X-ray Inspection System Research Articles

The Detection of Pest Contaminants in Chocolate Using Visible-Near-Infrared Single-Pixel Imaging Technology.

Food safety is gaining increasing attention worldwide. Currently, low-density organic foreign objects such as insects are extremely challenging to detect using conventional metal detectors and X-ray inspection systems. This study aimed to develop a visible-near-infrared single-pixel imaging (Vis-NIR-SPI) method to detect small insects inside food. The advantages of Vis-NIR light include its ability to analyze samples non-destructively and measure multiple components simultaneously and quickly, while SPI is robust against dark noise, high scattering, and high equipment costs. The experimental results demonstrated that (1) the newly designed system effectively reduces scattering effects from the highly scattering sample (intralipid 20%), allowing for the capture of information beyond the capabilities of a charge-coupled-device camera; (2) insects positioned behind ham and bread were readily detectable using the imaging reconstruction algorithm; and (3) even for chocolate samples with very high light absorption, only 1 uncontaminated sample out of 100 was mistakenly classified as contaminated, yielding an overall accuracy of 99%. This high level of accuracy underscores the potential of the Vis-NIR-SPI method to provide reliable detection while maintaining sample integrity. Furthermore, this method is cost-effective, offering a practical and efficient solution to improve quality control processes and consumer trust in the food industry.

Implementation of dual-energy material decomposition technique in stationary CT baggage scanner withπ-angle sparsity for enhancing threat detection

Two-dimensional X-ray inspection systems are widely used in aviation security applications; however, they have inherent limitations in recognizing the three-dimensional (3D) shapes of hidden objects. Therefore, there is a growing demand for the implementation of advanced 3D X-ray inspection systems at airports for more accurate detection of threats in luggage and personal belongings. In this study, we designed a new stationary computed tomography (CT) baggage scanner with π-angle sparsity (i.e., 20 pairs of X-ray sources and line detectors were placed within a scan angle of 180°) and compressed sensing (CS)-based reconstruction, and implemented a dual-energy material decomposition (DEMD) technique in the proposed system to separate soft and dense materials of an examined object to enhance threat detection. To validate the efficacy of the proposed approach (CS/180°/P20), we conducted a feasibility study using numerical simulation before its practical implementation. Polychromatic projections were emulated at X-ray tube voltages of 60 and 140 kVp, and DEMD was applied to the projections prior to CT reconstruction. Conventional and dual-energy CT images were reconstructed using both standard filtered-backprojection (FBP) and state-of-the-art CS-based algorithms to compare the image quality. According to our simulation results, the CS-reconstructed images were almost unaffected by the clearly evident streak artifacts on the FBP-reconstructed images because of the use of 20 extreme sparse-view projections, and the image quality of the dual-energy CT images obtained using the proposed CT configuration was similar to that obtained using the conventional CT configuration with 720 dense projections, indicating the efficacy of the proposed approach. Consequently, high-quality dual-energy CT images of soft and dense materials were successfully obtained using the proposed stationary CT configuration.

Dense metal corrosion depth estimation

Introduction: Metal corrosion detection is important for protecting lives and property. X-ray inspection systems are widely used because of their good penetrability and visual presentation capability. They can visually display both external and internal corrosion defects. However, existing X-ray-based defect detection methods cannot present and estimate the dense corrosion depths. To solve this problem, we propose a dense metal corrosion depth estimation method based on image segmentation and inpainting.Methods: The proposed method employs an image segmentation module to segment metal corrosion defects and an image inpainting module to remove these segmented defects. It then calculates the pixel-level dense corrosion depths using the X-ray images before and after inpainting. Moreover, to address the difficulty of acquiring training images with ground-truth dense corrosion depth annotations, we propose a virtual data generation method for creating virtual corroded metal X-ray images and their corresponding ground-truth annotations.Results: Experiments on both virtual and real datasets show that the proposed method successfully achieves accurate dense metal corrosion depth estimation.Discussion: In conclusion, the proposed virtual data generation method can provide effective and sufficient training samples, and the proposed dense metal corrosion depth estimation framework can produce accurate dense corrosion depths.

