X-ray imaging diagnosis based on toroidally bent crystal

A focusing spectrometer with toroidally bent crystal is designed for X-ray monochromatic imaging. The focusing properties of toroidally bent crystal and spherically bent crystal in Bragg geometry are discussed, and the conditions for optimized two-dimensional (2D) imaging of X-ray source are proposed. X-ray backlight imaging experiments have been carried out in Research Center of Laser Fusion. A toroidally bent crystal of mica was used as the imaging element with curvature radii of 290 mm and 190 mm in meridional and sagittal planes, respectively. With the high collection efficiency of the bent crystal spectrometer, high quality visible 2D X-ray backlighting images were obtained by the imaging plate. It is demonstrated that, the toroidally bent mica crystal can be used for X-ray monochromatic backlight imaging. The analysis of the spectral information in sagittal direction shows that, the toroidally bent crystal spectrometer has a spatial resolution about 100 μm, which meets the design requirement. (authors)