Sensitivity analysis and test results of the electronic component base to the effects of heavy charged particles

The work is devoted to the study of the sensitivity of the electronic component base (ECB) to the effects of heavy charged particles. At the same time, the degree of sensitivity is distinguished depending on the functional group of ECB products to the effects of ionization radiation from outer space and on the design and technological design of ECB products. The paper presents the characteristics and conditions for the use of ECB in the radio-electronic equipment of outer space to ensure minimal sensitivity to the effects of ionization radiation and to the thyristor effect. After the sensitivity analysis of ECB products is carried out, a preliminary selection of ECB is performed, requiring testing. The article discusses the criteria for determining the ECB that requires testing and is possible to use without testing. The methods of increasing the durability of radio-electronic equipment of space equipment and the directions of optimization of the methodology of analysis of ECB lists are determined.

Ionization Radiation Shielding Effectiveness of Lead Acetate, Lead Nitrate, and Bismuth Nitrate-Doped Zinc Oxide Nanorods Thin Films: A Comparative Evaluation

The fabrication of Nano-based shielding materials is an advancing research area in material sciences and nanotechnology. Although bulky lead-based products remain the primary choice for radiation protection, environmental disadvantages and high toxicity limit their potentials, necessitating less costly, compatible, eco-friendly, and light-weight alternatives. The theme of the presented investigation is to compare the ionization radiation shielding potentialities of the lead acetate (LA), lead nitrate (LN), and bismuth nitrate (BN)-doped zinc oxide nanorods-based thin films (ZONRs-TFs) produced via the chemical bath deposition (CBD) technique. The impact of the selected materials’ doping content on morphological and structural properties of ZONRs-TF was investigated. The X-ray diffractometer (XRD) analyses of both undoped and doped TFs revealed the existence of hexagonal quartzite crystal structures. The composition analysis by energy dispersive (EDX) detected the corrected elemental compositions of the deposited films. Field emission scanning electronic microscope (FESEM) images of the TFs showed highly porous and irregular surface morphologies of the randomly aligned NRs with cracks and voids. The undoped and 2 wt.% BN-doped TFs showed the smallest and largest grain size of 10.44 nm and 38.98 nm, respectively. The linear attenuation coefficient (µ) values of all the optimally doped ZONRs-TFs measured against the X-ray photon irradiation disclosed their excrement shielding potency. The measured µ values of the ZONRs-TFs displayed the trend of 1 wt.% LA-doped TF > 1 wt.% LN-doped TF > 3 wt.% BN-doped TF > undoped TFs). The values of μ of the ZONRs-TFs can be customized by adjusting the doping contents, which in turn controls the thickness and morphology of the TFs. In short, the proposed new types of the LA-, LN- and BN-doped ZONRs-TFs may contribute towards the development of the prospective ionization radiation shielding materials.

Evaluation of Conventional Radiographic Systems in Shahid Sadoughi University of Medical Sciences: A Multi-Centric Quality Control Study

Introduction: Generally, the benefits of radiological examinations performed on individuals far outweigh their risks; however, this is not true when the radiographic system fails to work properly. Therefore, to avoid such errors, it is crucial to frequently perform Quality Control (QC) checks in an imaging facility. Material and Methods: A total of 11 highly-referred centers out of 62 radiology rooms located in Yazd province were included in this investigation, and QC tests comprising light/radiation field alignment, the accuracy of kilovoltage and exposure time, reproducibility of kilovoltage, exposure time, and output, and linearity of output against exposure time and milliamperage were performed for each equipment. The light and radiation field alignment test were carried out by a quantitative assessment of digital images of a collimator template (PTW-Freiburg, Germany). The measurements were made by a Barracuda package and a Multi-Purpose Detector (MPD). Results: In terms of the light/radiation field alignment check, unit A failed to satisfy the national regulations. Concerning the timer reproducibility, 64% of the units failed to meet the criteria. All of the devices passed the rest of the checks satisfactorily. Conclusion: This study uncovered that most of the radiology rooms in Yazd province are in an adequate situation based on the QC tests; however, more than half of the units do not satisfy the timer reproducibility criteria. Hence, more supervision needs to be directed at these systems by qualified radiation safety officers who are responsible for the protection of the population against ionization radiation.

Reducing fetal radiation dose in computed tomography for pregnant patients: A literature review

To diagnose diseases during gestation period including renal stones, appendicitis, and pulmonary embolism in pregnant patients, computed tomography (CT) can be a golden standard. Due to CT examination, the fetus is prone to receiving a considerable dose which is the result of direct or scattered (external and internal scattered radiation) beams. The effects of ionization radiation on fetus include mutagenesis and carcinogenesis, therefore, it is essential to reduce fetus dose for pregnant patients who undergo CT examination during gestation period. This article aims to review approaches that are effective in reducing fetal dose in pregnant patients.

Crystallization of CsPbBr3 single crystals in water for X-ray detection

Metal halide perovskites have fascinated the research community over the past decade, and demonstrated unprecedented success in optoelectronics. In particular, perovskite single crystals have emerged as promising candidates for ionization radiation detection, due to the excellent opto-electronic properties. However, most of the reported crystals are grown in organic solvents and require high temperature. In this work, we develop a low-temperature crystallization strategy to grow CsPbBr3 perovskite single crystals in water. Then, we carefully investigate the structure and optoelectronic properties of the crystals obtained, and compare them with CsPbBr3 crystals grown in dimethyl sulfoxide. Interestingly, the water grown crystals exhibit a distinct crystal habit, superior charge transport properties and better stability in air. We also fabricate X-ray detectors based on the CsPbBr3 crystals, and systematically characterize their device performance. The crystals grown in water demonstrate great potential for X-ray imaging with enhanced performance metrics.

Shaping the structure of a GMC with radiation and winds

ABSTRACT We study the effect of stellar feedback (photodissociation/ionization, radiation pressure, and winds) on the evolution of a Giant Molecular Cloud (GMC), by means of a 3D radiative transfer, hydrosimulation implementing a complex chemical network featuring H2 formation and destruction. We track the formation of individual stars with mass $M\gt 1\, {\rm M}_{\odot }$ with a stochastic recipe. Each star emits radiation according to its spectrum, sampled with 10 photon bins from near-infrared to extreme ultraviolet bands; winds are implemented by energy injection in the neighbouring cells. We run a simulation of a GMC with mass $M=10^5\, {\rm M}_{\odot }$, following the evolution of different gas phases. Thanks to the simultaneous inclusion of different stellar feedback mechanisms, we identify two stages in the cloud evolution: (1) radiation and winds carve ionized, low-density bubbles around massive stars, while FUV radiation dissociates most H2 in the cloud, apart from dense, self-shielded clumps; (2) rapid star formation (SFR$\simeq 0.1\, {\rm M}_{\odot }\, {\rm yr}^{-1}$) consumes molecular gas in the dense clumps, so that UV radiation escapes and ionizes the remaining $\mathrm{H\,{\small I}}$ gas in the GMC. H2 is exhausted in 1.6 Myr, yielding a final star formation efficiency of 36 per cent. The average intensity of FUV and ionizing fields increases almost steadily with time; by the end of the simulation (t = 2.5 Myr) we find 〈G0〉 ≃ 103 (in Habing units), and a ionization parameter 〈Uion〉 ≃ 102, respectively. The ionization field has also a more patchy distribution than the FUV one within the GMC. Throughout the evolution, the escape fraction of ionizing photons from the cloud is fion, esc ≲ 0.03.