Source-optic-crystal optimization for compact monochromatic imaging

A compact monochromatic imaging system was designed with an optimal combination of a low power molybdenum source, collimating optic and monochromatizing crystal. The microfocus source was characterized for spot size, source depth, source intensity and source uniformity. Two different polycapillary collimating optics were characterized for collecting radiation from the low power divergent source and redirecting it into a parallel beam. The focal distance, transmission with respect to energy, output uniformity and exit angle divergence were measured. Monochromatization was then achieved by diffraction from a variety of single crystals. For each crystal, the rocking curve width was measured. To predict the actual resolution for the monochromatic imaging, a theoretical 3-dimension resolution calculation was developed. The measured angular resolutions for the horizontal and vertical directions were slightly different and were in good agreement with theoretical values. The measured and theoretical intensity after monochromator crystals showed the expected trade-off between high intensity and high resolution.