Improvement of parameters X-ray television systems on the basis of electronic converters

Abstract

Flat Panel Detectors (FPD) emerge as a next-generation digital x-ray technology. The numerous advantages of flat panel detectors over x-ray film, computed radiography image plates, and image-intensifier tubes are given. They include time efficiency through bypassing chemical processing and the ability to digitally transfer and enhance images. The most important parameters of different technologies are discussed. The comparison table of modern FPD is presented.Emergence and distribution of industrial television, creation of different types of vacuum transfer tubes, in particular for x-ray range, and then and their solid-state analogs promoted use and development the x-ray TV systems of methods of researches. In comparison with radiographic these methods have essential advantages and open essentially new opportunities of researches. With creation and mass introduction of modern computer facilities, in particular her attraction to processes of registration, visualization and processing of shadow x-ray images of objects. Now the special branch is put by x-ray TV systems of pulse action that are widely used in medicine, defectoscopy, military science and different technological processes. Thanks to a number of essential positive qualities (the small weight and dimensions, simplicity of a design, an opportunity of both the panoramic, and directed raying, the low power consumption and also an opportunity to control dynamic objects and processes) devices have received the greatest use in technology of nondestructive control of materials in non-stationary conditions.The device and the scheme of operation of the x-ray electron-optical converter with an axial arrangement of the receiver is considered. As the converter light signal matrixes on the basis of charge-coupled devices, and also CMOS sensors are used. Transformation of x-ray radiation to the image, available to the operator, takes place several stages. At each step of transformations primary information is distorted that leads to deterioration in the visual image. Key parameters of x-ray electron-optical converter are specified, shortcomings of this type of technologies are noted.By means of digital the x-ray TV systems of systems it is possible to receive images which quality is much higher qualities of x-ray films and computer radiography. As a result of the big relation signal/noise for digital detector system possible indication of defects, is less than the size of pixel. The sizes of solid-state detectors several times smaller for x-ray electron-optical converter. Besides they have no geometrical distortions and reflections. Other advantage of flat detectors is much faster processing of results at rather high quality of the image which gives a gain in time. The digital X-ray analysis allows to reduce a dose of x-ray radiation due to installation of an exposition at which the necessary noise level is supported.The development and improvement of technologies and technical means in the x-ray non-destructive control has taken the way of using highly stable sources of radiation, modern radiation converters, computer methods of their management, application of the newest methods of digital image processing and their analysis. There is an active transition of control systems with the use of radiation x-ray electron-optical converter to systems using multi-element transducers manufactured by microelectronics: amorphous selenium and amorphous silicon. The use of a television channel in such systems greatly expands the functionality of the equipment.Ref. 36, fig. 4, tabl. 3