Development of x-ray mirror foils using a hot plastic deformation process

In this paper, we present a silicon reflector developed through a hot plastic deformation process and used as a lightweight, high-angular-resolution x-ray mirror. We deformed the silicon substrate using conical dies with a curvature radius of 100 mm. The measured radii of the reflector were approximately 100 µm greater than the design values. Due to a gap between the die and the reflector toward the edge, it is probable that the substrate did not reach the yield point, and an elastic spring back occurred. In addition, we have evaluated the x-ray imaging capability of the plastically deformed silicon reflector for the first time, to the best of our knowledge. The estimated angular resolution is 1.76 arc min from the entire reflector, and 0.52 arc min in the best region. For the enhancement of the imaging capability, we may improve the shape of die and determine the best parameter set for the deformation.