Thu Apr 04 10:05:02 2024 INFO: Fill completed in 4min 58secs
Gerardo confirmed a good fill via camera. TCmins close to trip temps, it is chilly outside, 40F (4C)
Here are two plots which show the same thing: the excess low frequency noise noted yesterday 76924 has gotten better but we are still worse at low frequency than we were April 2nd.
The first plot is just a DARM comparison (without cleaning, CAL DELTA L), the second is a plot of the low frequency blrms ( BLRMS 2 is brown is 20-29 Hz, BLRMS 3 is pink is 38-60 Hz).
The third plot shows the same blrms against a ground motion blrms, ground motion doesn't seem to be an explanation.
TITLE: 04/04 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 5mph Gusts, 3mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.35 μm/s
QUICK SUMMARY:
Nice night for H1 on this rainy morn. H1's currently been locked for almost 7.5 hrs (currently in observing). There was about 90min of non-observing time for a lockloss, but it looks like H1 came back A-OK (with only a handful of locklosses on its way back up).
Additional Note: Squeezer team was here early to jump on O4Break-COMMISSIONING shortly after 8am local.
Artem, Camilla, Louis, Oli Charge measurements analysis code (see InLock_Charge_Measurements wiki) has been translated from Matlab to python with following significant changes: * Channels H1:SUS-(QUAD)_L3_ESDAMON* are used, which are already calibrated to voltages and therefore don't require additional filters in the code; * At the same time channel H1:CAL-DELTAL_EXTERNAL_DQ does require calibration, which was not applied previously and now it is ("6-pole, 6-zeros transfer function"); * Transfer function "from m DARM to N force" was pulled from SUS model every time in Matlab code (dampjngfjlters_QUAD_2014-11-10_LLO_model.mat); now it is saved to static text file and loaded from there; * Uncertainties are added for all coefficients. Attached to this post is comparison of "old" and "new" analysis results. First thing that jumps out is that numbers are completely different. However this is not necessarily a bad thing. Here's a quote from Jeff: "I don't really have an intuitive map between the units of the in-lock charge measurement plots vs. well, anything. My instinct is to gravitate to what the calibration group creates - the unit-full numbers for the ESD actuation strength in units of (gamma-alpha) = [ N/V^2 ] (using the notation of Eq. 10 from [1]). That group thinks the latest best value for that number, as of May 10th 2023 was 2.545e-11 N/V^2 ( see the text table at the bottom page 11 of LHO:69696 ). And yet, the ETMX results from these in lock charge measurements report that the value is around (1650 - 4100) = -2.450e+3 [N/V^2]. Do we understand that 14 orders of magnitude discrepancy?" [1] LIGO-T1700446 With the new scripts the value I get for a measurement around that (May 9 2023) time is gamma-alpha = -2.973887691585383e-11. Besides this though, there are differences: * Signs appear to be flipped, currently I don't understand why. * Also some measurements (particularly for ITMX for some reason) have very low coherence in my calculations, I had to lover threshold from 0.25 used in Matlab code in order to process those. In principle, low coherence should be reflected in uncertainty, but I guess up to a point, for too low values this does not hold anymore. All scripts are available here: https://git.ligo.org/artem.basalaev/inlock_charge_measurements, hopefully accessible by everyone. Note that I can't update scripts in the control room anymore since I don't have remote access. The versions currently available there are buggy early versions of my scripts (but also old Matlab versions are still there). As of now, use gitlab link above instead if you want to try running them, also in the control room.
TITLE: 04/04 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: TJ
SHIFT SUMMARY: Locked most of the shift, but lost lock after 7 hours. The alignment doesn't look too bad, especially after running an initial alignment.
LOG:
23:00UTC Detector relocking and at OMC_WHITENING
23:01 NOMINAL_LOW_NOISE
23:10 Observing - SDF diff for TCSCS reverted(attachment1)
23:13 Pushed out of Observing by sqz fc losing lock
23:31 Back into Observing
03:36 Earthquake mode activated due to incoming earthquake from Japan
04:16 Seismic to CALM
06:10 Lockloss (76944)
06:46 Started a manual initial alignment due to PRMI only wanting to catch on a diagonal 0 1 mode despite my adjustments to PRM and BS
06:59 Finished initial alignment, relocking
Currently Observing and have been Locked for 5.5 hours
Closes FAMIS#26291, last checked 76669
Corner Station Fans (attachment1)
All fans are looking normal and within range.