YOLO-CID: Improved YOLOv7 for X-ray Contraband Image Detection

Currently, X-ray inspection systems may produce false detections due to factors such as the varying sizes of contraband images, complex backgrounds, and blurred edges. To address this issue, we propose the YOLO-CID method for contraband image detection. Firstly, we designed the MP-OD module in the backbone network to enhance the model’s ability to extract key information from complex background images. Secondly, at the neck of the network, we designed a simplified version of BiFPN to add cross-scale connection lines in the feature fusion structure, to preserve deeper semantic information and enhance the network’s ability to represent objects in low-contrast or occlusion situations. Finally, we added a new object detection layer to improve the model’s accuracy in detecting small objects in dense environments. Experimental results on the PIDray public dataset show that the average accuracy rate of the YOLO-CID algorithm is 82.7% and the recall rate is 81.2%, which are 4.9% and 3.2% higher than the YOLOv7 algorithm, respectively. At the same time, the mAP on the CLCXray dataset reached 80.2%. Additionally, it can achieve a real-time detection speed of 40 frames per second and 43 frames per second in real scenes. These results demonstrate the effectiveness of the YOLO-CID algorithm in X-ray contraband detection.

Shielding design for the control room of an X-ray cargo container inspection system using Monte Carlo simulations

In the present research, the shielding of the control room of an X-ray inspection system was designed by MCNP Monte Carlo simulation code in order to reduce the dose rate of the control room below the acceptable value of 0.5 μSv/h. To do this, after the simulation of the linear electron accelerator, accelerator carrier truck, container and ground, the required thickness of leads have been calculated for each walls of the control room. It was found that the thickness of the required lead for each walls of the control room is different from 2 mm to 1 cm. In this situation, the dose rate inside the control room would be 0.3 μSv/h (with the relative uncertainty of 11%). The mass of the lead used in this case was equal to 2.2 tons.

The application of dual energy X-ray soil screening in forensic archaeology

The need to forensically search soil for small artefacts at a burial site or traces of evidence in a deposition site is a common task shared by investigators and forensic archaeologists. In forensic casework, the importance of finding small pieces of evidence, such as personal effects or ballistic fragments, cannot be overstated as it can assist in the positive identification of the deceased, give an insight into the manner and cause of death, and identify any perpetrators. The soil search methods known as wet and dry sieving, are cumbersome, time-consuming and have limited success for some soil types. This often leads to the decision not to search, resulting in missed opportunities to identify potential evidence.The primary aim of this study was to investigate if a dual energy X-ray baggage scanner could be used to search for items of potential forensic interest in soil. A trial was conducted using a Smiths Detection ScanTrailer 100100 V-2is mobile X-ray inspection system to establish if it could be used to detect organic, inorganic, and metallic items located within soil. The soil type and natural variables such as water and organic content were adjusted to simulate different environments. The baggage scanner was found to provide a quick and easy way to detect items contained within various soil types, particularly in a sand rich matrix. It is estimated that using this method to search 1 m3 of soil, when broken down into samples that are < 13 cm in depth, would take around one hour to complete, compared with 100 to 150 person-hours by manual sieving. This is believed to be the first use of dual energy X-ray technology for this purpose and shows the potential for further research and use of this method in forensic archaeology.

Contaminant detection using a CZT photon counting detector with TDI image reconstruction

Food x-ray inspection systems are designed to detect unwanted physical contaminants in packaged food to maintain a high level of food safety for consumers. Modern day x-ray inspection systems often utilize line scan sensors to detect these physical contaminants but are limited to single or dual energies. However, by using a photon counting detector (PCD), a new generation of food inspection systems capable of acquiring images at more than two energy bins could improve discrimination between low density contaminants. In this work, five type of contaminants were embedded in an acrylic phantom and imaged using a cadmium zinc telluride (CZT) PCD with a pixel pitch of 330 μm. A set of images were acquired while the phantom was stationary, and another set of images were acquired while the phantom was moving to mimic the movement of a conveyor belt. Image quality was assessed by evaluating the contrast-to-noise ratio (CNR) for each set of images. For imaging times larger than 25 ms, the results showed that the moving phantom data set yielded larger CNR values compared to a stationary phantom. While conventional x-ray inspections often utilize line scan sensors, we report that physical contaminant detection is possible with a CZT PCD x-ray imaging system.

Degradation mechanism analysis for SiC power MOSFETs under repetitive power cycling stress

In this work, investigation on the degradation behavior of 1.2 kV/52 A silicon carbide (SiC) power MOSFETs subjected to repetitive slow power cycling stress has been performed. Electric characteristics have been characterized periodically over the stress and the respective degradation mechanisms have also been analyzed. A comprehensive degradation analysis is further conducted after the aging test by virtue of the x-ray inspection system, scanning acoustic microscope, scanning electron microscope, emission microscope, etc. Experimental results reveal that both the degradation of the gate oxide on the chip-level and the degradation of the bond wire and solder layer on the package-level have emerged over the cyclic stress. Specifically, growths of threshold voltage (V th) and gate leakage current (I gss) are thought to be relevant with the degradation of gate oxide by SiC/SiO2 interface states trapping/de-trapping electrons on the chip-level, while the appearance of fatigue in the bond wire and the delamination of the solder layer imply the degradation on the package-level. This work may provide some practical guidelines for assessments of the reliability of SiC power MOSFETs in power conversion systems.

