TITLE: 07/08 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

Internet went down 15:09 UTC for what seemed like less than a minute. Cause: Automatic Switching from Boise Connection to Seattle.
Lockloss 15:11 UTC due to an earthquake.
https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1404486684

We moved PR3 back to it's previous position while in Input_Align.
Sheila is touching up the COMM And DIFF beat notes.
17:14 UTC Earthquake passed through and was not announced.
Comissioning started at 17:16 UTC

Nominal_Low_Noise reached at 18:31 UTC.
Observing reached at 18:32 UTC

LOG:                                                

TITLE: 07/08 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 4mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

Observing and Locked for almost 6 hours. Everything going well.

We made a PRCL excitation we should later be able to use to create a PRCL FF, saved in  lsc/h1/scripts/feedforward/PRCL_excitation.xml and exported .txt files.

Naoki, Sheila

We did the OMC fringe wrapping measurement as Sheila did in 77452.

The template for OMC fringe wrapping is in /ligo/home/sheila.dwyer/OMC/OMC_fringe_wrapping.xml.

This time, we fixed the excitation on OMC L and changed the OFI temperature. The frequency of excitation is 0.65 Hz and amplitude is 13.8 um peak to peak on H1:SUS-OMC_M1_DAMP_L_IN1_DQ. The nominal OFI temperature is 25 and we changed it to 35. We waited for OFI witness temperature to reach the target value. We changed it back to 25 after the measurement.

As shown in the attachment, the OFI temperature of 25 looks slightly better than 35, but IFO was locked for only an hour and still thermalizing so we should repeat this measurement after thermalization.

The MSR UPS unit went briefly into battery backup due to an input power problem at 13:51:31

It was only on battery power for 2 seconds before it switched back to facility power.

Attached plot shows the corner mains phases at GPS time 1404420709.52

Mon Jul 08 08:17:16 2024 INFO: Fill completed in 17min 12secs

Gerardo confirmed a good fill curbside. Outside temps 30C (86F).

TITLE: 07/08 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: SEISMON_ALERT
    Wind: 5mph Gusts, 3mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO Locked and Observing for 9 Hours.
everything seems to be functioning well.
 

Daniel, Nutsinee

I was intrigued by the Twin Sisters Rock feature in the brand new spare SHG Terry and Karmeng put together so I did a little bit of digging. A quick summary is that we believe the Twin Sisters Rock feature were caused by the phase mismatch between the red and the green inside of the SHG cavity. We believe the dichroic coating of the SHG back mirror might be a suspect since the coating specifications can not be found. However, the phase mismatch doesn't neccessary explain the Mount Saint Helens in the 6 year-old SHG we are currently using. 

The equation used to fit the data came from Gonzalez, Nieh, and Steier 1973 equation1. The equation looks similar to the usual sinc^2 function we know and love except that it's taken the phase mismatch between 532 and 1064 and the air dispersion into account in the cos^2 term. This paper also shows that the experimental data doesn't necessary match the model (Fig.3). The problem is we have to related deltaK*l term to temperature. This was done using Kato and Takaoka 2002. This left us with K_0. The only unknown-ish term here is the nonlinear coefficient d_eff inside of K_0. We used d_eff = 10pm/V as suggested by Leonardi et al 2018. After I wasn't able to get a sensible result Daniel pointed out that unit in K_0 doesn't add up. We replaced K0 with equation1 from Arie et al 1997.

The function is also very sensitive to polling length of the crystal. Since we don't have the exact number of the polling length, we picked a polling length such that deltaK is 0 at 34.6 C (optimal phase match condition). The polling length we got was 8.99608um. I believe the crystal polling length according to Raicol is 9um.

The function in the end looks like this. I was able to fit Karmeng's Twin Sisters Rock using sensible parameters (d_eff = 10pm/V, circulated 1064 power of 2W, Boyed-Kleinman focusing parameter = 0.9, and a phase shift of Pi/2). Other variations of the spare SHG plots can be explained by shifting this phi variable.

We suspect the coating of the SHG back mirror might be to blame. None of the SHG plots found in SURF reports (Nathan Zhao, Andre Medina) look symmetric like they should. 

The zip file of the python code is also attached.

