Modeling VRALA,The Next-Generation Actuator For High-Density, Tick Secondary Mirrors For AstronomyC. Del Vecchio, G. Agapito, G. Tomassi, and E. De Santis
National Institute for Astrophysics, Arcetri Astrophysical Observatory, Firenze, Italy
University of Cassino, Cassino, Italy
The next-generation of Extremely Large Telescopes adaptive optics systems require high-order, long-stroke, quite large deformable mirrors. Higher forces and greater actuator densities than the ones provided by the current technology are needed, still maintaining the severe accuracy and bandwidth requests. Based on a very simple magnetic circuit, providing a compact device, the VRALA actuator accomplishes this very demanding goal. With an efficiency of about 7 N/W and an overall radius that allows actuator separations as low as 25 mm, the deformable mirror can be actuated with large forces on small spatial scales, with a little thermal impact, and/or its thickness can be increased, in order to simplify the manufacturing.