High-Energy X-ray Radiation Registration Model

It is proved the necessity for carrying out computing experiments according to the mean value and the square of registered X-ray photons absorbed energy of in a scintillation detector. The offered imitation model of the transfer and registration of high-energy X-ray radiation in a sensing volume of CsI and CdWO[4] scintillation detectors is based on a Monte Carlo method. The model considers leakage of secondary photons and electrons. It is offered approaches to justification of adequacy of the developed model of a high-energy X-ray radiation registration

Features of X-ray Absorption Densitometry of Large-size Objects with Variable Thickness

Features of formation and processing of the primary radiometric signals in the digital high-energy X-ray absorption densitometers for the homogeneous objects with variable thickness are examined. The densitometer's equation based on the polynomial approximation of the object's ray thickness dependence from its mass thickness is proposed. Guidance to select the capacity of the analog-digital converter is given. There is one example of the densitometer's equation coefficients calculation to examine the carbon, aluminum and steel wares with the mass density from 15 to 80 g/cm{2}. It was shown that disagreement of the experimental and estimated values of the ray thickness for the similar mass thicknesses of the testing object is conditioned by the scattered radiation. On the high-energy digital radiography set with the X-ray source - the betatron MIB-4.5/9 the accuracy of the experimental estimation of the density was within 0.0086 g/cm{3} for the steel ware thickness from 25 to 100 mm

Informativeness Improvement of Hardness Test Methods for Metal Product Assessment

The paper presents a combination of theoretical suggestions, results, and observations allowing to improve the informativeness of hardness testing process in solving problems of metal product assessment while in operation. The hardness value of metal surface obtained by a single measurement is considered to be random. Various measures of location and scattering of the random variable were experimentally estimated for a number of test samples using the correlation analysis, and their close interaction was studied. It was stated that in metal assessment, the main informative characteristics of hardness testing process are its average value and mean-square deviation for measures of location and scattering, respectively

The Mathematical Model of Image, Generated by Scanning Digital Radiography System

The mathematical model of image, generated by scanning digital radiography system is present. This model takes into account the X-ray energy spectrum transformation of the test object and a noise due to the quantum nature of radiation. The calculation results confirm the importance of fluctuations of the absorbed energy of the registered photon for the small size of the scintillation detectors

The Selection of Computed Tomography Scanning Schemes for Lengthy Symmetric Objects

The article describes the basic computed tomography scan schemes for lengthy symmetric objects: continuous (discrete) rotation with a discrete linear movement; continuous (discrete) rotation with discrete linear movement to acquire 2D projection; continuous (discrete) linear movement with discrete rotation to acquire one–dimensional projection and continuous (discrete) rotation to acquire of 2D projection. The general method to calculate the scanning time is discussed in detail. It should be extracted the comparison principle to select a scanning scheme. This is because data are the same for all scanning schemes: the maximum energy of the X–ray radiation; the power of X–ray radiation source; the angle of the X-ray cone beam; the transverse dimension of a single detector; specified resolution and the maximum time, which is need to form one point of the original image and complies the number of registered photons). It demonstrates the possibilities of the above proposed method to compare the scanning schemes. Scanning object was a cylindrical object with the mass thickness is 4 g/cm2, the effective atomic number is 15 and length is 1300 mm. It analyzes data of scanning time and concludes about the efficiency of scanning schemes. It examines the productivity of all schemes and selects the effective one

Application of dual energy method for non-destructive testing of materials designed to work in extreme conditions

The description of the dual energy method (DEM) for non-destructive testing (NDT) of materials and products is presented. It highlights the key factors that determine its accuracy and performance and shows the possibilities for its further improvement. The correlation between the quantum noise level and the DEM precision of the effective atomic number was found

Experimental Research of High-Energy Capabilities of Material Recognition by Dual-Energy Method for the Low- Dose Radiation

The algorithm to produce primary radiographs, its transformation by dual energy method and recognition of the object materials were enhanced based on the analysis of experimental results. The experiments were carried out at the inspection complex with high X- ray source - betatron MIB 4/9 in Tomsk Polytechnic University. For the reduced X -ray dose rate, the possibility of recognition of the object materials with thickness from 20 to 120 g/cm{2} was proved under the condition that as the dose rate is reduced by the defined number of times, the segment of the image fragment with the reliably identified material will increase by the same number of times

Adequacy Criteria of Models of the Cargo Inspection System with Material Discrimination Option

Generalized adequacy criteria for mathematical models in order to discriminate materials in X-ray inspection systems by the dual-energy method were developed. Two main approaches of the examination systems to produce the adequacy criteria by the final and the intermediate parameters of the dual-energy method were analyzed. The criteria were specified in respect to the discrimination by the effective atomic number and by the method of level functions. Experimental and theoretical estimates of the discrimination parameters of the test object constituents scanned by fan beams of X-ray radiation with the maximal energies of 4.5 and 9 MeV are given

State of the Art and Development Trends of the Digital Radiography Systems for Cargo Inspection

Increasing requirements for technical parameters of inspection digital radiography systems are caused by increasing incidences of terrorism, drug trafficking and explosives via variety of transport. These requirements have determined research for new technical solutions that enable to ensure the safety of passengers and cargos in real-time. The main efforts in the analyzed method of testing are aimed at the creation of new and modernization of operated now systems of digital radiography as a whole and their main components and elements in particular. The number of these main components and elements includes sources of X-ray recording systems and transformation of radiometric information as well as algorithms and software that implements these algorithms for processing, visualization and results interpretation of inspection. Recent developments of X-ray units and betatrons used for inspection of small- and large-sized objects that are made from different materials are deserve special attention. The most effective X-ray detectors are a line and a radiometric detector matrix based on various scintillators. The most promising methods among the algorithms of material identification of testing objects are dual-energy methods. The article describes various models of digital radiography systems applied in Russia and abroad to inspection of baggage, containers, vehicles and large trucks

Generation and Analysis of Wire Rope Digital Radiographic Images

The paper is dealt with different structures of the digital radiographic system intended for wire rope radiography. The scanning geometry of the wire rope is presented and the main stages of its digital radiographic image generation are identified herein. Correction algorithms are suggested for X-ray beam hardening. A complex internal structure of the wire rope is illustrated by its 25 mm diameter image obtained from X-ray computed tomography. The paper considers the approach to the analysis of digital radiographic image algorithms based on the closeness of certain parameters (invariants) of all unit cross-sections of the reference wire rope or its sections with the length equaling to the lay. The main invariants of wire rope radiographic images are identified and compared with its typical defects