AS, KA, DH

As part of the HAM6 alignment work, we used OM1 to center the beam on OM2, and adjusted the OSEMs to the proper half-open-light values.

Thanks to the rotation of the septum window by Keita et al., the beam was well-centered on OM1 (see Koji's post on the new beam alignment in the chamber).  We had to perform some not-so-gentle manipulations of the pitch adjustment screw at the bottom of the mirror holder to get the OM1 mirror to pitch enough forward that the beam was centered on OM2.  In the end this required the use of an extra class-A nut to properly balance the mirror, and the removal of the tip-tilt's backplane (which holds the OSEMs) to allow us to access the mirror holder (and the screw hole) from the back.  There were some tense moments of tip-tilt frustration, but in the end the screw+nut combination was just right for the pitch adjustment.

Once the beam to OM2 was aligned we checked the OMEM DC values and adjusted LL and LR to center the flags.  The flag of the LL magnet is no longer touching the side of the OSEM (although it is close).  The attached spectrum shows the OSEM signals for OM1; the mirror is free, the damping works, the beam is in the right place, we are happy.