Andrei, Sheila

We've observed that upon IFO switching its state to OBSERVING (H1:GRD-IFO_OK), we observe the so-called bounce modes of mirror suspencions at freqeuencies around 27.041 Hz in H1:SQZ-FC_LSC_DOF2 channel. These modes can be present in measurements for over 10 minutes. We have checked the occurances of these events over a few days, which will hopefully help us to determine the exact suspencion responcible for this behavior (Bouncemodes.png, /ligo/home/andrei.danilin/Documents/Oscillations.xml).