Curved crystal x-ray optics for monochromatic analysis and imaging

Monochromatic x-ray imaging has been shown to increase contrast and reduce dose relative to conventional broadband imaging. However, clinical sources with very narrow energy bandwidth tend to have limited intensity and field of view. In this study, focussed fan beam monochromatic radiation was obtained using doubly curved crystal (DCC) x-ray optics. The technique could be used with a variety of clinical sources for monochromatic slot scan imaging. The intensity was assessed and the resolution of the focussed beam was measured using a knife-edge technique. A simulation model was developed and comparisons to the measured resolution were performed to verify the accuracy of the simulation to predict resolution for different conventional sources. A simple geometrical calculation was also developed. The measured, simulated and calculated resolutions agreed well. Adequate resolution and intensity for mammography was predicted for appropriate source/optic combinations.;Since DCC optics are employed in crystallography and x-ray fluorescence systems and may find application to imaging, it is increasingly important to understand how optic defects impact performance for these systems. The simulation model assessed the effects of misalignment and optic defects on system parameters such as intensity, beam size, and resolution. Simulation results were compared to optics measurements. Rapid reproducible measurements of optics quality are important both for performing systematic studies of optics defects and for assessing individual optics. A simple operator-independent alignment technique was developed that was also beneficial in ensuring optimal beam intensity in analysis systems. The measurements and simulations were in good agreement and provided insight into essential optics parameters.;The optics were used in powder diffraction due to the advantages of the intense focused beams. Measurements were made using a low power microfocus source for several small inorganic samples. Diffracted peak width, resolution, and intensity were analyzed. The measured resolution was much smaller than the peak width due to the focussed beam, and was limited by the pixel size of the area detector. Resolution and intensity were in good agreement with those obtained from simple geometrical calculation. The simulation model was also used to understand the diffraction ring shape and width.