Outbuilding Fans (attachment2)
MX_FAN1_370_1 has started again(see last week's) with the jumps in noise (or I guess jumps down). These jumps in noise are still well within range. All other fans are looking normal and are within range.
Closes FAMIS 26441
BRS Y looks fine
BRS X was fine for majority of last month, had a hiccup a day or two ago but is now back in its nominal state. alog 76888 shows that it was touched yesterday so that may be it - tagging Seismic.
TITLE: 04/03 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Aligning
INCOMING OPERATOR: Oli
SHIFT SUMMARY:
Winds have not been as bad as last night, but for most of the day they have hovered just below 20mph.
Issues with Initial Alignments continue, but piecewise alignment seems to work....a little. Have had 4 locks which made it deep into ISC Locking (1 to NLN & 3 with locklosses at Transition From ETMx); Here are the 3 locklosses: 1396196815, 1396200017, & 1396216609. For two of these locklosses one similarity is an Analog board saturation for IMC REFL SERVO SPLITMON.
LOG:
TITLE: 04/03 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 22mph Gusts, 16mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.26 μm/s
QUICK SUMMARY:
Just got into OMC_WHITENING
My first time running this new TCS FAMIS check. Camilla happened to be nearby and she mentioned that the plot looks good and no notes/comments needed, but screenshot of the plots are attached.
Naoki, Eric, Camilla
We tried the PSAMS coarse scan from 0 to 200 with 100 step for two PSAMS. So 9 PSAMS setting in total. The nominal PSAMS is 100/100 and we tried 0/0. Unfortunately, when we tried 100/0, the lockloss happened. For each PSAMS setting, we ran the SCAN_ALIGNMENT with asqz-optimized and took 5+5 minutes quiet sqz/asqz data. The attachment shows the result. The 0/0 has much worse anti squeezing and large frequency dependence compared to 100/100. However, we are not sure if the mode matching is really worse or alignment is bad with 0/0 although we ran SCAN_ALIGNMENT. We will try to compensate the ZM alignment change caused by PSAMS change tomorrow.
no sqz (10 min)
PDT: 2024-04-03 11:40:00 PDT
UTC: 2024-04-03 18:40:00 UTC
GPS: 1396204818
asqz with 100/100 (5 min)
PDT: 2024-04-03 12:25:07 PDT
UTC: 2024-04-03 19:25:07 UTC
GPS: 1396207525
sqz with 100/100 (5 min)
PDT: 2024-04-03 12:34:10 PDT
UTC: 2024-04-03 19:34:10 UTC
GPS: 1396208068
asqz with 0/0 (5 min)
PDT: 2024-04-03 13:13:17 PDT
UTC: 2024-04-03 20:13:17 UTC
GPS: 1396210415
sqz with 0/0 (5 min)
PDT: 2024-04-03 13:33:50 PDT
UTC: 2024-04-03 20:33:50 UTC
GPS: 1396211648
Due to hysterisis in the PSAMs offsets, to get the same strain gauge values, the PSAMS values are now 135/115 for same strain gauge, accepted in sdf. May have slightly overshot in ZM4, plot attached. Naoki reran the SCAN_SQZANG script to find optimum sqz angle 188, this gave us 146Mpc range.
Addressed TCS Chillers (Tues [April 3] 1327-1349pm local) & CLOSED FAMIS #27786:
Notes from locking this morning (with Alignment woes and Transition from ETMx locklooses)
After spending 3hrs trying to get through an alignment yesterday afternoon, and since H1 was having issues after this morning's lockloss and multiple Initial Alignment cycles (and also after talking with TJ [owl shifter]), decided to REVERT all suspensions (except squeezer) to a time before last night's lock.
Chose time when ISC LOCK was in the Alignment state (#11) and picked a time within a minute of the end of when it was in this state. (Still not sure if that is the best way to pick a time, because how would one know if ALL sus were in an "aligned" state.) So---I reverted to the following time:
Alignment #1: Going for a Manual Alignment to slowly go through each alignment state since some states are broke.
Lock#1: Selected PRMI (locked within 15sec), but had a lockloss at Transition From ETMx.
Then there were several early-state locklosses.
Had another Transition From ETMx lockloss at 1719utc (note: during this lock and before the lockloss, Jim brought the BRSx back in-loop (at 1656utc)---we hadn't been using it for the last day or so.).
Finally, H1 made it to NLN at 1805utc.
