Schematic display of the ray-optical approach phase contrast formation mechanism for a circular cross-section object being irradiated by a parallel and monochromatic x-ray beam. The image is detected at a distance from the object plane.
Schematic display of the wave-optical approach phase contrast formation mechanism for a circular cross-section object being irradiated by a spherical and monochromatic x-ray beam generated by a point source located at a distance from the object plane. While, the image is detected at a distance from the object plane.
Influence of imaging system spatial resolution on the phase contrast signal for a diameter nylon wire. The simulated signals, obtainable with a parallel and monochromatic beam, were computed following both the considered theoretical models: the wave optical (wo) and the ray-optical (ro) approaches. (a) Simulated signals obtainable with an ideal detector (i.e., with an infinite spatial resolution). (b) The same signals after being convolved with a FWHM detector response function.
Phase contrast images of a diameter nylon wire acquired at three different energies and at three different sample-detector distances. (a) and . (b) and . (c) and . (d) and . (e) and . (f) and . (g) and . (h) and . (i) and .
Simulated diameter nylon wire signal ( and ) sampled at (a) and three examples of the same signal sampled at (b). The solid, dashed, and dotted curves in Fig. 5(b) show three different (i.e., starting from different initial points) step samplings of the curve shown in Fig. 5(a). The simulation is based on the diffraction formalism and takes into account the unsharpness due to geometry and image receptor response function.
diameter nylon wire experimental data (dots) superimposed on simulated data (solid line). (a) and . (b) and . (c) and . (d) and . (e) and . (f) and .
Comparison between diameter nylon wire simulated signals, sampled at , obtained following the two considered models: the wave optical (solid line) and the ray-optical (dots) approaches. (a) and . (b) and . (c) and . (d) and .
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