Sat CP1 Fill

Sat Nov 01 10:08:48 2025 INFO: Fill completed in 8min 44secs

 

Sat Morning Ops Shift Report.

TITLE: 11/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.87 μm/s 
QUICK SUMMARY:

Walking in H1 was unlocked and had been for a while.
Looks like it was a H1 called the Ryan S and gave him a  rough 2ndairy useism night for the Owl Shift last night.

I took OPS_Observatory mode back to Microseism since the useism is still elevated unfortunately. I was however able to lock DRMI for a short stint before a lock loss. 
We have a 28ft waves in the Gulf of Alaska, and 17ft waves off the coast of WA. Let's see what sort of locking we can do. 
But on the bright side.... the STS BLRMS dont look as bad, the wind is low, and I can get DRMI to lock! Maybe we can get locked and stay locked throughout this. 
 

Ops Owl Assistance

H1 called for assistance at 08:20 UTC as it was struggling to relock. Understandable, as the secondary microseism has been rising today and is now to the point where all STS BLRMS are well into the red. After 90 minutes, I finally got H1 to lock DRMI despite good-looking alignment, but it fell apart as it was checking ASC. I'll keep at it for a while, but if the microseism doesn't improve, I may leave H1 down for the night.

OPS Friday EVE shift summary

TITLE: 11/01 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: One lockloss with an easy relock, I've left damping off for EX mode1. We've been locked for just over 2 hours.
LOG:

01:29 UTC lockloss

03:41 While in ADS_TO_CAMERAs I saw the 1Hz start so I brought us to ASC Hi Gn and sat for a few minutes before reverting, I slowly stepped through states above LASER_NOISE

03:48 UTC Observing

04:20 UTC The DARM fom started to timeout and lose connection and would stop displaying the data periodically

04:55 UTC Restarted NUC25 to try to revive pimon which I noticed was not running, running just the launch.sh gave an error for it. (The restart did not work either)

01:29 UTC lockloss

01:29 UTC lockloss, there was a wiggle in PR_GAIN right before the LL. Lockloss tool looks to be offline for the last hour.

Spooky Halloween Ops Day Shift Report.

TITLE: 10/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
H1 stayed locked througout the entire shift But there was some DARM commotion from 20 ~40 Hz today 
The "Control Room Collectived" decided, warrantlessly, to blame the person slowly driving the boom lift down the length of the beam tube sealing cracks in the top of the beam tube.
We got him on the phone, and the PEM expert asked him to dance do a Seismic injection [18:08 UTC] while we watched him from the roof cameras. 
Turns out the 20-40 Hz noise was not from the boom lift  & may have been from the artillery range west of here.
 

18:59 Superevent Candidate S251031cq  !!

LOG:
                                                                                                                                                                                                                                                                                                

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:01	FAC'	Randy	MidX	N	Caulking Beam tube & Robert's Seismic Injection test	20:05
18:06	FAC	Kim	Receiving	N	Lifting receiving door	18:11
20:04	SPI	Ryan S	Optics lab	N	Cleaning opitcs	20:50
22:38	OPS	RyanC	Optics lab	N	Swap dust monitors for huddle test	22:47

OPS Friday EVE shift start

TITLE: 10/31 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 8mph Gusts, 6mph 3min avg
    Primary useism: 0.11 μm/s
    Secondary useism: 0.48 μm/s 
QUICK SUMMARY:

• Secondary microseism is elevated, just below the 90th percentile
  • The range has been slowly dropping over the long lock
• We've been locked for over 22 hours
• Wind is low
• Some violin damping settings are not in as GRD won't let me
  • If we drop OBS I'll fix this, the main method od DAMP_FULL_POWER needs to run again

POP measurements vs model

M. Todd, S. Dwyer

---

Overall Summary: we cannot learn enough from the POP measurements in HAM1 to constrain the values of PR2 and PR3.

