Please excuse the lateness of this report. Such a corrector plate improves the spot size, but the spot size then has an angular dependence. A corrector plate was a possibility for the future, but will not be pursued now.
Preliminary conclusion is that slumping appears to work well.
33 such segments will be needed to build a mirror. Rosanna discussed plans for mounting segments. Segments will initially have x,y,z,theta,phi adjustment, though some of these degrees of freedom may be discarded later. Hans agreed to ship Rosanna 2 or three Aluminum segments for comparison with slumped mir. Or will the building temperature be stable enough.