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Reports until 14:19, Monday 07 April 2025
H1 SUS
ryan.crouch@LIGO.ORG - posted 14:19, Monday 07 April 2025 - last comment - 09:47, Tuesday 08 April 2025(83780)
Power power outage OSEM recovery / Offset check

Oli, Ibrahim, RyanC

We took a look at the osems current positions for the suspensions post power outage to make sure the offsets are still correct, the previously referenced "Golden time" was 1427541769 (the last drmi lock before the vent). While we did compare against this time we mainly set them to before the poweroutage.

Input:

IM1_P: 368.5 -> 396.1, IM1_Y: -382.7 -> -385.4

IM2_P: 558.0 -> 792.0, IM2_Y: -174.7 -> -175.7

IM3_P: -216.3 -> -207.7, IM3_Y: 334.0 -> 346.0

IM4_P: -52.4 -> -92.4, IM4_Y: 379.5 -> 122.5

SR2_P: -114.3 -> -117.6, SR2_Y: 255.2 -> 243.6

SRM_P: 2540.3 -> 2478.3, SRM_Y: -3809.1 -> -3825.1

SR3_P: 439.8 -> 442.4, SR3_Y: -137.7 -> -143.9

Output:

ZM6_P: 1408.7 -> 811.7, ZM6_Y: -260.1 -> -206.1

OM1_P: -70.9 -> -90.8, OM1_Y: 707.2 -> 704.5

OM2_P: -1475.8 -> -1445.0, OM2_Y: -141.2 -> -290.8

OM3_P: Didn't adjust, OM3_Y: Didn't adjust

Comments related to this report
ibrahim.abouelfettouh@LIGO.ORG - 15:19, Monday 07 April 2025 (83789)

Input:

PRM_P: -1620.8 -> -1672, (Changed by -51.2) PRM_Y: 579.6 -> -75.6 (Changed by -655.2)

PR2_P: 1555 -> 1409 (Changed by 146), PR2_Y: 2800.7 -> -280.8 (Changed by -3081.5)

PR3_P: -122.2 -> -151 (Changed by -28.8), PR3_Y: -100 -> -232.4 (Changed by -132.4)

MC1_P: 833.3 -> 833.3, MC1_Y: -2230.6 -> -2230.6 (No change)

MC2_P: 591.5 -> 591.5, MC2_Y: -580.4 -> -580.4 (No change)

MC3_P: -20.3 -> -20.3, MC3_Y: -2431.1 -> -2431.1 (No change)

Attached are plots showing the offsets (and their relevant M1 OSEMs) before and after the suspension was reliably aligned.

Images attached to this comment
oli.patane@LIGO.ORG - 15:45, Monday 07 April 2025 (83793)

Comparing QUADs, BS, and TMSs pointing before to after outage. All had come back up from the power outage with a slightly different OPTICALIGN OFFSET for P and Y, due to the power outage taking everything down, and then when systems got back up, the OPTICALIGN OFFSETS were read from the sus sdf files, and those channels aren't monitored by sdf and so had older offset values. I set the offest values back to what they were before the power outage, but still had to adjust them to get the top masses pointed back to where they were before the outage.

'Before' refers to the OPTICALIGN OFFSET values before the outage, and 'After' is what I changed those values to to get the driftmon channels to match where they were before the outage.

SUS Before After
ITMX    
P -114.5 -109.7
Y 110.1 110.1 (no change)
ITMY    
P 1.6 2.0
Y -17.9 -22.4
ETMX    
P -36.6 -45.7
Y -146.2 -153.7
ETMY    
P 164.6 160.6
Y 166.7 166.7 (no change)
BS    
P 96.7 96.7 (no change)
Y -393.7 -393.7 (no change)
TMSX    
P -88.9 -89.9
Y -94.3 -92.3
TMSY    
P 79.2 82.2
Y -261.9 -261.9 (no change)

 

camilla.compton@LIGO.ORG - 08:37, Tuesday 08 April 2025 (83805)

HAM7/8 suspensions was brought back, details in 83774.

camilla.compton@LIGO.ORG - 09:35, Tuesday 08 April 2025 (83807)ISC

Betsy, Oli, Camilla

The complete story:
Ryan S had found a "good DRMI time" were all optics were in thier aligned state beofre HEPI lockign or venting: 1427541769 gps.
We had planned to go back to this time, but there was then some confusion about whether we wanted a time with the HEPIs locked or not and the team decided to go back to the time directly before the power outage, so that there is a typo is Ryan's original alog.
Everything actually got put back to a time before the power outage, when all suspensions were in the ALIGNED guardian state, (e.g. Sunday 6th April ~16:00UTC or times around then). However some of the ISI's were tripped at that time: HAM2, HAM7, BSC1, BSC2, BSC3, OPs overview attached. 
As we went and checked the IMC alignment yesterday 83794 (and saw flashes on IM4_TRANS suggesting MCs and IM1,2,3 are good), we do not want to move the alignment again so are staying with everything at this "before power outage time"...for better or worse.

We rechecked that everything was put back to this time, looking at the M1 DAMP channels for each optic, e.g. H1:SUS-OM1_M1_DAMP_{P,Y}_INMON:

  • OM1,2,3, ZM6
  • SRM,2,3
  • IM1,2,3,4
  • Quads, BS, TMS
    • Found that ETMX was 30urad off, same with ITMY Yaw, so Oli readjusted. All others were left as is.
  • Oli checked all other optics which were fine, within a few urad.

For each ndscope, 1st t-cursor on originally "good DRMI time" we had planned to go back to, second t-cursor on time we went back to.

Images attached to this comment
oli.patane@LIGO.ORG - 09:47, Tuesday 08 April 2025 (83808)

I checked the rest of the optics and verified that they all got put back to point where they were pointing before the power outage. I've also used one of the horizontal cursors to mark where the optic was at the "good DRMI time", and the other cursor marks where the optic is currently.

MCs

PRs

ZMs

FCs

Images attached to this comment
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