TITLE: 07/10 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 15mph Gusts, 13mph 5min avg
    Primary useism: 0.06 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is LOCKING at Lownoise_Coil_Drivers

TITLE: 07/10 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Relocking
SHIFT SUMMARY:

- Lockloss @ 15:57 - unknown cause

- Had to touch ALS Y slightly as INCREASE FLASHES failed twice and had to hit FORCE on the ALS X PLL overview to get the beatnote to 39 MHz, rest of locking was automated

- Held at OMC WHITENING to damp violins (~1 hour)

- Acquired NLN/OBSERVING @ 18:00

- 20:34 - 6.6 EQ from Antigua, 20:37 EQ mode activated, back to CALM @ 22:31

• Lockloss @ 20:45

- Currently relocking, fully automated so far @ OFFLOAD_DRMI_ASC

• Automation went through INCREASE FLASHES for ALS X and PRMI ASC

LOG:                                                                                                                                                                                                                                                                                                                                                                                                 

Lockloss @ 20:45, due to 6.6 EQ from Antigua

Trying to track down the origin of the 2.6 Hz peak, I looked at times during the lock acquisiton when the IFO is down, when only OMC ASC is on and when the IFO ASC is on. The first plot shows a compariison of OMC M1 damping signal, OMC ASC and IFO ISC in diffeerent configuurations. Some observations:

• the OMC moves a lot more when the OMC ASC is turned on
• it doesn't look like the 2.6 peak comes fm the OMC ASC along, but there are only ~15 seconds with OMC ASC on before the IFO ASC goes on
• it looks like the 2.6 Hzz peaks appears when the IFO ASC loops are in low-noise state

The second plot compares the OMC damping signal when the IFO is down vs nominal low noise: the OMC suspension is moving up to 100 times more when the IFO is in nominal low noise

Finally, I compared the OMC motion at LLO and LHO during the same nominal low noise time. The LHO OMC moves a lot more than the LLO OMC.

Althouhg there is no evidence that the 2.6 Hz peak is generated by the OMC controls, it is very prominent in the OMC damping signals. It seems that the OMC ASC at LHO has too large bandwitdh: it would be worth investigating if a low bandwidth control like at LLO would work, and whether it can also improve the 2.6 Hz situation: it is possible that the 2.6 Hz motion is residual IFO angular control, but the OMC ASC makes it problematic for DARM by moving the OMC

Mon Jul 10 10:07:23 2023 INFO: Fill completed in 7min 22secs

Travis confirmed a good fill curbside.

Below is the summary of the DQ shift for the week of 2023-07-03 to 2023-07-09

• The detector had very good uptime this week (observing 77%), and the range was consistently around 140 Mpc with a few Mpc fluctuations. During the last couple of days, it was on the lower side.
  • The reasons for most of the lock losses reported to be unknown.
• Almost all the locks begin with high violin modes, with rung-up violin modes even at 3 - 4 kHz. Between a lockless and relock, something seems to ring them up (alog 71063).
• The ~52 Hz line-like feature has gotten strong and changes its amplitude over hours time scale. We also see ~26.50 Hz, ~39.25 Hz, and 65.75 Hz features but not all simultaneously. The 52 Hz feature is dominant among these and shows a lot of variability. Sometimes the 52 Hz also looks like a two-line feature at that frequency. In the X-end accelerometers, we also see similar features, but it is unclear whether they are related to each other (we don't see strong coherence, not at least at 0.125 Hz resolution).
• The noise in the 10 - 60 Hz also varies a lot. It is also suggested that some of these features could come from calibration lines (non-linear/bilinear effects) (alog 71149).
• There is excess noise around the 120 Hz line, but it is mainly on the higher frequency side of it.
• Most strong omicron glitches tend to occur at specific frequencies like ~32 Hz, ~40 Hz, ~50 Hz, ~74 Hz, ~120 Hz, ~180 Hz, ~280 Hz, and ~400 Hz.
• We also see a wandering line at 4620 Hz (a few tens of Hz wander).
• In the Fscan, we see combs of 1.6611 Hz, 29.969 Hz, and 4.9842 Hz. They are present during the whole week.
• Sometimes we see excess noise in the PCALX RX and TX channels, but it does not seem to affect DARM (low amplitude ?).
• On July 5 and 6, we see step changes in the corner station's 10-30 Hz seismic BLRMS. It also appears in other ground motions (ACC) channels at specific frequencies (some pumps turning off ?).
• In Hveto, we see some of the ASC channels and EX_VMON_ETMX_ESDPOWER as the first few round winners. They tend to remove some of the large glitches we see.
• We see a relatively large number of glitches in the pyCBC short-duration triggers (with new SNR > 9).

The full DQ shift report with day by day details is available at https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20230703

Lockloss @ 15:57, DCPD saturations right before. SEI and wind motion is low. No evidence of any LSC/ASC ringups.

At the request of Louis Dartez and Jenne Driggers, we carried out a quick study on the impact of additional calibration lines added to H1 (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=69284). To avoid confusion by extraneous effects, we studied the impact of a simple 1Hz "notch" (i.e. a chunk of data removed in the analysis) centred at 24.5Hz (based on Louis' suggestion). We took the design sensitivity O4 PSD and simulated a high-SNR BBH signal. The full script and results can be found here: https://ldas-jobs.ligo.caltech.edu/~gregory.ashton/O4/calibration_lines/, but the key result is in this comparison plot (https://ldas-jobs.ligo.caltech.edu/~gregory.ashton/O4/calibration_lines/outdir_bbh_simulated_o4_data/combined_notch_False_notch_True.png) which shows the posterior distributions and matched-filter SNR with and without the notch. From this, it is clear that any differences are below the typical level of sampling uncertainty. Therefore, I do not foresee any negative impact from the addition of calibration lines to events observed during lock stretches where they are present.

