Progress report on using magneto-strictive sputtered thin films to modify the shape of a X-ray telescope mirror

There is a basic need both in X-ray astronomy and in synchrotron X-ray and neutron beam optics to be able to modify the shape of an optic via an external source of actuation. We describe a technique of shape modification that can be applied to thin walled (∼ 100-400 micron thickness) electroformed replicated optics or glass optics to improve the near net shape of the mirror as well as the mid-frequency (∼ 2-10 mm length scales) ripple. The process involves sputter deposition of a magnetic smart material (MSM) film onto a magnetically hard material (i.e., one that retains a magnetic field, e.g. the material in hard disk drives). The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback, locally magnetizes the surface to impart strain where needed. We describe the results of our current progress toward our ultimate goal of improving the angular resolution of grazing incidence optics.