I ran the A2L script descirbed here at the start of commissoning time this morning, and immediately after manually tuned P2L coefficents for the ETMs.  I was able to improve the CHARD P to DARM coupling by about 25dB compared to the script's result. I tried tuning the ITM coefficents, but there wasn't much room to improve them. 

I've updated the guardian values for ETMX, ETMY and ITMX (for a very small improvement on ITMX). 

Compared to the script, my adjustments were fairly coarse.  The script adjusted ETMX P2L from 3.1715 to 3.0875, while I then adjusted it to 3.35.  For ETMY the script adjusted it from 4.682 to 4.7747, I adjusted it to 4.5.  This resutls in the improvement shown in the attachment. 

Editing to add: we relocked with these new P2L values, and the CHARD P to DARM coupling is still fairly low early in the lock (3rd attachment).  The A2L coefficents aren't very sensitive to thermalization, which is good news.

J. Kissel, A. Effler

Executive Summary:

The calibration for all QTOP (D1001782) and TTOP (D1001242) coil driver's FASTIMON channels that are using the frequency-independent "current monitor" circuit of the broadband coil driver monitor circuit (D0902747) is 
    QTOP = 0.0114 [mA/ct] and 
    TTOP = 0.0153 [mA/ct],
respectively with the "[mA]" being current across the coil, and "[ct]" being "straight off the ADC" counts.

Derivation

From the math outlined in the "Other Files" of the older, "broadband" coil driver monitor circuit, D070480 and stitching together how various voltage signals passed around from page to page of the drawings, one can compute the calibration of the FASTIMON channels for a given coil driver as 

    FASTIMON ADC [ct] = voltage measured across two legs worth of output impedance in the coil driver board drawing
                        * ( [differential legs' voltage to single-ended output voltage converter node in the monitor board drawing]
                             * "single-ended voltage piped into only one leg of differential ADC" factor of two its DB25 output J1 in the interconnect drawing
                             * general standards 16-bit differential ADC calibration)
where
           calibration = (the stuff in parentheses)

         ADC [ct]        [                         "R1" [V_SE] ]    2 [V_DF]    2^16 [ct]      
    ----------------   = [ 2 * Z_OUT [V_DF / A] *  ----------- ] *  -------- * ----------- 
    Coil Current [A]     [                         "R2" [V_DF] ]    1 [V_SE]    40 [V_DF]     

where "R1" = R25, R35 = 10e3 [V/A], and "R2" = R24, R27, R29, R33 = 30e3 [V/A].


So, for the QUAD / Triple TOP coil driver (see circuit diagram D0902747 of chassis assemblies QTOP = D1001782 and TTOP = D1001242), that's, the output impedance of one leg is
    Z_OUT   = (R5+R1) || (R90+R91) 
            = (R5+R1) * (R90+R91) / (R5+R1 + R90+R91)

    Z_OUT^(QTOP) = (44 * 440) / (44 + 440) = 40.00 [V/A]
    Z_OUT^(TTOP) = (32 * 440) / (32 + 440) = 29.83 [V/A]
which makes the calibration

calibration_QTOP [ct/A] = 2 * 40.00 [V/A] * (10e3 / 30e3) * 2 * (2^16 / 40 [ct/V])
                        = 8.7381e+04 [ct/A]
      or 87.381 [ct/mA]
      or 0.0114 [mA/ct]

calibration_TTOP [ct/A] = 2 * 29.83 [V/A] * (10e3 / 30e3) * 2 * (2^16 / 40 [ct/V])
                        = 6.5165e+04 [ct/A]
      or 65.165 [ct/mA]
      or 0.0153 [mA/ct]

Q.E.D.

Gabeiele, Sheila, Camilla

• 16:20UTC: turned off LSC FF and L2L3LP filter in ETMY L2 DRIVEALIGN L2L
• 16:35 - 16:39UTC: ETMY L2 Excitation (FF off)
  • Needed the FF off so that we could turn the L2L3LP filter off.
• 16:40: turned on L2L3LP filter in ETMY L2 DRIVEALIGN L2L and LSC FF
• 16:51 to 16:55UTC: ETMX L2 Excitation (FF on)

FAMIS Link:  25989

Only CPS which looks higher at high frequencies (see attached) would be:

1. ITMx St1 V1 & V2
2. ITMy St1 V2

Wed May 01 10:13:10 2024 INFO: Fill completed in 13min 6secs

Gerardo confirmed a good fill curbside.

https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1398618745

PRM and SR3 saturations before the lockloss, 2.5 hours into the lock so we still haven't been able to take a thermalized calibration measurement. The only invasive/potential LL causing work going on was some PEM tests by Robert.

