Applied Radiation and Isotopes最新文献_第7页

A radiometric and elemental characterisation of sludge and scales found in Dutch geothermal plants 荷兰地热发电厂中发现的污泥和鳞片的放射性和元素特征

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-30 DOI: 10.1016/j.apradiso.2025.112412

Linde Pollet , Mikael Hult , Mirela Vasile , Gerd Marissens , Heiko Stroh , Sonja Schreurs , Wouter Schroeyers

Geothermal energy originates from the heat stored within the Earth's core. Thermal water from geological reservoirs is extracted to the surface to generate electricity or heat buildings and greenhouses. This thermal water contains various dissolved solids that can deposit, precipitate, and form scales in the installations as the water is brought to the surface. The dissolved solids contain primordial radionuclides. Workers are exposed to these radionuclides while maintaining and cleaning geothermal plants.

This study complements the limited research available on naturally occurring radionuclides in geothermal installations by examining their presence in various facilities across the Netherlands. Sludge and scale samples were provided from five different surface installations. The samples were analysed using radiometric methods (alpha-particle and gamma-ray spectrometry) and a non-radiometric method (energy dispersive X-ray fluorescence, EDXRF). EDXRF identified several hazardous elements, such as Lead, Arsenic, Chromium, and Thallium. In the scales, radiometric analysis detected three main radionuclides: ²²⁸Th, ²¹⁰Pb, and ²¹⁰Po. Furthermore, for both scales and sludges, a notable disruption in the equilibrium was observed in parts of the natural decay chains ²³²Th-²²⁸Ra-²²⁸Th and ²²⁶Ra-²¹⁰Pb-²¹⁰Po, complicating the correct assessment of the massic activity of the radionuclides and the appropriate disposal of the materials. These findings highlight the importance of mapping Naturally Occurring Radioactive Materials (NORM) during geothermal plant maintenance and accurately assessing their massic activity.

地热能来源于地核中储存的热量。地质储层中的热水被提取到地表用于发电或为建筑物和温室供暖。这种热水含有各种溶解的固体，当水被带到地面时，这些固体会在装置中沉积、沉淀并形成鳞片。溶解的固体含有原始放射性核素。工作人员在维护和清洁地热发电厂时就暴露在这些放射性核素中。这项研究通过检查荷兰各地各种设施中天然存在的放射性核素，补充了对地热装置中天然存在的放射性核素的有限研究。从五个不同的地面装置中提供了污泥和水垢样本。使用辐射测量方法（α粒子和伽马射线能谱法）和非辐射测量方法（能量色散x射线荧光，EDXRF）对样品进行分析。EDXRF识别出几种有害元素，如铅、砷、铬和铊。在尺度上，放射性分析检测到三种主要的放射性核素：228Th， 210Pb和210Po。此外，对于水垢和污泥，在自然衰变链232Th-228Ra-228Th和226Ra-210Pb-210Po的部分中观察到平衡的明显破坏，使放射性核素大量活性的正确评估和材料的适当处置变得复杂。这些发现强调了在地热电厂维护过程中绘制天然放射性物质（NORM）地图和准确评估其大规模活动的重要性。

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引用次数: 0

Experimental and Monte Carlo analysis of activation in a medical cyclotron target assembly 医用回旋加速器靶组件激活的实验与蒙特卡罗分析

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-24 DOI: 10.1016/j.apradiso.2025.112405

Ping Xu , Yemian Li , Qingbiao Wu , Yinglin Ma , Sixuan Zhuang , Zuolong Zhu , Yufei Wang , Lun Li

Radiological characterization of activated materials is a crucial step in the decommissioning and waste classification of medical cyclotron. This work combines on-site HPGe γ-spectrometry with FLUKA Monte Carlo simulations to characterize activation in the major components of a commercial ¹⁸F target assembly, namely the HAVAR foil, titanium window, niobium insert, and aluminum/stainless-steel structures. The measured and simulated results showed consistent radionuclide inventories, confirming that activation is initially dominated by short-lived nuclides, while long-lived isotopes such as ⁶⁰Co, ⁵⁸Co, ⁵⁴Mn, ⁶⁵Zn, ⁴⁶Sc, and ²²Na govern the residual dose rate after extended cooling. Among these, ⁶⁰Co in HAVAR and stainless steel, ⁴⁶Sc in titanium, and ²²Na in aluminum were identified as the key radionuclides determining clearance timeframes. Furthermore, this work established correlation between residual dose rates and the clearance levels of dominant radionuclides demonstrates that dose-rate measurements can serve as practical indicators for determining whether activated components meet clearance criteria after sufficient cooling. This study provides a quantitative basis for waste management of medical accelerators.

