Explore the vast range of titles available.

High voltage LCC resonant converters have been widely used in X-ray imaging systems in automobile nondestructive testing (NDT) applications. Low ripple voltage waveforms with fast-rising time under no-overshoot response are required for safety in such applications. The optimal state trajectory control (OTC) based on the state plane model is one of the most effective control methods to optimize transient response. Dynamic variations of the resonant voltages/currents are described as corresponding trajectories on the state plane. The transient relations can be determined by evaluating the geometric relationships of the trajectories. However, the LCC resonant converter has more state variables, resulting in more complex calculations that make the state trajectory control challenging. Furthermore, the startup duration is the most demanding process of the state trajectory control. In this paper, a digital implementation based on a hybrid controller built in a field-programmable gate array (FPGA) is proposed for LCC resonant converters with optimal trajectory startup control. A coordinated linear compensator is employed to control the switching frequency during steady-state conditions, hence eliminating the steady-state error. The experimental results were conducted on a 140-kV/42-kW LCC resonant converter for an X-ray generator. It achieves a short rising time of output voltage with no additional current or voltage stress in the resonant tank during startup compared to the conventional digital implementation control.

The possibility of the creation and the application prospects of the laser-electron X-ray generator based on Thomson scattering of laser radiation on a bunch of relativistic electrons are considered. Such a generator fills the existing gap between X-ray tubes and synchrotron radiation sources, which is several orders of magnitude in terms of the brightness, average intensity, size, and also in the construction and running costs.

The mass attenuation coefficient is a fundamental parameter in radiation physics and plays a pivotal role in understanding the interaction of ionizing radiation with matter. This study aims to determine mass attenuation coefficients of newly developed tissue equivalent phantom fabricated from jute fibres reinforced with epoxy resin and activated carbon as a filler. The composites were prepared based on four different filler levels (ranging from 0wt% to 5wt%). The produced phantoms are characterized in terms of half-value layer HVL (cm) relating to linear attenuation coefficient, μ (cm −1 ). The linear and mass attenuation coefficients for the composites with different wt% of filler were determined at three different kV settings of the X-ray generator, covering the lower energy range of normal diagnostic practice (50 kVp, 102 kVp and 109 kVp) and by using the half-value layer (HVL) method. Aluminum filters were used to determine the HVL values and subsequently calculated the attenuation coefficients. The value of attenuation coefficients of fabricated composite materials was contrasted with theoretical value through the utilization of XCOM software at the same energy levels. The results were in good agreement for all ranges of wt% composite. These findings not only have significant practical implications for radiation-related technologies and applications but also enhance material characterization techniques. Hence, the attenuation measurements conducted in this study validate the suitability of jute-reinforced epoxy resin, filled with activated carbon as a phantom material that mimics human tissue.

Defects within chip solder joints are usually inspected visually for defects using X-ray imaging to obtain images. The phenomenon of voids inside solder joints is one of the most likely types of defects in the soldering process, and accurate detection of voids becomes difficult due to their irregular shapes, varying sizes, and defocused edges. To address this problem, an X-ray void image segmentation algorithm based on improved PCB-DeepLabV3 is proposed. Firstly, to meet the demand for lightweight and easy deployment in industrial scenarios, mobilenetv2 is used as the feature extraction backbone network of the PCB-DeepLabV3 model; then, Attentional multi-scale two-space pyramid pooling network (AMTPNet) is designed to optimize the shallow feature edges and to improve the ability to capture detailed information; finally, image cropping and cleaning methods are designed to enhance the training dataset, and the improved PCB-DeepLabV3 is applied to the training dataset. The improved PCB-DeepLabV3 model is used to segment the void regions within the solder joints and compared with the classical semantic segmentation models such as Unet, SegNet, PSPNet, and DeeplabV3. The proposed new method enables the solder joint void inspection to get rid of the traditional way of visual inspection, realize intelligent upgrading, and effectively improve the problem of difficult segmentation of the target virtual edges, to obtain the inspection results with higher accuracy.

