X-ray Dual-energy Analysis Grating Design And Imaging Application Based On Scintillator Structure

X-ray phase contrast imaging technology has been becoming one of the cutting-edged research topics in the field of X-ray imaging.Taking advantage of the phase shift information,the X-ray phase contrast imaging is a technique to detect the internal composition and reveal the internal structure of the imaging object.In comparison with traditional X-ray absorption imaging,X-ray phase contrast imaging can be applied to the detection of weakly absorbing materials,which provides much better contrast-enhanced images.Therefore,X-ray phase contrast imaging shows great potential applications in the field of medicine,biology,materials science and non-destructive testing.At present,the X-ray grating-based phase contrast imaging based on Talbot-Lau interferometer is regarded as the most widely used strategy in X-ray imaging.However,there are many drawbacks in this method.Such as a stepping translation with high accuracy is required to move the grating,challenges in the fabrication of a high aspect ratio grating,complicated imaging steps,etc.Therefore,it is a pressing task to improving existing X-ray phase contrast imaging.In this thesis,we provide an alternative method to pursue a compact X-ray phase imaging system with high performance.Firstly,a new analyzer grating is designed to replace the existing analyzer grating and scintillation conversion screen in the X-ray imaging system,which is interlaced by the low-energy grid bars and the high-energy grid bars.Further,we simulate and optimize the parameters of the grating,such as the material and the thickness of the bars.Sirnce the analyzer grating we designed can get differential phase-contrast image by changing energy levels of X-ray once,it doesn't need phase-stepping device and rotated specimen Then,we discuss the processing technology and fabricate the dual energy analysis grating.Finally,an X-ray phase contrast imaging system is built based on the grating.The experiment results show that the improved X-ray Talbot-Lau interferometer can obtain differential phase-contrast image of specimen.This method is promising to facilitate the applications of X-ray phase-contrast imaging.