Designing the Actuator for the Next-Generation Astronomical Deformable Mirrors: a Multidisciplinary and Multiphysics Approach
The actuation system of the deformable mirror is one of the crucial components of an Adaptive Optics unit. One possible implementation comprehends a linear force motor and a capacitive sensor providing the feedback measure signal. Choosing a magnetic circuit that makes optimum use of the magnetic force delivered by a current and properly arranging the electrostatic geometry allows to obtain very good results.
This paper, after a description of the magnetic design, discusses the mutual relationships in the physics of the device: as the magneto-static and thermal responses as well as the fluid dynamics in the physical implementation interact, such computations are carried out in order to define the thermal impact of the actuator on the local environment as a function of the delivered force.