A Study on Radiation Imaging Mechanism and Characteristics in Different Inspection Systems

2021 ◽  
Author(s):  
Yuting Xu ◽  
Zhifang Wu ◽  
Qiang Wang

Abstract Radiation imaging, as a key issue in nuclear technology, has received considerable attention in the industry. It is widely used in nuclear medicine, Customs supervision, and many other areas. The objective of this investigation is to get insight into the principle, operation characteristics and image characteristics of radiation imaging. In this paper, an investigation on radiation imaging is conducted on three main inspection systems for Customs supervision, including small X-ray inspection machine, CT baggage inspection system, and large container inspection system. The principle, operation characteristics, evaluation indexes, pseudo-color processing and image characteristics are discussed in detail. The results indicate that the spatial resolution of small X-ray inspection machine is much higher than that of CT baggage/goods inspection system and large container/vehicle inspection system. It is a challenge to identify substances and specific shapes in the case of overlapping for small X-ray inspection system. Moreover, the mechanism of X-ray images is discussed as well. The radiation images are divided into three types, including two-dimensional, pseudo-color, high spatial resolution; two-dimensional, gray, high spatial resolution; three-dimensional, pseudo-color, high density resolution. The further investigation on machine inspection images is suggested to focus on the application environment. For some objects with specific characteristics, such as amorphous, explosive, the CT baggage inspection has much better performance than other systems. The research in this paper reveals the mechanism, parametric effect and imaging characteristics. It could provide a necessary foundation for the follow-up intelligent processing, detection, identification and annotation for radiation imaging in nuclear area. The research on inspection devices could lend strong experience to medical treatment, industry and many other fields.

1979 ◽  
Vol 44 ◽  
pp. 269-271 ◽  
Author(s):  
L.W. Acton ◽  
J.M. Mosher

The purpose of this research is to investigate the temporal and spatial relationships of activated filaments, soft X-ray production, and Ha flares. The X-ray data are from the Lockheed Mapping X-Ray Heliometer (MXRH) on 0S0-8 (Wolfson et al., 1975, 1977). This instrument has been operating continuously since July 1975. It responds to radiation from solar plasma above about 2 × 106K, provides a time resolution of 20 sec, a spatial resolution of 2-3 arc min and has a basic sensitivity roughly equivalent to the 1-8 Å full disc monitors of, e.g., the SOLRAD and SMS/GOES satellites (threshold ≈ 2 × 10-9W/m2). However, because of its spatial resolution the MXRH permits study of small X-ray events in individual active regions even when the integrated solar X-ray emission is high.


2019 ◽  
Vol 22 (3) ◽  
pp. 113-121
Author(s):  
Anatoly I. Mazurov ◽  
Nikolay N. Potrakhov

Introduction. X-ray methods are currently widely used in manufacturing of various products and components of the electronics industry, including micro- and nano-electronics. One of the most informative and illustrative methods is projection X-ray microscopy. Specialized X-ray systems for process control are developed and used in industry. The key element in the design of an X-ray inspection system is an X-ray tube. In the overwhelming majority of cases, X-ray inspection systems are based on collapsible microfocus x-ray tubes with constant pumping. This greatly complicates the design of the installation, increases its dimensions, weight and cost. Objective. Analysis of possible technical and technological solutions that improve the availability of the X-ray system for monitoring of electronic components while maintaining the information content of the control. Materials and methods. The article presents the results of analytical studies of assessment of the degree of influence of the main parameters of the X-ray tube – the size of the focal spot and the focal length – on the resolution of the resulting X-ray images. The advantages and disadvantages of two variants of the construction of the X-ray inspection systems are described: based on collapsible and based on sealed X-ray tubes. The dependence of the size of the focal spot on the voltage on the X-ray tube and on the power supplied by the electron beam to the target of the X-ray tube is analyzed. It is shown that sealed (from a vacuum pumping system) micro focus X-ray tubes can be successfully used as a radiation source in installations for X-ray inspection. It is concluded that in most cases, sealed tubes are more practical. Results. In solving of most problems of non-destructive testing of electronic components in the composition of the Xray system, X-ray sources based on sealed X-ray tubes can be successfully used. Due to this, dimensions, weight, and the cost of an X-ray system for monitoring of electronic components are substantially reduced. Conclusion. Sealed X-ray tubes are an effective alternative in the development of an X-ray system for monitoring of electronic components, which enables to fundamentally increase the availability of such a system.


Author(s):  
R. Hutchings ◽  
I.P. Jones ◽  
M.H. Loretto ◽  
R.E. Smallman

There is increasing interest in X-ray microanalysis of thin specimens and the present paper attempts to define some of the factors which govern the spatial resolution of this type of microanalysis. One of these factors is the spreading of the electron probe as it is transmitted through the specimen. There will always be some beam-spreading with small electron probes, because of the inevitable beam divergence associated with small, high current probes; a lower limit to the spatial resolution is thus 2αst where 2αs is the beam divergence and t the specimen thickness.In addition there will of course be beam spreading caused by elastic and inelastic interaction between the electron beam and the specimen. The angle through which electrons are scattered by the various scattering processes can vary from zero to 180° and it is clearly a very complex calculation to determine the effective size of the beam as it propagates through the specimen.


Author(s):  
J. R. Michael

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.


Author(s):  
Brian Cross

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.


Author(s):  
J. Zhang ◽  
D.B. Williams ◽  
J.I. Goldstein

Analytical sensitivity and spatial resolution are important and closely related factors in x-ray microanalysis using the AEM. Analytical sensitivity is the ability to distinguish, for a given element under given conditions, between two concentrations that are nearly equal. The analytical sensitivity is directly related to the number of x-ray counts collected and, therefore, to the probe current, specimen thickness and counting time. The spatial resolution in AEM analysis is determined by the probe size and beam broadening in the specimen. A finer probe and a thinner specimen give a higher spatial resolution. However, the resulting lower beam current and smaller X-ray excitation volume degrade analytical sensitivity. A compromise must be made between high spatial resolution and an acceptable analytical sensitivity. In this paper, we show the necessity of evaluating these two parameters in order to determine the low temperature Fe-Ni phase diagram.A Phillips EM400T AEM with an EDAX/TN2000 EDS/MCA system and a VG HB501 FEG STEM with a LINK AN10 EDS/MCA system were used.


Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.


1974 ◽  
Vol 113 (6) ◽  
pp. 360 ◽  
Author(s):  
O.M. Sumbaev ◽  
E.V. Petrovich ◽  
Yu.P. Smirnov ◽  
I.M. Band ◽  
Aleksandr I. Smirnov

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