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Reports until 20:47, Wednesday 18 December 2019
H1 SUS
cheryl.vorvick@LIGO.ORG - posted 20:47, Wednesday 18 December 2019 (53984)
ETMY violin mode damping: damping Mode 6 for the first time

ETMY violin mode damping gains are set at nominal for all modes except modes 1 and 6.  Mode 1's peak is so small I've turned off the damping.  I've started damping mode 6.  Mode 6 started with a gain of -0.1, which was slowly ringing it up.  I switched to a gain of +0.1.  I'm leaving this gain on mode 6, and am requesting it be monitored overnight, by checking the peak height in the spectra in the diaggui file called diaggui_tracking_ETMY_mode1_6.xml, which is in my home directory (first attachment is a snapshot of this dtt).  The dtt file has a reference from tonight at04:32 UTC, and opens with the X axis zoomed in to show only ETMY modes 1 and 6. 

Monitor filters for these two peaks currently overlap, so the numbers and ndscopes do not reflect each peak, thus the need to use dtt.

I updated the damping filter for mode 6.  As found, the mode 6 damping was biased toward the mode 1 peak, and I moved the filter up in frequency so that it's biased away from the mode 1 peak.  I've attached snapshots of the damping filters for modes 6 and 1, with vertical cursors showing the frequency of the peak each filter is damping.  Mode 1 damping filter is unchanged.

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