Simulation study of a novel ZnO nanowire cold cathode flat-panel x-ray source using EGSnrc for Talbot-Lau type grating interferometry

Talbot-Lau grating interferometry (GI) can conduct X-ray phase contrast imaging outside synchrotron facilities and simultaneously provide attenuation, differential phase contrast, and small angle scattering information about imaging samples, where periodically distributed X-ray line sources are required. In this study, we proposed a novel cold-cathode flat-panel X-ray source with micro-array anode target to generate such line sources without using grating G0. Its cathode was composed of densely arranged zinc oxide (ZnO) nanowires, which can generate electrons by field electron emission effect, whereas micro periodic distributed Al-Mo-Al strips were utilized as anode target. X-ray spatial distribution and spectrum of the source with different anode target period (p0) were studied via using EGSnrc. Structured X-ray illumination required for GI was obtained under Mo strips. Mean contrast of the X-ray spatial distribution under the Mo strips of flat panel sources with p0 of 3, 15, 30, 126 m were 33.36%, 81.98%, 91.55%, and 98.63%, respectively. The source can eliminate the use of G0 and thus related limitations of G0 on Talbot-Lau GI.