The high-luminosity LHC (HL-LHC) upgrade is presenting new challenges for particle detector technologies. In the CMS Muon System gaseous detectors, the increase in luminosity will produce a particle background ten times higher than at the LHC. To cope with the high rate environment and maintain current performance, the triple-Gas Electron Multiplier technology is a promising candidate for high-rate capable detectors for the CMS-ME0 upgrade project in the innermost region of the forward Muon Spectrometer of the CMS experiment. An intense R&D and prototyping phase is currently ongoing to prove that such technology meets the stringent performance requirements of highly efficient particle detection in the harsh background environment expected in the innermost ME0 region. Here we describe the recent rate capability studies of triple-GEM detectors operated with an Ar/CO 2 (70/30) gas mixture at an effective gas gain of 2 × 10 4 by using a high intensity 22 keV X-ray generator. Moreover, we present a novel foils design based on double-sided segmented GEM-foils, high voltage power distribution, and filtering, which the collaboration adopted for realization of the latter projects, and their impact on the performance of the detector in the light of new rate capability studies, with a summary of the ongoing R&D activities.

Radiation-based instruments have been widely used in petrochemical and oil industries to monitor liquid products transported through the same pipeline. Different radioactive gamma-ray emitter sources are typically used as radiation generators in the instruments mentioned above. The idea at the basis of this research is to investigate the use of an X-ray tube rather than a radioisotope source as an X-ray generator: This choice brings some advantages that will be discussed. The study is performed through a Monte Carlo simulation and artificial intelligence. Here, the system is composed of an X-ray tube, a pipe including fluid, and a NaI detector. Two-by-two mixtures of four various oil products with different volume ratios were considered to model the pipe’s interface region. For each combination, the X-ray spectrum was recorded in the detector in all the simulations. The recorded spectra were used for training and testing the multilayer perceptron (MLP) models. After training, MLP neural networks could estimate each oil product’s volume ratio with a mean absolute error of 2.72 which is slightly even better than what was obtained in former studies using radioisotope sources.

Optical readout of Micromegas gaseous detectors has been achieved by implementing a Micromegas detector on a glass substrate with a glass anode and a CMOS camera. Efficient X-ray radio-graphy has been demonstrated due to the integrated imaging approach inherent to optical readout. High granularity values have been reached for low-energy X-rays from radioactive sources and X-ray generators taking advantage of image sensors with several megapixel resolution. Detector characterization under X-ray radiography opens the way to different applications from beta imaging to neutron radiography. Here we will focus on one application: neutron imaging for non-destructive examination of highly gamma-ray emitting objects. This article reports the characterization of the detectors when exposed to a low activity neutron source. The response of the detector to thermal neutrons has been studied with different field configurations and gap thicknesses.

The long-term stability in terms of gain and energy resolution of a prototype triple Gas Electron Multiplier (GEM) detector has been investigated with high rate X-ray irradiation. Premixed Ar/CO2 (80:20) and (90:10) gases have been used for this stability study. A strong Fe55 X-ray source is used to irradiate the chamber. The uniqueness of this work is that the same source has been used to irradiate the GEM prototype and also to monitor the spectra. This arrangement is important since it reduces the mechanical complexity of using an X-ray generator as well as the cost of the setup. A small area of the chamber is exposed continuously to the X-ray for the entire duration of the operation. The effect of temperature and pressure on the gain and energy resolution is monitored. The result of the long-term stability test for a triple GEM detector using Ar/CO2 (70:30) gas mixture has been reported earlier [1]. The results with Ar/CO2 (80:20) and (90:10) gas mixtures for the same chamber are presented in this article.

The paper presents a general theoretical framework and related Monte Carlo simulation of novel type of the X-ray sources based on relativistic Thomson scattering of powerful laser radiation. Special attention is paid to the linac X-ray generators by way of two examples: conceptual design for production of 12.4 keV photons and presently operating X-ray source of 29.4 keV photons. Our analysis shows that state-of-the-art laser and accelerator technologies enable to build up a compact linac-based Thomson source for the same X-ray imaging and diffraction experiments as in using of a large-scale X-ray radiation facility like a synchrotron or Thomson generator based on electron storage ring.

One approach to the design, experimentation, parameter setting, and assembly of an X-ray generator get performed to reduce radiation emission (microgray μ G y ) without neglecting the power of the beam emission ( KVp ). A combination gets made in the manufacture of the transformer coil between turns of the secondary winding S k , with the number of turns of the filament F i . As a result, we obtained a transformer with an emissivity between the desired parameters and the optimum beam power. We classify feasible and infeasible cases in the assembly of X-ray devices using support vector machines. In addition, the tools used for statistical inference were non-parametric tests, such as the modified Friedman test and post-hoc Quade and Conover tests. Finally, we obtained a good image with an excellent resolution without exposing people to high radiation emissions.