Last night Corey ran a simulines measurement shortly into the start of the lock, 84908. This measurement was mainly done as a test to confirm simulines wasn't breaking the lock, so we were not well thermalized. We can first report that simulines did not break the lock, so the previous lockloss that occurred during the simulines measurement was likely unrelated to simulines itself.

GPS start of measurement: 1433563079

I did a time machine on the calibration monitor screen for the GPS start of the measurement.

I was able to generate a report by running pydarm report --skip-gds

I have attached the generated PDF from this report, and I took a screenshot of the first page since there is an interesting result. The sensing function shows a large spring, which is probably due to the fact that we are operating with a significant SRCL offset, which is designed to compensate for 1.4 degrees of SRCL detuning, 84794.

However, it is important to remember that this calibration measurement was made while the IFO was unthermalized, but the SRCL offset measurement I linked here was performed with the IFO thermalized.

The results from this calibration report are saved in /ligo/groups/cal/H1/reports/20250610T035741Z/

Camilla and I swept the LVEA this morning between locks. The VAC team still has HAM1 pumps to turn off and valve in, as well as a setup with a laptop on the Y arm near the manifold, and a turbo on the output arm. They will get to this later in the day. Other notable things found on out walk through:

• Unplugged RF analyzer, SR785  by PSL racks
• Unplugged two extension cords under HAM2/3
• Unplugged dust monitor by BSC8 and moved the network cable to the dust monitor in the beir garten.
• HAM4 cable mechanically grounding to HEPI crossbeam on -Y side.
• Moved a few accelerometer cables draped over HEPI cross beams.

The heating coil in zone 2A of the LVEA was repaired this morning. There will be some variation in the trending while the PI loop adjusts. 

The CDS SDF has had 1 diff for the past 4 days because the second outlet of the EY Tripplite power-strip was turned on around 9am Friday 06jun2025. Strangely EY's lights were not turned on at all on Friday, so either this was a mistake for something had been plugged into the outlet ahead of time.

Asking around the control room, no one knows why this was turned on. Because driving to EY and entering the VEA is invasive on locking, we elected to turn it off for now.

Following the drop in LN2 level over the last few days (see plot) we decided to bump up the alarm level from 80% to 85% on all CPs to give the vacuum team an earlier warning that the PID controls system is not able to maintain a nominal level.

alarms was restarted 08:16 with the following change

Channel name="H0:VAC-LX_CP2_LT150_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP2 Pump LN2 Level">
Channel name="H0:VAC-MY_CP3_LT200_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP3 Pump LN2 Level">
Channel name="H0:VAC-MX_CP5_LT300_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP5 Pump LN2 Level">
Channel name="H0:VAC-MX_CP6_LT350_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP6 Pump LN2 Level">
Channel name="H0:VAC-EY_CP7_LT400_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP7 Pump LN2 Level">
Channel name="H0:VAC-EX_CP8_LT500_PUMP_LEVEL_PCT" low="8.5e+01" high="9.9e+01" description="CP8 Pump LN2 Level">
 

TITLE: 06/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 1mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.18 μm/s
QUICK SUMMARY:
H1 was in IDLE when I arrived.
I will start trying to lock now.
 

TITLE: 06/09 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: n/a tonight
SHIFT SUMMARY:

LOG:

