Phase-contrast hard X-ray microscope with a zone plate at the photon factory

Abstract

A Zemike-type phase-contrast X-ray microscope with a zone plate and a phase plate has been developed at the Photon Factory BL3C 2 . The zone plate had the outermost zone width of 0.1 μm and the diameter of 155 μm. Parallel monochromatic X-rays of 9 keV were incident on a specimen and a direct beam transmitted through the specimen was focused on the back focal plane of the zone plate where a phase plate was placed. Two types of phase plates were tested. One was an aluminum foil with a pinhole, and the other was a gold wire embeded in epoxy resin. Using the aluminum phase plate, a tantalum line pattern as fine as 0.2 μm could be imaged. Almost transparent specimens, such as polystyrene beads of 2.8 μm in diameter could be also observed. Using the gold phase plate, a tantalum line pattem as fine as 0.1 μm could be imaged.