TITLE: 02/20 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Relocking
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 2mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.42 μm/s
QUICK SUMMARY: Just lost lock from a nearby earthquake. Barely saw it on the picket fence before we lost lock, but our control signals were moving. For the 8 hour lock that just ended, 4 hours ago there was a step down in the range and then less stable range. DARM looks to have more noise in the 80-200Hz area, my screenshot doesn't show it completely. Violin mode 6 was slowly ringing up overnight.

TITLE: 02/20 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

IFO is LOCKING at LOCKING_ALS (Once again, we lose lock in the last few mins of shift...)

IFO is in NLN and OBSERVING as of 03:07 UTC.

Overall very calm shift in which we seem to have improved squeeze locking, improving range to what it was before last weekend.

We had one Lockloss seemingly caused by oscillations in PRCL in the seconds before the losing lock - alog 82916. According to the first OLG PRCL measurements from alog 82920, Elenna found that the PRCL2 gain was low by about 30-40%. Following this, she made a change to up the gain from 1 to 1.4 (alog 82917). Accepted SDF attached.

While 1.4 was a bit too high and caused a PRCL ring-up and a LL at LOWNOISE_LENGTH_CONTROL (where the gain switches on), the next setting of 1.2 worked! We were able to fully automatically re-lock and get to NLN and OBSERVING. Before I went into OBSERVING, I took another OLG PRCL measurement, which is the second measurement in alog 82920.

Other than this, the infamous IY Mode 5_6 Violin has been ringing up, visible in the top right screen of the attached screenshot, which shows mode 6 as slowly increasing since Lock. New settings may be needed for this.

Just as I was about to submit, we had a LL, though there wasn't the characteristic PRCL ring-up from the last few LLs. It also doesn't look environmentally caused since wind is low, there are no EQs and microseism is high, but unchanged mostly from the beginning of the day. Currently experiencing known ALS lock issues.

LOG:

None

TJ, Ibrahim, Sheila, Elenna

Measured PRCL OLG at 2 different times during NLN - both attached.

First (done by TJ) at 3hrs into NLN -  Screenshot 1.

Second at 15 minutes into seperate NLN. This one was done after a PRCL-related lockloss (alog 82916) at which point Elenna changed the PRCL2 Gain from 1 to 1.2 (alog 82917) - Screenshot 2.

I increased the PRCL2 gain that is set in lownoise length control from 1.0 to 1.4 to increase the overall PRCL loop gain by 40%. We have been seeing locklosses with 11 Hz oscillations that are probably due to marginal stability in PRCL. I changed line 5577 of the ISC_LOCK guardian, saved, and loaded. Ibrahim will post an alog with more info and open loop gain plots.

Lockloss that matches the ones from over the weekend, where PRCL becomes unstable and oscillates at 11Hz in the seconds before the Lockloss.

TITLE: 02/20 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: The shift started out with a lock loss just before commissioning time. We took this opportunity to move PR2 spot while out of lock to find the baffle edges. We then relocked and Sheila and Oli fixed and issue we had causing lock losses at transition from ETMX (alog82912). We went back to observing for a few hours before stepping out to tune the SQZ angle and run a quick PRCL OLG. Results on the latter will be posted by Ibrahim later after he takes another to compare.
LOG:

• 1556 Lock loss
• 2133 Observing
• 0007 Out of observing to tune SQZ and run PRCL OLG
• 0018 Observing

TITLE: 02/20 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 144Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.60 μm/s
QUICK SUMMARY:

IFO is in NLN and COMISSIONING

The plan is to optimize SQZ via SQZ angle adjustment followed by a PRCL Open Loop Gain Measurement since there is some evidence that PR is experiencing noise at certain problem frequencies. Then, we go back to OBSERVING

Back to observing after a lock loss, some commissioning time, and trying to fix the transition from etmx lock losses.

useism is still high and our range is a bit low at 145Mpc. If the range doens't improve with more thermalization, we will take it out for some tuning.

Oli, TJ, Sheila

There have been several locklosses over the last day from the LOWNOISE_ESD_ETMX state, which happened while the gain was ramping down ITMX darm control and ramping up ETMX control.  This is similar to what Elenna was trying to avoid by adjusting ramp times in 81260 and 81195, which was also at a time when the microseism was high.

