Follow up from Tuesday maintenance: Daniel upgraded the Beckhoff slow controls software to no longer error on a version mismatch for the new timing cards installed in h1susex and h1omc0 (for new LIGO DAC and variable Duo-Tone frequency respectively).

I have changed the CDS HW stat code to no longer check that the EX timing error was solely due to the version mismatch. I also reverted the SYS_TC3_TIMING.adl file, removing the temporary blurb I had put in there explaining the expected EX error.

I took the opportunity to upgrade the timing entry on the CDS Overview to a system block. This will turn RED if there are any timing errors, or MAGENTA is the timing system freezes. Clicking on it opens the timing overview, please see attached.

Fri Dec 13 10:10:07 2024 INFO: Fill completed in 10min 3secs

Jordan confirmed a good fill curbside.

The mystery glitching this team has been thoroughly investigating was present again for ~30 minutes starting at approximately 6 UTC on Dec 13, as seen in this range time series.  HVeto runs over this time period highlight H1:SQZ-FC_LSC_DOF2_OUT_DQ as the most correlated channel (same as in 81587), this time with a significance of 200 (a significance of > 10 is of interest). After checking omega scans of example glitching in the strain data, there is clear glitching present again in this squeezer channel. Similar to previous occurrences of this noise, it promptly appeared and then disappeared. 

Laser Status:
    NPRO output power is 1.832W
    AMP1 output power is 70.23W
    AMP2 output power is 137.1W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 2 days, 16 hr 5 minutes
    Reflected power = 23.33W
    Transmitted power = 106.0W
    PowerSum = 129.4W

FSS:
    It has been locked for 0 days 5 hr and 21 min
    TPD[V] = 0.7857V

ISS:
    The diffracted power is around 2.8%
    Last saturation event was 0 days 5 hours and 21 minutes ago
Possible Issues:
        PMC reflected power is high

TITLE: 12/13 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 35Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 2mph Gusts, 0mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.73 μm/s
QUICK SUMMARY:

Wet drive in with H1 locked over 3.75hrs after Oli had a wake-up call for SDF diffs overnight.  H1 range is hovering around 150Mpc.  Over the last 24hrs, µseism has creeped up from ~95th percentile to above it.  Currently have had INVALID dust alarms for Vacuum Prep Lab.  There was a YELLOW SDF Diff for the CDS DIFF box on the CDS Overview, but it greened up as I was typing about it.

Was called by H1 Manager, we were at NLN but there were some SDF diffs that needed to get accepted to go in to Observing. They're related to the SRCL changes done yesterday, so I acepted them and we went into Observing.

TITLE: 12/13 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: Very quiet shift with H1 locked and observing for the entirety; current lock stretch is up to 24.5 hours. Secondary microseism is on the rise.

TITLE: 12/13 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: We stayed locked the whole shift, 19hours. PRM camera is blue, 2ndary microseism seems to have flatlined, its likely from storms both off the coast and near Greenland as the arms see similar phase differences from the CS. Low frequency noise seems intermittently elevated based on DARM and SQZ dtts.
LOG:                                                  

• 16:30 UTC dropped Observing to start the calibration sweep
  • 17:00 UTC Commissioning started
  • 20:05 UTC back to Observing
• 20:19 - 20:21 UTC TCS_ITMY_CO2 laser lost lock and relocked itself at ~5% lower power based on the LSRPWR_MRT and 0.05W on the LSRPWR_HD_PD

TITLE: 12/12 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 8mph Gusts, 5mph 3min avg
    Primary µseism: 0.04 μm/s
    Secondary µseism: 0.48 μm/s
QUICK SUMMARY: H1 has been locked for 18.5 hours.

• Wind is low, microseism has been elevated today
• Vac prep lab dust monitor is still reporting as disconnected even after Ryan C.'s power cycle

[Robert, Jenne]

We've updated the Jitter cleaning coeffs.  Robert had noticed that the last few weeks we've really had some jitter peaks in the ~100-200 Hz range (additional to our normal jitter peaks), so we looked at retraing the jitter cleaning.

