Wed Feb 07 10:09:46 2024 INFO: Fill completed in 9min 42secs

Gerardo confirmed a good fill curbside

TITLE: 02/07 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: Maintenance
    Wind: 2mph Gusts, 0mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.30 μm/s
QUICK SUMMARY: The LVEA is still laser hazard with some more HAM7/6 work planned today.

Preparations:

ASC-AS_C was centered using SRM. It was moving more than I'd have liked but it was OK.

Confirmed that Irises on HAM6 were centered.

The laser beam was on both of OMC QPDs but sadly they were pretty off-centered. Things were swinging more than I'd have liked but anyway I roughly centered the beam on both QPDs using OM1/2/3.

This means that, due to the cable rerouting/retouching we've done when we put the shroud panel on last week (alog 75651), OMC is hanging at a different angle. That's OK as far as DAC of OM1/2/3 won't saturate once we pump down.

This also means that both WFSs are not centered at all. That's OK, we can pico.

OMCR was good:

We visually checked the centering on the OMCR diode using a viewer card. It was OK in that it's not close to the edge, so we left it as is. The distance from the edge of the V-damp to the OMCR is pretty mush the same as Julian's photo from Jan/31 (alog 75653).

OMC trans video beam doesn't come out of the shroud:

I scanned the OMC PZT2 and was able to see that the DCPDs are flashing, but no beam was visible on the steering mirror of the OMC trans video beam.

We removed the +X+Y-side short shroud panel, and immediately I saw the beam, it was faint but obvious using the IR card and the viewer combined. It was already hitting the steering mirror, and the beam was roughly going to the direction of the video viewport.

Using a ruler and the IR viewer card, we found that the beam height was, very roughly, 4" from the OMCS cage to the steering mirror. Maybe it was a tad low.

Rahul placed a ruler on the ISI table to mark the rough beam position close to the +X door, see his picture.

We put on the shroud panel and the beam is gone no matter what. We even did Betsy/TJ/Fil/RichM/Peter/Koji/Calum trick (alog 28944) they did back in 2016 to move the -X-Y-side short panel around more than designed, without success.

It's very hard to find where the beam is at the panel location. Since we know where the beam is at the edge of HAM6 close to video viewport, we can use a laser pointer to back trace the beam path and see if the baffle hole should move to +X or -X direction, but that won't change the fact that we couldn't bring the beam out with the shroud panel.

Fundamental problem is that the exit hole in the shroud panel is too small.

We cannot find OMC trans unused beam at all:

We also tried to see the unused OMC trans beam that comies out into -X-Y direction, but couldn't. Maybe the power of that beam is much smaller than the video beam.

Because of this, and because they did the aforementioned Bests/TJ/Fil/RichM/Peter/Koji/Calum trick for the old OMC, and because there's no position reproducibility whatsoever once that trick is used and the panel removed and reattached, there's no guarantee that the beam will come out once the panel is installed.

If the panel weren't there, it's unimaginable that the beam will miss the V-dump. Again, the problem is that the hole is too small. That was a problem in 2016, and that is the problem now.

How can we move forward:

Could we NOT reinstall the two problem shroud panels in -X-Y and +X+Y side?

Today's activities:
- EX pumpdown status: ~9.3E-8, exactly 1 week from the start - pretty good
- EX RGA bakeout: it is being baked, see details here: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=75750 ; RGA scan next Monday
- The purge air was disconnected from the input beam port, as HAM3 has been already closed. Now it is only at the OMC and HAM7 ports
- The new Agilent leak detector is now set up. It will be tested during the HAM6 RGA leak testing

Continuing from our plumbing escapades (alog75715 ) Jason and I confirmed there were no table leaks overnight and then fired up the freshly refurbished CO2X laser. Using our Thorlabs powermeter we saw 53W coming out, nice. The alignment was pretty far off in yaw though, so we had to do more alignment than last time we swapped the CO2Y laser (alog65393). We eventually got the beam to line up well on the irises and then had to translate the anular mask a small amount to match the main beam.

More details and pictures to come.

TITLE: 02/07 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: LVEA Laser Hazard all day today. Vent work today was in HAM6 and HAM7.
LOG:                                                                                                                                                                                                                                                                                                                                                                                                                                                               

Naoki, Camille, Julian, Rahul

Summary: We measured beam profiles in HAM7 and HAM6 using the SQZ beam, after the PSAMs offloading work from 75677 75709 and the alignment work from 75732. We noticed that there is a lot of astigmatism on the beam in HAM6, but not in the HAM7 location that we were able to reach with the profiler. 

Details:

In HAM6 we measured at three locations marked by the letters a,b,c in the sketch that Julian will attach. The red lines in the sketch show the irises. 

Location 6A is 1.75 inches from the iris, Location 6B is 2 inches from the iris (closer to OM1).  At location 6C we measured the beam in reflection off OM1, 23.25 inches after OM1.  (The fast shutter is further in the -Y direction in chamber than what is shown in the CAD drawing).  We also would like to measure at position 6D, once the second iris is removed. 

