Daniel, Vicky. We offloaded the TTFSS crystal frequency offsets of ~1.5 GHz to the temperature knobs on the laser controllers again, following the final successful swap to the O1 laser last week lho81426.

The initial to final laser crystal temperature we set on the knobs:

• SQZ 26.07 C --> 25.58 C
• ALS X 26.40 C --> 25.92 C
• ALS Y 30.00 C --> 29.53 C  (finicky broken temperature knob on this laser controller)

Recap of process:

1. Noted the laser temp when TTFSS was running to lock laser to new PSL frequency. This is the "target" temperature we want to offload to knobs.
2. Turned off TTFSS and set crystal frequency to 0 MHz.
3. Note the initial laser temp. Move laser crystal temperature knob to the "target" temperature.
4. Relock TTFSS and check for mode-hopping.

From start (Sept 2024) to end (Nov 2024) of laser swapping saga:

• SQZ:    24.83 C --> 25.58 C
• ALS X: 24.8 C --> 25.92 C
• ALS Y: 28.59 C --> 29.53 C

Recent auxilary laser adjustments:

• 80922: 1st adjustment for O3 NRPO freq
• 81074: 2nd adjustment for O3 NRPO freq (b/c it was mode-hopping)
• 81108: 3rd adjustment for O3 NRPO (after finally tuning laser out of mode-hop zone). ALS Y had to be re-adjusted the next day due to mode-hopping 81117.
• Here: After final NRPO swap to O1 laser.

Bypass will expire:
Tue Nov 26 03:29:36 PM PST 2024
For channel(s):
    H0:FMC-CS_FIRE_PUMP_1
    H0:FMC-CS_FIRE_PUMP_2
 

FAMIS 31061

This week's trends capture how things compare pre- and post-NPRO swap towards the end of last week. Generally things are looking good and have been stable since the swap with probably the most notable change being the drop in PMC transmitted power by ~2W and rise in reflected power by ~5W. We suspect this to be due to slightly worse mode-matching into the PMC, which we plan to check in the coming weeks.

TITLE: 11/26 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 7mph Gusts, 4mph 3min avg
    Primary useism: 0.12 μm/s
    Secondary useism: 0.32 μm/s
QUICK SUMMARY: H1 lost lock this morning at 14:12 UTC due to a M6.1 quake out of Japan and has been down since (meaning magnetic and charge measurements were not run). Moving ISC_LOCK to 'IDLE' and SEI_ENV to 'MAINTENANCE' for maintenance day.

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

TITLE: 11/26 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 04:24 UTC

Overall a pretty calm shift with one Lock Acquisition that required an initial alignment - all fully auto.

Of note:

• Lost lock 02:51 UTC without a clear cause - alog 81479
• While relocking, reloaded PEM_MAG_INJ and SUS_CHARGE guardians per Camilla's request - alog 81474

LOG:

None

Unknown cause Lockloss (confirmed not PSL/IMC). While microseism is high, there weren't any EQs or other PEM events to cause an LL.

The Lockloss analysis tool is giving an OMC DCPD tag

TITLE: 11/25 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

A bit of a busy morning with convoys of concrete trucks arriving onsite (for a pour for the new storage warehouse), discovering a ringing up violin mode, and then getting ready for Monday Morning Commissioning!  

Rahul has new violin settings for ETMy Mode1 and ITMy Mode5 (aka 05 & 06)--see alog81465 .  Operators will need to enter these settings by hand until Rahul accepts them.

Also:  If H1 drops out of Observing, be sure to LOAD the guardians she mentions in alog81474.