---

We double checked all the distances reported from alog 84307 and the distances of the POP lens in the model, and we found a 3(ish) cm discrepancy. We corrected this discrepancy before doing any fitting or analysis. We use the portion of the measurements in front of the POP lens (towards the POP LSC diode),  as they contain enough information at each Gouy phase region in the beam evolution, to fit for a q-parameter in front of the POP lens. We can propagate this to where the other measurements are behind the POP lens to get an understanding of the focal length of the POP lens. Figure 1 shows a plot of the fitted q from the portion of measurements compared to the ones not used.

We saw that this q-parameter was not well collimated behind the POP lens, making us think that the focal length may not be exactly what is in the model/reported. We adjusted the focal length by +2% (reducing lensing power) as is listed in the tolerance of the optic (see D1300313), and found much better agreement with the un-fitted measurements. This is shown in Figure 2, which shows that the overlap with the measurements before the POP lens is better, but the overlap with the model q-parameter is not as good as we would like.

We then increased the radius of curvature of ROM RH3 mirror (in HAM3) by +1%, and saw that the model beam becomes well overlapped with the fitted q-parameter fromt the measurements. This is shown in Figure 3.

Overall, I think this tells us that because we can tweak the parameters of the lenses in the POP path within their specs to give us the overlap we want with the Input mode through the PRC, we cannot use these measurements as a constraint on the values of the PRC telescope optics. It would be great if we could get a few beam profile measurements in transmission of PR2, without the POP lens or RH3 mirror but getting the IMC locked while HAM3 is vented seems unlikely.

Correlation between ITMX and ITMY ESD bias settings and near-30 Hz near-100 Hz line amplitudes

[Joan-Rene Merou, Alicia Calafat, Sheila Dwyer, Robert Schofield]

We have analyzed the evolution of the near-30 Hz and near-100 Hz comb amplitudes, continuing with the work on aLOG 87414. In that alog was shown how there appeared to be a correlation between the ITMY ESD bias and the amplitude of the near-30 Hz and near-100 Hz combs.

In this study, we first listed all time intervals between ITMX and ITMY bias changes from the study Robert Schofield did and reported on aLOG 78925 and the associated entries. Robert changed the biases in a number of occasions "for determining the ITM biases that minimize coupling of electronics ground noise". We wanted to see if this was also true for minimizing the amplitude of lines in DARM.

The full list of constant-bias segments in-between changes is shown in the following table, which defines the start and end GPS times, along with the corresponding ITMX and ITMY bias values. We have added a few data points in between the ones shown in the related Robert aLOGs.


  

    

      
const_start_gps
      
const_end_gps
      
ITMX_bias
      
ITMY_bias
    
  
  

    
1403650000
1403651100
0
0
    
1403651220
1403653448
0
-39
    
1403653569
1403655679
0
170
    
1403655799
1403657640
0
-222
    
1403657760
1403804070
0
0
    
1403804192
1403804365
0
77
    
1403804489
1403807629
0
-80
    
1403807751
1403809555
0
-20
    
1403809816
1403812204
-40
-40
    
1403812324
1403816907
36
-40
    
1403817127
1403820880
36
0
    
1403821000
1403912193
0
0
    
1403912517
1403914518
20
-20
    
1403914684
1403917205
-19
19
    
1403917405
1404317823
0
0
    
1404317979
1404319278
-20
-22
    
1404319453
1404320829
20
-20
    
1404320940
1404341414
0
0
    
1404341526
1404342991
0
-20
    
1404343117
1404344533
0
-40
    
1404344655
1404346187
40
-40
    
1404346300
1404413221
0
0
    
1404413147
1404416077
0
-40
    
1404416200
1404417200
0
0
  


For each of these intervals, we performed custom Fscan analyses using DARM and the 5-26 ADC channel as input data with 128 s Tsft. Each Fscan job covered one of the constant-bias segments, allowing us to investigate whether higher ITM biases corresponded to larger spectral peaks in the resulting spectra. The attached plots show the relative amplitude of the first harmonic for the two strongest combs identified near 30 Hz and 100 Hz.

