Magnetic smart material application to synchrotron X-ray optics: prospects and current progress

Abstract

Magnetic smart materials (MSMs) offer an alternative to the typical piezo-electric actuators that are currently being used to control X-ray optics on beam lines. MSMs combined with an overcoating of a magnetic hard material means a deformable mirror whose non-reflecting side is coated with a MSM plus magnetic hard overcoat can work in a power-off mode. The process works by using an electromagnet (EM) to impose a magnetic field in the bilayer of MSM and magnetic hard overcoat. Once the EM is turned off, the mirror settles to a new shape within minutes. The new shape can then remain intact for days. Since the EM is not fixed to the mirror, the exact placement of the magnetic field can be adjusted by relocating the EM. This feature allows for fine-scale adjustments and avoids the “dead pixel” replacement problem common with piezo patches that are attached to the mirror. We will give an overview and a progress report.