Optimization of a CZT photon counting detector for contaminant detection

In the food industry, X-ray inspection systems are utilized to ensure packaged food is free from physical contaminants to maintain a high level of food safety for consumers. However, one of the challenges in the food industry is detecting small, low-density contaminants from packaged food. Cadmium zinc telluride (CZT) photon counting detectors (PCDs) can potentially alleviate this problem given its multi-energy bin capabilities, high spatial resolution and ability to eliminate electronic noise, which is superior to the conventional energy integrating detector (EID). However, the image quality from a CZT PCD can be further improved by applying an optimized energy bin weighting scheme that maximizes energy bin images that provide the largest image contrast and lowest image noise. Therefore, in this work, five contaminant materials embedded in an acrylic phantom were imaged using a CZT PCD while the phantom was in constant motion to mimic food products moving on a conveyor belt. Energy bin optimization was performed by applying an image-based weighting scheme and these results showed contrast-to-noise ratio (CNR) improvements ranging between 1.02–1.91 relative to an equivalent EID acquisition.

Development of a high resolution x-ray inspection system using a carbon nanotube based miniature x-ray tube.

A new concept for a non-destructive testing device using a novel carbon nanotube (CNT) based miniature x-ray tube is proposed. The device can be used for small-scale internal inspection of objects. To investigate the effectiveness of the proposed concept, the device was fabricated and its performance was systematically analyzed. The non-destructive testing device consists of a CNT based miniature x-ray tube, a scintillator, an optical lens, and a detector. The size of the focal spot needed to identify objects as small as 5 µm was calculated through simulation. An electron optics simulation software, E-GUN, was used to optimize the geometries of both the focusing cup and the x-ray target to achieve the desired focal spot size of the x-ray tube. The CNT based miniature x-ray tube was fabricated using the brazing process, and an NdFeB focusing lens was used to further reduce the focal spot size. XR images were obtained using the fabricated device and the spatial resolutions of the images were evaluated using the modulation transfer function (MTF). The fields of view (FOVs) per probe are 7.1 mm2 and 1.8 mm2 when using a 5× optical lens and a 10× optical lens, respectively. The FOV can be increased by increasing the number of probes incorporated into the device. MTF10 values were determined to be 105 lp/mm and 230 lp/mm when using the 5× optical lens and 10× optical lens, respectively. By using an optical lens to enlarge the XR images, the effect of focal spot was minimized and clear XR images were obtained.

Organization and Conduct of Surveillance of Radiation Safety of the Population in Preparation and Holding of 2018 FIFA World Cup in Saint Petersburg

The purpose of the study was a hygienic assessment and generalization of practical experience of the St. Petersburg Rospotrebnadzor Office and the Center for Hygiene and Epidemiology in St. Petersburg acquired within the framework of the established powers in supervision and control of radiation safety of the population and combating radiation terrorism when preparing and holding mass events of 2018 FIFA World Cup in St. Petersburg. Materials and methods. We used the materials on planning and implementing measures to ensure radiation safety of the population and reports of the St. Petersburg Rospotrebnadzor Office and the Center for Hygiene and Epidemiology in St. Petersburg for 2016–2018. Results. We made a hygienic assessment of comprehensive measures for supervision and control over ensuring radiation safety of the population in preparation for mass sporting events, summarized the practice and efficient results of organizing and conducting monitoring of the radiation situation, radiation monitoring at infrastructure facilities, including radiological studies during the construction and reconstruction of sports facilities, and radiation control of baggage X-ray inspection systems used at the sites of sporting events for additional security measures. A scheme of organizing radiation monitoring of building materials and products delivered to sports facilities under construction was developed to eliminate excessive costly spectrometric studies while guaranteeing effectiveness of radiation monitoring. We demonstrated that an important step in the integrated approach to ensuring radiation safety was the control over introduction of additional safety measures immediately at the facilities operating on radioactive substances and posing radiation hazard in St. Petersburg, taking into account the category of their potential radiation hazard, as well as the preparedness of specialized Rospotrebnadzor units to promptly respond to emergency situations. Activities of the Regional Interdepartmental Operational Headquarters for Security showed absolute efficiency of interdepartmental cooperation between federal and municipal executive authorities.

