TITLE: 08/19 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 16mph Gusts, 12mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.15 μm/s 
QUICK SUMMARY:

- H1 is still locked - going on 16 hours

- All systems stable, DMs read out ok, SEI motion low

TITLE: 08/18 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: H1 has been at locked for almost 8 hours. Quiet shift after H1 locked except for one brief drop out of observing.

• 23:12 Reached NLN
• 23:29 Started observing (17 minutes for camera servos, seems a bit long)
• 04:31 Dropped observing from SQZ issue
  • From SQZ_SHG guardian: "PZT voltage limits exceeded."
  • All guardians were brought back to their nominal states automatically within 3 minutes
  • Automation seems to have worked just fine, but tagging SQZ just in case
• 04:34 Resumed observing

LOG:

No log for this shift.

State of H1: Observing at 153Mpc

H1 has been locked and observing for almost 4 hours. Range has increased to above 150Mpc in the past hour, possibly from the wind dying down?

Genevieve, Lance, Robert

To further understand the roughly 10Mpc lost to the HVAC (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=72308), we made several focussed shutdowns today. These manipulations were made during observing (with times recorded) because such HVAC changes happen automatically during observing and also, we were reducing noise rather than increasing it. The times of these manipulations are given below.

One early outcome is that the peak at 52 Hz in DARM is produced by the chilled water pump at EX (see figure). We went out and looked to see if the vibration isolation was shorted, it was not, though there are design flaws (the water pipes arent isolated). We switched from CHWP-2 to CHWP-1 to see if the particular pump was extra noisy. CHWP-1 produced a similar peak in DARM at its own frequency. The peak in accelerometers is also similar in amplitude to the one from the water pump at EY. One possibility is that the coupling at EX is greater because of the undamped cryobaffle at EX.

Friday HVAC shutdowns; all times Aug. 18 UTC

15:26 CS SF1, 2, 3, 4 off

15:30:30 CS SF5 and 6 off

15:36 CS SF5 and 6 on

15:40 CS SF1, 2, 3, 4 back on

16:02 EY AH2 (only fan on) shut down

16:10 EY AH2 on

16:20 EY AH2 off

16:28 EY AH2 on

16:45 EY AH2 and chiller off

16:56:30 EY AH2 and chiller on

17:19:30 EX chiller only off, pump stays on

17:27 EXwater pump CHWP-2 goes off

17:32: EX CHWP-2 back on chiller back on right after

19:34:38 EX chiller off, CHWP-2 pump stays on for a while

19:45 EX chiller back on

20:20 EX started switch from chiller 2 to chiller 1 - slow going

21:00 EX Finally switched

21:03 EX Switched back to original, chiller 1 to chiller 2

FAMIS 25595, last checked in alog 72166

The levels for both EX FAN1 vibrometers increased slightly just over a day ago, but still well within range.

All other fans look very similar to last check and within acceptable ranges.

TITLE: 08/18 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Austin
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 19mph Gusts, 13mph 5min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.18 μm/s
QUICK SUMMARY: H1 is relocking, currently at MAX_POWER

• CDS, SEI, SUS, dust all okay. Winds and microseism are moderately high

TITLE: 08/18 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

- EX saturation @ 16:47

- Lockloss @ 17:36 - cause unknown

- Locking was automated, acquired NLN @ 18:41, OBSERVE @ 18:57

- Lockloss @ 18:57 - cause uknown, though microseism is a bit elevated - scope attached

- H1 MANAGER began an IA which went smoothly, but are now having some issue with the IMC randomly unlocking at different states of ISC LOCK

• Attaching witness sensors for MC1/2/3 and PZT values over the course of the past day - 1 / 2, both seem to look ok
• Possibly high useism could be causing the issue? 3rd locking attempt seems to be going well

- Leaving H1 to Ryan S. relocking at MOVE SPOTS

LOG:                                                                                                                                                                                                                                                                                                                                                                                                               

I added another L4C under HAM1 for the feedforward test I've been running there. We were locking, so I was trying to minimize the time under the chamber and didn't get a picture in situ, but the attached picture shows the cradle that Tyler 3d-printed for me. This is tucked next to the -x/-y, southeast pier of HAM1. I will probably try to put a cover over this next week, but for now it's just sitting under the chamber, aligned roughly along the IFO X arm. I haven't had a chance to add calibration filters or add alignment values to the HAM1 model, so the only channel for the data so far is the input 3DL4CINF_B_X_IN1_DQ channel.

Second image is some data from DTT looking at asds on top, with calibrated HEPI L4C X and HAM2 STS X. No calibration on the 3DL4C, the fact that the microseism isn't visible makes be think the 3d printed isn't stable enough. LLO says they may have some nicer purpose built metal clamps. Coherence is on the bottom, it's kind of low above 10 hz, it would probably help to have another X sensor.

The l4c serial number is L41501.

I tracked how various combs in the strain channel have changed in frequency over time using the autolines-complete.txt files for the daily FSCAN spectra (TSFT 1800s). I found that the 9.474, 9.475, and 9.480Hz combs have been changing in frequency over the course of O4, and have identified some key dates that warrant further investigation. I tracked the combs' frequency-roaming behavior by selecting a tooth which appeared often and was high-frequency. This was n=65 for the 9.474Hz comb, n=70 for the 9.475Hz comb, and n=64 for the 9.480Hz comb. The graphs of frequency over time I generated are available below. 

