A novel portable,high-luminosity monochromatically tunable x-ray microscope

A novel experimental setup for transmission x-ray microscopy is presented. It is based on the use of a point isotropic x-ray source and a single spherical crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized and enlarged using a spherical crystal and, lastly, imaged using a detector downstream of the crystal. We demonstrate by ray tracing technique and experimental testing that this system allows microscopy studies with image resolution better than the dimensions of the source, high magnification ratios, and great field of view. Microscopes using this model can be easily built using different micro x-ray sources, like conventional x-ray tube generators, x-rays emitted by laser generated plasmas or synchrotron radiation. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in a wide range of Bragg angles (20°<Theta;<45°) is demonstrated for the first time. High quality monochromatic (δλ/λ∼10-5-10-3) images with high magnification about 15-35 times and spatial resolution (<10 μm) over a large field of view (few mm2) were obtained. Some possible applications and preliminary experimental verification of the feasibility of the setup are also presented.