Abstract 120

Submitted by Thomas RIMMELE

Authors

T. Rimmele (1), K. Richards (1), S. Hegwer (1), F. Woeger (1), J. Marino(2), D. Schmidt (3)

Affiliations

(1) National Solar Observatory; (2) University of Florida; (3) Kiepenheuer Institut für Sonnenphysik.

Abstract

Solar observations are performed over and extended field of view and the isoplanatic patch over which conventional adaptive optics (AO) provides diffraction limited resolution is a severe limitation. The development of multi-conjugate adaptive optics (MCAO) for the next generation large aperture solar telescopes is thus a top priority. The Sun is an ideal object for the development of MCAO since solar structure provides “multiple guide stars” in any desired configuration. At the DST we implemented a dedicated MCAO bench with the goal of developing well-characterized, operational MCAO. The MCAO system uses 2 deformable mirrors conjugated to the telescope entrance pupil and a layer in the upper atmosphere, respectively. DM2 can be placed at conjugates ranging from 2km to 10km altitude. For our initial experiments we have used a staged approach in which the 97 actuator, 76 subaperture correlating Shack-Hartmann solar adaptive optics system normally operated at the DST is followed by the second DM and the tomographic wavefront sensor, which uses three “solar guide stars”. We have successfully and stably locked the MCAO system on artificial objects (slides), for which turbulence screens are generated directly in front of the DMs, as well as solar structure. We present preliminary results and discuss future plans.