The paper investigates the features of a new source of X-ray spontaneous radiation based on the channeling of electrons (of mainly low energies) in the main crystallographic charged planes (100), (110) and (111) of a BaTiO3 crystal at temperatures above the Curie temperature, when this crystal with a perovskite structure is in the cubic (paraelectric) phase. It is shown that the depths of the potential wells (in all the main planes on one period there are two such wells with different depths) change slightly with increasing temperature up to the melting temperature. It is shown that a significant contribution to the interaction potentials is made by the Coulomb terms from the uncompensated effective charges of the positively charged Ba2+, Ti4+ ions and the negatively charged O2− ion of the BaTiO3 crystal. The features of the spectral distributions of spontaneous radiation, as well as possible optimal parameters, were investigated for different electron energies and angular dispersions of the electron beams. The comparison of the obtained spectra with similar dependences in lithium halide crystals and in diamond, silicon and germanium crystals traditionally used for channeling was carried out.
{"title":"On an efficient source of X-ray spontaneous radiation based on electron channeling in the main planes of a barium titanate crystal in the cubic phase","authors":"N.V. Maksyuta, V.I. Vysotskii, A.O. Stakhova, D.N. Maksyuta","doi":"10.1016/j.radphyschem.2026.113630","DOIUrl":"10.1016/j.radphyschem.2026.113630","url":null,"abstract":"<div><div>The paper investigates the features of a new source of X-ray spontaneous radiation based on the channeling of electrons (of mainly low energies) in the main crystallographic charged planes (100), (110) and (111) of a BaTiO<sub>3</sub> crystal at temperatures above the Curie temperature, when this crystal with a perovskite structure is in the cubic (paraelectric) phase. It is shown that the depths of the potential wells (in all the main planes on one period there are two such wells with different depths) change slightly with increasing temperature up to the melting temperature. It is shown that a significant contribution to the interaction potentials is made by the Coulomb terms from the uncompensated effective charges of the positively charged Ba<sup>2+</sup>, Ti<sup>4+</sup> ions and the negatively charged O<sup>2−</sup> ion of the BaTiO<sub>3</sub> crystal. The features of the spectral distributions of spontaneous radiation, as well as possible optimal parameters, were investigated for different electron energies and angular dispersions of the electron beams. The comparison of the obtained spectra with similar dependences in lithium halide crystals and in diamond, silicon and germanium crystals traditionally used for channeling was carried out.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113630"},"PeriodicalIF":2.8,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-08DOI: 10.1016/j.radphyschem.2026.113610
Blanche Krieguer, Sylvain R.A. Marque, Samuel Dorey, Fabien Girard, Yelin Ni, Leonard S. Fifield, Nicolas Ludwig, Nathalie Dupuy
Sterilization of biopharmaceutical products has commonly employed gamma radiation from cobalt-60, a radioisotope with associated security and supply chain risks. Increased use of non-radioisotope alternative ionizing energy technologies, such as electron beam (e-beam) and X-rays, is promising but has been hindered by lack of thorough evaluation of the compatibility of these techniques with product materials. This study investigates radical generation in a polyethylene (PE)/ethylene-vinyl alcohol copolymer (EVOH)/PE multilayer film product (Sartorius Flexsafe® with the S80 film) under varying e-beam and X-ray irradiation conditions to address data gaps for these materials and technologies. Utilizing a full factorial design of experiments (DoE), we examined the effects of irradiation technology, dose level, dose rate, processing temperature, and ambient oxygen concentration on radical formation, as quantified by electron spin resonance (ESR). Our results indicate that the type of ionizing technology (e-beam vs. X-ray) does not significantly affect radical concentration generation in the materials. However, higher doses and lower temperatures were found to correlate with increased radical concentrations, while elevated oxygen levels effectively suppressed radicals through a presumed scavenging mechanism. For e-beam processing, a higher dose rate reduced radical accumulation, while the opposite trend was found for X-ray irradiation. Complementary Fourier-transform infrared spectroscopy (FTIR) and principal component analysis (PCA) revealed subtle oxidation differences of PE under specific irradiation conditions.