In these color scatter plots the X and Y axes represent the ITMX and ITMY bias voltages, respectively. The color scale encodes the relative amplitude ratio (or signal-to-noise ratio) of the selected comb harmonic. These plots correspond to DARM (GDS-CALIB-STRAIN-CLEAN).
From the visual inspection, there appears to be a consistent trend where higher absolute ITMY bias values correspond to larger peak amplitudes, the same could be true for ITMX values, but the data does not appear to be conclusive. It would be interesting to get data points with much higher absolute values of ITMX bias.
Here is one example for the first harmonic of the highest near-30 Hz combs:



Although these results currently refer only to the first harmonic of each comb, this correlation already suggests a relationship between ITMY bias magnitude and the peak amplitude.

We also generated the same set of plots for the H1:PEM-CS_ADC_5_26_2K_OUT_DQ ADC channel, to test whether the observed trend in DARM is also visible in the ground current monitor. From these additional plots, the correlation appears less clear. For the near-30 Hz comb. It appears that changing ITM bias values does not change the comb amplitude in the ground monitor. Showing an example for the same comb as before:



The current analysis only considers a single harmonic per comb. The next steps are to extend the study to higher harmonics of these combs and check whether the same behavior is observed in other comb families beyond the 30 Hz and 100 Hz series.

FMCS LVEA/VEA fans off for a few minutes between 05:10 and 05:15 early Thursday morning

Eric, Dave:

Following up on the end station VEA temperature excursions yesterday morning, Eric noticed that the fan accelerometer channels looked strange just prior to that time.

The attached plot shows that most, but not all, of the LVEA/VEA fans were turned off for about 1min40sec each, with the turn off times not coincident, but over a period of several minutes.

FAN	Turn Off	Turn On	Duration
EY	05:13:10	05:14:44	1min34
EX	05:12:32	05:14:13	1min41
MY	05:12:24	05:14:10	1min46
MX	05:11:41	05:13:19	1min38
LVEA-FAN1	05:12:28	05:14:10	1min42
LVEA-FAN2	05:12:31	05:14:12	1min40
LVEA-FAN3	05:10:57	05:12:30	1min33

LVEA-FAN4 is always zero. FAN5 and FAM6 have a signal but no change around this time.

Fri CP1 Fill

Fri Oct 31 10:08:00 2025 INFO: Fill completed in 7min 56secs

Jordan confirmed a good fill curbside.

Comparing model and measurements of the corner cavities

M. Todd, S. Dwyer

---

Sheila had the idea to use the measurements that Leo and Camilla took of the SQZ beam and OMC scans to constrain the values of some of the output optics (OM1 and OM2 especially), as they are under scrutiny in our work as well. 

Leo, Camilla, and Jennie performed OMC scans with the SQZ seed beam to estimate the mode matching of the SQZ beam to the OMC. The mismatch they estimated was between 2.2 and 2.9%. See alogs 86445, 85775.

Using the finesse model, we can propagate the q-parameter that was estimated from beam profiles (see alog 85917) to the OMC and check its mismatch with the OMC eigenmode. The path is summarized: ZM5->ZM6->OFI->SRM->OFI->OM1->OM2->OM3->OMC_IC.

The model estimates that this q-parameter measurement propagated from ZM5 to the OMC input coupler has a 2.3% mismatch with the OMC eigenmode. This gives us a lot more confidence in the radius of curvature of OM2, which was previously one of the optics we believed to have a different RoC compared to the reported value. Especially given that if we use the value of OM2 that would remedy the discrepencies in other measurements vs. models (see alog 87872), this would make the modeled mismatch of the SQZ beam to the OMC around 8.6%, which is far from measurements.

 

EY environment monitor went offline again 04:30 Fri 31oct2025 PDT

While I was at EY yesterday for h1seiey recovery I took the opportunity to look at the Geist Watchdog 1250 Environment Monitor (env-ey-1) which at the time was not pingable. I verifed that the unit was updating its front panel display (put my finger over the light sensor). I reseated the ethernet cable (no indication of a problem there) and then power cycled the unit. After restarting the EPICS IOC (cds_env_ey.service on cdsioc0) the EPIC channels came back to life.

At 04:30 this morning the unit went offline again (for the third time). The plot certainly suggests this unit's ethernet port goes offline when the room temperature drops into the mid-70s degF. I will schedule a unit replacement.