In the first attachment the bottom panel is the subtraction before the update.  The top panel is after the update.  You can see that indeed the red in the upper panel does a better job of subtracting than the lower panel for most of the range.  There may be a little tiny bit of extra noise at a low level below ~70 Hz that most searches will not notice, but the long-duration searches (eg stochastic) may see it.  However, Robert and I agree that the major benefit makes this an overall win, so I have accepted the new jitter coefficients in both the safe and observe.snap files.

The second screenshot is of the range, where the time cursor shows when the new jitter cleaning started.  Since we were squishing this in at the end of commissioning, it's a little hard to see here the range improvement, but I put it in anyway just so it's a little more clear when exactly the 'reset' button in the bottom row was pushed to reset the cleaning coefficients.

Sheila, Camilla. Repeat of 78776, continuing 81575.

During the emergency July/August OFI vent, we accidentally left off the SRCL ASC offsets and the OM2 heater. Today we tried to find best SRCL1 ASC offsets with OM2 heater off. We could improve CAL FCC (but kappaC decreased) with SRC1 ASC YAW offset (-0.62) and adjusted SRCL LSC offset (-140) with SQZ FIS data. This decreased the range so we reverted settings back to nominal. May continue next week and look at FC de-tuning, OMC ASC offsets and LSC FFs as these may need to be updated too. 

We repeated the setup in 81575, turned off SRCL LSC offset, opened the POP beam divertor, turned off SRCL1 ASC loops and then moved SRM in pitch and Yaw (0.1urad steps in groups of 5urad). Saw no change in pitch but an offset in yaw improved the FCC (but decreased KappaC). Could see ASC-OMC_NSUM's changing so we may need to update OMC offsets too. could see RF18 increase. FCC (couple cavity pole) increased 4.5Hz. Plots here and here.

Added a -0.62 offset into SRC1 (need to put into ISC_LOCK / sdf / lscparms). Then turned back on SRC1 ASC (ramp time 0.1s turned on offset and on button at same time).

Repeated SQZ FIS vs SRCL de-tuning dataset from 80318, this gave us the SRCL offset of -140 to use:

• 18:12:30 - 18:21:00 UTC: No Squeezing ref0
• 18:29:30 - 18:33:00 FIS 0 deg SRCL offset (phase 133deg) ref1
• 18:36:00 -18:38:30 FIS -90 deg SRCL offset (phase 156deg) ref2
• 18:41:30 - 18:44:00 FIS -190 deg SRCL offset (phase deg186) ref3
• 18:52:15 -  18:54:30 FIS -290 deg SRCL offset (phase deg205) ref4
• 18:57:00 - 19:00:00 FIS -390 deg SRCL offset (phase deg219) ref5

Outputs from Sheila's 80318 code attached: DARM spectra, fitted SRCL de-tuning to model, offset fit that gave us -140. 

Once we reverted the changes, you can see here that the: range increased 5MPc, FCC decreased 4.4Hz, kappaC increased 0.8%, RF18 decreased, RF90 increased.

Commissioning wrapped up and we resumed observing at 20:05 UTC, we've been locked for 14:40.

A comprehensive method to periodically check suspension anomalies in various OSEMs

spectrums.py - is a collection of functions that can be used to study fluctuations of various OSEM suspensions over time.

git link: https://git.ligo.org/hanford_osem/hanford_OSEM/-/blob/main/spectrums.py?ref_type=heads

How to use it:

We can git pull from the link above. In any LIGO cluster terminal or Jupyter we can use igwn-py kernel and import just the following dependency:

from spectrums Import *

# define a time segment object:
time_seg = time_segment()

In the prompt this will ask to enter a ref_time (reference time), this would be gps time when OSEMs were known to have no anomalies. Once pressed enter, it will ask for check_time, this would be another gps time which is being checked against ref_time. Finally it will ask to enter duration. For a long duration this might take a long time to execute. Keeping duration =180 (in seconds) is a reasonable choice.
This will create a time segment object as a dictionary.