{"title":"Evaluation of the impact of e-beam and X-ray irradiation conditions on radical generation in PE/EVOH/PE multilayer film","authors":"Blanche Krieguer, Sylvain R.A. Marque, Samuel Dorey, Fabien Girard, Yelin Ni, Leonard S. Fifield, Nicolas Ludwig, Nathalie Dupuy","doi":"10.1016/j.radphyschem.2026.113610","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113610","url":null,"abstract":"Sterilization of biopharmaceutical products has commonly employed gamma radiation from cobalt-60, a radioisotope with associated security and supply chain risks. Increased use of non-radioisotope alternative ionizing energy technologies, such as electron beam (e-beam) and X-rays, is promising but has been hindered by lack of thorough evaluation of the compatibility of these techniques with product materials. This study investigates radical generation in a polyethylene (PE)/ethylene-vinyl alcohol copolymer (EVOH)/PE multilayer film product (Sartorius Flexsafe® with the S80 film) under varying e-beam and X-ray irradiation conditions to address data gaps for these materials and technologies. Utilizing a full factorial design of experiments (DoE), we examined the effects of irradiation technology, dose level, dose rate, processing temperature, and ambient oxygen concentration on radical formation, as quantified by electron spin resonance (ESR). Our results indicate that the type of ionizing technology (e-beam vs. X-ray) does not significantly affect radical concentration generation in the materials. However, higher doses and lower temperatures were found to correlate with increased radical concentrations, while elevated oxygen levels effectively suppressed radicals through a presumed scavenging mechanism. For e-beam processing, a higher dose rate reduced radical accumulation, while the opposite trend was found for X-ray irradiation. Complementary Fourier-transform infrared spectroscopy (FTIR) and principal component analysis (PCA) revealed subtle oxidation differences of PE under specific irradiation conditions.","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"250 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-08DOI: 10.1016/j.radphyschem.2026.113619
Renato R.W. Affonso , Roos S.F. Dam , William L. Salgado , Ademir X. da Silva , César M. Salgado
The accurate characterization of flow regimes and volume fractions in multiphase flows is essential for optimizing industrial processes. This study introduces an artificial intelligence framework that integrates gamma-ray attenuation measurements with artificial neural networks to predict these parameters under controlled static conditions and steady-state conditions. A collimated 137Cs source and NaI(Tl) detectors arranged in narrow-beam geometry were used to acquire pulse height distributions. Training and testing datasets were generated using the MCNPX radiation transport code, simulating stratified and annular two-phase flow configurations with fixed, non-dynamic interface. Experimental validation using static wavy-flow phantoms, designed to reproduce interface profiles without temporal evolution, confirmed the ability of the neural models to classify flow regimes with 100 % accuracy and to predict volume fractions with mean relative errors of 1.0 % for simulated data and 4.1 % for experimental measurements. These finding demonstrate the physical consistency of the MCNPX–ANN framework under controlled conditions and establish a robust baseline for future extensions to dynamic multiphase flow systems.
{"title":"Benchmarking gamma–ANN predictive models using MCNPX: A controlled static flow study","authors":"Renato R.W. Affonso , Roos S.F. Dam , William L. Salgado , Ademir X. da Silva , César M. Salgado","doi":"10.1016/j.radphyschem.2026.113619","DOIUrl":"10.1016/j.radphyschem.2026.113619","url":null,"abstract":"<div><div>The accurate characterization of flow regimes and volume fractions in multiphase flows is essential for optimizing industrial processes. This study introduces an artificial intelligence framework that integrates gamma-ray attenuation measurements with artificial neural networks to predict these parameters under controlled static conditions and steady-state conditions. A collimated <sup>137</sup>Cs source and NaI(Tl) detectors arranged in narrow-beam geometry were used to acquire pulse height distributions. Training and testing datasets were generated using the MCNPX radiation transport code, simulating stratified and annular two-phase flow configurations with fixed, non-dynamic interface. Experimental validation using static wavy-flow phantoms, designed to reproduce interface profiles without temporal evolution, confirmed the ability of the neural models to classify flow regimes with 100 % accuracy and to predict volume fractions with mean relative errors of 1.0 % for simulated data and 4.1 % for experimental measurements. These finding demonstrate the physical consistency of the MCNPX–ANN framework under controlled conditions and establish a robust baseline for future extensions to dynamic multiphase flow systems.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113619"},"PeriodicalIF":2.8,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents a simulation-based design of a gamma backscatter imaging system integrated into an intelligent Pipeline Inspection Gauge (PIG) for detecting internal corrosion in sour gas pipelines. Monte Carlo simulations using the TOPAS toolkit were conducted to evaluate the influence of photon energy, detector dimensions, material composition (including pipeline and defect filler materials), and shielding on backscattered photon intensity and the deposited energy in NaI detectors.
