Elli, Thomas

In our attempt to decouple the motion of ETMY in pitch and yaw to the Hartmann sensor beam motion, we have been actuating on ETMY with a frequency of .35 HZ and an amplitude of 50 counts on the M0 stage and running a transfer function. Then changing the lenses on the table to alter the imaging path length till we get a nominal length so that the transfer function is at a minimum. The plot is attached below showing the actuation in yaw, we might need to do more measurements in yaw and then proceed on to pitch.  We're looking for a minimum coherence of at least .9