We were getting hit by a 6.1 from Vanuatu at the time, https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1418832746.

SEI went to earthquake mode 1 minute before the LL.

TITLE: 12/21 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 14mph Gusts, 10mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.49 μm/s
QUICK SUMMARY:

We've been locked for 6 hours

2ndary microseism is increasing, wind is low/moderate

TITLE: 12/21 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 159Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: H1 has been locked and observing for about 4.5 hours. Been a quiet evening since H1 relocked early this shift.

• 00:11 - Lockloss - alog81930
• 01:38 - Observing

FAMIS 26348, last checked in alog81819

All fans look well within acceptable noise levels and largely unchanged from last check.

Lockloss @ 00:11 UTC - link to lockloss tool

Locked for about 1.5 hours. No obvious cause, but interestingly the first saturating suspension here was ETMY L2, which I don't think is typical.

TITLE: 12/21 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: 2 locklosses, recovering from the last one currently. New o4b record of 47 hours?
LOG:                                                                                                                             

20:59 UTC lockloss from a 47 hour lock which I think is the new O4b record. Easy relock with an IA, which I had to help out inbetween SR2 and SRY align as it got couldn't get SRY (lots of SRM sats), I reran SR2 and them SRY was fine.

00:11 UTC lockloss

TITLE: 12/21 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 3mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.41 μm/s
QUICK SUMMARY: H1 has been locked for just over an hour. If there's a lockloss this evening, I plan to adjust the ISS RefSignal to bring the diffracted power back up to around 4% (currently down to around 2.5%).

• Wind is low; secondary microseism moderate
• LAB2 dust monitor error (known)

New calibration lines turned on 7/25/2023 resulted in unexpected additional inter-modulation products. These new calibration lines were turned off on 8/9/2023.

When looking at coherence data between the main detector and safe channels, we expect no change in the before-during-after periods of the new calibration lines and additional inter-modulation products. However, in “safe” channel CS MAG EBAY LSCRACK Y, we see coherence jump at the specific frequencies of the calibration lines and inter-modulation products. This indicates that the channel may actually be unsafe.

Plots for H1_PEM-CS_MAG_EBAY_LSCRACK_Y_DQ  before / during / after

Research Presentation: https://dcc.ligo.org/G2402592

ETMX glitch lockloss tool

Fri Dec 20 10:11:13 2024 INFO: Fill completed in 11min 10secs

TC-B is still elevated by about +30C compared to TC-A and did not reach the trip temp.

Closes FAMIS#26473, last checked 81396

 HEPI pump trends looking as expected(ndscope). There is a period of rapid change in the pressure at EX 28 days ago, right after TJ put in his alog (linked above) about the pressure being a bit weird, and that's because Jim and Mitchell had gone out to investigate it (81399).
 

TITLE: 12/20 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 160Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: SEISMON_ALERT
    Wind: 3mph Gusts, 2mph 3min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.32 μm/s
QUICK SUMMARY:

• We've been locked for 41.5 hours!
• 2ndary microseism is steady, low wind, theres a small EQ shaking us (5.5 from Vanuatu)
• PMR and PR2 cameras are blue
• If we lose lock we want to transition the LVEA back to laser safe

TITLE: 12/20 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:
H1 Still locked for 32 hours! Currently Observing.
Aside from the breif Internet outage nothing really happened.
Violins looking good, No Pi's ringing up or nothin.
This is a good start going into the holidays.

 

TITLE: 12/20 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 157Mpc
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 7mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.34 μm/s
QUICK SUMMARY:
CDS & GS internet connectivity to the outside world went down. Issues due to Core Switch work?
Outage lasted from 2:00 UTC to ~ 2:24 UTC. 

IFO stayed locked during that time, We now have a 28+ Hour lock. 
Control over the IFO was maintained throughout the entire outage.
Local networks stayed up and running just fine.
I called Dave & Jonathan, Jonathan told me to wait it out, as it's just a switch updating , rebooting, and falling back to another network.
I presume the falling back to the other network bit took some time.

