Adjustable X-Ray Mirrors Based on Plastic Electroactive Polymer Actuators for the Lynx Mission

摘要

The proposed soft X-ray mission Lynx will combine sub-arcsecond imaging capabilities with a roughly one order of magnitude larger collection area than NASA's Chandra observatory. Achieving such a large increase of the effective area while keeping costs manageable requires the use of adjustable optics for in-orbit corrections for mirror deformations. In this contribution, we report on the possibility to use a novel class of low-voltage thin-film actuators based on electroactive polymers for the active control. Electroactive polymers can produce high strains at low voltages and are able to correct for the deformations of submillimeter-thick mirror shells. The films can be fabricated at comparatively low costs and offer an easily scalable technology which can implemented by industrial partners. With processing temperatures below 140°C. electroactive polymer films can be deposited on glass mirror substrates without the risk of thermally induced imperfections. The combination of excellent angular resolutions and a large mirror will enable Lynx to detect the first accreting black holes, to study the evolution of galaxies and growth of cosmic structure, and to detect and constrain the properties of the Warm-Hot Intergalactic Medium (WHIM) theorized to account for the large fraction of missing baryonic matter in the Universe.