• 2310 Locking
  • 0011 OMC Whitening & Cal Lines were turned off, so.....
  • 0011 DARM OLG measurement run (elenna)
  • 0024 LOCKLOSS
• 2340 Had trouble bring up the alog webpage (could bring up other CDS webpages (on my gc laptop and and 
• 0009 Francisco out of PCal Lab
• 0024 Locking
  • Ran check Mich Fringes + PRMI since DRMI was not great.  Once PRMI locked, touched up with PRM since it is currently not used for ASC.  DRMI then locked fine.
  • Also, for this lock, Elenna guardianized ISC_LOCK to get H1 
  • 0134 OMC Whitening
  • 0136 LOCKLOSS
• Game Plan For night: 
  • Want to run the Simulines calibration measurement as soon as H1 completes the NLN state---Last week, H1 would lose lock from simullines, so this is to see if there's still issue. 
  • If H1 makes it through simullines, check on SQZ.  If SQZ has issues, contact Vicky for touch-up
  • Once H1 is thermalized, run full suite of calibration measurements
• 0137 Next Lock
  • spent time tweaking PRMI (instead of running a more full alignment); this eventually worked
  • 0301 Max Power complete (So this is the "start time for thermalization"  I thought I heard people say after 2hrs is fine for thermalization, but the wiki says 3hrs.
  • 0309 OMC Whitening & waiting for violins to damp---so Calibration could be run
  • 0320 Flipped sign on ITMx Mode13 gain to -0.2
  • 0321 NLN (but not fully green due to OMC Whitening/rung up violins)
  • 0511 LOCKLOSS!!!  :(
• 0357-0421 SimuLines measurement started.  This is not an "official" measurement because H1 is not thermalized.  This is mainly to see if this measurement causes a locklosses as noted on Jun5 (alog 84834).  This successfully completred measurement did NOT cause a lockloss.
• 0435 switch ITMy M5 from FM6+FM8+FM10, gain= 0.01  to (2W settings of) FM6+FM7+FM10, gain = 0.01 (because this mode was the only one increasing after about an hour into the lock.  
  • Ultimately saved these settings in the hopes of running over night (but we had a lockloss).  
  • 0526 Saved lscparams & LOADED ISC_LOCK and VIOLIN_DAMPING_STATES nodes.
• Taking ISC_LOCK to IDLE overnight because H1 has been requiring assistance for alignment of DRMI most of the day.

Elenna C., Corey G., Oli P.

With this being the first lock at NLN post the HAM1 vent, and since we had a rung up fundamental violin, decided to address for overnight operation.  It looked liked like it was our infamous ITMy MODE5/6. 

Before Oli left, they mentioned that if IY M5/6 rings up it might be worth it to try 2W settings if it rings up. 

Sure enough, it was slowing ringing up and with Elenna also assisting, we decided to change the settings.  Here they are:

NEW:

ITMy MODE5 :  FM6 + FM7 + FM10, gain = 0.01

OLD:

ITMy MODE5 :  FM6 + FM8 + FM10, gain = 0.01

The 3rd image shows when the change was made marked with the cursor and how the mode begins turning around about 10min  later.  Saved this new change in lscparams and hit LOAD on the VIOLIN DAMPING STATES and ISC LOCK notes.

I did some quick reconciliation of some of the observe SDF diffs. An easy one was all dark offsets. I also accepted many of the ASC SDFs, since I am responsible for many of them. This includes things like PD phasing, new intrix values, gain changes, etc. I also accepted several LSC SDFs, which also includes PD phasing, matrix changes, feedforward changes, and the MICH filter change. The only one I am not familiar with in the attached screenshot is the MCL trig threshhold.

Headline summary: We are very nearly back to NLN, only prevented in returning by the violin modes which are too high to engage OMC whitening. We have not yet been able to calibrate because of a very fast lockloss of unknown source.

The alog was down for most of the afternoon and evening, so I will do my best here to copy mesages from the mattermost chat, which served as the temporary alog.

Minor struggles in returning to full lock:

• The first lock, we did have to by-hand reduce the CARM offset to go to CARM_TO_REFL successfully.
• We reset the green references after ASC converged.
• The next lock (after setting green references and doing an initial alignment) this worked automatically, so no changes were made to guardian.
• MICH P rang up one lockloss, so I reverted the MICH ASC control to an older high bandwidth design. We will need to check the impact on the noise later

Once we achieved full power, we proceeded to try to solve some of the final instabilities leftover from last week. Changes made to avoid locking stability problems:

• New order of states. We now run: Max Power > Low Noise Coil Drivers > Transition from ETMX > Low noise ESD ETMX > Low Noise ASC > Low noise Length Control
  • we got a lot of saturation warnings because of the amplitude of the ADS lines in coil drivers, so the guardian now turns OFF the lines completely, and then turns them back on in lownoise ESD
  • I didn't change state numbers, but I changed the order, and some of the weights to ensure this is the path taken
  • this was tested successfully
• We no longer engage the DHARD P boost in FM8. This may have some effect on the noise which must be checked later
• We tested laser noise suppression; there are no problems
• While in OMC whitening, I ran a quick DARM OLG with Fransisco. There is slightly less phase, but overall it looks fine, at least compared to the reference. However, we don't have a lot of phase margin in general, should we fix that?