A dual-ring detection system, featuring paired detectors positioned on opposite sides of a cylindrical scanning region, is proposed based on initial results. The system's ability to detect defects with varying cross-sections, depths, and filler materials was evaluated using photon energies corresponding to Ir-192, Cs-137, and Co-60 gamma sources. Quantitative relationships were established between detector signal characteristics and defect parameters such as width, depth, and volume.
Findings show that photon energies in the ranges of 300–800 keV offer maximum contrast in backscatter intensity between steel pipe material and defect fillers. Higher photon energies also enable detection of deeper defects, with a saturation depth of about 32 mm observed for Co-60 photons in API 5 L X65 steel. Detector sensitivity increases nearly exponentially with detector size. Additionally, analysis of the paired detector signal shape enables accurate estimation of defect dimensions and volume. The smallest defect volume examined in this study was 10 mm3 with paraffin as filler, and it was clearly detectable in the measured signals.
These results support the feasibility of a high-resolution dual-ring detector gamma backscatter system for advanced in-line PIG-based pipeline inspection.
本研究提出了一种基于仿真的伽马后向散射成像系统设计，该系统集成到智能管道检测仪表（PIG）中，用于检测含硫气体管道的内部腐蚀。利用TOPAS工具箱进行蒙特卡罗模拟，评估光子能量、探测器尺寸、材料组成（包括管道和缺陷填充材料）和屏蔽对NaI探测器中后向散射光子强度和沉积能量的影响。在初步研究的基础上，提出了一种双环检测系统，其特征是一对探测器位于圆柱形扫描区域的两侧。利用Ir-192、Cs-137和Co-60伽马源对应的光子能量，对该系统检测不同截面、深度和填充材料缺陷的能力进行了评估。建立了探测器信号特征与缺陷宽度、深度、体积等参数之间的定量关系。结果表明，在300 ~ 800 keV的光子能量范围内，钢管材料和缺陷填料的后向散射强度对比最大。更高的光子能量也可以检测更深的缺陷，在API 5 L X65钢中观察到Co-60光子的饱和深度约为32 mm。探测器的灵敏度几乎随探测器尺寸呈指数增长。此外，对配对探测器信号形状的分析可以准确估计缺陷的尺寸和体积。本研究中检测的最小缺陷体积为10 mm3，以石蜡为填充物，在测量信号中可以清楚地检测到。这些结果支持了高分辨率双环探测器伽马反向散射系统用于先进的基于pig的管道检测的可行性。
{"title":"Simulation-based design of a gamma-source compton backscatter imaging system for intelligent pipeline inspection gauge (PIG) applications in sour gas pipelines","authors":"Mohammadreza Parishan , Rasool Safari , Vahed Moharramzadeh , Maryam Bordbar , Zahra Rakeb , Reza Faghihi","doi":"10.1016/j.radphyschem.2026.113599","DOIUrl":"10.1016/j.radphyschem.2026.113599","url":null,"abstract":"<div><div>This study presents a simulation-based design of a gamma backscatter imaging system integrated into an intelligent Pipeline Inspection Gauge (PIG) for detecting internal corrosion in sour gas pipelines. Monte Carlo simulations using the TOPAS toolkit were conducted to evaluate the influence of photon energy, detector dimensions, material composition (including pipeline and defect filler materials), and shielding on backscattered photon intensity and the deposited energy in NaI detectors.</div><div>A dual-ring detection system, featuring paired detectors positioned on opposite sides of a cylindrical scanning region, is proposed based on initial results. The system's ability to detect defects with varying cross-sections, depths, and filler materials was evaluated using photon energies corresponding to Ir-192, Cs-137, and Co-60 gamma sources. Quantitative relationships were established between detector signal characteristics and defect parameters such as width, depth, and volume.</div><div>Findings show that photon energies in the ranges of 300–800 keV offer maximum contrast in backscatter intensity between steel pipe material and defect fillers. Higher photon energies also enable detection of deeper defects, with a saturation depth of about 32 mm observed for Co-60 photons in API 5 L X65 steel. Detector sensitivity increases nearly exponentially with detector size. Additionally, analysis of the paired detector signal shape enables accurate estimation of defect dimensions and volume. The smallest defect volume examined in this study was 10 mm<sup>3</sup> with paraffin as filler, and it was clearly detectable in the measured signals.</div><div>These results support the feasibility of a high-resolution dual-ring detector gamma backscatter system for advanced in-line PIG-based pipeline inspection.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113599"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.radphyschem.2026.113613