ABOUT TECHNOLOGIES OF X-RAY SYSTEMS FOR CONTROL OF ELECTRONIC COMPONENTS

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.

High‐speed display‐delayed planar X‐ray inspection system for the fast detection of small fishbones

AbstractThe fast detection of native hazardous material (fishbones) and foreign material contamination (metals, stones, pen caps, etc.) have limited mass production and good sale of fish fillets in aquatic product processing plant. In this work, we developed a high speed display‐delayed planar X‐ray inspection system, which could be applied to rapidly and efficiently distinguish small fishbones in fish fillets and foreign material contamination with fish fillets. It had a high resolution of short metal lines (at least 2 mm in length and 0.2 mm in diameter) and small fishbones (4 mm in length and 0.6 mm in diameter). Moreover, it could be applied to efficiently distinguish small fishbones in frozen fish fillets. The theoretical and practical basis of high speed high resolution display‐delayed X‐ray inspection system is also discussed in this work. All the results confirmed that this system was efficient, fast, and convenient for the detection of small fishbones. This work provides a useful way for fast detection of small fishbones in fish fillets in aquatic product processing plant.Practical applicationsThe practical application of this article is to identify the native hazardous material (fishbones) and foreign material contamination (metals, stones, pen caps, etc.) in mass production of fish fillets in aquatic product processing plant by high‐speed display‐delayed X‐ray system. Compared with traditional finger touching and eye observing method, high‐speed display‐delayed X‐ray system can be applied to identify fishbones and foreign materials quickly and conveniently. Moreover, this system had a high resolution of small fishbones (4 mm in length and 0.6 mm in diameter), which could satisfied the international food standard of “standard for quick frozen fish fillets.” Especially, it could be applied to efficiently distinguish small fishbones in frozen fish fillets.

X-ray non-destructive testing – an essential tool during modern aeronautics material technology design and development

The X-ray non-destructive testing process is carried out by the system, which includes: the object of control (OC); source of radiation; detector; operator. The X-ray radiation and the object of control interaction formed the radiation image as X-ray doze distribution in accordance with the properties of the OC. At this stage, useful information about the OK is formed, which one is partially lost, partially distorted, and veiled with noise when the radiation image is converted into an optical one. The optical image is analyzed by operator, and the result of the control depends from his physical and emotional state.This article presents a phased analysis of the entire radiation monitoring system. The first stage is the radiation image formation. Theoretical estimate of X-ray inspection system minimum detected defect size was made using space frequency spectrum analysis. The second stage is the transformation of the radiation image into an optical one. We represented the simulation of this process and obtained a modulation of how the operator sees the X-ray optical image and makes a decision about the OC state. Analyzed the X-ray digital image formation and determined the energy choice criteria when applied digital radiography.

Limited-View X-Ray Tomography Combining Attenuation and Compton Scatter Data: Approach and Experimental Results.

X-ray inspection systems are critical in medical, non-destructive testing, and security applications, with systems typically measuring attenuation along straight-line paths connecting sources and detectors. Computed tomography (CT) systems can provide higher-quality images than single- or dual-view systems, but the need to measure many projections leads to greater system cost and complexity. Typically, off-angle Compton scattered photons are treated as noise during tomographic inversion. We seek to maximize the image quality of limited-view systems by combining attenuation data with measurements of Compton-scattered photons, exploiting the fact that the broken-ray paths followed by scattered photons provide additional geometric sampling of the scene. We describe a single-scatter forward model for Compton-scatter data measured with energy-resolving detectors, and demonstrate a reconstruction algorithm for density that combines both attenuation and scatter measurements. The experimental results suggest that including Compton-scattered data in the reconstruction process can improve image quality for density reconstruction using limited-view systems.

Operando Analysis of Thermal Runaway in Lithium Ion Battery during Nail-Penetration Test Using an X-ray Inspection System

The thermal runaway of a lithium ion battery (LIB) during a nail-penetration test was investigated using an LIB internal short circuit observation system equipped with an X-ray scanner (LiSC scanner). Using high-speed moving images and high-precision voltage measurements, the layer-by-layer internal short circuit caused by the nail was clearly observed during nail motion. Following this motion, gas generation outside the cell, which is well-known in thermal runaway, was observed. The main causes of smoke are speculated to be the boiling of the electrolyte and/or decomposition of the active materials owing to heating by the short circuit current. The initial behavior of the short circuit before gas generation was clearly observed. Therefore, gas generation, which is well-known to indicate an internal short circuit of the cell, and the electrical behavior of the short circuit during the nail-penetration test were observed separately. This LiSC scanner allowed us to analyze the details of the internal short circuit of the cell, and it is expected to lead to significant advancements in the safety of LIBs.

