TITLE: 11/27 Eve Shift 2030-0200 UTC (1230-1800 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: The last of the PEM measurements were done this evening when H1 was locked, but a couple of locklosses (both of which seemed to be caused by activity in sensitive areas in the LVEA) limited the amount of time at low noise. Following the most recent lockloss, I'm leaving H1 in 'IDLE' for the long weekend before the upgrade phase begins on Monday.
LOG:

• 20:56 - NLN; PEM measurements resuming
• 23:32 - Lockloss
• 01:13 - NLN
• 01:37 - Lockloss

TITLE: 11/26 Eve Shift: 0030-0600 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: 8mph Gusts, 5mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.16 μm/s 
QUICK SUMMARY: H1 is relocking and currently up to LOWNOISE_ESD_ETMX. More PEM measurements ongoing today and into this evening.

• Wind low, microseism dropping slightly and right above 50th percentile
• All other systems nominal

TITLE: 11/26 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: We've had two locklosses today, both while people where out on the floor. Relocking has been fairly automated, we had a TCS CO2Y laser issue that we resolved. We are relocking at MOVE_SPOTS as of 20:30 UTC. LVEA zone4G got a bit warm but its leveled out.
LOG:

• 15:57 UTC GRB-Short E620044
• 17:50 UTC lockloss
  • 18:48 UTC TCS CO2Y tripped off, IR error. Sheila went to the LVEA to reset the controller which cleared the IR alarm but it was still reporting no power and a low current, She then went and reset the power supply in the Mezzenine this didn't solve the issues either. After Daniel tried toggling the laser off and on we saw the IR light start to flash on and off which from TJ is a sign that the cable might be loose. Sheila and Daniel went out and checked out the cable and reset the controller again which brought it back!
  • 19:10 UTC GRB-Short E620052
  • 19:18 UTC NLN
• 19:58 UTC lockloss
  • IMC took 7 minutes to lock

Both the pump (532nm) and fundamental (1064nm) have now been alignment to the VOPO cavity based on the mode matching setup described in this log. 

From the mirror specification (C2500221), the theoretical escape efficiency is calculated to be 98.5% (derived from the decay rate of the mirror, k_in,r / k_in,tot).

The escape efficiency from the VOPO reflection is 97.9% (calculated from the photodiode reflection, trans/refl = (2nesc - 1)^2).

In short, input alignment done, rear seed injection is the next to go, escape efficiency checked, and the photons escaping the cavity with the enthusiasm of a PhD student during a conference lunch break.

19:58 UTC lockloss, there was a big fuzzy oscillation in PR_GAIN right before LL

Wed Nov 26 10:05:20 2025 INFO: Fill completed in 5min 16secs

17:50 UTC lockloss, there was an ISI BS saturation a few seconds after the lockloss.

Kevin, Sheila

Over the last few days we've run ADF sweeps a few times.  Here's a record of what happened and file names.  

The files are in /ligo/gitcommon/squeezing/sqzutils/data

 Nov 22 08:31 HF_10kHz_11_2025.h5 IFO had been powered up for 11:00, sweep started at about 14:50 UTC Nov 22.  NLG 24.3, measurement is in 88224.   Something seemed to go wrong towards the end of the sweep, we aren't sure what. 
 Nov 22 12:38 HF_10kHz_11_2025_2.h5  IFo had been powered up for 15:10, same lock as the previous measurement, same NLG measurement, sweep started at about 19 UTC.  

Nov 25 00:36 HF_10kHz_11_2025_b4_CO2_step.h5  IFO had been powered up for 4:20, in this sweep I didn't turn off the SQZ angle servo based on the ADF, so the demod phase was moved around during the sweep, making this data not useful.

Nov 26 01:56 HF_10kHz_11_2025_b4_CO2_step2.h5 last night's first scan, started only 38 minutes after power up at about 8:18 UTC Nov 26th.  The amplified seed was 7.8e-3, unamplified seed didn't happen correctly with the script but the waveplate hasn't moved since previous measurements of that level at 2.9e-4 (88223), giving an NLG of 26.9.  (Edit, I redid the unamplified seed measurement, it looks like 3.2e-4 now, making the NLG 24.4 for these last two measurements, which has been consistent (24.3 or 24.4) for the last week. 