The plan was to try testing simulines again, however! We have had multiple very fast locklosses with no known origin. Two have happened shortly after arriving at OMC whitening. These are not coming from ASC and I don't see any ringup in DARM or LSC loops.

TITLE: 06/09 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 18mph Gusts, 9mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.17 μm/s
SHIFT SUMMARY:

Covering for Ryan C.
OFI Returned to aligned... No output. Apparently this is normal.

SRM already aligned by Elenna.
Attempting to start relocking 19:00 UTC
Potential Lockloss from FIND_IR when I requested SEI_ENV to cycle between Maintenance & CALM.

Lots of saturations when we ran through LOWNOISE_COIL_DRIVERS

Unknown Lockloss from Low_Noise ASC ( We manualed over a handful of States and Ended up manualing back to this state.)

Adjusted the ALS polarization of both X and Y arms.
Ran a Manual_Initial_Alignment Finished @ 22:26 UTC

No internet do to a GC switch restart 22:40 UTC. Internet back up a few moments later.


Lots of saturations when we ran through LOWNOISE_COIL_DRIVERS again, we did not lose lock either time.

Lockloss due to DHARD P ring up while in LOW_NOISE_LENGTH_CONTROL.

LOG:

TITLE: 06/09 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 13mph Gusts, 7mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.16 μm/s
QUICK SUMMARY:

Locking work continues with H1 getting past 60W and commissioners focusing on ASC steps around LOWNOISE states (most recent lockloss was a DHARD pitch ring up. 

As for locking, it looks like H1 is locking decently, but Tony did say he ran a recent Manual Alignment.  Alignment-wise we are still running manually with PRC step only being partly run---basically take to PRX and touch up ASC-AS_A by hand via PRM (this is what we have been doing the last few weeks).

Plans are to take H1 to MAX POWER and continue ASC work.

Oh and for the forecast tonmight, we have a warning of high winds!  (We are also very hot---just under 105degF now).

I copied the contents of C:\SlowControls on h1brsex and h1brsey onto a usb stick. I committed changes local to h1brsex into svn. I ran svn update on h1brsey. I was just expecting the changes I committed from h1brsex to show up, but a whole lot more did. I guess no one had run svn update in a long time. It appeared to complete without conflicts and reported that it was now at revision 6189. I started committing files to svn on h1brsey that I thought did not conflict between the two machines, but I think I accidentally committed one that does. I committed local changes on h1brsey to /trunk/BRS2 C#/BRSReadout/configs/LHOEY.config, but afterward found that there are also local changes to the same file on h1brsex.

Ibrahim, Rahul

Rahul and I installed the BBSS Vibration Absorbers. We then took more B&K measurements and Rahul is analyzing them. Pictures attached.

Weekly TCS Chiller Water Level Top-Off FAMIS 27815

TCSX - 30.5 No water added
TSCY - 10.5 no water added

Reported in https://dcc.ligo.org/T2200289 .

Green Refs reset now that we had all of the 2W ASC on and converged.  SDFs saved in the safe.snap

• ITMX: Superluminescent Diode QSDM-790-5 
  • S/N 06.18.001 - removed alog#61892 - will disposition*
  • S/N 06.18.002 - removed with 0.8mW alog#66179 - will keep as used spare. 
  • S/N 07.14.254 - removed alog#44201 - will disposition*
  • S/N 07.14.256 - removed alog#41411  - will disposition*
• ITMY: Superluminescent Diode QSDM-840-5
  • S/N 03.20.479 - new in sealed box
  • S/N 06.16.005 - new in sealed box
  • S/N 11.17.126 - removed with 0.19mW alog#66179  - will disposition*

* Added to ICS DEFECT-TCS-7753, will give to Chrisitna for dispositioning once new stock has arrived.