Performance analysis of the adaptive secondary mirror for the UH2.2 telescope

TNO and industrial partners are developing a new type of adaptive secondary mirrors (ASM) for the University of Hawaii 2.2-meter telescope, consisting of 210 actuators, in an overall volume of ø63cm by 15cm height, and having an aspherical convex mirror-shell of 3,5mm thickness. The novel actuator technology enables a compact system without active cooling that can be retro-fitted within the same mass and volume of an existing passive secondary mirror. This development enables affordable and reliable ASM systems for the world’s larger telescopes as well as the many telescopes in the 2-4 meter class. This paper presents the overall design of this ASM and focusses on the performance analysis regarding its figure quality, its dynamical behavior and the related closed loop performances.