Now, we can either check the OSEM fluctuations directly by running the following command:

host = 'nds.ligo-wa.caltech.edu'
osem_fluctuations(time_segments = time_seg, host=host)

This will show us available OSEMs and we can enter at least one or a list of OSEMs that we wish to investigate. It may take a few minutes to get all the plots. Checking individual OSEMs might be time consuming, a quick alternative is to check their BLRM values first:

check_blrms(time_segments = time_seg, 
            host=host, 
            fs = 256, 
            lowcut = 15, 
            highcut = 20,
            threshold = None)

Runing this function allows us to enter either one or a list of OSEMs like before to have their BLRM values printed. We can apply a threshold of choice to see which OSEM(s) look problematic. Then only check plots of those OSEMs in osem_fluctuations() function.

Today we ran a correlated noise measurement for 1 hour starting at 1416594379, meaning that the detector was locked, thermalized, and with no squeezing engaged for this period of time. We left calibration lines on during the measurement. The measurement was preceeded by a calibration measurement as well, see alog 81461.

During the measurement I ran a script that I edited from Sander Vermeulen that collects the full 524kHz OMC DCPD channels (H1:OMC-DCPD_{A,B}0_IN1) (see Jeff Kissel's comment in alog 69398 which gives a good description of how these channels are created). The data from these two channels was saved in in hdf5 files as 1 second frames. Those files can be found in /ligo/home/elenna.capote/OMC_DCPD/242511-102557/, and on the DCC at this file card: T2400394.

Sheila noted one large glitch at UTC 18:35, so this data may need to be gated around that time.

Edit: the resulting zip file is 9GB so the DCC cannot host it. I am thinking of other ways to share this data with others....

Editedit: added box link to DCC for data access.

This morning there was a range drop on H1 (163Mpc down to about 151Mpc, see attachment#1).  Was working on trying to figure out how to run the Range Check measurements, but while chatting with Vicky on Teamspeak, she reminded me about the daily CP1 Fill can affect range (see attachment #2 which is plot from Dave's alog)  ....and the effect certainly lines up! (Also see Oli's alog from Sept here.)  The time in question is 1802-1812utc (1002-1012amPT).  I will not share the Low-Range-Plots I took for 1810utc since CP1 Fill is most likely the culprit.

However, a note about the range is that it has not really returned to 163Mpc---it's hovered at 157Mpc post-CP1-Fill for the last 4+hrs.

So I ran another Low Range DTT for about an hour ago (2117utc/1317PT).

• ASC:  Can see noisier CHARD_Y & CHARD_P (attachment #3)
• LSC:  MICH, PRCL, & SRCL are noisier at various frequencies (attachment #4)
• IMC WFS:  There are some noisy IMC WFS B pit & yaw peaks (attachment #5)

Ansel reported that a peak in DARM that interfered with the sensitivity of the Crab pulsar followed a similar time frequency path as a peak in the beam splitter microphone signal. I found that this was also the case on a shorter time scale and took advantage of the long down times last weekend to use  a movable microphone to find the source of the peak. Microphone signals don’t usually show coherence with DARM even when they are causing noise, probably because the coherence length of the sound is smaller than the spacing between the coupling sites and the microphones, hence the importance of precise time-frequency paths.

Figure 1 shows DARM and the problematic peak in microphone signals. The second page of Figure 1 shows the portable microphone signal at a location by the staging building and a location near the TCS chillers. I used accelerometers to confirm the microphone identification of the TCS chillers, and to distinguish between the two chillers (Figure 2).

I was surprised that the acoustic signal was so strong that I could see it at the staging building - when I found the signal outside, I assumed it was coming from some external HVAC component and spent quite a bit of time searching outside. I think that this may be because the suspended mezzanine (see photos on second page of Figure 2) acts as a sort of soundboard, helping couple the chiller vibrations to the air. 

Any direct vibrational coupling can be solved by vibrationally isolating the chillers. This may even help with acoustic coupling if the soundboard theory is correct. We might try this first. However, the safest solution is to either try to change the load to move the peaks to a different frequency, or put the chillers on vibration isolation in the hallway of the cinder-block HVAC housing so that the stiff room blocks the low-frequency sound. 

Reducing the coupling is another mitigation route. Vibrational coupling has apparently increased, so I think we should check jitter coupling at the DCPDs in case recent damage has made them more sensitive to beam spot position.

For next generation detectors, it might be a good idea to make the mechanical room of cinder blocks or equivalent to reduce acoustic coupling of the low frequency sources.