Present status of the nanotomography system at BL47XU at spring-8 and its efficiency improvement using double-condenser optics

Abstract

Although imaging x-ray nanotomography developed at beamline BL47XU of SPring-8 has reached a spatial resolution less than 200 nm, poor intensity and low signal-to-noise ratio are more serious problems in the system using zone plate optics. Improvement of the diffraction efficiency of Köhler illumination optics is attempted by doubling two condenser zone plates, which have a constant grating pitch of 200 nm. Although a long longitudinal distance between two condensers is possible (∼100 mm), efficiency varies periodically as the distance is changed due to the Talbot effect. A maximum efficiency close to 0.3 is obtained with a periodic distance of approximately 500 μm. © 2011 American Institute of Physics.