TITLE: 07/10 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 141Mpc
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 13mph Gusts, 10mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.06 μm/s 
QUICK SUMMARY:

- IFO has been locked for 4 hours

- CDS/SEI/DMs ok

TITLE: 07/10 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 141Mpc
SHIFT SUMMARY:

• 1 Lockloss, mostly automated relocking, violin ringups as usual from the LL
• We've been locked for 4:00 as of 15:00UTC
• Handing off to Austin

Lock#1:

Locked upon arrival, LL at 07:57UTC with a DCPD saturation. This LL isn't showing up on H1locklosses, lock time of 2:27.

Lock#2:

Xarm was failing increase flashes repeatedly and complaining about PLL beatnote running out of range, it wasn't able to get a good H1:ALS-X_FIBR_LOCK_BEAT_FREQUENCY. I simply turned on the autolocker by clicking "Force" on the Xend PLL medm and within 30 seconds it locked at a good beatnote and power. I then turned it off by clicking "No Force".

Went through PRMI which locked fairly quickly, then back to DRMI which also caught quickly.

While in OMC_WHITENING damping violins I noticed the SQZ manager was reporting "SQZ ASC AS42 not on??" around 10:00UTC, So I followed Vicky's instructions from LHO alog71083 and went to RESET_SQZ_ASC then back to FREQ_DEP_SQZ and it fixed it.

The wind has been increasing over the past few hours, gusts up to 45mph as of 12:30UTC but its calming down

LOG:

No log for this shift

We had a lockloss at 07:57, relocking was mostly automated I only had to intervene to help Xarms PLL lock. I had to hold in OMC_WHITENING for about 1.5 hours for the violins to damp. Back in NLN and Observing as of 11:00 UTC.

IFO is still not locked. Daniel and Austin (during and post-shift) and thankfully now, Camilla have all tried helping but so far we don't know what the problem is. Here are some of the leads.

Initial Alignment is not, and has not been working since 12PM today (and from last week's initial alignment, this seems to be a known issue). Firstly, MICH_BRIGHT and MICH_DARK do not lock according to guardian (but they seem to lock according to Austin and Daniel at the start of the shift). The behavior of the MICH trace is oscillating between the threshold (4000 cts) and 0, which is odd. After getting MICH "as locked as possible", we (Daniel, Austin and I) manualled over to SRC locking, which also failed in a similar way. Initial alignment did not work at all. According to Daniel, the gain had to be bumped 10x to lock MICH but then the init_alignment just failed completely afterwards (everything swinging). I tried touching the various documents' manual alignment sliders (BS, SRM, SR2) to no avail. Even during SRC manual locking, the differential in the "high highs" and "low lows" was nowhere near what it trended as. With zero indications of the problem after parsing through the code and attempting to call other people, Camilla offered help.

With this help, we could not get locked still so we thought to try normal locking without any confirmation that initial alignment works. Somehow, this worked. IFO is currently powering up. DRMI locked easily while bumping the BS during Engage_DRMI to better the usual signal traces.

In diagnosing the issues with the help of past alogs and trends, the last time MICH offloaded successfuly was June 26th. It failed on the 1st, 3rd and today. While the locking issue seems to have been fixed, we still have not fixed the initial (incl. manual) alignment locking problems. Expecting to be locked within the next 30 minutes now.

Special thanks to Austin, Daniel and Camilla for volunteering their time to assist with this eventful eve.

I came in to investigate the ITMX ISI troubles. Seems like the problem was (is?) an issue with the ISI coil drivers, which is a new one for me.

What I tried so far this morning:

1. Killing all requested drives in the model, turned off masterswitch.

2. Checked rack, all of the chassis seemed to be in a normal state, no missing lights.

3. Power cycled ISI interface chassis, T240 chassis. No change.

4. Turned off all the coil drivers. Boom, oscillation goes away. See attached trend. L4Cs go to 0 when I turn off ISI interface chassis, but come back  in oscillating state. The ring down is when I powered off the coil drivers.

5. Turned each coil driver one at a time to see if it comes back. All quiet, but there is a kick each time a chassis gets turned on. Must be some offset somewhere in the electronics? Model is still requesting 0. I haven't seen that before, worth doing some more testing.

6. Turned on damping loops, everything is still quiet.

7-? Start bringing ISI back. Get sidetracked by blend settings not being INIT'd in SDF....

Following along Gabriele's work to understand noise from modulation of low frequency lines in DARM, I made a noise comparison today using DARM with no calibration lines. We stayed in NLN CAL MEAS (all cal lines off) long enough to get a good measurement of GDS CALIB STRAIN with no calibration lines. I compared this with GDS CALIB STRAIN NOLINES during times when the calibration lines were on. See attached plot. The difference is small, but I think it is evidence that we are seeing some of these low frequency peaks like the 2.6 Hz modulating the calibration lines and causing excess noise. Even though the NOLINES channel has the calibration lines subtracted, we do not subtract any bilinear effects from the calibration lines. I grabbed a couple different random times from recent locks to make sure I wasn't getting fooled by transient noise.

Our range jumped up to 147-151 Mpc during times when the calibration lines were off, which I think is a combined effect of the additional sensitivity from no lines and also no other peaks from line modulations. Usually our range is around 145 Mpc.