If the coating is not to blame, I wonder if it's time we think about redesigning a SHG that is more tolerant to the assembly line errors.

TITLE: 07/08 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: One lock loss during the shift. During reacquisition I moved PR3 a little bit to help the comm beat note. After an initial alignment it went straight up and we've been observing for 2.5 hours now.
LOG:

• 0341 lock loss
  • The COMM beatnote was -18dBm when I got ALS locked, so I started running an initial alignment and then moved PR3 small amounts to see if it would quickly help. I ended up moving PR3 P from -122.2 -> -121.6 and Y from 98.8 -> 98.6. This brought the beatnote up to around -14.5dBm and ALSX power moved up as well. when DRMI locked POP18 looks to be higher than it was the last handful of locks over the last few days.
• 0528 Observing

Lock loss 1404445312

5 hours and 42 mins seems like a standard lock for this week. LSC-DARM saw an odd wiggle before lock loss, normally I see an ETMX output that matches this but I didn't see that this time.

I have replaced the original viewport covers so the LVEA is ready to go to laser safe.

At the last minute I finally found a beam on the MC baffle by HAM3. The beam is on the +X side of the baffle, near the hole for the viewport for the PRM camera. I will see if it moves with the CP when I return.

TITLE: 07/07 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Aligning
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

Similar shift to yesterday (except we're around 102degF!), with a 4-5hr lock and 2-3hr reacquisition (with rough locking for the first 90min). 

(Since Observing time is precious, I didn't even think of running a calibration since L1 & V1 were UP all the times I could have run a calibration.)

Robert was onsite as well as JennyW for an RRT shift.
LOG:

• 1458 H1 back to Observing after 2.5relock with RyanS intervention (owl) to get thru issues w/ alsy.
  • IXm13 looking good with its new settings and 1kHz is 2 orders of magnitude lower than what we were having ~18hrs when it was rung up.
• 1934 Lockloss Of The Shift (after a 4hrs41min lock)
  • 1939-1959 Running Initial Alignment
  • For locking, first (2) locklosses were early and due to ALS glitches seen for both X & Y arms as noticed yesterday (before an alignment).  So for next lock, I paused at Locking Arms Green and then Locking ALS.  Then had no issues getting past these early steps.  Just odd and new behavior.
  • Sadly DRMI was a little sad/dead looking at first, but then flashes got better and looked centered, but still no dice.  Selected PRMI after about of 7min of DRMI locking....PRMI locked, but lost lock during PRMI ASC (possibly due to Japan EQ).
  • Several more ALS glitch locklosses, even with pauses.
  • Made it through PRMI, and then while trying to acquire DRMI, noticed the glitching appearing on both alsx & y a few seconds before the lockloss. 
  • ....and after about 100-110min, H1 finally makes it past DRMI and continues without a hitch.  (Robert suggests we have an opitc which gets hot, causes lockloss, takes time to cool down, and then allows us to relock.  Sounding about right.)

Commissioning time has been reduced recently by lock losses and other issues, so I have been trying a new technique for determining the ITM biases that minimize coupling of electronics ground noise. I have been making slow adjustments of the bias during observation, recording the times of those slow changes, and then monitoring the coherence between DARM and the current clamp on the electronics grounding cable in the CER for the new settings.

The times of the slow changes during observation mode, and the bias setting I have tried, are listed in 78791, 78767, 78734 and this log. The figure compares the original settings for O4b, the setting that we guessed would be best, 0V,0V, and the setting that was consistently better, ITMX: 0, ITMY: -40 V (a setting of -4 in the offset window).

TITLE: 07/07 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 10mph Gusts, 8mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY: Corey got us relocked and we've been running good for an hour.

Link to report

• The duty cycle for this week was 63.3%
• Some days, the lock losses were due to earthquakes, some due to ETMX motion and some have unknown causes.
• Average range was between 155-160 Mpc, with some days have big dips due to wind motion.
• The week has relatively high wind motion with moderately high seismic motion.
• The End BSC 10 has constant high amplitude low frequency noise.
• The HVETO round winners were different every day.
• FScan: All plots have appeared with all days having the line count well below the threshold.

Lock loss 1404369750

Again, not seeing much of anything on any of the plots. Another 4-5 hour lock.