[Rahul, Keita, Betsy, Koji]

Preparation work to extract the existing OMC has been completed. We will continue with the OMC extraction tomorrow morning.
The overall work procedure for the OMC replacement is summarized in G231106 https://dcc.ligo.org/LIGO-G231106.

= OMC shroud panel removal =

While waiting for the beam from the squeezer to come, we started the removal of the OMC shroud panel in parallel. The work was done along with the procedure E1600164.
The removed panels were placed on a stainless steel table in the HEPA booth of HAM6 (Attachment 1). The panels were not covered to prevent accidental placement of objects on them.

During the work, a beam dump was removed from the table to make the removal work possible. This beam dump is to kill one of the weak transmissions of the OMC.
Betsy took the photo record of the location, but it is safely trivial how it should be aligned.

= SQZ beam marking and alignment =

The beam was delivered to HAM6 and was pinned down with two irises on the ISI table.
The irises were placed just after the beam entered HAM6 (next to OM2) and just before OM1 (next to the fast shutter).
This means that these indicators are not affected by the alignment in HAM6.
They were placed by eyeballing, so their precision was as such. By default, both the irises were set to the maximum opening.

Next, the beam alignment was servoed towards the WFS heads using the DC centering ASC loops.
As soon as the control was applied, both QPDA and QPDB of OMC showed significant signals with total light level of ~1e-3 (Attachment 2).
When the light was blocked (at the squeezer?), the value dropped to almost zero, confirming that this was a real beam.
This is very good news as we'll be able to find the beam arrival using the OMC QPDs when we try to align the new OMC.

= Holding suspension mass =

Next, we proceeded to hold the suspension masses. Rahul and Koji worked in the chamber on the ISI table for the following operations.

To hold the intermediate mass:

• First, the top blade was fixed with stopper screws.
• Next, we tried to fix the middle mass with two 1/4-20 nuts, but this caused some wobbling of the suspension. So, we first decided to fix the middle mass with smaller side EQ-stops. This process has not been described in E1600164. (to be updated)
• Once the middle mass was fixed horizontally, the vertical dof was also fixed firmly with the small EQ-stops and the 1/4-20 hex nuts.

Then, moved onto fixing the OMC:

• The bottom EQ stop for the OMC was left as they could not touch the OMC. The side (long side) EQ stops were extended and are holding the OMC horizontally.
• The Top EQ stops for the OMC were removed by removing the L-shaped brackets on both sides.

= Removing the electronic cables from the OMC =

Upon removing the electronics cables, one person held the cable harness on the OMC breadboard to prevent the OMC from wobbling too much.
The removed cables were wrapped around the top part of the suspension frame to keep them out of the way of the further work.

At this point, it was just at 5pm, so we exited from the chamber.

Next Steps:

• Extraction of the OMC
• Migration of the balance masses to the new OMC
• Final cleaning of the new OMC
• New OMC installation

TITLE: 01/22 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC (covering for the latter half of the shift)
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM7 irises are in place, OMC work in HAM6 is ongoing.
LOG:                                                                                                     

WP 11635
WP 11637

The following high voltage power supplies were powered on this morning:

1. HAM7 - PZT and P-Sams
2. HAM6 - PZT and Fast Shutter

The pressure interlock system bypassed.

Camera 20 failed and was restarted.  The server runs on h1digivideo1, but was not being monitored by monit.  That's been corrected.

The Calibration group has been working hard to produce and release the LHO uncertainty budget for the first half of O4a. The case at LHO has proven to be significantly more involved than LLO's for a variety of reasons. 


LHO started the run at a much higher power, which led to a much more severe "thermalization" effect for the first hours of each lock stretch
the IFO was quite unstable at 76W, which meant that we had more locklosses & therefore spent more time "thermalizing"
the power was lowered to 60W in late June
there were signifcant periods during which we could not trust the online TDCFs
 


There are probably a few more reasons that I'm not recalling right now. The most challenge has been dealing with the thermalization periods as they contribute the most to our uncertainty at low frequencies. Moreover, the thermalization effect is very different between the time periods at which the IFO was operating at 76W compared to when it was operating at 60W.

