Room: Exhibit Hall | Forum 1
Purpose: Flat-panel x-ray source, as a promising imaging device, is still in the development phase. It is time consuming to figure out the optimal physics parameters of components by manufacturing each specific flat-panel X-ray tube. And itâ€™s necessary to study the beam quality of flat-panel X-ray sources by some theoretical analysis for providing design guidance to the development of the prototype device. Therefore, we propose a scheme for the beam quality of the flat panel X-ray source based on Monte Carlo simulation
Methods: The flat panel X-ray source uses ZnO nanowire (NW) as cold electron emitters. Assuming every ZnO NW emitter and pattern presents the same characterization and produces the identical distribution of fluence. The total fluence map was accumulated by shifting ZnO NW pattern. Then the calculated spectrum of the fluence was compared with the measured spectrum for validating the proposed MC scheme. The spectrums with various silica glass thickness, tungsten target thickness and anode voltage are analyzed for figuring out the optimal physics parameter in the device. For quantitative analysis of beam quality, in-air exposure, half-value layer and mean energy are also calculated as three important parameters of beam quality.
Results: The comparison between the calculated spectrum of the beam and the measured spectrum were basically the same. Then, the spectrums with various silica glass thickness, tungsten target thickness and anode voltage were calculated. Further, quantitative analysis of beam quality found the optimal target thickness as 1000nm in the current device at 40 kV anode voltage
Conclusion: The proposed MC simulation method has been validated with the realistic measurement of flat-panel X-ray sources. It also shows great potential for analyzing the beam quality of flat-panel X-ray sources and optimizing the thickness of tungsten target film and silica glass.
Funding Support, Disclosures, and Conflict of Interest: National Natural Science Foundation of China (81301940 and 81428019), National Key Research and Development Program (2016YFA0202003), Guangdong Natural Science Foundation of China (2016A030310388 and 2017A030313692), and Southern Medical University Startup fund (LX2016N003).