1. Theoretical and experimental analysis of the modulated phase grating X-ray interferometer
- Author
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Hunter Meyer, Joyoni Dey, Sydney Carr, Kyungmin Ham, Leslie G. Butler, Kerry M. Dooley, Ivan Hidrovo, Markus Bleuel, Tamas Varga, Joachim Schulz, Thomas Beckenbach, and Konradin Kaiser
- Subjects
X-ray interferometry ,Modulated phase grating ,Diffraction grating ,Dark-field ,Porosity ,Medicine ,Science - Abstract
Abstract X-ray grating interferometry allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, resulting from X-ray attenuation, refraction, and small-angle scattering, respectively. The modulated phase grating (MPG) interferometer is a recently developed grating interferometry system capable of generating a directly resolvable interference pattern using a relatively large period grating envelope function that is sampled at a pitch that is small enough that X-ray spatial coherence can be achieved by using a microfocus X-ray source or G0 grating. We present the theory of the MPG interferometry system for a 2-dimensional staggered grating, derived using Fourier optics, and we compare the theoretical predictions with experiments we have performed with a microfocus X-ray system at Pennington Biomedical Research Center, LSU. The theoretical and experimental fringe visibility is evaluated as a function of grating-to-detector distance. Additionally, quantitative experiments are performed with porous carbon and alumina compounds, and the mean normalized dark-field signal is compared with independent porosimetry measurements. Qualitative analysis of attenuation and dark-field images of a dried anchovy are shown.
- Published
- 2024
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