Kiwamu, Evan

Yesterday after maintence time ITMY bounce mode was rung up.  Eavn and Kiwamu damped it with the following settings: +60 degrees phase shifter, bandpass at 9.73 (FM2+FM4 in ITMY_M0_DARM_DAMP_V) and a gain of -0.03.  We did not add this to the guardian, since we have not seen ITMY get rung up before we are assuming something unusual happened yesterday.  

Also, the ETMY roll mode damping which uses AS A 45 has changed sign.  the settings that evan found which worked today are -100dB, a bandpass at 13.9, no phase shift and a gain of -8.  

For bounce and roll, there shouldn't be any need to gues at which optic is rung up, if the motion is large enough.  If a mode is badly rung up we can usually see the bounce mode in the top mass vertical osem and the roll mode in the L2 witness sensors, either Pitch or Yaw.  Attached here is a template that is stored in /ligo/home/sheila.dwyer/Locking/BOUNCE_ROLL_MODE_CHECK.xml.  It shows you spectra and coherences with DARM of local sensors that should be used to identify which optic is rung up when our normal bounce or roll damping is not working. If the damping as it is in the guardian is not working, we shoudl turn off the damping to avoid confusion and run this template to identify which optic is the culprit.