Patrick T., Filiberto C., Richard M., Dave B., Jonathan H., Jim W.

WP 13262.

The summary of the work is detailed in the permit. There were some additional code changes needed to fix a scaling issue and some others made to clean things up. The only thing that should be left is to restart the DAQ to remove three channels.

IOC code:
https://git.ligo.org/cds/software/ads/ads-utils 9b98c481d6f9ab129fa4bc54475e05383d304aa2
https://git.ligo.org/cds/software/ads/epics7-ads c72c97eb4d1558d9de5c03234e90c8c651aab99b (in container), 9e5a10a014beeb0cb7b021649c459a0fa0488be7 (used to generated EPICS db)

PLC code:
https://git.ligo.org/cds/ifo/beckhoff/io 65f59557c1fefc90f4befc9338bd29a1fb27d8e0
https://git.ligo.org/cds/ifo/beckhoff/lho-hepi 3fd31d58fafc08e4d5a84dce1d0d57dfd8b6b74e

Shoshana, Alexandra, Jim, Arnaud, Fil

Yesterday's activity log: 

• Shoshana and Jim suspended the first CRS with flexures and after a first round of balancing obtained a resonant frequency of 37mHz (using the Panasonic optical interferometer -HL-G105- to read the frequency, see picture). We had to add x8 8-32 screws (8) at the bottom of the CRS to compensate for a high COM. As per the SW model the balance mass type 2 in d230099 used in the mass adjuster, and the new coupler (-v4) move the COM up by 43um (compared to the MIT build). We will swap d230099 to type 1, which will help reduce the number of Ti screws we have to use.  Table below shows the COM position wrt to the flexure center point with different mass adjuster configurations:

• Alexandra confirmed the signal chain from each HOQI was working with the TIA we received from Caltech. The HOQI board D2300154 has some minor wiring issues on the monitor signals, but we can use the TP internal to the board instead for now. 
• Fil has started wiring the interlock system to the H2-PSL enclosure so we can turn on the laser.

TITLE: 06/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 8mph Gusts, 4mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s 
QUICK SUMMARY:

BSC2 cartridge will be flying back in after lunch today! The LVEA will be going to LASER SAFE soon but is currently still LASER HAZARD

(Jordan V., Gerardo M.)

We have noticed that the dew point at the dryer towers has been increasing since opening to HAM7 and or related to power glitch last Saturday, we are still looking into it.

We have had a constant dew point at the dryer towers of -72 ^oC, and now we are at -57 ^oC, because of those numbers we ran a short test, once work was finished for the day in-chamber, we stopped the purge air to the LVEA to see what the effect was on the drying tower's dew point, it changed but very slow, we started at -57 ^oC and after 20 minutes we ended up at -59 ^oC, and we noted that the right tower may be in trouble since the dew point did not improved while this tower "works", the dew point instead went up by the one degree, erasing the improvement of the left tower.  We will look more into it.

To complete the test we took a dew point measurement at the point of use in the LVEA, and we got a -40.7^oC, getting close to a bad dew point, and remember this is while no in-chamber work is going on, so please mind those C3 soft covers on chamber doors, thank you.

A. Effler, R. Schofield, R. Short

All of the new SLiC baffles have been installed on both ITMX and ITMY (both the test mass and compensation plate sides), but the CP side of ITMX still will need some alignment positioning touched up. Earthquake stop brackets on the test mass faces for both quads were also swapped out to accommodate for the new baffles.

One person always remained near the open door in BSC1 while others were around the corner working in BSC3, and oxygen monitors were worn out of an abundance of caution.

[Nathan Holland, Jenne Driggers]

TL;DR

DC to 30 mHz BLRMS have been working as of 2022 - see LIGO-T2200025. These can be added to the BLRMS monitoring screen, and hopefully will be useful. They may need appropriate calibration. See attachment 1 for an example.

More Information

Historically the DC to 30mHz BLRMS did not work - they would diverge to +/- infinity after some time. This was corrected as of 2022, see LIGO-T2200025, by changing the C code in the RTCDS. This RTCDS change was approved in ECR LIGO-E2200027 and has been active for some time. One example of the relevant channels is H1:PEM-CS_SEIS_LVEA_VERTEX_X_BLRMS_0MHZ30, e.g. for the DC to 30 mHz seismic BLRMS at the LVEA along the x direction. Attachment 1 shows a 5 minute trace of the second trends for this channel.