After lockloss from a 2hr44min lock, H1 had issues with early-state locklosses. It also ended up looking misaligned via a dead DRMI acquisition. So ran CHECK MICH FRINGES + PRMI (which needed PRM tweak). DRMI also needed SRM yaw-tweaks. After this H1 returned to our old friend Transition From ETMx and had a lockloss here (3rd time this has happened today).
For recent locking, the Y-arm was not locking. So it automatically went through a round of INCREASE FLASHES (which took a long time) and resulted in a not very great alignment with flashes much lower than what one could get by tweaking by hand when Unlocked---which is what I ended up doing. (It feels like with winds above 10mph the green arms have been having issues sadly.)
We got some no squeeze quiet time almost an hour into lock this morning and our low frequency noise looks worse than yesterday - so impacting our range.
Sensor correction is on (confirmed by Corey).
Not sure what has changed.
Template is saved as /ligo/home/jennifer.wright/Documents/Noise_DARM/20240403_DARM_comp_sqz_no_sqz2.xml
I compared this with NO SQZ quiet times from yesterday, 17th March, and December 2023 during O4a. These other times were all after thermlisation.
https://ldas-jobs.ligo-wa.caltech.edu/~gabriele.vajente/bruco_1396204818_GDS_CALIB_CLEAN/
Low frequency coherence with CHARD_P and HAM1
PRCL is high, but we've seen something at this level even before
No smoking gun for 30-40 Hz
The spectrogram attached here (whitened to the median of the "good" DARM spectrum from yesterday) shows hints that the excess noise is not very stationary. BruCo and coherence might not give us much info, but I'm running it nevertheless
OMC suspension MASTER_OUT signals look unchanged after Jeff's modification
More corroborative evidence that changes to the OMC ASC control signal path through the OMC SUS is not causing the excess noise in DARM -- LHO:76929.
It does seem possble that we are clipping on the LSC pop diode. The attached screenshot shows that compared to the lock April 2nd we have very smiilar arm circulating powers, but 0.3% less power on LSC POP.
We've previously seen clipping on POP cause low frequency nosie like this: 74641 69931 The second screenshot shows what these trends looked like at that time, it was much more clear that we had a clipping problem then.
Ran the data for the In Lock SUS Charge Measurements that ran this morning. Like Camilla said (76895), the excitations only worked for the ETMs, so although I am attaching all four plots, note that the last plot point for the ITMs is March 13th (ETMX, ETMY, ITMX, ITMY).
Adding these measurement results also calculated with new scripts. As far as I can see, similar trends show up with the caveat that signs of variables are sometimes different. By the way this makes me wonder a bit. We'd assumed that ETMX got charged up during the break, but the absolute value of beta and beta2 (which determine linear force component strength - see eq.3 in T1700446) for ETMX in last two measurements go down in both old and new calculation. Isn't it the opposite of what we'd expect?
J. Oberling, R. Crouch, T. Guidry
Since the last update we have tried a couple of things.
First, we attempted to align the FARO to the BSC2 chamber directly. We placed the FARO in the biergarten and shot the chamber-side door flanges. We used the SMR to sweep along the outside of the +X side of the +Y door flange, and the +Y side of the +X door flange. The shots were done as circles, which we could then place a point at circle center to represent the center of the door flange. The hope was we could then project lines to represent the X and Y axes, and use that to align to our origin using a Plane/Axis/Center Point alignment routine. I won't go into much detail, as it didn't work. We used this alignment to look at PSI-6 in the biergarten, and it was off by over 1cm; we then looked at LV-35 and that one was off by even more. I don't remember exact values as we didn't save screenshots since the devaiations were so large. Let's say that if these deviations were true, I'm not sure how we would have a functioning, aligned, and alignable IFO. So, that experiment didn't work, moving on.
Today we decided to try using height marks 901, 902, and 903 to set our Z axis alignment. We looked at marks 901 and 902 with an autolevel and compared them to our BSC2 door flange scribe average we had used the water tube level to measure (alog 75974) and the listed local Z coordinate from T1100187. Results:
Not bad, and definitely not the almost +4mm the FARO was measuring for these marks w.r.t. BTVE-1. If we use our differential height survey from alog 75771 we can also calculate the local Z axis coordinate for mark 903, which comes out to -79.8 mm (versus the listed coordinate of -79.9 mm from T1100187), and again not the almost +4mm reported by the FARO when measured w.r.t. BTVE-1. It's looking more and more like there was some error in the Z axis position of BTVE-1; whether that error was in setting the monument itself or in setting BSC2 w.r.t. to BTVE-1 we cannot say. The fact of the matter is that when compared to BSC2 as it sits right now based on our water level survey, the height marks we've looked at are pretty close to their listed coordinates and BTVE-1 is definitely not. We also happened to do the same differential height survey with BTVE-1 (also in alog 75771), so we can calculate a local Z coordinate for BTVE-1 based on our height mark 903 (which we have now tied to BSC2 Z=0). Doing so gives a local Z axis coordinate for BTVE-1 of -1060.3 mm (Z903 - deltaZBTVE-1/903 = -79.8 - 980.5); this becomes -1060.9 mm once we convert to our global coordinate frame (which is decidedly not the -1057.2 mm all of the old documentation lists it as).
