WP 11832

While troubleshooting TTFSS (alog 77403), Sheila and Camilla found issues with the D2300329 Laser Locking Fiber Beat Note Chassis. Unit was replaced with spare. SQZ team reports outputs back to nominal.

Removed unit had power regulator board D100217 failed. Output capacitor C7 was shorting +15V rail to ground. Power regulator board replaced.

Installed Chassis S2300259
Removed Chassis S2300258

Jennie W, Sheila

Now we have our camera servo offsets that we found on the 17th tuned in we ran the A2L script again. The code is

userapps/isc/h1/scripts/run_all_a2l.sh

I saved these values in lscparams.py in userapps/isc/h1/guardian/ and accepted the sdfs in OBSERVE.snap.

Sheila, Jennie W

While Sheila runs a Bruco I checked the coherence from LSC - SRCL, PRCL, MICH,  and ASC-MICH, DHARD and CHARD to DARM.

The first image is from our lock last night, the second is the same set of measurements from Monday night when we had a range of 156 MPc (left cursor).

Comparing the two it looks like PRCL coherence is slightly worse since Monday, CHARD looks about the same, DHARD is slightly worse in pitch but better in yaw, ASC-MICH is about the same, PRCL is a bit worse, SRCL is about the same and LSC-MICH is a bit worse.

Thu Apr 25 10:10:20 2024 INFO: Fill completed in 10min 16secs

Jordan confirmed a good fill curbside.

We've gone out of Observing at 1600UTC to start the 3 hour planned commissioning time in coordination with LLO and Virgo.

TITLE: 04/25 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 132Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 3mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY: Locked and Observing for 2 hours. Looks like Ryan C had some SQZ issues overnight. I imagine that we will be doing more investigations into the alignment shift today.

H1 called for assistance as the SQZer lost lock and has been struggling to relock, its been stuck waiting for the TTFSS to lock, it says "Check crystal frequency, can try 45MHz" which is a notification I haven't seen before and I can't find any reference in the WIKI. I'm calling out for SQZ help

TITLE: 04/25 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 134Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
LOG:

Rode out a 5.5 Mag Earthquake from New Zealand.
Violins look great!
H1 Is still locked and Observing.

I put in the Lock Aqusition survey in here https://docs.google.com/forms/d/e/1FAIpQLSf_RhE5fjtL9cNhyY6dXtBunM4tonBBwgikZwr1Hg0CBkGn2A/viewform because I could not find the link to the new Lock Aqusition Survey.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

TITLE: 04/25 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 148Mpc
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 12mph Gusts, 10mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:

After manual Initial_Alignment
We tried to get locked but there were issuses getting DRMI 1F and then PRMI.
I then touched the Beam Splitter and SRM a little bit to try and get PRMI locked with no luck.
I then took IFO to Check mitch fringes. Where it struggled some more to get past PRMI.
I then Took the IFO to Initial Alignment.
After Initial_Alignment H1 was able to get past DRMI locking and got to Nominal_Low_Noise.
Nominal_Low_Noise @ 1:31 UTC
SQZrs were touching up SQZ alignment and to get the SQZ system locked. https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=77400
OBserving at 2:32 UTC

Tony, Nutsinee, Vicky

We re-aligned SQZ to the current IFO AS port alignment, got from basically no sqz at all, to ~4.5dB at the end.

Screenshot. First I aligned ZM4 P/Y by ~hundreds counts to see a sqz signal again in transmission of OMC, then manually walked a bit with ZM6. Then I engaged AS42 ASC (zm5/6), which helped a bit to bring the alignment closer, but leaving ASC on for too long caused alignment to run away (so I cleared history on it and started over). I ran AS42 briefly a couple times until improvement to RF3 signal stopped, then offloaded, then some manual walks, then again. Could not use SCAN_ALIGNMENT (zm4/6) - it's range is way too big right now that LO loses lock, so we need to back off the scan range. Manually adjusted SQZ angle to maximize yellow 350 Hz / blue 1.7 kHz blrms.

Overall biggest slider moves were in YAW: ZM4_Y +600, ZM6_Y +270, secondarily ZM4_P +70.

OMC_RF3_RFMON went from around -22 (noise floor around -25), to -10 at squeezing (ofc more with antisqz). SQZ went from basically totally misaligned to almost -4.5dB, with this series of manual walks and ASC attempts. On net, probably still broadly reducing noise with sqz vs. adding noise, so we decided to call it and accept SDFs on the ZMs, so Tony could go to observe.

Edit to add: Alignment and sqz angle are probably not that optimized still. Something interesting - when I first aligned and got something, squeezing needed an RF6 demod phase below 100 deg. When aligning more and with ASC help, the sqz angle moved back up to ~177 deg (where it is left now). Before, we had been operating at around 190-200 deg. Can add those trends here tomorrow. I'm a bit surprised how big much the sqz angle changed with alignment. Unsure if it's maybe a clue in tracking down why the sqz angle is drifting so much recently (for example if alignments, either sqz or ifo, are drifting and those drifts can be compensated in part by changing the sqz angle).

I have accepted the following SDF Diffs to get into observing.
I am waiting for the SQZs to make some quick changes to get the SQZ alignment optimal for Observing.

I took some transfer functions of OFI this afternoon, the references from the template were fairly old (2021), I trended the OSEM basis, and output filters gain as well at the suggestion of Jeff for the reference and things have changed. The basis matrix has different values and the gains signs have been flipped, so that may be why the magnitudes are different. The TFs don't show anything obviously wrong.

The templates are located at: /ligo/svncommon/SusSVN/sus/trunk/OFIS/H1/OFI/SAGM1/Data/

We've asked Tony to try locking the IFO with SR3 and SR2 in these very different positions.  With these optic positions, we don't want the AS_C offsets in place that we used to get locked yesterday.  So, I have now accepted in safe.snap for the ASC model that the AS_C offsets are off (but I've left the numerical values). 

If we're unable to lock, then the plan is to ask Tony to revert SR2 and SR3 and turn back on those offsets.  Since the offset switches are part of SDF revert, to turn them on the plan should be to go Sitemap -> ASC -> Overview -> AS_C (bottom left) -> Turn on the offsets and save the diff in SDF.

First attachment is my saving the safe.snap file with the offsets off.  Second attachment is where the offset buttons are.

The best build-ups were immediately after this good time when we changed the PIT2 and YAW3 but this made the range worse.