Possibly this has been discussed in the past at the Friday SEI meetings, and no use yet, has been found for this BLRMS band. It may be interesting to properly calibrate these channels, place them on the monitoring screens, and then see if they are of use.

Sheila, Begum, Ryosuke, Camilla

Sheila checked that FC1 is now working as expected but was not in May 90462.

Started the morning by setting FC1 to the FC REFL iris ZM1,2,3 sliders set to 90183  (when Sheila had the beam on SQZT7), we then set irises after ZM1 and ZM3. Doing this clipped the return beam on B:L1 aperture, this is expected as we could not get the return beam through the OPO when FC was aligned in Feb.  Later we realized that this doesn't make scene, so set ZM1,2,3 sliders set to when we had good FC flashes in  89694 and then FC1 was moved to get the beam centered on the  FC REFL iris, again this clipped the return beam on B:L1 aperture but the beam was considerably higher at the ZM3 iris than when we originally set it. Around or a little higher than 6.25". Tomorrow we will fully think this though and compare to O4 times. 

We locked the OPO SUS iteratively looking at the beams off the OPO. It was finally lock with the FC REFL beam getting to the second iris but not centered and when we changed the alignment to the IR SQZT7 alignment, the beam made it through both irises when closed. 

Sheila, Begum, Ryosuke then took beam profiles of the beam after ZM1 and ZM2 with the borrowed Phasics camera.

Procedure checklist for both stations completed.  No issues were identified at this time.

MY: Scroll pump hours: 243
       Turbo pump hours: 105
       Crash bearings: 100%

EY: Scroll pump hours: 1304
       Turbo pump hours: 916
       Crash bearings: 100%

Closing WP 13279 and FAMIS 79948 and 79949

WP 13292
BSC2 Flange Layout - D1003079

Part of the BBS upgrade required moving the SUS BS field electronics from the SUS-R6 rack to the SUS-R2 rack. A new set of field cables were pulled from SUS-R2 to BSC2 flange E3 per D1003079. The old cables at the flange were disconnected and labeled as spares to avoid confusion. Access to the flange is limited as we now have the platform and dial indicators that limit access to the flange. The dial indicators were bumped. SEI team was notified.

TITLE: 06/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM2 and HAM7 laser hazard work continued, the ITMY baffles installation progressed, and the SPI electronics are being staged into the LVEA. The cartridge is planned to be flown back into chamber tomorrow.
LOG:         

• 15:05 UTC Light pipe open
• 18:24 UTC SUS OPO WD trip
• 23:09, 23:13 UTC ITMX SUS then SEI WD tripped

Before locking down the ITM suspensions as part of the new baffle installations, we measured the positions of each test mass and compensation plate (CP) from the outer bevel to the inner cage:

EDIT: clarifying that "left" and "right" here refer to when looking at the face of either the test mass or CP, so left and right flip when going between TM and CP on the same suspension.

ITMY

Compensation Plate -

• Left: 9mm
• Bottom: 24mm
• Right: 8mm

Test Mass -

• Left: 14mm
• Bottom: 22.5mm
• Right: 16mm

ITMX

Compensation Plate -

• Left: 8.5mm
• Bottom: 20.5mm
• Right: 8mm

Test Mass -

• Left: 13mm
• Bottom: 20mm
• Right: 16mm

See attached photots for Anamaria's sketches of nominal positions and how they relate to the baffles.

Jennie W

Summary: JAC WFS A and B readout has been phased.

I used Sheila's tremplate for the IMC WFS phasing (see Daniel's alog #89457 here when the IMC WFS was rephased in March) to make one for JAC WFS phasing. Since the length control is all done through CDS and does not use a common mode board the actuation channel to use is H1:JAC-L_SERVO_EXC.

The template is saved in userapps/h1/ioo/templates/dtt/JAC_wfs_phase.xml

New values were saved in the h1ascimc safe.snap.

Here is a photo of the WFS 'Settings' screens with the value to change highlighted in red and the Q and I error points highlighted in green. When running the template a line is injected into the JAC lenght control loop at 8 Hz. To phase the readout of the WFS segments, change the red-highlighted phases to minimise the line you inject in the Q error point channels, H1:JAC-WFS_{A,B}_{Q1,Q2,Q3,Q4)_ERR_DQ

Last Friday, HAM7 was vented and the mega cleanroom was on, but chamber doors were on, FC1 sliders were at 100 urad P, -162 urad Yaw, and the M3 witness sensors were -90 urad pitch, -15 urad.  Since then, there was a power outage, the chamber doors are off and the purge air is on, and tha DAC has been changed as it was not working 90454.  Now, with the same slider settings (100 urad P, -162 yaw), M3 withness sensors are at 24 urad pitch, -204 urad yaw.  

