITLE: 02/12 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: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.28 μm/s 
QUICK SUMMARY:

• HAM1 work continues today
• Lots of patches of thick fog around town and site

TITLE: 02/12 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM1 work continues, HAM7 is pumping down.
LOG:                                                                                                                             

18:15 UTC HAM7 SEI SW watchdog trip from a H7 crash, FE & ADC errors on IOPSUSH7 SUSFC1, SUSSQZIN SUSAUXH7, IPC and DK error on SEIH7.

Dave restarted everything ~20 minutes later

Following alog 89115, we found that the old batch crystal from that alog (S/N10252003) had a big chip at one corner. It is pretty bad we don't want to use that.

Betsy found another old batch (S/N10252007, "inspected 12/21/11" and UF tag dated 4/21/09), so we A-B-ed that one with the spare new batch (S/N B1913108).

The beam path was made as level as possible at 3" height using a beam leveling tool (a black metal thing with a tiny aperture at each inch of height).

We put the crystal on a platform that is roughly 2" 29/32 (which is about 2.4mm lower than 3"). The crystal is 4x4x40mm so that's about the right height.

We spent some time to make YAW alignment as good as we can for each of the crystals.

We scanned the beam in PIT from top to bottom (or bottom to top), each extreme is where the beam is almost clipped (but not actually clipped) by the top or the bottom face of the crystal.

Look at the attached, the new batch (left column) clearly shows multiple beams even though the focus is not as sharp as the old batch photos. As we misalign in PIT, the dark place moves relative to the main beam and the contrast changes too, but multiple ghost never went away. At the extrema (very close to the top or bottom edge) it looked as if the beam is better but I'm not sure it actually was.

The old batch (right) didn't show such a behavior. The beam shows something like a diffraction pattern but no separate ghost beams. Everything moved with the main beam.  Not sure if the diffraction pattern came from the aluminum surface or EOM, but clearly this is MUCH better than the new batch.

Note, due to the apparatus (the steering mirror is 20" upstream of the EOM), we haven't searched in a huge PIT angle space, it's actually roughly +-4mrad or so, the angle is not negligible but it's more parallel displacement scan than an angle scan.

Also note, when the crystal was put in place it seems that there's some vertical deflection which was different for the old and the new. On the top two pictures, there's no change in the input alignment into the crystal. 

Based on this observation, I'd say using the old batch makes sense. LHO people (Jennie, Rahul, Betsy and myself) had a brief conversation with Masayuki and MichaelL and we all agreed that that's the way to go.

J. Kissel

After conferring with Sina about the results from LHO:89047 and armed with the plan described at the tail end of LHO:89099, went into the optics lab to improve the rapid iteration of beam waist diameter measurement by concocting an optical layout that can measure the beam at two z positions at the same time.

See attached diagram and physical setup.

Note -- the optical table has become over populated with in-vac EOM crystal characterization (and additional beam-scanning set up), so Keita and I shared space by having his setup be at 3 inch beam height and me at 4.5 inch setup. This just barely cleared his beam scan, so I intend to further increase my beam height to 5 inches.

I only have preliminary results (without having changed the collimator lens position at all yet), but they showed hints of astigmatism, so I suspect:
    - the polarization of the emitted beam from the fiber collimator
    - the beam splitters
    - clipping on the beam scan from Keita's setup.

Will confer with the team.

I ran the chilled water pumps at the Mid stations this morning to exercise the bearings and seals. This will affect the temperature trending of the glycol loops but this is expected. 

Wed Feb 11 10:11:01 2026 INFO: Fill completed in 10min 58secs

It took much longer than expected but we set up the beam path for the RTP test in the OSB optics lab.

Since more power makes it easier to see the ghost beams, I removed the beam dump that used to receive most of the red power (~530mW) and directed the beam to the front of the table (red path in the attached). I stole the steering mirror that used to be used for the low power P-pol path (circled in red). The low power p-pol path is now simply blocked. No other change was made to low power S-pol path (orange) as well as green path (green), but the beams are blocked by beam dumps. If you want to use these, simply unblock.

The beam radius will be 300~400 um or so at the location we plan to put the RTP (represented by a green rectangle in the second attachment). Elenna will post the plot of the beam size measurement.

The third picture shows the containers for different RTP. Left is the one for the crystal in HAM1. The middle seems to be from the same batch. Right looks different, on the bottom of the container there's a label saying "I/O something something 2017" so this is likely the old one.

We didn't have time to actually test the crystals, wait for tomorrow's udpate.

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.

(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.