H1 is currently at 13.5hrs for this current lock (and that's even after a low fly-by from a chinook helicopter!).
LOG:

• FRS 32746 filed for 2.5hrs of DOWN-time due to Washington earthquake overnight
• 1602 Concrete truck (1st of 5!) let through gate; this is for new warehouse floor pour
  • 1722, 1740, 1805 Arrivals of later trucks I happened to see on the camera
  • 1849 Cement crane truck leaves (last cement truck lefft around 1835)
• 1623-1826 ETMy Mode 1 gain taken from 0.1 to 0.0 (due to violins ringing up)
  • Tony also noted IY Mode5 (took gain to 0)
  • Rahul finished and found new damping settings.
• 1636-1935 Out for COMMISSIONING
  • 1855, 1121 ISC_LOCK re-LOAD-ed (camilla, sheila)
• 1645-1722 Optics lab cleaning (karen)
  • 1737-1824 MY cleaning (karen)
  • 1822-1912 MX cleaning (kim)
• 1637-1711 Calibration run
• 1745 PCal prep in Pcal lab for Maintenance (tony)
• 2039 Received automated Monthly Alerting system phone call. Sirens may be heard at 2100utc (1pmPT)
• 2302-2307 Chinook helicopter hovered fairly low and was clearly loud inside the OSB.  The Chinook flew from over the Y-arm in the direction of the Corner to EY.

TITLE: 11/25 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 157Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.55 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING as of 19:35 UTC (13 hr lock)

Everything seems quiet, especially violins, which have been a recent issue.

Ibrahim, TJ

Beginning after the first NPRO Swap recovery on 10/30, there have been 7 or so instances of SRM M3 tripping during PREP_FOR_SRY in initial alignment, predominantly due to Y saturation. TJ and I are investigating.

So far, we know that SRM sees elevated noise while in PREP_FOR_SRY, particularly after SRM re-alignment. We've also found that AS_C SUM is too low to be considered locked at this state, but that ALIGN_IFO guardian continues with SR initial alignment, leading to the WD trip. The current hypothesis is that SRM is catching onto a wrong mode, but tricking the automation into continuing alignment.

The first screenshot shows the incidence of the WD tripping during initial alignment happening frequently after 10/30. There is one instance of it happening 10/16 but nothing in the near past before that.

The second shows one recent instance of this trip, leading to the WD trip.

I edited the sys/h1/guardian/injparams.py and  sus/h1/guardian/SUS_CHARGE.py code to move the magnetic injections and in-lock charge measurements 20 minutes earlier tomorrow, usual start times are 7:20am and 7:45am. Moved to 7 am and 7:25am, should be over by 7:40am. If we drop out of observing, can an operator please reload PEM_MAG_INJ and SUS_CHARGE guardians.

Aim to turn CO2 laser off  at 7:40am tomorrow, before the lockloss to see if we see similar SQZ alignment changes related to CO2 lasers as LLO does: 72244.

Adrian, Robert S.

We examined hours-long stretches of data from the H1:PEM-CS_ACC_HAM2_PRM_Y_DQ accelerometer because it featured a few short-duration, broadband transients every hour (figure 1). These transients are not seen in other chamber accelerometers or GS13s (figure 2), so we suspect the cable or signal conditioning box for the accelerometer is failing. It sounds like Lance has some time to check this tomorrow during the maintenance period.

On 11/12/24 Rahul ran the OPLEV charge measurements, I processed them this afternoon...

ETMY's charge seems to be slightly trending up in UL and LL but looks stagnant in UR. The charge is >= 50 V in LL_{P,Y} and UL_Y.

ETMX's charge looks to have a small upwards trend and is >= 50 V in all DOFs and quadrantss. The charge looks to have risen ~5-10 V in a little over a month over the DOFs and quadrants. The error in the measurement for EX is also larger than we usually see, the secondary microseism was elevated during these measurements.

Over the weekend, we've had greatly improved stability because of the PSL swap.  The IFO range has been mostly below 160Mpc, with short times near 165Mpc in the first hour of each lock.