We also measured beam profiles on the -X side of the HAM7 table, location 7A is 6.25" in the +X direction (closer to ZM5) from the iris, 7B is 8.25" from the iris in the + X direction, and location 7C is 12" from the iris in the +X direction.  We weren't able to move the profiler further into the chamber without blocking the beam heading towards FC1.

We measured 13.5% widths, with A1 as the vertical axis and A2 as horizontal. 

* strain guage still drifting

Stll left to do:

• Measure distance from HAM6 first iris to OM1. 
• Measure distance from HAM7 iris (on -X side of table) to ZM5.
• take a better photo of the beam position on ZM5.
• try to put beam profile in location of iris near OM1 (location 6D).

Useful distances from Don:

Don Griffith sent us some useful distances in HAM7 which are useful for interpreting these measurements, based on the CAD model that he updated in in March 2022 based on the as built photos of HAM7 (D1900365-v1). 

• B:M4 (last optic on VIP) to ZM4 = 1086.36mm
• ZM4 to ZM5 = 1681.23mm
• ZM5 to Beam Diverter + 1183.54mm
• ZM5 to Edge of Table = 1822.70mm
• ZM5 to ZM6 = 4680.61mm

The EX RGA tree has been leaked checked and wrapped with heat tape/foil for bake out. It will be slowly ramped up to 150C and baked for the next week or so. The area around the tree has been marked with caution tape.

Once baked, it will be pumped with a 10l/s ion pump.

There were some reports of the dust monitors possibly not reporting to EPICS the correct counts so I went out to the LVEA and took some pictures of DMs to then trend the count channels and I confirmed that DM5 (by HAM3) and the spare DM next to it is working but not writing to EPICS, DM10 (Biergarten), and DM6 (megacleanroom by HAM7) are working/communicating fine. 

Tue Feb 06 10:07:29 2024 INFO: Fill completed in 7min 25secs

Gerardo confirmed a good fill curbside.

Pumps running smoothly.

FAMIS 19970

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

Jonathan, Erik, Dave:

The CDS Load Mon EPICS system was installed on the two sshd servers; cdsssh and cdslogin. Due to a later version of python3 on these machines, the pcaspy code required a modification for the collections module. The IOCs running on cdsssh and cdslogin needed to be restarted, which includes the alarms and locklossalert services.

I have restored the locklossalert settings. The vacuum HAM6 alarms bypass continue through to Mar 11, but the alarm counters were reset so the email sequence has restarted.

I have added CDSSSH and CDSLOGIN to the CDS_HOST_STATS MEDM (see attached)

The new channels will be added to the EDC+DAQ on a target-of-opportunity basis.

TITLE: 02/06 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: Maintenance
    Wind: 4mph Gusts, 2mph 5min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.34 μm/s
QUICK SUMMARY: Planned activities for today include more HAM7 alignment, final checks for HAM6, finish TCS CO2X laser swap, and various vac work around site.

Workstations were updated and rebooted.  This was an OS package update.  Conda packages were not updated.

Sheila, Rahul, Camille, Julian, Naoki

After ZM4 and ZM5 PSAMS offload in 75677 and 75709, we aligned ZM4/5/6 with seed and successfully offloaded the DAC outputs of ZM4/5/6.

Fig 1 and 2 show the ZM slider values before and after our alignment work.

Before moving ZMs, first we checked the alignment of two irises in HAM6 and HAM7. The irises in HAM7 were OK, but the irises in HAM6 were not centered, so we moved SRM to center two irises in HAM6. 

Fig 3 and 4 show the SRM slider values before and after our alignment work.

After the SRM alignment, the H1:ASC-AS_C_NSUM_OUT16 was around 0.2 with 36dB whitening gain and 80 of H1:SQZ-RLF_QPD_A_SUM. 

For yaw, we reduced ZM6 yaw from 489 to 390 and compensated the alignment of two irises in HAM6 by ZM4. Since the DAC output of ZM4 got large, we made the ZM4 yaw slider value 0 and mechanically offloaded the ZM4 yaw.

For pitch, we reduced ZM6 pitch from 1072 to 0 and compensated the alignment of two irises in HAM6 by ZM4 and ZM5. After that, two irises in HAM7 were not centered anymore so we moved the height of two irises in HAM7. Since the DAC output of ZM4 and ZM5 got large, we made the ZM5 pitch slider value 0 and mechanically offloaded the ZM4 and ZM5 pitch.

We will measure the beam profile in HAM7 tomorrow.

The previous timing master which was again running out of range on the voltage to the OCXO, see alog 61988, has been retuned using the mechanical adjustment of the OCXO.

Today's readback voltage is at +3.05V. We will keep it running over the next few months to see, if it eventually settles.