Rebooted h1guardian1 at 1547UTC so that we could start with fresh fresh and it would become easier to manage any file differences with help from some of Dave's new screens and scripts.

All nodes started up on their own, and Ryan C helped me recover them all back to a maintenance state.

I went to test the high gain ASC states I made for SEI_ENV this morning while we were still locked this morning. The good news is that there were no errors in the code and it did exactly what I asked of it. The bad news is that we lost lock while transitioning back to a low gain state. This wasn't a great test though because I had a brain fart and forgot to change the thresholds for the test. The high gains were turned on, then immediately turned back. So I'm not entirely sure if the lock loss was from the transition back, or just the fact that we quickly flipped it back and forth. 

The major change between what SEI_ENV does and what the script the operators use right now is that the sleep timers between engaging/disengaging each loop are almost completly gone. At minimum for the next test it seems that we need some for the return back to low gain, or maybe increased tramps.

On the bright side, it looks like the structure of the node and the code seems to work, just need to tune it a bit. For now I've returned this node back to its normal operation, without the high asc states.

M. Todd

Today I ran another OMC scan (following last week's instructions alog 87316 and 87342) after the morning lockloss to see if could a better measurement of the hot state overlaps.

I was still limited to about 12 minutes after the lockloss, so we expect some amount of difference in the full hot state.

I've plotted the results on top of last week's scans, in yellow. Analysis of this will follow in a comment.

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

The second stage heating contactor had burned up, reducing heating capacity. This is why the zone had difficulty maintaining set point on 10/13. I replaced the ruined contactor and checked functionality. 

TITLE: 10/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 15mph Gusts, 10mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.26 μm/s 
QUICK SUMMARY:

• Secondary microseism looks to be rebounding after increasing into the night
• We've been locked for ~19 hours
  • PEM_MAG_INJ node is in error (Key error 'freq_low')
  • The operator WS was stuck at "failed to unmount" when I arrived
• 11:33 UTC Superevent S251014cn

TITLE: 10/14 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

IFO is in NLN and OBSERVING (~10 hr lock)

2:53 - SQZ Dropped

4:10 - SQZ recovered, back to OBS

Mostly quiet shift except for the SQZ dropping due to FC lockloss.

The Squeezer FC lost lock due to FC2 alignment walking away from a lockable GR_LOCKED configuration. As per the wiki, I trended the last time we had a stable lock and reset values for FC1, FC2 and ZM3 (P/Y). Then, I tuned FC2 a bit more to maximize GR_TRANS output. This worked.

Interestingly, I first tried an alignment from a few days ago but this didn't work. I did this because FC2 has been increasing quite a bit in the last few days (screenshots) - probably worth looking into. The values I set FC suspensions to (using opticalign sliders)

FC2 P: 1558, FC2 Y: 109.6 

FC1 P: -899.6, FC1 Y: -74

ZM3 P: -66.25 ZM3 Y: -463

I hope this issue doesn't happen again during OWL shift though the trend below from a few days ago shows FC2 P going up for the last few days seemingly with SQZ compensating in its alignment. Anecdotally, it seems related to the temperature since there's a diurnal breathing day to day (lows at night, highs in the day). Tagging SQZ to look at FC2 and FC.

LOG:

TITLE: 10/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Locked for 4 hours. We had one lock loss during commissioning time today, though it does not seem to be caused by any commissioning activites. useism is on its way up, and the wind is gusting above 30mph at times. 
LOG:

• 1543 Commissioning start
• 1740 GRB short E609775
  • Since we were already commissioning we will not stand down
• 1747 Lock loss
• 1817 GRB short E609786
  • Relocking, no stand down
• 1917 Observing

In 86964 I ran a side by side comparison of the powers at various ports before and after the power outage so we could determine what, if anything had changed. Although it generally seemed like we had regained or even increased the powers everywhere, kappa C has indicated that the optical gain reduced. Our current kappa C has been consistently near 0.98 since the outage.

However, I calculated the full optical gain value today from the most recent calibration report (20251012T200500Z) and the current exported report on August 23 (20250823T183838Z). Each report lists H_c in ct/m. I also chose a time just before each report was measured to calculate the OMC-DCPD_SUM/LSC-DARM_IN1 transfer function that provides the mA/ct calibration value.

It seems like our optical gain between these two times has actually stayed the same to much less than a percent. I'm not sure what to make of this with regards to the calibration, given that the calibration report suggests an overall magnitude change in the sensing function (that we are correcting in the TDCFs), but in actuality the magnitude of the sensing function has remained constant.