Faezeh Yousefi, Abbas Shokri, Fatemeh Torabi, Hossein Khosravi, Alireza Soltanian, Abbas Farmany
Dental radiography, while essential for diagnosis and treatment, poses ionizing radiation risks necessitating effective shielding. Traditional lead aprons, though widely used, suffer from weight, rigidity, and environmental toxicity limitations. This study investigates graphene-bismuth nanocomposite as a lead-free alternative, synthesized via Hamer's method and characterized by FTIR, XRD, and TEM. Analytical results confirmed nanocomposite formation, with XRD peaks at 30.55° and 32.1°, FTIR absorption at 534 cm-1, and TEM-verified bismuth oxide crystals on graphene nanosheets. Radiation shielding performance was evaluated using nanocomposite-coated leather samples tested with a Geiger-Müller counter at 60-70 kVp. At 60 kVp, the nanocomposite demonstrated superior attenuation to lead (LAC: 4.05 vs 3.24 cm-1; MAC: 1.15 vs 0.29 cm2/g; RPE: 55.6% vs 44.4%) with lower HVL (0.17 vs 0.21 cm), TVL (0.57 vs 0.71 cm), and MFP (0.25 vs 0.31 cm). Comparable performance was observed at 70 kVp (LAC: 1.35 vs 1.30 cm-1; RPE: 47.8% vs 45.7%). These findings demonstrate graphene-bismuth nanocomposites' potential as lightweight, flexible, and environmentally friendly radiation shielding for dental applications, addressing key limitations of conventional lead-based materials.
牙科放射照相虽然对诊断和治疗至关重要，但也存在电离辐射风险，需要有效的屏蔽。传统的铅围裙虽然被广泛使用，但存在重量、刚性和环境毒性的限制。本研究研究了石墨烯-铋纳米复合材料作为无铅替代品，通过Hamer的方法合成，并通过FTIR， XRD和TEM进行了表征。分析结果证实了纳米复合材料的形成，XRD峰在30.55°和32.1°，FTIR吸收在534 cm-1， tem验证了氧化铋晶体在石墨烯纳米片上。用60-70 kVp的盖革-迈勒计数器测试纳米复合涂层皮革样品的辐射屏蔽性能。在60 kVp下，纳米复合材料表现出优越的铅衰减（LAC: 4.05 vs 3.24 cm-1; MAC: 1.15 vs 0.29 cm2/g; RPE: 55.6% vs 44.4%）， HVL (0.17 vs 0.21 cm), TVL （0.57 vs 0.71 cm）和MFP （0.25 vs 0.31 cm）较低。在70 kVp时观察到类似的性能（LAC: 1.35 vs 1.30 cm-1; RPE: 47.8% vs 45.7%）。这些发现证明了石墨烯-铋纳米复合材料作为轻质、柔韧、环保的牙科辐射屏蔽材料的潜力，解决了传统铅基材料的主要局限性。
{"title":"Graphene-bismuth nanocomposite enhance X-ray radiation shielding at 60 and 70 kVp energies","authors":"Faezeh Yousefi, Abbas Shokri, Fatemeh Torabi, Hossein Khosravi, Alireza Soltanian, Abbas Farmany","doi":"10.1016/j.radphyschem.2026.113613","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113613","url":null,"abstract":"Dental radiography, while essential for diagnosis and treatment, poses ionizing radiation risks necessitating effective shielding. Traditional lead aprons, though widely used, suffer from weight, rigidity, and environmental toxicity limitations. This study investigates graphene-bismuth nanocomposite as a lead-free alternative, synthesized via Hamer's method and characterized by FTIR, XRD, and TEM. Analytical results confirmed nanocomposite formation, with XRD peaks at 30.55° and 32.1°, FTIR absorption at 534 cm<ce:sup loc=\"post\">-1</ce:sup>, and TEM-verified bismuth oxide crystals on graphene nanosheets. Radiation shielding performance was evaluated using nanocomposite-coated leather samples tested with a Geiger-Müller counter at 60-70 kVp. At 60 kVp, the nanocomposite demonstrated superior attenuation to lead (LAC: 4.05 vs 3.24 cm<ce:sup loc=\"post\">-1</ce:sup>; MAC: 1.15 vs 0.29 cm<ce:sup loc=\"post\">2</ce:sup>/g; RPE: 55.6% vs 44.4%) with lower HVL (0.17 vs 0.21 cm), TVL (0.57 vs 0.71 cm), and MFP (0.25 vs 0.31 cm). Comparable performance was observed at 70 kVp (LAC: 1.35 vs 1.30 cm<ce:sup loc=\"post\">-1</ce:sup>; RPE: 47.8% vs 45.7%). These findings demonstrate graphene-bismuth nanocomposites' potential as lightweight, flexible, and environmentally friendly radiation shielding for dental applications, addressing key limitations of conventional lead-based materials.","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"57 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accurate photon shielding analysis in complex, multi-layered