Spooky Halloween Ops Morning Shift Report.

TITLE: 10/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 5mph Gusts, 4mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.45 μm/s 
QUICK SUMMARY:

The tree leaves have fallen on to the rocks,  while the  IFO has been locked.
For 14 hours now, we've been observing, what's out in the universe? What's a swirling? 
Waiting for a pair of big monsterous Black Holes to spiral out of control. Into the center of something bigger than Sol.
I hope your day is spooky and you get a sweet treat for your costume
Happy Halloween from LHO Control Room.
 

Violin damping - ETMX mode 6 (beating with ETMX mode1)

ETMX mode 6 was rung up when Oli gave me a phone call. After trying few settings unsuccessfully, I noticed that ETMX mode 1 was beating with mode 6 (they sit closely).

I have turned off the damping for ETMX mode 1 and then started damping ETMX mode 6 with nominal setting and this seems to be working fine.

Ryan Short also confirmed that the DCPD is now looking great (was increasing earlier due to the rung up modes).

Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

After remotely rebooting h1seiey and seeing that the 4th ADC is now completely absent from the PCI bus, the next test was a power cycle of the IO Chassis.

Procedure was:

Stop h1seiey models, fence from Dolphin and power down the computer.

Dave (@EY):

power down the IO Chassis (front switch, then rear switch)

Power down the 16bit-DAC AI Chassis (prevent overvoltage when IO Chassis is power up)

Power up the IO Chassis (rear switch, then front switch).

The chassis did not power up. Tracking it back, the +24V-DC power strip was unpowered, the laser interlock chassis which is also plugged into this was powered down. This tripped all the lasers.

Fil came out to EY with a spare ADC

Dave & Fil (@EY):

We opened the IO Chassis and removed the 4th ADC. With this slot empty Fil powered up the DC power supply with the IO Chassis on, it did not trip.

We powered down the IO Chassis to install a new ADC. We are skipping the slot the old ADC was in, because it could be a bad slot.

The second DAC was moved from A2-slot4 to A3-slot1, the new ADC was installed in A2-slot4, leaving the suspect A2-slot3 empty.

We powered the IO Chassis on with no problems, then we powered up the h1seiey computer. The models started with no issues, I was able to reset the SWWD.

The chassis was buttoned up, pushed into the rack, and the AI Chassis were powered back up.

Marc is fixing a cracked cap on the old ADC so we can test it offline.

ADCs:

old ADC (Removed)	110204-18
new ADC (Installed)	210128-28

 

HAM1 POP path beam profile and distance measurements

location number on drawing	distance	horizontal 13.5% diameter [um]	vertical 13.5% diameter [um]	photo of profiler location	photo of profiles	photo of beam scan measurements
1	52 mm from dichroic M10	6243	64040	here and here	9022	9023
2	147 mm from dichroic M10	6202	6365	9028	9026	9027
3	119 mm from HR of 50/50 BS M15, also 295mm from center of lens L2	870	874	9031	9030	9029
4	153 mm from HR of 50/50 BS, approximate location of LSC diode	279	284	9035	9032	9033
5	128 mm from HR of 50/50 BS	721	726	9036	9037	9038
6	139 mm from HR of 50/50	483	490	9041	9040	9039
7	353 mm from HR of 50/50 BS	3280	3372	9042	9043	9044

Camilla made these measurements with 20W input power into the IMC, PRM and ITMY misaligned single bounce beam.  We didn't place the 90/10 BS M12 in the pop path yet so that we would have about 35uW to measure beam profiles. There's a rough pen sketch of where these locations are in this photo.

Camilla also made ruler measurements of some distances:

• PM1 to 50/50 BS M15 is 405mm
• PM1 to center of L2 is 229 mm
• center of L2 to M15 is 178 mm
• dichroic M10 to PM1 is 360 mm
• bottom of periscope  (M8 or M9) to dichroic M10 482mm
• HR side of M15 (50/50 BS) to front of LSC diode box is 158 mm, diode itself is 3 mm proud of diode box.