Nov 26 08:15 HF_10kHz_11_2025_after_CO2_1hour.h5 this morning's sweep, IFO had been powered up for 7 hours, CO2s had been stepped from 1.7W each to 0.9W each for 1.5 hours when the sweep started at about 14:37 UTC Nov 26th. NLG should be the same as for above, 26.9.   24.4

TITLE: 11/26 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 146Mpc
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 7mph Gusts, 4mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.17 μm/s 
QUICK SUMMARY:

• We've been locked for 7.5 hours
• Sheila has a script running right now, it should finish around 16:00 UTC
• Microseism still looks to be slightly trending down
• Standdown query failure, I'll restart it

TITLE: 11/26 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: We had 2 locklosses, the first was easy to recover from, the second is still in progress. We're at MAX_POWER right now.
LOG:      

• 20:49 UTC lockloss a minute after reaching NLN, there was a big oscillation in EX_L3
• 22:29 UTC Back to NLN
• 01:21 UTC lockloss, ETMX glitch
• 01:35 UTC IA
  • 02:41 UTC DRMI finally locks
  • 03:12 UTC lockloss at LOW_NOISE_ESD_ETMY

Last night I ran a longer version of the full magnetic injection suite starting at about 03:10 UTC, and it finished at 07:33 UTC. This used the same parameters as last week's run, except I doubled the injection time to 5 minutes each.

Exact times and injection parameters are in the usual log directory for the magnetic injections: /ligo/www/www/exports/pem/WeeklyMagneticInjection/logs/1448075483.txt

[Joan-Rene Merou, Alicia Calafat, Sheila Dwyer, Jenne Driggers]

We have entered the LVEA and went to the Beer garden. There, we first turned off the Low Voltage ITM ESD Driver D1600092, first the 15V switch and then the medium voltage switch. In order to turn it on again, it should be reconnected in the opposite order. With the voltage request set to 0 and chassis powered off, we have unplugged the SHV cables going to the chamber and plugged into Robert's ground boxes, which we used to ground to the rack which is grounded to the chamber. This has been done at both drivers (See attached photos).

Afterwards, we have changed the code at /opt/rtcds/userapps/release/isc/h1/guardian/ISC_LOCK.py in order that the LOWNOISE_COIL_DRIVERS will go to LOWNOISE_ESD_ETMY instead of TRANSITION_FROM_ETMX. This has been done by changing lines 6670 and 6674, moving the ", 15" step from line 6670 to 6674. Finally, we communicated the change to the operator and loaded the guardian.

I made plots of anti-symmetric power P_AS vs. power at reflected port of OMC P_OMC_REFL during the DARM offset step measurement on September 4th, (see LHO alog #86785 and 87629).

I had to use the Beckhoff reported power for this (H1:OMC-REFL_A_DC_POWER) as the front-end channel is calibrated wrongly (see LHO alog #87648).

I also plotted the P_OMC_REFL vs.  P_DCPD, ie. reflected vs. transmitted power for the OMC.

The plots for our two measurements taken at different times during IFO thermalisation are below, both were taken when OM2 was hot.

Jennie W, Sheila,

I took a long time to post this as have been working on other things...

We carried out a test (see LHO alog #86785) to look at the effect of DARM offset stepping on the power at OMC-DCPD_SUMS and OMC-REFL (transmitted through and reflected from the OMC). We did this with the heater on OM2 off as is nominal.

We then meant to redo these measurements once we heated up OM2 to change the mode-matching of the IFO to the OMC.

Unbfortunately we lost lock at about 15:06 UTC while Corey was taking out first measurement before heating up the OM2.

The meausrement is shown in this image, I have mislabelled it as 'third measurement' but it was the first. The optical gain is shown just before this measurment to be 0.994.

Then we waited as long as we could under out initial parameters of being finished cooling the OM2 again by 1:45pm.

We took another measurement at 1 hr 25 mins into lock after two false starts where I forgot to turn off the ASC. The optical gain was measured right before we started the measurements to be 0.978 but was still thermalising.

And then we took a third 2 hrs 59 minutes into lock, the IFO should be thermalised but the temperature of OM2 was still trending upwards a bit. Optical gain was 0.986.

We can use the slope of the power at the antisymmetric port (P_AS) vs. the power at the DCPDs (P_DCPD) as the DARM offset changes to estimate the throughput of carrier through the OMC which allows us one estimate of the loss.

The plots of this throughput are here for the cold state (minus the points taken after we lost lock), here for the partially thermalised state, and here for the thermalised state.

I am also in the middle of using the plot of P_AS varying with power at the OMC reflected port (P_REFL) to get a better estimate of the mode-mis match between the interferometer and the OMC.