Mon May 06 10:12:36 2024 INFO: Fill completed in 12min 32secs
Gerardo confirmed a good fill curbside.
Sheila, Jenne, Tony, Camilla
We've had locklosses in DRMI because the PRCL gain has been to high when locked on REFL1F. Tony looked and thinks that this started on 77583, the day of our big shift in the output alignment.
Today we acquired DRMI with half the gain in the PRCL input matrix for 1F, this one acquisition was fast. I've attached the OLG measurements for PRCL and MICH after the change.
Tony is working on making histograms of the DRMI acquisition times, before the 23rd, from the 23rd to today, and eventually a histogram from today for the next few weeks to evaluate if this change has an impact on the DRMI acquisition times.
Jenne also found that it seems out POP18 build up seems higher in DRMI since the 23rd.
I'm no longer quite so sure about the conclusion that Pop18 is higher, or at least enough to really matter.
Here are 2 screenshots that I made extremely quickly, so they are not very awesome, but they can be a placeholder until Tony's much more awesome version arrives. They both have the same data, displayed 2 ways.
The first plot is pop18 and kappaC versus time. The x-axis is gpstime, but that's hard to interpret, so I made a note on the screenshot that it ranges from about April 20th (before The Big Shift) to today. Certainly during times when the optical gain was low, Pop18 was also low. But, Pop18 is sometimes high even before the drop in optical gain. So, probably it's unrelated to The Big Shift. That means that the big shift in the output arm is not responsible for the change in PRCL gain (which makes sense, since they should be largely separate).
The second plot is just one value versus the other, to see that there does seem to be a bit of a trend that if kappaC is low, then definitely Pop18 is low. But the opposite is not true - if pop18 is low kappaC isn't necessarily low.
The last attachment is the jupyter notebook (you'd have to download it and fix up the suffix to remove .txt and make it again a .ipynb), with my hand-typed data and the plots.
I actually didn't load the guardian at the time of this change, so it didn't take effect until today.
So, we'd like histograms of DRMI acquitisiton times from before April 23rd, from April 23rd until today, and for a few weeks from today.
Using the Summary pages I was able to get a quick google sheet to give me before and after Histograms of how long ISC_LOCK was in DRMI 1F.
First Sheet's data is before Nov 18th 2024, consisting of 100 gpstimes and durations where ISC_LOCK was in AQUIRE_DRMI_1F.
Second Sheet's data is After Nov 18th 2024. Consisting of 100 gpstimes and durations where ISC_LOCK was in AQUIRE_DRMI_1F
Interesting notes about ISC_LOCK.
ISC_Lock will request PRMI or Check MITCH Fringes some where between 180 seconds and 600 seconds, depending on how much light is seen on AS_AIR.
If AS_AIR sees flashes above 80 then ISC_LOCK will not kick us out of DRMI until 600 seconds.
So it looks like one of the changes that happened on or around Nov18th made the Flashes on AS_Air higher but we are still not actually locking DRMI.
We had fewer Aquire DRMI durations, over 180 Seconds before Nov 18th's changes.
TITLE: 05/06 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 15mph Gusts, 13mph 5min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY:
When I arrived the IFO was in REDUCE_RF45_MODULATION_DEPTH.
We made it up to Transition_From_ETMX before a lockloss.
The wind is fairly Gusty today.
Here is DQ Shift Report During this week :
TITLE: 05/06 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:
IFO is in NLN and OBSERVING (6 hr 31 min lock). This is the longest lock in the last 24 hrs (4 brief locks in between).
I did not experience any of the issues that occured earlier in the week.
The squeezer phase angle had to be adjusted after 2-3 hrs (noticed the range going down, then noticed the SQZ not at its optimum) and was able to bring the range back up to what it was prior.
LOG:
None
IFO is in NLN and Observing as of 00:33 UTC (2 hr 35 min lock)
Nothing else of note
Anamaria, Sheila, Robert
We scanned the biases for three test masses to find the coupling minimum for currents that we injected onto the building ground. The optimal ETMY bias was 115 V in January of 2023, 170 V in Aug. (72308) and 200 V now. With ITMX at 0V, the optimal for ITMY was 60 V in March of 2023 (68053) and -222 V now, The figure shows some of the bias scans.
