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Reports until 00:01, Friday 07 February 2020
H1 SUS
cheryl.vorvick@LIGO.ORG - posted 00:01, Friday 07 February 2020 - last comment - 18:53, Friday 07 February 2020(54956)
violin mode damping 7 Feb 2020
  1. corrected ITMX mode 9 monitor filter, was watching 504.1786Hz, peak that is being damped is at 504.16Hz (medm to be updated)
  2. adjusted ITMX modes 1 and 9 monitor filters to reduce overlap (snapshots of new and old attached)
    1. old mode 1 monitor filter
    2. butter("BandPass",8,504.135,504.155)gain(120,"dB")
    3. old mode 9 monitor filter
    4. butter("BandPass",8,504.169,504.189)gain(120,"dB")
    5. new mode 1 monitor filter
    6. butter("BandPass",8,504.130,504.150)gain(120,"dB")
    7. new mode 9 monitor filter
    8. butter("BandPass",8,504.155,504.175)gain(120,"dB")
  3. created a monitor filter for a newly identified peak at 1001.31Hz
    1. so it's been in DARM before, but not rung up recently
    2. talked with Rahul and Robert, and it's not confirmed as a violin, but likely is a voilin at that frequency
    3. I put the new monitor filter in the ITMX mode 20 monitor filter
    4. ITMX has 8 modes, so mode 20 would be it's 9th, a clue that this is a mode that is not yet identified
    5. medm still says 998.82 (Hz) in red, this will be updated shortly
    6. Patrick verified 4 SDF changes that were a result of creating this filter and entering gains, etc, and accepted them in SDF, alog 54953
  4. damping gains adjusted during this current lock for:
    1. ITMX modes 9, 17, and 19
    2. ITMY modes 7, 18
    3. ETMX mode 3
    4. ETMY modes 1, 5, 6, 7, 8, 12, 18, 20
      1. modes 7 and 8 are restored to nominal
      2. mode 20 is running on the previously tested new damping filter, FM7
      3. using the FM7 to damp mode 20, mode 18 damping needs to be off, gain set to zero, and mode 12 gain is lowered to 0.2
      4. mode 20 gain is at 2.0, and I'd like to set the TRAMP time for mode 20 to 20 seconds, up from 10 seconds, after discovering tonight that mode 20 does not react well to changes in gain larger than 0.2-ish, so a longer TRAMP would be helpful for this mode
      5. since mode 20 is damping well, though slowly, I'm leaving the damping in this configurations, and am asking the Owl OPS to keep watch
        1. keeping watch means monitoring modes 12, 18, and 20, both the drive (which should be decreasing for modes 12 and 20), and the RMSLP_LOG10_OUTMON channels for all 3 modes, which should be holding steady, or decreasing
        2. plot attached shows this state for all 3 modes
    5. snapshots of all changed modes are attached
      1. all can be reverted to nominal damping gains at any time, EXCEPT ETMY mode 20, which would also need the damping filter changed back to FM1 (while the gain on that mode is zero)
      2. all nominal gains can be identified using the "Print lsc params" button on the violin mode medm
Images attached to this report
Comments related to this report
camilla.compton@LIGO.ORG - 03:23, Friday 07 February 2020 (54961)
Link

At 09:06 I noticed ETMY mode 20 OUTMON starting to increase. Strange as it had worked so well for Cheryl for the last 3 hours.
I reverted the ETMY gains (modes 12, 18, 20) at 09:33 UTC, maybe I should have left it longer to see what would happen. 
Attached is plots of applied gain with OUTMON below for modes 12, 18, 20 over the last 7 hours. Cheryl's gain changes are at~ - 20,000 s, the revert at -6000s.
Images attached to this comment
yannick.lecoeuche@LIGO.ORG - 08:21, Friday 07 February 2020 (54964)
Link

To be clear, the ETMY damping gains were reverted, but not the Mode20 filterbank changes, as we were worried we would get knocked out of Observe.

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