Simulation of X-Ray Television System Output Signal Based on CMOS-Matrixes

Abstract

Various X-ray television systems are used for radiation control of materials and products, both indirect conversion of radiation images and direct conversion systems. X-ray television system type "X-ray screen - optics - CMOS-matrix" have a number of advantages over others: the ability to change the X-ray scintillation screen, which allows you to change the size of the working field and other system parameters; short image acquisition time; simplicity of construction; small dimensions and weight; low cost. The development of digital X-ray television systems requires the solution of important scientific and technical problems, which include: increasing the signal-to-noise ratio and, accordingly, the sensitivity of control, increasing the quantum efficiency of image converters, optimizing operating modes to ensure high quality radiation images.The aim of this research was to develop a model of X-ray television system. A physical and topological model of X-ray image transformation in X-ray television systems of the “X-ray screen — optics — CMOS-matrix” type has been developed during research. The math model allows to calculate the characteristics of X-rays at the output of the X-ray tube and the object under study, the intensity of the screen, the light intensity on the surface of the CMOS matrix after passing the optics, calculate the charge packet in a pixel and the output signal systems. The block diagram of the X-ray television system includes the following components: X-ray machine, object, scintillator (screen), mirror and lens with CMOS-matrix. The first stage of creating a through mathematical model is to simulate X-rays at a certain distance from the anode of the X-ray tube. The second stage of creating an end-to-end mathematical model of X-ray television system based on CMOS matrices of the optical range is the modeling of the process of converting X-rays, which corresponds to the shadow X-ray image of the object, into visible range radiation.The developed physical and topological model of X-ray image transformation in X-ray television systems of the type "X-ray screen - optics - CMOS-matrix" allows us to calculate the characteristics of X-ray television system at the design stage, which will save time and money on system development and also select the optimal modes of operation for the study of certain materials. The found results are a perspective direction in development of technology of research of materials that will allow to reduce cost of installations for researches.