materials remains a critical challenge, primarily due to the inherent limitations and empirical nature of traditional multi-layer buildup factor (BUF) formulas. We introduce a novel data-driven paradigm, reformulating this challenge as a sequence modeling problem. Our core contribution is a multi-scale Mamba framework, leveraging the efficiency and selective memory of the State Space Model (S6) to capture the complex, sequence-dependent physics and hierarchical physical interactions of photon transport through stratified media. Trained on a high-fidelity dataset of nearly 100,000 Monte Carlo simulations, our framework accurately predicts the complete post-shielding photon flux energy spectrum, a leap beyond single-value BUF approximations. The model accurately quantifies the non-commutative effect of layer ordering, achieving an remarkable relative deviation of less than 20% for over 95% of unseen cases. This study establishes our multi-scale Mamba framework as a powerful and precise tool for the rapid analysis of complex radiation shields, promising to enhance design optimization and personnel safety in engineering applications.
{"title":"A multi-scale Mamba framework for advanced multi-layer photon shielding analysis","authors":"Junyi Chen, Chenghao Cao, Shaoning Shen, Tianyuan Guo, Jingang Liang","doi":"10.1016/j.radphyschem.2026.113626","DOIUrl":"10.1016/j.radphyschem.2026.113626","url":null,"abstract":"<div><div>Accurate photon shielding analysis in complex, multi-layered materials remains a critical challenge, primarily due to the inherent limitations and empirical nature of traditional multi-layer buildup factor (BUF) formulas. We introduce a novel data-driven paradigm, reformulating this challenge as a sequence modeling problem. Our core contribution is a multi-scale Mamba framework, leveraging the efficiency and selective memory of the State Space Model (S6) to capture the complex, sequence-dependent physics and hierarchical physical interactions of photon transport through stratified media. Trained on a high-fidelity dataset of nearly 100,000 Monte Carlo simulations, our framework accurately predicts the complete post-shielding photon flux energy spectrum, a leap beyond single-value BUF approximations. The model accurately quantifies the non-commutative effect of layer ordering, achieving an remarkable relative deviation of less than 20% for over 95% of unseen cases. This study establishes our multi-scale Mamba framework as a powerful and precise tool for the rapid analysis of complex radiation shields, promising to enhance design optimization and personnel safety in engineering applications.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113626"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.radphyschem.2026.113615
I. Alhagaish, M. Alobeid, Z.Y. Khattari
This study investigates the effect of structural, physical parameters on the radiation shielding properties of Ag(12-x)Tlx-A zeolite frameworks with varying 81Tl204 content (x = 2, 3, 4, 5). Structural analysis reveals that increasing Tl atoms content enhances unit cell volume (Vc = 1835.12–1860.87 Å3), density (ρ = 2.602–2.887 g/cm3), and atomic packing factor (APF = 0.297–0.315). Effective atomic numbers (Zeff) range from 48.68 to 60.44 at E = 0.015 MeV, correlating with superior mass attenuation coefficients (MAC) that increase Tl + content or a substitution of 47Ag108 by 81Tl204 atoms. These values were found to be 38.328, 45.822, 52.851, 59.457 cm2/g for Ag/Tl = 5.0, 3.0, 2.0, 1.4 respectively at E = 0.015 MeV. The LAC values also show significant improvement as a function or either density or APF, especially at low photon energies (i.e., 2.164<LAC<3.720 cm−1 for 2.602<ρ < 2.887 and 0.297<APF <0.315 at E = 100 keV), while maintaining efficiency at higher energies dominated by Compton scattering. These findings emphasize the potential of Tl-doped zeolites for advanced radiation shielding in nuclear, medical, and industrial applications.