As part of uncertainty generation we processed the high frequency roaming Pcal lines to measure the sensing function and inform the uncertainty budget from 1-5 kHz. More on the implementation details of this process will be shared in another alog and linked here as a comment. One detail worth noting here has to do with the fact that for O4 we're using a new report-based calibration infrastructure based on pyDARM. Each time a new set of calibration measurements are taken, the data gets processed (by either a member of the Calibration team or an LHO operator) using the pyDARM tools. The data processing step produces a report PDF file and a multitude of by-product intermediate data files. These files and the PDF are all collectively called a "report."

In December, I provided Lilli with a set of re-generated reports that included the newly processed high frequency roaming line data at LHO. This is similar to the work-flow the Calibration group employed for LLO earlier in the run. She then calculated uncertainty budgets for the first half of O4a, ending on October 1, 2023. However, all uncertainty envelopes before GPS 1371427218 were clearly wrong. As an example, the last "bad" GPS time is 1371394818 (calibration_uncertainty_H1_1371394818.png) and the first "good" GPS time is 1371427218 (calibration_uncertainty_H1_1371427218.png). 

As an additional check, Lilli used the systematic error monitoring lines to compare them against and overlay them over the uncertainty budget. The uncertainty checks can be found at: https://ldas-jobs.ligo-wa.caltech.edu/~ling.sun/lho_unc_v0.5/monitoring/. Looking specifically at the checks corresponding to the "last bad" and "first good" GPS times, we can see that at GPS 1371394818 (uncertainty_consistency_check_H1_13713948180_13713984180_GDS-CALIB_STRAIN.png), the envelope disagrees with the data taken directly using the systematic error lines. Meanwhile, the same check at GPS 1371427218 (uncertainty_consistency_check_H1_13714272180_13714308180_GDS-CALIB_STRAIN.png) does match the direct measurement much more closely. This indicates that 1.) the uncertainty envelope during the "bad" times is likely wrong (good news) and 2.) that there is probably a bug in how the data that is passed to the uncertainty envelope generation is processed (i.e. a bug or bad parameter in the report generation at LHO).

Over the past few weeks, I've been trying to find this bug. I first ruled out mismatches between the front end settings (filter files, FM slots, gains, etc.) between the CAL-CS copy of the DARM loop, the actual DARM loop, and the pyDARM parameter files that are meant to mirror the (actual) DARM loop (except, of course, for the 3.2kHz pole that we already knew was missing from CAL-CS at the time).

It turns out that our suspicion that there was a problem in the report generation was correct. This bug caused every report's pyDARM_H1.ini file to be populated with wrong MCMC-fitted parameters for both the sensing and actuation functions from the start of O4a until roughly June 22, 2023. There are four places that the pyDARM report system records fitted MCMC values: the PDF report, an MCMC JSON file dump, an MCMC HDF5 file dump (that includes the entire MCMC chain), and the pyDARM parameter file that has been populated with the new parameters. I was able to identify the issue by comparing these four different data products against each other to check for self-consistency. In the affected period, they all matched except for the pydarm_H1.ini files. The tools I wrote for this is attached as check_ini_vs_chain.py and its output is attached as out.txt. The output compares the fitted sensing and actuation parameters for all reports marked valid so far in O4a.

Fixing this bug for report 20230620T234012Z and regenerating the uncertainty envelope and the consistency check with the systematic error lines at GPS 1371394818 resolves the discrepancy. See uncertainty_consistency_check_H1_1371391218_1371394818_GDS-CALIB_STRAIN.png.