Now that we have local Z coordinates for 901, 902, 903, and BTVE-1 that have all been tied to BSC2 Z=0, we used these to set a new alignment. First, we need global Z coordiantes for our 3 height marks. We got these by using a autolevel to set a magnetic nest inline with the height mark to be measured. The FARO was put into an intial alignment using BTVE-1, PSI-1, PSI-2, and PSI-6 (X and Y are generally pretty good, Z is off but we don't care yet), and we then placed the SMR on the nest we placed inline with 903. From this we got an X/Y coordinate for the nest that we could use to calculate our global Z. Once this was done we added 903 into the alignment routine, and removed PSI-1, PSI-2, and PSI-6 for the Z axis fit. we then moved the FARO to a position where we could see 901 and 902 and shot them in the same way we did 903. Ultimately, we ended up with an alignment using BTVE-1, PSI-1, PSI-2, and PSI-6 for X and Y and 901, 902. and 903 for Z. The coordinates used for the height marks were (format is [X,Y,Z]):
Tyler has a screenshot of the results of the alignment that he'll post as a comment to this alog. One thing to note here: We were not using the new BTVE-1 Z as part of the Z axis alignment, only marks 901, 902, and 903. It's somewhat comforting to see the Z axis coordinate of BTVE-1 as calculated by the alignment routine as close as it is to what we think the nominal shoud be based on our water level survey of BSC2. The PSI monuments are all out, especially PSI-2. I'm not sure how concerning this is, as we don't trust the Z coordinates of the PSI monuments anyway.
One caveat here, all of the height marks we used are almost in a line down the Y axis, with very little deviation in the X axis coordinate (a deltaX of less than 7mm across ~25m of the Y axis). I'm not entirely confident we're picking up the global tilt of our X axis with this configuration. We want to take this alignment and test and refine it; first thing we can do is get some more height marks spread along the X axis to hopefully catch the global X axis tilt. More to come!
Kevin and Vicky helped to get the old range comparison plots from the noise budget working with some updates to the noise budget. The first plots show the spectra, range integand and the cumulative range for a comparison between O4a and a few days ago. This is range calculated by gwinc, the sensmon range is shown in the legend.
Looking at the darm spectra and the range difference plot here, you can see that we gained about 15Mpc of range from low frequency improvements including DARM offloading. Above 40Hz our recent sensitivity has been worse, we lose 15 Mpc from the decreased sensitivity beween 40-100 Hz and another 7 or so from the worse sensitivity above 100Hz.
Last night we had slightly better BNS range after the squeezer alignment work 76757 , the same comparison of O4a to last night shows that we are loosing less range from 65-300 Hz, as shown in this plot as well.
I've also made this comparison for no squeezing, using times from 76537 and 76540: here. This shows that without squeezing the mid frequency sensitivity (30-70Hz) has gotten worse which is costing roughly 10Mpc of range.
Elenna's sensitivity comparison from a few weeks ago contains helpful links to recent changes: 76449
first of all, apologies that the axis labels were switched in the above plots.
Second, instructions if you'd like to make these plots yourself for your own times:
cd /ligo/gitcommon/NoiseBudget/aligoNB/production_code/
conda activate aligoNB
open gps_reference_times.yml and either chooose some times from the list or add your own time dictonary. If you add a time, please add it below the LHO and LHO_NO_SQZ entries (those are the ones that the noise budget uses), and add a helpful comment describing your time.
open H1/darm_integral_compare.py and edit lines 85 and 91 (after_gps_dict = gps_dict['LHO_ER16_April4'] and b4_gps_dict = gps_dict['LHO_O4a_postvent']) so that it will plot your chosen tmes.
python H1/darm_intergal_compare.py
Your plots will be saved in /ligo/gitcommon/NoiseBudget/aligoNB/out/H1/darm_intergal_compare/