We have finally confirmed that the current BBSS build is stable for both LHO and LLO, and we have figured out the model parameter set that matches the builds, so I've finally gone ahead and merged the parameter changes from the parameter set we had been using as the default for a while, bbssopt_2025_d0plus3p0_l1mins3p0_m2plus0p3_FDRd1plus3p5.m, into bbssopt.m (r12435). The differences between the original FDR parameter set (from T2000599-v1) and this hopefully final set are as follows:

• d4 -= 1e-3         Adjustment to get better fit to measurements 76071, 82138
• l3 -= 4.5e-3    Loop length change 79004
• d1 += 3.5e-3    Equal to blade position = -4mm
• m2 += 0.3           Mass added to M2
• d0 += 3e-3       Height change of added spacer
• l1 -= 3e-3      Wire length change to counter height added by spacer

I have used my compareallbbss_tfs.m script (CSWG:11252) to make comparison plots between the BSFM, the original FDR parameter set from T2000599-v1, and this parameter set. This parameter set has been uploaded to T2000599 as -v4.

Here are the latest H1 safety results from the November 2024 injections (sorry for the very long delay): https://drive.google.com/drive/folders/1CgwhWlKpG9CFnaiLvHnF2bWZVyHMN4gz?usp=sharing. It'd be great if folks could take a quick scroll through this spreadsheet (sorted by statistically most unsafe at the top) and see if there are any channels which have been determined to be unsafe (column F) which shouldn't be, or if there are any that should be added to the channel lists. Thanks!

Fri Jul 11 10:07:27 2025 INFO: Fill completed in 7min 24secs

Jordan confirmed a good fill curbside.

Closes FAMIS#28462 , last checked 84837

CO2 Trends (ndscope1)

Everything is looking good

HWS Trends (ndscope2)

Everything is generally looking good, with both ITMX and ITMY SLEDPOWERMON slowly going down, which they tend to do. The only possible concern I can see would be that zooming out to almost a year ago (ndscope3), it looks like the level that ITMX SLEDPOWERMON is at now is a lower value than it has been in the past year.

Since we had a few PI-caused locklosses last week, we realized that the PI monitor (PIMON) didn't seem to be running properly and saving the data 524 kHz DCPD data at the end of the lock. TJ has been trying to debug the issue. In the meantime, I have left PIMON running on a control room computer that I am logged into, and the lockloss data is being saved into /ligo/gitcommon/labutils/PIMON/locklosses and the script plot_locklosses.py in /ligo/gitcommon/labutils/PIMON can be used to plot the data from the locklosses.

Fortunately, we haven't had any PI locklosses that we know of since last week. Whenever control room computers are rebooted, we need to restart the script.

To allow for the longer acquisition times we've been seeing to catch D/PRMI despite good-looking alignment and buildups, I've doubled the timers in ISC_LOCK for DRMI to try PRMI and PRMI to try MICH_FRINGES from 10 minutes to 20 minutes each. Changes have been loaded and committed to SVN.

Lockloss @ 15:41 UTC after 18 hours locked - link to lockloss tool

No obvious cause that I can see.

FAMIS 26430

Laser Status:
    NPRO output power is 1.853W
    AMP1 output power is 70.03W
    AMP2 output power is 140.2W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 23 days, 22 hr 6 minutes
    Reflected power = 23.42W
    Transmitted power = 105.4W
    PowerSum = 128.8W

FSS:
    It has been locked for 0 days 18 hr and 23 min
    TPD[V] = 0.7448V

ISS:
    The diffracted power is around 3.7%
    Last saturation event was 0 days 21 hours and 23 minutes ago

Possible Issues:
    PMC reflected power is high

TITLE: 07/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 16mph Gusts, 10mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY: H1 has been locked and observing for 17 hours.

• Wind moderately low, microseism rising but still low
• ALl other systems nominal

TITLE: 07/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 148Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY:

IFO is in NLN and OBSERVING since 21:43 UTC (7 hr lock!)

Extremely quiet shift in which there were no saturations, no SQZ drops and 1 Superevent!

Nothing else to report

LOG:

None

TITLE: 07/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 144Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Currently Observing at 145Mpc and have been Locked for 2 hours. Wind seems to be coming down.

Lots of struggles relocking today after the 17:54 lockloss due to increase of winds and gusts as well as issues with treh ALSX crystal frequency. Eventually made it up.

LOG:

14:30UTC Observing and Locked for 11 hours
15:00 Out of Observing for Commissioning
17:54 Lockloss
    - Issues with ALSX crystal frequency
    - Issues with wind
    - Ran IA
    - Many lower level locklosses from wind and ALSX crystal frequency
    - Lockloss from TRANSITION_FROM_ETMX due to wind
21:43 NOMINAL_LOW_NOISE
21:48 Observing

TITLE: 07/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 145Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 26mph Gusts, 9mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING as of 21:43 UTC

Conditions look great except for slightly high winds (same as yesterday). Have been in the control room for about an hour and there have been no SQZ locklosses!

Looks like the ITMY R0 alignment tramp was accepted in SDF at 300seconds from its usual 30sec back in June 16. This has been accpeted at 30sec now.