TITLE: 01/22 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:

Big Tasks Of The Day:  (1) HAM7 doors taken off, (2) HAM7 work begins, & (3) Laser Hazard in LVEA / EX is back to SAFE
LOG:

• Alarm Handler:
  • 1643 Zone 2A temperature
• 1520 Furniture moving work (randy)
• 1617-1956 Technical cleaning around HAM7 (LVEA) (karen & kim)
• 1632-1933 HAM7 doors morning (jordan, gerardo)
  • 1632jordan, 1652gerardo, 
  • HAM7 ISI tripped
• 1638 FARO system surveying (jason, ryanC)
• 1646 Cable search around CER & HAM6 for HAM7 alignment later (fil)
• 1652 Turning down purge air on output arm (gerardo)
• 1655 Prep & tool search in optics lab (camilla)
• 1700-1858 HAM6 SUS TFs (rahul)
• 1706-1715 LVEA & FARO team checks (tyler)
• 1721 Sealing up PCal & transitioning EX to laser SAFE (tony)
  • 1755 EX laser SAFE!
• 1735 SEI_ENV node work (tj)
• 1738-1741 Dropping off Contamination Control kit at HAM6/7 (mitch)
• 1754-1801 West Bay trip to grab tools for EX (mitch)
• 1759 Betsy beginning her in/out of LVEA for vent activities
  • 1759 Taking Eric O to check out H7 door work.
• 1801-1843 Dropping off EX kits for EX flange baffle work later (mitch)
• 1805 Ramped down the PZTs (or was it a P-SAMS thing?) to zero in prep for High Voltage being turned ON (sheila)
• 1825 Incoming 7.0EQ from Kyrgyzstan area.
• 1840 Locking HAM7 ISI (jim)
• 1847 High voltage (pzt/P-SAMS) turned ON (fil)
• HAM6 SQZ work
  • 1856 Prep/staging for HAM6 OMC work (koji)
  • 1935 Prep/staging for HAM6 OMC (rahul)
• HAM7 SQZ work
  • 1943 Moving ZMs around (austin)
  • HAM7 team beginning in-chamber work (sheila, julian, naoki, vicky, camilla)
  • Tried to find a Humidity sensor for in-chamber work....found some in Richard's office, Betsy grabbed them, and Betsy running a RH sensor out to the HAM7 team.
• 1906 Quick visit in the PCal lab (tony)
• 1932 Prep for Transitioning LVEA to Laser SAFE!!! (Camilla)
• 2057 Running equipment down for Wind Fence at EY (randy)
• (Handed off my shift to TJ at 1pm PST)

When looking over flows and temperatures at the LVEA, I noticed that the supply of AHU 2 was low and Supply Fan 4 was manually disabled. The most likely cause of this is from our quarterly lubrication which took place last week and the fan most likely never got brought back up. I physically visited the fan to verify it was all-clear and brought it back into service.

T. Guidry

Ibrahim, TJ, Camilla, Naoki,

Looking at how the ZM4,5,6 alignment has shifted both with the vent and recent temperature changes in the LVEA.

Attached is ZM4/5 P/Y alignment since the last time we were SQZing to vented now,  there is large changes of ZM5 (470urad in Pit and 230urad in Yaw). Alignment sliders haven't changed but SQZ ASC would have been changing some alignment when the IFO was locked.

ZM6 has large changes (1300urad in Pit and 280urad in Yaw). Currently DAMPED but alignment sliders are the same. Edit: DAMPED turns off the alignment sliders, once Austin brought back to ALIGNED it had moved <100urad.

We expect some changes from bouyancy of air. The HAM7 SUS are currently  "aligned" with the doors being taken off HAM7. Jim hasn't locked the ISI yet. Looking at ZM4,5,6 alignment, last vent, IFO locked, and now.

Ibrahim is looking at temperatures and alignment since our last vent.

Mon Jan 22 10:04:41 2024 INFO: Fill completed in 4min 37secs

In order to further test out the environment automation for the SEI_ENV node, I've removed all state requests of its subborndinate nodes to allow this node to make it's transitions without actually doing anything. In other words, SEI_ENV will change state, but nothing will actually be changing outside of this node. We will run it like this for the duration of the break.

If there are model restarts for any of the ISI models, it would be a good idea to re-request the SEI_CONF state of SC_OFF_NOBRSXY to verify that we are still in the correct sensor correction state.

FAMIS 20012

Temperatures all around have been less than stable recently, but that's not terribly surprising with ongoing vent activities.

The FSS TPD signal has plummeted in the past 10 days; we may need to touch up the FSS path on-table to fully fix this, but we'll likely wait towards the end of the commissioning break.