All systems recovered the way Jonathan said they would. He advised me to wait it out if there is another one, and to call him again if things went down after 3 :00 UTC (7pm local) .
So far so good.
 

This alog follows up LHO:81769 where I calibrated the ASC drives to test mass motion for all eight arm ASC control loops. Now, I have taken the noise budget injections that we run to measure the ASC coupling to DARM, and used that to calibrate an angle-to-length coupling function in mm/rad. I have only done this for the HARD loops because the SOFT loops do not couple very strongly to DARM (notable exception to CSOFT P, which I will follow up on).

The noise budget code uses an excess power projection to DARM, but instead I chose to measure the linear transfer function. The coherence is just ok, so I think a good follow up is to remeasure the coupling again and drive a bit harder/average longer (these are 60 second measurements). This plot shows the noise budget injection into calibrated DARM/ASC PUM drive [m/Nm] transfer function, and the coherence of the measurement.

I followed a similar calibration procedure to my previous alog:

• Go from "H1:ASC-[DOF]_[P/Y]_OUT_DQ"  to Nm of PUM torque using G1100968
  • I made sure that I corrected by an erroneous factor of two that I found previously
  • Some of these injections were done after the ETMX DAC change. However, Daniel noted this alog for me, 80023, so the calibration for the ASC should not change significantly.
•  transform this N*m PUM drive to radians of test mass motion using the PUM-TST state space suspension model transfer function, which is calibrated into real units (radian/Nm)
  • I did all of this in python, so I used Kevin's exported quad state space model, found here: T2300299
  • I used the damped model which applies the ETMX top mass damping filters
• Multiply by 1e3 to convert to mm/rad

I did not apply the drive matrix here, so the calibration is into ETM motion only (factor of +/-1), whereas the calibration into ITM motion would have an additional +/- 0.74 (+/- 0.72 for yaw) applied.

HARD Pitch Angle to Length coupling plot

HARD Yaw Angle to Length coupling plot

Overall, the best-measured DOF here is CHARD Y. In both CHARD Y and DHARD Y, there seem to be two clear coupling regions: one fairly flat region above 20 Hz in CHARD Y and above 30 Hz in DHARD Y, reaching between 20-30 mm/rad. Below, there is a steep coupling. This is reminiscient of the coupling that Gabriele, Louis, and I measured back in March and tried to mitigate with A2L and WFS offset. We found that we could reduce the flatter coupling in DHARD Y by adjusting the A2L gain, and the steeper coupling by applying a small offset in AS WFS A yaw DC. We are currently not running with that WFS offset. The yaw coupling suggests that we have some sort of miscentering on both the REFL and AS WFS which causes a steep low frequency coupling which is less sensitive to beam centering on the test mass (as shown by the A2L tests); meanwhile, the flat coupling is sensitive to beam miscentering on the test mass, which is expected (see e.g. T0900511).

The pitch coupling has the worst coherence here, but the coupling is certainly not flat. It appears to be rising with about f^4 at high frequency. I have a hard time understanding what could cause that. There is also possibly a similar steep coupling at low frequency like the yaw coupling, but the coherence is so poor it's hard to see.

Assuming that I have my calibration factors correct here (please don't assume this! check my work!), this suggests that the beam miscentering is higher than 1 mm everywhere and possibly up to 30 mm on the ETMs (remember this would be ~25% lower on the ITMs). This seems very large, so I'm hoping that there is another errant factor of two or something somewhere.

My code for both the calibrated motion and calibrated coupling is in a git repo here: https://git.ligo.org/ecapote/ASC_calibration

TITLE: 12/20 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 159Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 2mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.32 μm/s
QUICK SUMMARY:
H1 has been locked for over 26 Hours.
Current plan: stay in Observing.

Note:
Dust mon LAB2 still not reporting back correctly.
 

TITLE: 12/20 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 162Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Locked for 26.5 hours so far. We took calibration measurements this morning, followed by 3 hours of commissioning time.
LOG:

• 1630 Out of Observing to start calibration measurement and then commissioning
• 2007 Observing