Lockloss July 07, 2025 17:54 UTC during commissioning due to commissioner error after over 14 hours locked (LL website not loading)

Camilla, TJ, Dave:

Last Thursday 26th June 2025 alog85373 I restarted the HWS camera control code. We hoped this would improve the 2Hz noise comb in DARM. Initial results for F-Scan (observing) suggest it has not made much, if any difference. 

Attached F-Scans show the spectra on sun22jun2025 and mon30jun2025. The 2Hz comb (blue squares) look unchanged.

More investigation is needed to verfiy we are indeed disabling the frame aquisition on all HWS cameras when H1 is in observation.

Jennie W, Sheila, Ryan C, Ibrahim, Corey

Over the last 3 weeks three DARM offstep measurements (where we change the DARM offset to look at the fraction of the light from the differential mode which makes it past the OMC) have been taken.

This is so we can get data points to compare to my model of ARM to OMC mode-matching. These were done at three different CO2 X power levels.

Measurement 1: 2025/06/18 20:44:55 UTC

CO2 central heating on ITMX: 1.698W

CO2 central heating on ITMY: 1.694 W

The test is run with /ligo/gitcommon/labutils/darm_offset_step/auto_darm_offset.py . The data is processed with plot_darm_optical_gain_vs_dcpd_sum.py .

Graphs of the power after the OMC vs. optical gain are in the first plot,  optical gain vs. offset and anti-symmetric port power vs. power out of the omc are in this document.

The average contrast defect is 1.07 mW, the junk light is 679 mW, the transmission of the differential mode light at the AS port by the OMC is 1/1.217 = 82.2%.

Measurement 2: 2025/06/20 15:11:46 UTC

CO2 central heating on ITMX: 1.698 W

CO2 central heating on ITMY: 1.711 W

The test is run with /ligo/gitcommon/labutils/darm_offset_step/auto_darm_offset.py . The data is processed with plot_darm_optical_gain_vs_dcpd_sum.py .

Graphs of the power after the OMC vs. optical gain are in the first plot,  optical gain vs. offset and anti-symmetric port power vs. power out of the omc are in this document.

The avergae contrast defect is 1.03 mW, the junk light is 677 mW, the transmission of the differential mode light at the AS port by the OMC is 1/1.212= 82.5%.

Measurement 3: 2025/06/30 15:06:50 UTC

CO2 central heating on ITMX: 1.698 W

CO2 central heating on ITMY: 1.721 W

The test is run with /ligo/gitcommon/labutils/darm_offset_step/auto_darm_offset.py . The data is processed with plot_darm_optical_gain_vs_dcpd_sum.py .

Graphs of the power after the OMC vs. optical gain are in the first plot,  optical gain vs. offset and anti-symmetric port power vs. power out of the omc are in this document.

The avergae contrast defect is 1.09 mW, the junk light is 694 mW, the transmission of the differential mode light at the AS port by the OMC is 1/1.212= 82.5%.

This is not a very good test for our purposes as I think we want a larger change in mode-matching from thermal tuning to inform our simulations of Arm->OMC mode-mis-match.

Each time we have stepped the CO2Y down (all these darm offset measurements were meant to be repeated after decreasing the CO2 power) for this test (measurement 2 on the 20th June, alog 85238 shows attempt from 23rd June, alog 85335 shows attempt from the 25th June, alog 85429 is measurement 3) we have lost lock, so we might not be able to repeat this measurement with a larger CO2 step.

Jennie W, Sheila, Elenna

In order to get data for mode-matching and for Elenna to get data to calibrate sideband heights we ran some mode scans after the SR3 heater was turned on last night.

16:55:24 UTC Carried out single bounce OMC scan at 10W PSL input with sensor correction on HAM6 on, high voltage on for PZT driver in HAM6, sidebands off , SRM mis-aligned, ITMY mis-aligned, DC 3 and 4 on, OMC ASC on.

Excitation freq changed to 0.005 Hz as the top peak of the TM00 mode looked squint so could have been saturating. Lowering this frequency prevented this.

Ref 15-17 corresponds to dcpd data, pzt exc signal, pzt2 dc monitor.

Then mis-aligned ITMX and aligned ITMY (Sheila had to re-align SR2 to centre on ASC-AS_C).

Measurement starts at 17:08:18 UTC.

Ref 18-20 corresponds to dcpd data, pzt exc signal, pzt2 dc monitor.

Traces saved in 20250516_OMC_scan.xml. The top left plot is the first scan bouncing beam off ITMX, the second scan is the bottom right bouncing off ITMY.

The top right is the two plots of the PZT2 DC voltage monitor. That is, the current voltage applied to the PZT. The bottom left is the plot of the voltage ramp applied to the PZT2 on the OMC for this measurement.

The ndscope attached shows the power in mA transmitted through the OMC on the top, then the PZT used for the scan DC voltage underneath, then the input PZT voltage underneath that, then the reflected power from the OMC in mW, then at the bottom the SR3 heater element temperature in degrees.

Elenna did two more scans in single bounce with sidebands back on and different modulations depths in each.