{"title":"Impact of 81Tl204 substitution on the radiation shielding efficiency of Ag(12−x)Tlx-A zeolite frameworks","authors":"I. Alhagaish, M. Alobeid, Z.Y. Khattari","doi":"10.1016/j.radphyschem.2026.113615","DOIUrl":"10.1016/j.radphyschem.2026.113615","url":null,"abstract":"<div><div>This study investigates the effect of structural, physical parameters on the radiation shielding properties of Ag<sub>(12-x)</sub>Tl<sub>x</sub>-A zeolite frameworks with varying <sub>81</sub>Tl<sup>204</sup> content (x = 2, 3, 4, 5). Structural analysis reveals that increasing Tl atoms content enhances unit cell volume (V<sub>c</sub> = 1835.12–1860.87 Å<sup>3</sup>), density (ρ = 2.602–2.887 g/cm<sup>3</sup>), and atomic packing factor (APF = 0.297–0.315). Effective atomic numbers (Z<sub>eff</sub>) range from 48.68 to 60.44 at E = 0.015 MeV, correlating with superior mass attenuation coefficients (MAC) that increase Tl <sup>+</sup> content or a substitution of <sub>47</sub>Ag<sup>108</sup> by <sub>81</sub>Tl<sup>204</sup> atoms. These values were found to be 38.328, 45.822, 52.851, 59.457 cm<sup>2</sup>/g for Ag/Tl = 5.0, 3.0, 2.0, 1.4 respectively at E = 0.015 MeV. The LAC values also show significant improvement as a function or either density or APF, especially at low photon energies (<em>i.e</em>., 2.164<LAC<3.720 cm<sup>−1</sup> for 2.602<ρ < 2.887 and 0.297<APF <0.315 at E = 100 keV), while maintaining efficiency at higher energies dominated by Compton scattering. These findings emphasize the potential of Tl-doped zeolites for advanced radiation shielding in nuclear, medical, and industrial applications.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113615"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.radphyschem.2026.113592
Douglas E. Peplow , Cihangir Celik , Mathew W. Swinney , Daniel E. Archer , Andrew D. Nicholson , Mark S. Bandstra , Brian J. Quiter
Gamma-ray spectra measured by traditional detectors contain features that result from a combination of the effects of detector materials/geometry, the incident gamma-ray energy, and the angle of entry. The features, such as the full-energy photopeak, Compton continuum, annihilation peak, and escape peaks, are governed by simple relationships depending on incident energy and have been known for a long time. Monte Carlo computer simulations of gamma rays interacting with a detector will show these features, and with a resolution function applied, the results should look similar to real measurements. The traditional approach to creating a detector response function requires many separate simulations of monoenergetic gamma rays striking the detector. This paper presents a new approach to developing computed detector response functions. The new approach involves a much smaller number of monoenergetic gamma-ray simulations and uses interpolation to quickly generate the responses of gamma rays that were not simulated. During the interpolation process, the underlying physics equations are used to accurately compute the response of a given energy gamma ray from the small set of simulations. Such work enables accelerated generation of synthetic radiation detector data.