TITLE: 01/22 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: 6mph Gusts, 4mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.24 μm/s
QUICK SUMMARY:

After site closure due to weather Fri, today the site is OPEN and road conditions were much less treacherous.  There was No 8am Coordination Meeting (items were discussed last week).

Alarm Handler audible Alarms this morning: 

• FMCS Temperature for zones 3A & 3B.
• PEM's PSL Dust Monitor 102

Not that it matters for O4Break, Microseism has taken a big drop DOWN from 0.5um/s to  0.2um/s.

Attached below are the snapshots of the transfer function measurements I took yesterday before we kick start the in-chamber work next week. The suspensions look healthy and is currently in air.

The templates are stored at the following location,

OPO

/ligo/svncommon/SusSVN/sus/trunk/OPOS/H1/OPO/SAGM1/Data

2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_L_0p02to50Hz.xml
2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_P_0p02to50Hz.xml
2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_R_0p02to50Hz.xml
2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_T_0p02to50Hz.xml
2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_V_0p02to50Hz.xml
2024-01-20_2350_H1SUSOPO_M1_WhiteNoise_Y_0p02to50Hz.xml

ZM5

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM5/SAGM1/Data

2024-01-20_2340_H1SUSZM5_M1_WhiteNoise_L_0p01to50Hz.xml
2024-01-20_2340_H1SUSZM5_M1_WhiteNoise_P_0p01to50Hz.xml
2024-01-20_2340_H1SUSZM5_M1_WhiteNoise_Y_0p01to50Hz.xml

ZM4

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM4/SAGM1/Data

2024-01-20_2330_H1SUSZM4_M1_WhiteNoise_L_0p01to50Hz.xml
2024-01-20_2330_H1SUSZM4_M1_WhiteNoise_P_0p01to50Hz.xml
2024-01-20_2330_H1SUSZM4_M1_WhiteNoise_Y_0p01to50Hz.xml

ZM3

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM3/SAGM1/Data

2024-01-20_2320_H1SUSZM3_M1_WhiteNoise_L_0p01to50Hz.xml
2024-01-20_2320_H1SUSZM3_M1_WhiteNoise_P_0p01to50Hz.xml
2024-01-20_2320_H1SUSZM3_M1_WhiteNoise_Y_0p01to50Hz.xml

ZM2

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM2/SAGM1/Data

2024-01-20_2320_H1SUSZM2_M1_WhiteNoise_L_0p01to50Hz.xml
2024-01-20_2320_H1SUSZM2_M1_WhiteNoise_P_0p01to50Hz.xml
2024-01-20_2320_H1SUSZM2_M1_WhiteNoise_Y_0p01to50Hz.xml

ZM1

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM1/SAGM1/Data

2024-01-20_2310_H1SUSZM1_M1_WhiteNoise_L_0p02to50Hz.xml
2024-01-20_2310_H1SUSZM1_M1_WhiteNoise_P_0p02to50Hz.xml
2024-01-20_2310_H1SUSZM1_M1_WhiteNoise_Y_0p02to50Hz.xml

HSTS (FC1)

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/FC1/SAGM1/Data

2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_L_0p02to50Hz.xml
2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_P_0p02to50Hz.xml
2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_R_0p02to50Hz.xml
2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_T_0p02to50Hz.xml
2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_V_0p02to50Hz.xml
2024-01-20_2300_H1SUSFC1_M1_WhiteNoise_Y_0p02to50Hz.xml

The suspensions were set to ALIGNED state after the measurements were complete.

Sun Jan 21 10:05:17 2024 INFO: Fill completed in 5min 13secs

A sputtery fill, TC temps were noisy. Standard and zoomed in trends attached.

Procedure M1300464

The following high voltage power supplies/electronics were powered off in preparation for the corner vent.

1. CER Mezzanine - ESD HV
2. CER Mezzanine - Fast Shutter
3. CER Mezzanine - OMC PZT
4. CER - SR3 and ITM heaters
5. LVEA - Fast Shutter Driver Chassis - Disabled and powered off
6. MER Mezzanine - HAM7 PSAMS
7. MER Mezzanine - HAM7 Piezo