活性物质的放射学表征是医用回旋加速器退役和废物分类的关键步骤。这项工作将现场HPGe γ能谱法与FLUKA蒙特卡罗模拟相结合，以表征商业18F靶组件的主要部件的活化特性，即HAVAR箔、钛窗、铌嵌件和铝/不锈钢结构。测量和模拟结果显示了一致的放射性核素清单，证实了激活最初由短寿命核素主导，而长寿命同位素如60Co， 58Co, 54Mn, 65Zn， 46Sc和22Na在延长冷却后控制残留剂量率。其中，haar和不锈钢中的60Co、钛中的46Sc和铝中的22Na被确定为决定清除时间的关键放射性核素。此外，这项工作建立了残留剂量率与主要放射性核素清除水平之间的相关性，表明剂量率测量可以作为确定活性成分在充分冷却后是否满足清除标准的实用指标。本研究为医用加速器废弃物管理提供了定量依据。

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引用次数: 0

Dose coefficients to the fetus and offspring from intakes of radionuclides by the mother 母亲摄入放射性核素对胎儿和后代的剂量系数。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-23 DOI: 10.1016/j.apradiso.2025.112387

Vladimir Spielmann, Augusto Giussani

引用次数: 0

Gamma radiation cured polyester resin for restoration of cultural heritage wood γ射线固化聚酯树脂修复文化遗产木材。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-23 DOI: 10.1016/j.apradiso.2025.112404

Maria Aparecida M.G. Pereira, Maria José Alves. Oliveira, Larissa Otubo, Leni M.P.R. Lima, Pablo Antonio Salvador Vasquez

In the process of restoring and conserving cultural heritage artifacts and documents, a wide range of coatings based on resins and adhesives are used, including natural products and various types of synthetic polymers. The aim of this study was to examine the effectiveness of polyester-based resins with polymeric monomers cured by gamma radiation without a catalyst. These resins are typically used to impregnate wooden artifacts that have been compromised by insect damage and cannot be consolidated using other methods. Gamma radiation has been effectively used to treat cultural heritage objects, such as rare books, sacred or museum images, and canvas paintings. It is used for insect control, disinfection of harmful microorganisms, such as fungi and bacteria, and for creating new materials for restoration. For this study, formulations of polyester resin, methyl methacrylate monomer (MMA), and styrene (SM) were prepared with different concentrations and combinations. In the absence of catalysts, these formulations were exposed to gamma radiation at a dose of 50 kGy and a rate of 1 kGy/h. After curing, they were analyzed using gel fraction, thermogravimetry (TGA), differential scanning calorimetry (DSC), infrared (FTIR), scanning electron microscopy (SEM) and Optical microscopy (MO). The results show that polyester-based resins were successfully cured by gamma radiation without catalysts or chemicals. This process provides a form of long-lasting protection against fungi, bacteria, and insects, as well as protection against moisture exchange with the environment. These findings demonstrate the effectiveness of the proposed methodology in the conservation and preservation of wooden artworks, being capable of providing support, stability, and quality to the object.

在修复和保护文化遗产文物和文献的过程中，使用了广泛的基于树脂和粘合剂的涂料，包括天然产品和各种类型的合成聚合物。本研究的目的是检查聚酯基树脂的有效性与聚合单体固化的伽马射线无催化剂。这些树脂通常用于浸渍被昆虫破坏的木制文物，不能用其他方法加固。伽玛射线已经被有效地用于处理文化遗产，如珍本书籍，神圣或博物馆图像，帆布画。它被用于控制昆虫，消毒有害微生物，如真菌和细菌，并为修复创造新的材料。在本研究中，制备了不同浓度和组合的聚酯树脂、甲基丙烯酸甲酯单体（MMA）和苯乙烯（SM）的配方。在没有催化剂的情况下，这些配方以50千戈瑞的剂量和1千戈瑞/小时的速率暴露在伽马辐射下。固化后，采用凝胶分数法、热重法（TGA）、差示扫描量热法（DSC）、红外（FTIR）、扫描电镜（SEM）和光学显微镜（MO）对其进行分析。结果表明，在没有催化剂和化学物质的情况下，用伽马射线成功固化了聚酯基树脂。这个过程提供了一种对真菌、细菌和昆虫的持久保护，以及对与环境的水分交换的保护。这些发现证明了所提出的方法在保护和保存木制艺术品方面的有效性，能够为物体提供支持、稳定性和质量。