In 89751, Oli noted that turning on the purge air caused a shift of -29urad in the bottom mass osems.  If purge air were the only difference between now and Friday, we would expect M3 witness osems to say -120 urad, if the purge air is similar to what it was in December.  So, it seems like the electronics change has changed the realtionship between the slider value and the witness sensor.  

On May 7th, we moved the pitch alignment slider by 140 urad, and the M3 witness only saw a move of 10 urad.  Today, when we move the slider by 262 urad, the M3 witness osems see a shift of 317urad, so the suspension is actuating now, but seems not to have been in May.  

As part of WP 13284, the unused 8" gate valve on the X-beam manifold section was removed and the port was blanked off.  We will need to remember to leak check this flange during pumpdown.

WP13772 TW0 Offload

Dave:

I have finally completed the TW0 offload which I started way back at 08:54 Saturday 30th May. It was interrupted soon after at 09:30 Saturday with the first of two power outages. It was restated 07:00 Monday 1st June and completed the file copy at 22:17 Monday night. 

NDS0 was restarted Tuesday morning to serve from the archive area, but sush7 and other issues delayed the file deletion from TW0 till Wednesday.

This morning I deleted the old files from TW0 between 07:40 - 10:05. SSD-RAID usage on TW0 went from 94% to 3%, ready for the next 6 months of trends.

Camilla, Betsy, TJ, Fil, Ryan C, Richard, Erik, Dave

We had a very strange problem with the first 20bit-DAC in h1sush7, which h1susfc1 uses for its six M1 drives (T1, T2, T3, LF, RT, SD). Even though h1iopsush7 reported that DAC0 was driving correctly, there was no voltages being produced by the AI chassis.

We are in the early stages of figuring out what was wrong and how it got fixed. Due to HAM7 in-chamber urgency, once it started working we handed h1sush7 over the the HAM7 team.

Summary of what we did is:

tried various power cycles of IO Chassis and AI Chassis, no change. Put DVM onto DAC cable at rear of AI Chassis, looking at CH0 initially. No voltage. IOP correctly detected loss of AI.

With IO Chassis powered up, but computer down, Fil saw 3.5V on CH0, which went to 0V as soon as the computer was powered up. We are not sure this is normal behaviour, but we saw it on two different 20bit-DAC cards. 

Next we replaced the 20bit-DAC, no change. Old (removed) 210303-09 New (installed) 210303-14.

Erik reminded us that since this is the first DAC in the IO Chassis, we can test CH7 with the DUOTONE loop back (IOP feeds ADC0-CH31 directly into DAC0-7, switches relays on Interface cards which routes DAC0-7 into ADC0-30). We turned this on, ADC0-30 saw the DT. 

Next we replaced the DAC's ribbon cable and interface card. This make things worse, no CH0 signal and now no Duotone. Interface old (removed) S1101353, new (installed) S1000868.

Thinking that ribbon cables are more likely to fail than IF cards, we went back to the original IF card S1101353, installed another ribbon cable, and shuffled DAC0 over to the second Adnaco backplane. THIS FIXED IT.

Several changes were made here, so we are not sure if it was the slot move or the ribbon cable or both.

Here is the original card layout (not shown A4-1 = BIO0)

and here is the one we ended up with (ADCs shuffled one left in A2, 20DAC0 moved to A2-1)

We tested the first 6 channels (CH0-CH5) using h1susfc1 by untripping the watchdogs and driving the DAC with a FM offset of 10000, resulting in a 20bit-DAC drive of ~40000 counts, which gives 0.7V DAC output. CH7 was tested with the Duotone.

I was reminded that on the 1st December 2025 the h1iscex 18bit-DAC to 20bit-DAC upgrade failed with no drive on the new DAC. That was also the first DAC, and at the time we tested the DUOTONE signal (in fact DAC-DT is always on for CAL). In that DAC all the channels were not operational, and replacing the DAC fixed it immediately. So it looks like today's problem is different, and a much more insideous one because internally everything looks nominal but no voltage is actually sent by the DAC.