Magnetostrictively deforming the surface of a silicon wafer at two locations

The only way to increase the sensitivity of X-ray telescopes without significantly increasing their size (compared to existing telescopes) is to use thinner mirror shells. However, to maintain the figure of thin mirror shells, their shape will need to be adjusted after they are mounted and/or actively controlled during flight. Here we describe progress toward developing a method that can be used to do both. The core of the concept is to coat thin (<500 μm) X-ray mirrors with a ~10 μm layer of magnetic smart material (MSM). When an external magnetic field is applied to the MSM layer it will expand or contract, changing the shape of the mirror. We have previously demonstrated that this method can be used to generate a single localized deformation on the surface of a test sample. Here we present work to study how two deformations affect each other. The first deformation that we created has a height of ~5 μm. The second deformation, generated by applying a magnetic field to the sample 4 mm from the first position, has a height of ~1 μm. It is likely that the second deformation is smaller than the first because the two areas where the magnetic field was applied were close to each other. This could have caused the MSM to already be partially expanded in the second area when the field was applied there.