I went into the PSL to check out possibilities for redoing the top periscope piezo mirror mount, which I think is responsible for the 250 Hz peak in DARM at LLO (Link). The secondary purpose was to check the recovery time for a 10 minute incursion. The IMC did not loose lock but suffered intensity spikes beginning when I went in, and quickly dissapating so that they were gone by an hour after I left. The plots show MC2 TRANS and ISS_AOM_DRIVER_MON in an overview and a zoom into one of the intensity spikes. The zoom suggests ISS oscillations. The step in MC2 TRANS was when Evan, seeing the spikes, shut down the gaurdian. 

Robert, Evan