Wednesday Eve Ops Summary

TITLE: 04/26 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Calibration
SHIFT SUMMARY:

- IFO was locked until 23:34 UTC when there was a DCPD saturation and a subsequent lockloss - Reason unknown

- Lock #1-2:

- GRD needed to do an increase flashes on X but it was able to catch ALS after

- Unfortunately it could not find IR on ALS COMM and flashes were not getting better after ~5 minutes so I tried to rerequest FAST_SEARCH so GRD could cycle through the offsets again, but had a subsequent lockloss ~3 minutes after this request was made

- Jenne noticed that the H1:LSC-TR_X_NORM_OUTPUT channel was hovering below 0 (~ -0.6, which shouldn't be the case since this channel looks at the DC ouput of a PD and you cannot have negative photons), and recommended that we zero the COMM offset values.

• In order to do this, we took the value in the H1:LSC-TR_X_QPD_B_SUM_INMON channel (found on LSC --> LOCKING --> TR CARM (bottom right ish) --> TRX QPD B SUM Overview), and then zeroed out that value by taking the inverse value of that channel, and inputting it into H1:LSC-TR_X_QPD_B_SUM_OFFSET (the offset channel directly below)
• After this was reset, we tried to let GRD find ALS COMM flashes to no avail, then tried to manually cycle through the entire offset range, but could not get any good flashes (capped out at 0.1)
• We are cutting our losses and doing an initial alignment (read Notes portion before continuing to Lock #3)

- Lock #3:

- After finishing an initial alignment after the troubleshooting saga - looks like we are stuck at the same spot as we were before despite all our changes :))

- AHA, something interesting - Ran through INIT one more time but this time ran through CHECK_SDF and FINALLY was able to catch CHECK_IR

• Coincidence? Possibly. But definitely worth looking into the SDF_REVERT state tomorrow. Something to chew on though, if this is the culprit to the issue, how come there was no issue locking today/yesterday - both of which were post SDF_REVERT changes?
• Tried looking in SDF to see if any of the SDF_REVERT models monitor slider values, but couldn't find anything like that

- Acquired NLN @ 06:35 UTC!

- Other Notes:

- Having issues with initial alignment, seems to be stuck in ACQUIRE_XARM_IR, Gabriele and I are looking into it

Issue Troubleshooting Log:

•  After some trouble shooting, we saw that there was no light on the TR_X QPD, so we trended PR2, PR3, and IM4 sliders to see if anything moved but all looked ok
• The WD trip shortly after so we decided to restart the initial alignment to check green alignment
• The second initial alignment worked fine, but again we ran into the issue at ACQUIRE_XARM_IR. This time we tried walking the 3 aforementioned suspensions to try and increase flashes on TR_X, with not much luck - we then trended the M1 IM4 and M3 PR2 witness sensors and saw that they did move about ~2 hours ago, scope attached below - we tried reverting the witness sensors back to the old spot, but flashes did not improve (pain)
• After this we contacted Jenne for help with locking and she recommended lowering the LSC TRIG thresh value (H1:LSC-XARM_TRIG_THRESH_ON, found on the LSC Trigger Matrix) to 0.1 to see if we can even catch it. After painstakingly moving IM4, PR2, and PR3 both P and Y to try and catch to this lower threshold (with the intent of then trying to get flashes up to 0.5), we gave up and tried instead running a manual initial alignment...stay tuned.
• Jenne came on TS to help troubleshoot, suggested we tried to align IR on Y arm instead of X - no luck :(
• Next we tried, running the dark offsets scripts found in: ./isc/h1/scripts/dark_offsets/dark_offsets_exe.py (Attached accepted SDF changes for ALSX/Y)  - hit INIT on ISC LOCK - then trying another manual initial alignment
• Same issue - trying to retouch PR2/IM4
• :'(²
• Jenne tried to change the PSL POWER SCALE OFFSET value to 1/1.5 and then walking the suspensions again - negative
• Ok hail mary time - we reverted all suspensions back to original time when the last initial alignment was completed - ~1366491294
• Worth noting that after this revert, we DID see good flashes in LSC-TR_X briefly but quickly went away, interestingly enough I trended back the guardian states on ISC LOCK and flashes improved at READY and went back down to 0 once it went to SDF_REVERT. Screenshot attached
• Post revert - we decided to skip SDF REVERT - touch up green arms and try another manual alignment...SUCCESS! Finally able to catch XARM IR
• INITIAL ALIGNMENT IS DONE #dontletyourdreamsbedreams - on to ISC LOCK

Jenne's comments regarding the ISS loops during this whole debacle:

I checked that the number that Daniel said in a comment that he had turned to zero from ten, went back to 10 via guardian or some SDF thing, and tried disabling the whole ISS second loop output, no change

And, I put that offset 'thirdloop' (even though it's not actually for the 3rd loop anymore) back to the 500-ish val. All no success

- 1:05 UTC - ITMX ST/2 WD Tripped - This is weird...no one is in the LVEA, plot attached

 

- Leaving the IFO locked at NLN and in UNDISTURBED, twas an eventful night to kick off ER15 🥲, but we are back in business!
LOG:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
19:56	LVEA	LAZER HAZARD	LVEA	YES	THE LVEA IS LASER HAZARD	16:57
22:42	CAL	Tony & Jeff & Evan	Ctrl Rm	n	Calibration Sweep	00:17
23:52	ISC	Gabriele/Elenna	PSL Racks	Y	Swap CARM noise injecton to freq noise injection	23:56
00:05	VAC	Gerardo	LVEA	YES	Move racks	00:14