{"title":"Interpolation of computed gamma-ray detector response functions","authors":"Douglas E. Peplow , Cihangir Celik , Mathew W. Swinney , Daniel E. Archer , Andrew D. Nicholson , Mark S. Bandstra , Brian J. Quiter","doi":"10.1016/j.radphyschem.2026.113592","DOIUrl":"10.1016/j.radphyschem.2026.113592","url":null,"abstract":"<div><div>Gamma-ray spectra measured by traditional detectors contain features that result from a combination of the effects of detector materials/geometry, the incident gamma-ray energy, and the angle of entry. The features, such as the full-energy photopeak, Compton continuum, annihilation peak, and escape peaks, are governed by simple relationships depending on incident energy and have been known for a long time. Monte Carlo computer simulations of gamma rays interacting with a detector will show these features, and with a resolution function applied, the results should look similar to real measurements. The traditional approach to creating a detector response function requires many separate simulations of monoenergetic gamma rays striking the detector. This paper presents a new approach to developing computed detector response functions. The new approach involves a much smaller number of monoenergetic gamma-ray simulations and uses interpolation to quickly generate the responses of gamma rays that were not simulated. During the interpolation process, the underlying physics equations are used to accurately compute the response of a given energy gamma ray from the small set of simulations. Such work enables accelerated generation of synthetic radiation detector data.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113592"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.radphyschem.2026.113621
Giovanna Salustiano Barros da Silveira , Lucio Pereira Neves , Arthur de Souza Borges Zuchetti Alves , William de Souza Santos , Ana Paula Perini
Chest radiography is essential in neonatal intensive care units (NICUs), but repeated exposures raise concerns due to the high radiosensitivity of newborns. This study aimed to estimate entrance skin dose (ESD) and absorbed organ doses in neonates undergoing chest X-ray examinations, under varying exposure parameters, using Monte Carlo simulation. A realistic NICU scenario was modeled in MCNP 6.3 Monte Carlo code, including a mobile X-ray unit, an incubator, and ICRP 143 neonatal reference phantoms. Simulations were performed for tube voltages ranging from 45 to 65 kV and radiation field sizes of 10 15, and 20 × 20 cm. Experimental validation was carried out using a water phantom and a solid-state dosimeter. ESD ranged from 15.36 to 59.81 Gy, with a mean of 36.45 Gy. Absorbed organ doses varied widely: brain (0.14–1.31 Gy), lens (0.13–1.33 Gy), esophagus (6.46–52.51 Gy), stomach (25.50–118.40 Gy), liver (13.98–78.64 Gy), red bone marrow (0.71–10.50 Gy), kidneys (2.89–25.23 Gy), thyroid (1.82–29.59 Gy), and lungs (4.88–39.46 Gy). Dose increases were driven primarily by higher tube voltages and, most significantly, by the inclusion of the organ within the primary beam. These findings highlight the importance of strict collimation and optimized parameters in neonatal radiography, reinforcing the ALARA principle.
{"title":"Organ and skin dose assessment in neonatal chest radiography using Monte Carlo simulation","authors":"Giovanna Salustiano Barros da Silveira , Lucio Pereira Neves , Arthur de Souza Borges Zuchetti Alves , William de Souza Santos , Ana Paula Perini","doi":"10.1016/j.radphyschem.2026.113621","DOIUrl":"10.1016/j.radphyschem.2026.113621","url":null,"abstract":"<div><div>Chest radiography is essential in neonatal intensive care units (NICUs), but repeated exposures raise concerns due to the high radiosensitivity of newborns. This study aimed to estimate entrance skin dose (ESD) and absorbed organ doses in neonates undergoing chest X-ray examinations, under varying exposure parameters, using Monte Carlo simulation. A realistic NICU scenario was modeled in MCNP 6.3 Monte Carlo code, including a mobile X-ray unit, an incubator, and ICRP 143 neonatal reference phantoms. Simulations were performed for tube voltages ranging from 45 to 65 kV and radiation field sizes of 10 <span><math><mrow><mo>×</mo><mspace></mspace><mn>10</mn><mo>,</mo><mn>15</mn><mspace></mspace><mo>×</mo><mspace></mspace></mrow></math></span>15, and 20 × 20 cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>. Experimental validation was carried out using a water phantom and a solid-state dosimeter. ESD ranged from 15.36 to 59.81 <span><math><mi>μ</mi></math></span>Gy, with a mean of 36.45 <span><math><mi>μ</mi></math></span>Gy. Absorbed organ doses varied widely: brain (0.14–1.31 <span><math><mi>μ</mi></math></span>Gy), lens (0.13–1.33 <span><math><mi>μ</mi></math></span>Gy), esophagus (6.46–52.51 <span><math><mi>μ</mi></math></span>Gy), stomach (25.50–118.40 <span><math><mi>μ</mi></math></span>Gy), liver (13.98–78.64 <span><math><mi>μ</mi></math></span>Gy), red bone marrow (0.71–10.50 <span><math><mi>μ</mi></math></span>Gy), kidneys (2.89–25.23 <span><math><mi>μ</mi></math></span>Gy), thyroid (1.82–29.59 <span><math><mi>μ</mi></math></span>Gy), and lungs (4.88–39.46 <span><math><mi>μ</mi></math></span>Gy). Dose increases were driven primarily by higher tube voltages and, most significantly, by the inclusion of the organ within the primary beam. These findings highlight the importance of strict collimation and optimized parameters in neonatal radiography, reinforcing the ALARA principle.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113621"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.radphyschem.2026.113624
Su Chul Han, Heerim Nam, Il Sun Jeong, Ji Chan Lee, Jin Dong Cho, Hyebin Lee, Jason Joon Bock Lee
Introduction
Deep inspiration breath-hold (DIBH) is widely used to reduce radiation exposure to the heart and lungs in patients with breast cancer. The integration of surface-guided radiation therapy (SGRT) with DIBH has gained attention, and several studies have explored its feasibility. This study aims to validate the workflow of the ExacTrac Dynamic (EXTD) system and evaluate its geometric accuracy in DIBH treatments.