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引用次数: 0

Investigation toward the production of 236gNp via the 232Th + 7Li reaction: Synthesis of 236mNp and 234Np 232Th + 7Li反应制备236gNp的研究：236mNp和234Np的合成

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-23 DOI: 10.1016/j.apradiso.2025.112397

Akihisa Nakajima , Yuta Hayakawa , Ayumu Nagai , Akihiko Yokoyama , Hiromitsu Haba , Yukiko Komori , Takuya Yokokita , Yuma Sakakieda , Keisuke Sueki , Shinya Yamasaki , Aya Sakaguchi

Neptunium-236g (^236gNp) has been focused as a candidate spike for the mass spectrometry of ²³⁷Np which is a long-lived anthropogenic radionuclide present in the environment. In order to evaluate the feasibility of synthesising ²³⁶Np, experiments were conducted to detect and quantify the by-product ²³⁴Np and the nuclear isomer ^236mNp produced in the nuclear reaction by irradiating ²³²Th with ⁷Li. First, the chemical separation method was developed for the ultra-trace amounts of Np produced from the main matrix of Th and from the fission-derived nuclides and Pa isotopes produced by side reactions, based on using two solid-phase extraction resins. As a result of applying the constructed separation scheme to irradiated Th foils and Th electrodeposited samples at the AVF Cyclotron of the RIKEN RI Beam Factory (Japan), ^236mNp was successfully detected in the ²³²Th+⁷Li system for the first time. Based on experiments with ²³²Th irradiated at ⁷Li beam energies of ca.29 MeV–42 MeV, the nuclear reaction cross sections for the production of ^236mNp were found to be in the range 0.12–0.39 mb. This finding indicated that the spike candidate ^236gNp was also produced by the proposed nuclear reactions.

镎-236g （236gNp）是存在于环境中的长寿命人为放射性核素237Np质谱分析的候选峰。为了评价合成236Np的可行性，采用7Li照射232Th核反应产生的副产物234Np和核异构体236mNp进行了实验检测和量化。首先，在两种固相萃取树脂的基础上，开发了从Th主基质和副反应产生的核素和Pa同位素中产生超微量Np的化学分离方法。在日本理研研究所束流工厂的AVF回旋加速器上，将所构建的分离方案应用于辐照后的Th箔和电沉积样品，首次成功地在232Th+7Li体系中检测到236mNp。在7Li束流能量为ca.29 MeV - 42 MeV的条件下，对232Th进行辐照实验，发现生成236mNp的核反应截面在0.12-0.39 mb范围内，这表明所提出的核反应也产生了候选尖峰236gNp。

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引用次数: 0

High-resolution intraoral tomosynthesis imaging using small focal spot multi-beam X-ray source technology 采用小焦斑多束x射线源技术的高分辨率口腔内断层合成成像。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-23 DOI: 10.1016/j.apradiso.2025.112406

Huaping Tang , Guoyu Li , Jinsong Pan , Jinmei Chen , Sheng Lai , Zhiqiang Chen

With the increasing demand for intraoral dental health assessment, it has become important to obtain more detailed and informative visual data. To obtain high-resolution dental imaging, this study conducts research on advanced X-ray imaging technologies. This study proposes adopting multi-beam X-ray source for achieving high-resolution 3D intraoral imaging. Key parameters such as focal spot size, detector pixel size, system magnification and line-pair resolution are systematically analyzed. A theoretical framework is established to derive the resolution formula for X-ray imaging, identifying key factors that affect imaging resolution. An experimental platform is constructed to conduct performance testing on the multi beam X-ray tube. The results show that X-ray tube is worked on an anode voltage of 70 kV and a current of 7 mA. The measured focal spot sizes ranged from 0.43 mm to 0.52 mm, with an average of 0.47 mm and a standard deviation of 0.028. Line-pair resolution tests confirmed that all focal spots achieved the target resolution of 16 lp/mm. