Sheila, Evan, Jeff B, Corey

Both yesterday and this morning, we had extremly rung up bounce and roll modes (both times because the IFO lost lock and DOWN was not run, yesterday for the reasons explained in comments to alog 20103, today because of a different snafu).

When this happens, we need to damp bounce on ETMY while locked on ALS.  To do this, it seems that we need to use a phase that is +150 degrees compared to the phase we use in full lock.  This phase shift comes from the difference between the DARM loop here and in full lock.  When locked on RF DARM, we need to use +120 degrees compared to the normal settings.

We also had difficulty yesterday with rung up roll modes.  To damp roll we use AS WFS, so we need to get to RF DARM before we try to damp them this way. One difficulty we had was that the roll mode notches in the PUMs were not wide enough (Evan adds that the notch needs to be wide because of the Shapiro effect), so that DHARD could saturate because of the roll mode.  

Bringing these things down when they are verry rung up is very slow, because the actuation authority is small compared to the amount of energy in the mode.  Fortunately, we are normally in the regime where the mode is small and it only takes a few minutes to damp them.