When a Fresnel zone plate is used as a coded aperture to image large-area sources of X-rays or gamma rays, it is necessary to use a half-tone screen. It is shown here that small-area sources, with such a system, will always produce strong ghost images or artifacts.
D. T. Wilson,
H. H. Barrett,
G. T. Demeester,
M. H. Farmelant,
"Point-Source Artifacts in Fresnel Zone Plate Imaging," Optical Engineering 12(4), 124133 (1 August 1973). https://doi.org/10.1117/12.7971646