TITLE: 05/01 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 2mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY: Just got back into Observing after a lock loss, fully auto relock. Planned commissioning today from 9-12 PT

TITLE: 05/01 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: We are Observing and have been Locked for 1.5 hours. Overall quiet night with two almost fully automated relocks. Reminder that LVEA is still Laser Hazard
LOG:

LVEA is still in LASER HAZARD

22:49 Detector Locked for 52 mins and just got into Observing
22:50 Lockloss after 1m 14s Observing

22:56 Lockloss at LOCKING_ALS
23:08 Lockloss from TRANSITION_DRMI_TO_3F
23:49 NOMINAL_LOW_NOISE
23:52 Observing

03:35 Superevent S240501an

04:34 Lockloss
04:49 Lockloss from TURN_ON_BS_STAGE2
05:38 NOMINAL_LOW_NOISE
05:40 Observing                                                                                                                                                          

Lockloss 05/01 04:34UTC

Have been Locked and Observing for almost 4 hours, and just got a notification about superevent S240501an

TITLE: 04/30 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Oli
SHIFT SUMMARY: Busy maintenance day, but the initial alignment and lock acquisition that followed were straightforward. Lost lock shortly after starting to observe.

• 14:58 - Lockloss at the end of in-lock SUS charge measurements
• 20:24 - Maintenance finished, starting initial alignment
  • Needed to move SRM in yaw quite a bit to lock align SRC
• 21:17 - Alignment finished, starting lock acquisition
• 21:58 - Reached NLN; fully automated acquisition
• 22:49 - Started observing after tuning SQZ and A2L
• 22:50 - Lockloss; no immediately obvious cause

The LVEA remains Laser HAZARD for more potential viewport tests during commissioning time this week.

LOG:

Lockloss at 04/30 22:50 UTC from unknown cause

TITLE: 04/30 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 8mph Gusts, 6mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.23 μm/s
QUICK SUMMARY:

Have been Locked for 52 minutes and just got to Observing

Functionality test was done on the following stations:

X-Mid turbo pump station;
     Scroll pump hours: 215.2
     Turbo pump hours: 125
     Crash bearing life is at 100%

X-End turbo pump station;
     Scroll pump hours: 7143.2
     Turbo pump hours: 1093
     Crash bearing life is at 100%

FAMIS tasks 24850 and 24874.

Naoki, Sheila, Camilla

After the output alignment shift reported in 77427, we tried to revert SQZ to the last successful SQZ-OMC scan in 77515 but when we increased throughput, AS_C alignment was bad. Today we translated the beam to get good throughput on AS_A/B and AS_C and a centered beam on AS_C with OMC DC centering loop running. This was a move of ZM4 -1000urad, ZM5 -650urad in yaw as reported by DAMP_Y_INMON channels

• We reverted all alignment sliders (ZM4,5,6 OM1,2,3 SRM) and PSAMS to April 16th (leaving PSAMS at 7.5V/0.55V pre-77268).
• Naoki injected the same amount of SQZ SEED power as previous OMC-SQZ scan
• We translated in YAW by yawing ZM5 negative 50urad to increase AS_A power and then yawing ZM4 negative to bring the beam back centered to AS_C. Tried the positive ZM5 direction beforehand and it got worse.
• At 19:49UTC we turned on the OMC DC centering loops.
• We had god throughput at 19:59UTC and  moved until we made things worse at ~20:00UTC and then backed off.
• Total ZM4,5 changes attached, sdf's attached.
  • Before 1st t-cursor is moving from optimum in-lock sqz to April 16th OMC-SQZ alignment.
  • Between t-cursors is our translation. We moved ZM4 -1000urad, ZM5 -650urad. ZM4 is at 24,000 counts out of available 32,000.

Attached shows previous April 16th OMC-SQZ scan compared to during today's translation and how we left the ZMs:

• AS_C power is similar (new 373 vs old 385). Around ~3% percent lower, it almost seemed correlated with oscillations in YAW which isn't good as could suggest some yaw clipping remains.
• AS_A/B power is similar/increased,  AS_A (new 74 vs old 75) and AS_B  (new 80 vs old 75). They were not the same as each other similar but this can be explained by the AS_C being  0.2 to 0.4 off in PIT and YAW in the April 16th scan.
• Centered on all AS_A/B/C PDs.

We're not sure how this change will effect in-lock SQZ as Vicky had to make big changed in 77400  and we may have seen that good OMC scan alignment isn't good SQZ alignment?

This morning I came into the control room as the magnetic injections were finishing, and ran the a2l script while the charge measurements ran.

I did this because after Jennie Wright ran A2L yesterday afternoon it was not well tuned: 77495

When Jennie ran it yesterday, the coherence was over the threshold for all 8 gains, so all 8 were adjusted.  This morning I ran it and the coherence was below threshold for ITMX P2L and ETMY Y2L, so those were not updated.  I increased their amplitudes in the run_all_a2L.sh script, but as I was re-running the IFO unlocked due to the charge measurements.

The attached screenshots show how it changed the optics that it did run for, this is a large difference from the values that Jennie got yesterday.  Jennie W ran the script 20 hours into the lock, while I ran it 37 hours into the same lock, so these were both with a well thermalized IFO. 

It seems that there may be two problems we are facing with tuning A2L, one that our process doesn't seem to always work well to minimize A2L, and second that it seems that the values may be changing over the course of a lock.

started scan of OMC alignment started with no squeezing: April 26th 2024 16:36:47 ended at 17:30 UTC