Diffraction-limited Microbeam with Fresnel Zone Plate Optics in Hard X-Ray Regions

Abstract

A hard X-ray microbeam with zone plate optics has been tested, and preliminary experiments on scanning microscopy have been performed. A Fresnel zone plate fabricated by the electron-beam lithography technique is used as an X-ray focusing device. The material of the zone structure is tantalum with thickness of about 1 µm, and the outermost zone width of the zone plate is 0.25 µm. A focused spot size measured by knife-edge scanning is 0.3 µm at an X-ray energy of 8 keV. Closer evaluation of the spatial resolution has been done by observing resolution test patterns in a scanning X-ray microscopy experiment, and fine patterns with a 0.2 µm-structure have been resolved.