On the 2nd, Robert Anamaria and I found settings that would set the biases to these values, but the EY value hasn't been correctly applied in the automated relocks since. (77647)
For ETMY, L3_LOCK_BIAS_OFFSET should be -4.9 while the L3_LOCK_BIAS_GAIN is -1 to produce a voltage readback of 200V. I've reset this in the guardian, which I might have done last week with a typo.
This has now been loaded so shoud be at the correct value from 16:00UTC 07 May 2024 77674 .
Anamaria, Robert
We photographed, from a second angle, the beamspot of a stray beam that I noticed last visit (76969 - Fig. 3 ). The photos (Figure 1) confirm that there is indeed a bright stray beam hitting, at a grazing angle, the bellows and other parts of the spool piece between HAM3 and the IMC tube.
I also wanted to measure the power of the stray beam that had been producing a large 48 Hz peak in DARM during early O3, in order to improve my scattering coupling calculations. This is the beam that reflects off of the PR2 scraper baffle and hits the illuminator viewport on HAM3, which we mitigated by inserting a black-glass viewport cover (52184). We were surprised by how bright the beam is, reaching 20 mW on the power meter (see Figure 2), even though we could not fit the whole beam on the meter. We estimate that the beam may reach 60 mW.
Finally, we made movies as we swept the ITMY compensation plate, hoping to see some indication of where the ghost beams are hitting, but did not. We will have to wait until Alena gives us the likely position of the CP ghost beams based on the angles that Anamaria showed us how to measure.
Minhyo, Anamaria,
I've calculated the point at which the tail of the Gaussian laser beam should touch the PR2 scraper baffle to reflect about 60 mW, following Anamaria's idea.
Assuming that the estimated beam size at the PR2 scraper baffle is 7.47 mm, and the total beam power is 3 kW, the beam touches the side of the PR2 scraper baffle's hole at a position 15 mm away (4 sigma) from the center of the beam. I'll include the calculation later on how the beam is actually positioned within the 70 mm aperture of the PR2 scraper baffle.
The original alog referenced above (52184) has photos that show that the aperture of the baffle is visible at the same location as the beam when the interferometer is unlocked, and argues that this means that the beam is hitting the edge of the baffle aperture.
Minhyo
1) Made typo in above comment from mine. The estimated beam radius 7.67 mm -> 7.47 mm (edited on the original comment as well)
2) I'll elaborate the result of calculation in above (15 mm from the center) in below:
Assuming the total power is 3 kW, the percentage of 60 mW power is 0.002%. Since the percentage of normal distribution for 4 sigma is 99.9937%, the partial integration in the upper limit is around 0.0032%.
Using this approximate number, I searched for the exact number to produce 0.002% with a 2D Gaussian beam model with a 3 kW power and 7.47 mm radius. From the beam model, it showed that integration from 4.11 sigma produces a power of around 0.0604 mW, suggesting that the beam is clipped at a point around 14.94 mm (4.11 sigma) from the center of the beam. I have attached a summary figure of my calculation.
Rechecked situation at LLO: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=70996
TLDR: we see the same, but seems much lower power. Will measure when we get the chance.
Lockloss due to local EQ in Idaho (EQ mode activated but wwasn't enough it seems).
Actually it was a 4.4 in north Utah (just showed up on USGS)
TITLE: 05/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:
Overall summery is that it's been earthquaking all day.
Another Incoming 5.6 mag Earthquake
Took this time to do another Initial_Alignment while the earthquake passed.
Reached Observing for the 3rd time today at 22:36 UTC
LOG:
no log
TITLE: 05/05 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 16mph Gusts, 12mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY:
IFO is in NLN and OBSERVING (47 min lock)
TITLE: 05/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: EARTHQUAKE
Wind: 19mph Gusts, 17mph 5min avg
Primary useism: 0.15 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:
First lock:
Ran Initial Alignment
Started Locking 15:28 UTC
Held in ENGAGE_DRMI_ASC for a 3-4 Minutes minutes after reading alog
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=77622
Had no problems in DRMI Locking.
