Three-dimensional X-ray fluorescence imaging with confocal full-field X-ray microscope

A confocal full-field X-ray microscope was performed for three-dimensional X-ray fluorescence imaging with sub-micron spatial resolution. The system consists of an illumination system that produces a sheet-like shaped X-ray beam micrified only in one direction, and an X-ray full-field microscope whose optical axis is normal to the illuminating “sheet-beam”. An arbitrary cross-sectional region of the object is irradiated by the sheet-beam, and X-ray fluorescence emission from this region is imaged simultaneously with the full-field microscope. Therefore, a virtual sliced image can be obtained with one-shot exposure, and three-dimensional observation is available only by a linear translation of the object. The experiment has been carried out at beamline 37XU of SPring-8. One-dimensional focusing total reflection mirror is used to produce the sheet-beam. Fresnel zone plate is used as the objective of the X-ray full-field microscope system. Charge-coupled device camera was used as an image detector.