Observations:
The 9.474Hz comb's n=65 harmonic initially increases in frequency from 05-24 to 06-05, and then sharply drops from 06-22 to 06-24
The 9.475Hz comb's n=70 harmonic initially increases sharply in frequency from 05-26 to 06-05, and then sharply drops from 06-21 to 06-23
The 9.480Hz comb's n=64 harmonic initially increases sharply in frequency from 05-30 to 06-05, and then sharply drops from 06-22 to 06-23

So it seems that all three combs' frequencies begin increasing in very early O4 until 06-05 and then abruptly decrease from 06-21 to 06-24. It's likely that the combs were affected by changes made to the interferometer during these periods -- I believe that the week of 06-21 (Sunday) was when we set the power back down to 60Hz. 

I checked several other combs as well (n=11 of 4.98423, n=13 of 29.96518, n=161 of 1.6611, and n=3 of 11.9044) and none of those have observable changes in frequency (they may still be roaming inside their frequency bins) so this feature seems fairly unique to the 9.4Hz family.

Fri Aug 18 10:06:53 2023 INFO: Fill completed in 6min 49secs

Gerardo confirmed a good fill curbside

Since we have to relock, I've switched the order of items in lownoise length control, so that we will change the main LSC gains first, then turn on the FF.  Hopefully that will address the issue that Daniel hypothesises is our problem, and we won't ring up the 102 Hz line.  If this does not work, do something like an

svn up ISC_LOCK.py

in the userapps/isc/h1/guardian/ folder to reveret to the previous file (which I had checked in just before I made this mod).  I have not checked in ISC_LOCK.py with this modification yet.

Lockloss @ 17:36, no obvious cause.

Closes 25492, last done August 4th.

Laser Status:
    NPRO output power is 1.829W (nominal ~2W)
    AMP1 output power is 67.15W (nominal ~70W)
    AMP2 output power is 135.3W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN

PMC:
    It has been locked 12 days, 1 hr 20 minutes
    Reflected power = 16.16W
    Transmitted power = 108.9W
    PowerSum = 125.1W

FSS:
    It has been locked for 1 days 12 hr and 5 min
    TPD[V] = 0.8903V

ISS:
    The diffracted power is around 2.6%
    Last saturation event was 1 days 14 hours and 9 minutes ago

Possible Issues: None

Attached are trends for 45 days of HEPI pressure signals.  There are no notable shifts.

TITLE: 08/18 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
1:27 UTC PSL Dust monitor alerts going off during high winds again.
3:29UTC random unknown drop out of OBSERVING. I saw no SDF DIFFS within a few seconds of the event and took the IFO back to OBSERVING.
6:42 UTC another random unknown drop out of OBSERVING. I saw no SDF DIFFS within a few seconds of the event and took the IFO back to OBSERVING.
Other than that it' s been a quiet night.

Current LOCK 25 hours!

LOG: Coyotes chewing on sprinkler nossles out back.

Robert did an HVAC off test. Here is a comparison of GDS CALIB STRAIN NOLINES from earlier on in this lock and during the test. I picked both times off the range plot from a time with no glitches.

Improvement from removal of 120 Hz jitter peak, apparent reduction of 52 Hz peak, and broadband noise reduction at low frequency (scatter noise?).

I have attached a second plot showing the low frequency (1-10 Hz) spectrum of OMC DCPD SUM, showing no appreciable change in the low frequency portion of DARM from this test.

Closes WP11368.

We've been seeing the CO2X laser regularly unlocking (alog71594) which takes us out of observing, today we swapped CO2X and CO2Y chillers to see if this issue followed the chiller.  Previously, swapping CO2Y with the spare stopped CO2Y from unlocking, alog54980.

The old CO2X (S/N ...822) chiller seems to be reporting a unsteady flow at the LVEA flow meter, see attached, suggesting the S/N ...822 chiller isn't working too well. This is the chiller TJ and I rebuilt in Febuary 67265. 

Swap. Following some of the procedure listed in alog#61325: turned off both lasers via medm, turned off and unplugged (electrical and water connections) both chillers, swapped the chillers, replugged in, turned chillers back on (one needed to be turned on via medm), checked water level (nothing added), turned on CO2 lasers via medm and chassis. Post-stick notes have been added to the chillers. Both lasers relocked with ~45W power.

• Before Aug-15 16:00UTC
  • TCSX: S/N ...822 (full S/N in 60547)
  • TCSY: S/N ...617 
• After Aug-15 16:00UTC
  • TCSX: S/N ...617 
  • TCSY: S/N ...822

Naoki and I unmonitored  H1:SQZ-FIBR_SERVO_COMGAIN and H1:SQZ-FIBR_SERVO_FASTGAIN from syscssqz observe.snap. They have been regularly  taking us out of observing (72171) by changing when the TTFSS isn't really unlocking, see 71652. If the TTFSS really unlocks there will be other sdf diffs and the sqz guardians will unlock. 

We still plan to investigate this further tomorrow. We can monitor if it keeps happening using the channels.