Characterization of SAC – x NiO nano-reinforced lead-free solder joint in an ultra-fine package assembly

PurposeThis study aims to investigate the NiO nano-reinforced solder joint characteristics of ultra-fine electronic package.Design/methodology/approachLead-free Sn-Ag-Cu (SAC) solder paste was mixed with various percentages of NiO nanoparticles to prepare the new form of nano-reinforced solder paste. The solder paste was applied to assemble the ultra-fine capacitor using the reflow soldering process. A focussed ion beam, high resolution transmission electron microscopy system equipped with energy dispersive X-ray spectroscopy (EDS) was used in this study. In addition, X-ray inspection system, field emission scanning electron microscopy coupled with EDS, X-ray photoelectron spectroscopy (XPS) and nanoindenter were used to analyse the solder void, microstructure, hardness and fillet height of the solder joint.FindingsThe experimental results revealed that the highest fillet height was obtained with the content of 0.01 Wt.% of nano-reinforced NiO, which fulfilled the reliability requirements of the international IPC standard. However, the presence of the NiO in the lead-free solder paste only slightly influenced the changes of the intermetallic layer with the increment of weighted percentage. Moreover, the simulation method was applied to observe the distribution of NiO nanoparticles in the solder joint.Originality/valueThe findings are expected to provide a profound understanding of nano-reinforced solder joint’s characteristics of the ultra-fine package.

X-ray inspection systems for electronic parts

An X-ray inspection is one of the basic methods of non-destructive testing along with optical inspection. Lack of Russian manufacturers in this sector of measuring equipment was a barrier for implementation of the State program «Development of the electronics and radio electronics industry, 2013–2025». High sensitivity X-ray flat panel detector and inspection system concept for non-destructive testing of electronic components were developed. The detector is based on CMOS sensor with pixel pitch 50 um. Key features of the flat panel detector are: limiting spatial resolution 10 LP/mm, reading speed 30 fps, anode voltage range from 20 to 300 kV. Availability of technologies for the production of microfocus sources and flat panel detectors allows creating X-ray inspection system for electronic components for the needs of the microelectronics industry.

Structural Assessment of Lead Free Solder Joint of Miniaturized Electronics Assembly

This paper presents a study on structural assessment of ultra-fine package assembly with nano-composites lead free solder joint after reflow soldering process. In this work, various nanoparticles (i.e. TiO2, Fe2O3 and NiO) with different weightage percentage (i.e., 0.01, 0.05 and 0.15 wt.%) were successfully incorporated into SAC305 solder paste using the mechanical solder paste mixer to synthesize novel lead-free composite solders. Effects of the nanoparticles addition on the quality of joining and fillet height between various weightage (wt.%) for the ultra-fine package assembly in the reflow soldering process have been investigated after the reflow soldering process by using the scanning electron microscope (SEM) system equipped with an energy dispersive X-ray spectroscopy (EDS) and XTV 160 x-ray inspection system. The experimental results show the increment of TiO2, Fe2O3 and NiO nanoparticles addition to 0.15wt.%, 0.05wt.% and 0.01wt.%, respectively, produce highest fillet height of each composition of nanoparticles solder paste. Among all these new composition of nanoparticles solder paste, NiO nanoparticles reinforced solder paste with 0.01wt.% yielded highest fillet height The miniaturized solder joints do not cause any problem in terms of solder voids. The findings show the capability of the reflow soldering process in assembling miniaturized electronics assembly and expected to provide a reference in electronic package industry.

Improvement of radiographic visibility using an image restoration method based on a simple radiographic scattering model for x-ray nondestructive testing

In conventional radiography, image visibility is often limited mainly due to the superimposition of the object’s structure under investigation and scattered x-rays. Several methods, including the antiscatter grid technique, the air-gap technique, and scatter correction methods using measurements, mathematical-physical modeling, or a combination of both, have been extensively investigated in an attempt to overcome these difficulties. However, these methods require special equipment, geometry, and extra work to measure the scatter characteristics. In this study, we propose a new image restoration method based on a simple radiographic scattering model in which the intensity of the scattered x-rays and the direct transmission function of a given object are estimated from a single x-ray image by using the dark-channel prior. We implemented the proposed algorithm and performed a systematic experiment by using a 450-kV industrial x-ray inspection system to demonstrate its viability for nondestructive testing. Our results indicated that the structure of the examined object was much more clearly visible in the restored image, considerably improving the radiographic visibility.