Had no problems in Transition_From_ETMX
Incoming 5.4 Mag Earthquake from Papua New Guinea
https://earthquake.usgs.gov/earthquakes/eventpage/us6000mwhz/executive
NLN Reached at 16:16 UTC
Observing reached at 16:19 UTC
Unknown lockloss 16:47 UTC https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1398962851
Screenshots attached to alog.
Relocking:
Tried a few times to get above DRMI. Made it to Check_AS_SHUTTERS then Lockloss.
Trying another Initial_Alignment just incase it is an Alignment issue before I start exploring more exotic issue.
5.4 Mag Earthquake off the coast of Ecuador
https://earthquake.usgs.gov/earthquakes/eventpage/us6000mwij/executive
Stopped at DRMI_LOCKED_PREP_ASC, Changed H1:LSC-PRCL1_GAIN from 8 to 4.
then proceeded to Transition_DRMI_To_3F where I stopped again to change the gain back to 8.
6.2 Mag Earthquake from Indonesia
https://earthquake.usgs.gov/earthquakes/eventpage/us6000mwjd/executive
I think we May have Survived this!
But we have 2 more 4.9's coming in from Chile.... I guess we will find out.
I guess I spoke too soon. :(
Lockloss https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1398975339
Sun May 05 10:13:13 2024 INFO: Fill completed in 13min 9secs
The atomic clock timing reference signal, which is being monitored by the MSR timing comparator, jumped by 0.29 seconds 04:16:16 UTC (21:16 Sat 04may2024 PDT).
This is the cause of the "C" in the timing status on the CDS Overview. This is a reference only, we will investigate Monday.
TITLE: 05/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 15mph Gusts, 11mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.10 μm/s
QUICK SUMMARY:
When I arrived H1 was LOCKING_ALS.
I let it try to lock itself twice. First it made it up to LOCKING_ALS before a lockloss. and on the second attempt it made it up to Engage_DRMI_ASC.
I then took ISC Lock to Initial Alignment.
EX had some ground moovement with might be coupled with the wind as it seems to be gusting. Though it looked strange because EY did not have the same apparent ground motion. We are expecting an R wave to hit from a 5.4 Mag Earthquake as well.
So Hopefully after the IA we should be goo to get locked again.
Tony, Rahul
ETMX09 was rung up (even though Ibrahim had set the gains off last night) and Tony was trying to fight the Guardian to try and damp this mode early this morning. We were out of Observing (for 15mins while we were figuring it out) and struggling to get in (violins too high message). Hence, at first we set the nominal values of gain in lscparam to zero, then set the violin damping guardian to Damp_Violins_Full_Power and then applied a fraction of the nominal gain. This seems to be slowly damping the mode.
Also then Tony was able to move back to Observing.
Will keep a watch over this mode (and others if needed) until we fully damp it.
I have updated the lscparams and loaded the Violin Guardian with the new gain settings for ETMX mode 09 as given below,
FM1+FM10 Gain = -6.0, Max gain = -8.0
Jennie, TJ, Camilla
The Operator team has been seeing more locklosses at state 557 TRANSISITON _FROM_ETMX, more so when the wind is high. Times: 1397719797; 1397722896; 1397725803; 1397273349, 1397915077
Last night we had a lockloss from 558 LOWNOISE_ESD_ETMX with a 9Hz ITMX L3 oscillation, see attached. Compare to a successful transition (still has glitch).
Note that there is a glitch ~30s before state 558 in both cases. H1:SUS-ETMX_L3_DRIVEALIGN_L2L and _L3_LOCK_L filter changes happens here. Are ramp times finished before these changes?
The timing of the glitch is 2 m 55 seconds after we get to state 557, this is the same time as in the 4 of the last 6 state 557 locklosses.
Louis, Camilla. Investigations ongoing but the timing of this glitch is suspiciously when the H1:SUS-ETMX_L1_LOCK_L gain and filters are changed, tramp is 1secinds but FM2 and FM6 foton filters have a 3 seconds ramp. There is an INPUT to this filter bank before the gain and filters are turned on. Plot attached.
In 77640 we show that the DARM1 filter change is the cause of the glitches/locklosses.