TITLE: 10/13 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 19mph Gusts, 14mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.31 μm/s 
QUICK SUMMARY:

IFO is in NLN and OBSERVING (4 hr lock)

Wind is pickign up. Secondary microseism is picking up. Hoping to stay quiet and locked for the shift.

For the SR3 P estimator, we had initially developed and installed blend filters (in H1:SUS-SR3_M1_EST_P_FUSION_MEAS_BP and H1:SUS-SR3_M1_EST_P_FUSION_MODL_BP filter banks), named pit_v1, that blended between the OSEMs on-resonance, and the estimator everywhere else (86452). After a bit, Brian Lantz made a pit_v2 that included OSEM damping at two extra frequencies because we were having issues with extra resonances at 0.65 and 0.75 Hz that weren't being damped (86510)(filter comparisons).
Eventually we realized the reason why those two peaks weren't being damped was because we had forgotten to include the model contribution to P from L, and we installed those needed filters(86567). However, we didn't swap the blend filters back to pit_v1 at the time.
So during relocking today (2025/10/13 19:05:00 UTC), I swapped us back to pit_v1. We will run with this until at least tomorrow morning and then verify that we don't see a difference in the damping of those two peaks.

Lock loss 1444412849

While it was during commissioning, it seems like it wasn't any of the activities going on at the time. Looks very much like the most recent lock losses we have that very quickly go.

Jennie W, Elenna

Today we changed the OFI temperature and monitored the OFI PD A power. At each temperature change, we reran Sheila's OMC fringe wrapping injection to replicate the measurement Sheila and Naoki did in alog 78942.

Results: we did not see a very significant change in the OFI PD A power when we changed the OFI temperature from 37.5 C to 25.5 C. We see a smaller scattering shelf at 25.5 C than we do at 37.5 C.

I saved Sheila's template over into my own directory as /ligo/home/elenna.capote/OFI/OMC_fringe_wrapping.xml

She had old references in that template (different from the alog) that were taken in Sept 2024. Those references indicated that an OFI temperature of 37.5 C had the smallest scattering shelf. Today, Jennie and I saw very little difference between the scattering shelves generated at 37.5 C (nominal temperature), 34.5 C and 30.5 C. Only when we measured at 25.5 C did we see the scatter shelf reduce slightly (plot).

In this plot, I added in Sheila's old references that show the exact opposite result a year ago. Specifically, the 25.5 C measurement from now is very close to the old 37.5 C measurement from a year ago.

At first, I didn't think there was much of a change in the power on OFI PD A. However, looking at the second trend, it looks like maybe the power dropped by a small amount. I might have needed to slow down this test more than I realized (plot). I saved this ndscope template in /ligo/home/elenna.capote/OFI/OFI_TEC.yaml

Today I began calibrating the camera servo signals into spot positions. I ran the A2L script at the nominal camera spot positions. Then, I changed the camera offset and waited for the camera servo to converge. Then I remeasured the A2L gain. Using the a2l_lookup function in /opt/rtcds/userapps/release/isc/common/scripts/decoup/BeamPosition the A2L gain can be converted into a spot position in mm. This is a slow process so it will take time to get the conversions for all.

E. Capote, J. Kissel, S.Dwyer

The ~1 Hz ring-up that had been marginally stable and transient is now fully unstable during the lock acquisition sequence as we recover from maintenance. The suspicion is that the change in ITM M0/R0 satamps might have changed the top mass damping loop OLGTF enough to augment the damped plant that's the plant for the never-really-well-designed L2DAMP that takes the L2 (or PUM) OSEMs and feeds back their sensor signal to the reaction chain top mass OSEMs actuators. But also, we've never measured these loops in any substantial form, so we wanted to just see what they were doing.

Attached are the results. Here're the templates:
    /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMY/SAGR0/Data/
        2025-07-08_2240UTC_H1SUSITMY_R0_WhiteNoise_0p02to50Hz_L2DAMP_OLGTF_P.xml
        2025-07-08_2240UTC_H1SUSITMY_R0_WhiteNoise_0p02to50Hz_L2DAMP_OLGTF_R.xml

Very little loop gain and only at 3.3 Hz. The loop stability is questionable at that frequency -- for a few averages the suppression (i.e. the gain peaking) looks really sharp around 3.3 Hz. 
T'was really tough to get good coherence; the excitation is pretty well tailored, but it's tough to fight the 1/f^6 suppression of the physical suspension and dirt coupling.
I had to turn OFF the R0 alignment offsets to get this data for pitch. (They were ON for the Roll measurement).

So -- perhaps not the source of the ~1 Hz IFO instability, but boy could this loop use some TLC in order to more effectively achieve its goals...