Methods
The evaluation process for the EXTD system consisted of three steps. First, the reproducibility of the system's 3D structured light camera in restoring the original positioning was evaluated by measuring the positional differences in lateral, vertical, and longitudinal directions. Second, we calculated the geometric differences in positioning between image-guided radiation therapy (IGRT) and EXTD systems using various anatomical phantoms. Finally, the geometric differences between the EXTD contour-based DIBH system and a respiratory gating system (RGSC) were compared using a sinusoidal wave signal implemented in a 4D motion phantom.
Results
The EXTD's 3D structured light camera demonstrated high reproducibility in pre-positioning, with deviations of 0.3 mm laterally, 0.3 mm vertically, and 0.7 mm longitudinally. Geometric differences between the IGRT and EXTD systems were minimal, with deviations within 1 mm and 0.30° in the final patient setup. When compared with RGSC, the EXTD system exhibited comparable results with an R2 value of ≥0.97 with amplitude differences below 0.3 mm.
Conclusions
The EXTD system demonstrated excellent geometric accuracy and reliable respiratory tracking performance, supporting its suitability for DIBH treatments.
{"title":"Evaluation of the surface-guided radiotherapy workflow accuracy and plausibility of deep inspiration breath hold technique implementation: A phantom study","authors":"Su Chul Han, Heerim Nam, Il Sun Jeong, Ji Chan Lee, Jin Dong Cho, Hyebin Lee, Jason Joon Bock Lee","doi":"10.1016/j.radphyschem.2026.113624","DOIUrl":"10.1016/j.radphyschem.2026.113624","url":null,"abstract":"<div><h3>Introduction</h3><div>Deep inspiration breath-hold (DIBH) is widely used to reduce radiation exposure to the heart and lungs in patients with breast cancer. The integration of surface-guided radiation therapy (SGRT) with DIBH has gained attention, and several studies have explored its feasibility. This study aims to validate the workflow of the ExacTrac Dynamic (EXTD) system and evaluate its geometric accuracy in DIBH treatments.</div></div><div><h3>Methods</h3><div>The evaluation process for the EXTD system consisted of three steps. First, the reproducibility of the system's 3D structured light camera in restoring the original positioning was evaluated by measuring the positional differences in lateral, vertical, and longitudinal directions. Second, we calculated the geometric differences in positioning between image-guided radiation therapy (IGRT) and EXTD systems using various anatomical phantoms. Finally, the geometric differences between the EXTD contour-based DIBH system and a respiratory gating system (RGSC) were compared using a sinusoidal wave signal implemented in a 4D motion phantom.</div></div><div><h3>Results</h3><div>The EXTD's 3D structured light camera demonstrated high reproducibility in pre-positioning, with deviations of 0.3 mm laterally, 0.3 mm vertically, and 0.7 mm longitudinally. Geometric differences between the IGRT and EXTD systems were minimal, with deviations within 1 mm and 0.30° in the final patient setup. When compared with RGSC, the EXTD system exhibited comparable results with an R<sup>2</sup> value of ≥0.97 with amplitude differences below 0.3 mm.</div></div><div><h3>Conclusions</h3><div>The EXTD system demonstrated excellent geometric accuracy and reliable respiratory tracking performance, supporting its suitability for DIBH treatments.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113624"},"PeriodicalIF":2.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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