The first attachment shows a comparison of the cleaned GDS strain sensitivity at the 165 Mpc time to later in the lock, along with coherences from the lower range time.  The sensitivity earlier in the lock was broadly better from 18-55 Hz, there are coherences with both ASC and LSC that are contributing to the noise from 18-27 Hz so we spent some time trying to address those.  The worse sensitivty from 27-55 Hz is not explained by these coherences, and the usual squeezing adjustments (81463 81458) don't seem to be able to help.  We might think about checking both the SRC detuning and the filter cavity detuning to see if they make an impact in this region.  We do seem to have slightly less high frequency squeezing than in the past.

To address the ASC coherences, I ran the A2L script that TJ put in userapps/isc/h1/scripts/a2l/a2l_min_multi.py  with the command python a2l_min_multi.py --all  The second attachment shows this script running, using an ndscope template that is in sheila.dwyer/ndscope/ASC/A2L_script_ADS.yaml  The first time through the pitch a2l gains for ETMY, ITMY and ITMX were all set to the maximum that the script checks, so we ran it again.   The third attachment shows the coherences (with no squeezing) after this A2L adjustment and Camilla's adjustment of the PRCL feedforward.   In the past we've seen that after running this a2l script we can do slightly better by dong a manual adjustment based on injections into CHARD or DHARD, (79921  80250) we haven't taken the time to check that today, but the script does seem to have helped in the frequency region where it's measuring.  It has made the CHARD Y coherence worse below 15 Hz, which we've seen consistently when the decoupling is good around 20-30 Hz. 

The last attachment shows a comparison of the DARM sensitivty in the high range early part of the lock, the lower later sensitivity, and currently after these retunings but without squeezing.  This suggests that our adjustments did a good job below 27 Hz where we the squeezing does have an impact in this frequency band where we haven't yet recovered the sensitivity.

Old A2L settings:

        'FINAL':{
            'P2L':{'ITMX':-1.0,
                   'ITMY':-0.39,
                   'ETMX':2.98,
                   'ETMY':4.72},
            'Y2L':{'ITMX':3.05,
                   'ITMY':-2.43, #+1.0,
                   'ETMX':4.9,
                   'ETMY':1.42 }

New A2L settings:

        'FINAL':{
            'P2L':{'ITMX':-0.66,
                   'ITMY':-0.05,
                   'ETMX':3.12,
                   'ETMY':5.03},
            'Y2L':{'ITMX':2.980,
                   'ITMY':-2.52, #+1.0,
                   'ETMX':4.99,
                   'ETMY':1.34 },

I have found new damping settings for ETMY mode01 and ITMY mode05/06, which are given below,

ETMY01

Nominal - FM1+FM6+FM10, Gain = +0.1 (+30deg phase)

New - FM1+FM8+FM10, Gain = +0.1 (+60deg phase)

ITMY 05/06

Nominal - FM5+FM6+FM7+FM10, Gain = +0.02 (-30deg phase)

New - FM5+FM6+FM8+FM10, Gain = +0.01 (+30deg phase)

I have not made any changes in the lscparam file, will check these new settings for a few lock stretches (also let microseism to settle down) before making them final.

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)

After the very successful PSL work this week, we're electing to not offload the temp changes for the ALS or SQZ lasers to their physical knobs tonight.  This means that they all need Crystal Freqs of something near 1.6 GHz (1600 in the channel H1:ALS-X_LASER_HEAD_CRYSTALFREQUENCY).  The new-ish ALS state CHECK_CRYSTAL_FREQ is written assuming that all the lasers have the changes offloaded to their knobs, so that the value in that channel is close to zero.  After we went through SDF revert, we lost those values (and the search values, which Daniel has updated in SDF for the weekend), so we we lost the PLL lock of the aux lasers.  The CHECK_CRYSTAL_FREQ state was 'fighting' us, by putting in candidate values closer to zero.  I've updated its candidate values to be closer to 1600.  Once we offload their temps to the knobs on their front panels (early next week), then we'll want to undo this change.

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.