Oli and I found that the problem with some of our transitions today was that the power on the DCPDs was dropping too low during the initial transition, we lost lock when it got to less than 1mA, in one of the sucsesful transitions it was as low as 4mA.  We edited the guardian to not turn off the darm boost (DARM1 FM1) before making the transition, and instead we are turning it off directly after transitioning control back to ETMX, before the other filter changes that happen in this state. 

This is the boost that we thought was causing locklosses when ramping off, 81638 which motivated Erik's quadratic ramping change 82263 which was then reverted 82284    82277.  Today Oli and I increased the ramp time on this filter from 10 to 30 seconds.  We have make the guardian wait the full 30 seconds for this ramp time, so this is making us wait longer in this state.

The attached screenshot shows the transition with the boost on on the left, and off on the right, the wiggle in the DCPD sum is about 1 mA rather than 15mA. 

Oli is thinking about adding a check for DCPD sum dropping low to the lockloss tool.

HAM7 & 8 look less noisy at high frequency, same with the BSCs especially ETMY.

Nutsinee pointed us to this 66765 where the squeezer pico was left on and caused a large line. 

Indeed, the HAM7/SQZT7  pico has been on since Jan 7th, when we were making homodyne measurements  82153 .  This must have been accepted in SDF, but I don't see any alog about it on the 7th.

Wed Feb 19 10:05:46 2025 INFO: Fill completed in 5min 43secs

TCmins [-62C, -60C] OAT (+1C, 34F) DeltaTempTime 10:05:47

To get in Observing I had to accept some SDF diffs for SQZ, and PCALY. There was also still a PEM CS excitation point open as well. There was a notification about PCALY OFS servo malfunction so I looked at it and it was railed at -7.83, so I toggled it off and back on and it brought it back to a good value. I also did not receive a call, a voicemail just appeared.

09:21 UTC observing

Daniel, Patrick, Jonathan, Erik, Fil, Ibrahim, Marc, Dave:

Starting around lunchtime and getting more frequent after 2pm the Timing system was showing errors with EY's fanout port_5 (the sixth port). This port sends timing to h1iscey's IO Chassis timing card.

At EY, Marc and I replaced the SFPs in the fanout port_5 and h1iscey's timing card. At this point we could not get port_5 to sync. We tried replacing the timing card itself, but no sync was possible using the new SFPs. Installing the original SFPs restored the sync, but the timing problem was still there. Moving to the unused port_7 (seventh port) of the fanout fixed the problem. We put the original timing card back into the IO Chassis, so at this point all the hardware was original and the fanout SFP had been moved from port_5 to port_6.

TITLE: 02/15 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Locking
INCOMING OPERATOR: Corey
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 04:16 UTC.

EDIT: IFO is LOCKING at SDF_REVERT after a 05:59 UTC Lockloss

Overall calm shift with one lockloss due to an Earthquake (alog 82821).

Other:

• We also survived another earthquake (4.9 from W Texas).
• Range is quite low due to bad high frequency squeezing, which I was told to expect. This will probably remain the case until more table work is done next week.
• I tried (from Sheila and Ryan S's recommendation) a small test to see if going into GREEN_ARMS_MANUAL, locking the arms manually, then going through in INITIAL_ALIGNMENT_OFFLOADED would bypass our ALS locking failures. Interestingly, this worked, allowing us to lock with normal locking without running into ALS problems - the investigation continues.
• Ryan's new FM 1,3,10 -1G EY Violin Mode 20 seems to have worked, reaching a pre-LL minimum of 0.18 before nouncing about that. As such after the reacquisition, I re-set those as the EY20 settings.

LOG:

None

I took a look at the locklosses during the calibration measurements the past week. Looking at DARM right before the locklosses, both times a large feature grows around ~42 Hz right before the lockloss. Sat LL Thur LL

Thursday:

DARM_IN was dominated by the 42 Hz long oscillation and a ~505 short oscillation until the LL, DARM_OUT was dominated by the harmonic of the violins ~1020 Hz.

Saturday:

DARM_IN had a long and a short oscillation, the fund violin modes, ~510 Hz and ~7.5 Hz, DARM_OUT was dominated by the harmonic of the violins ~1020 Hz

I'm not sure how to/where to see exactly what frequencies the simulines were injecting during and before the lockloss.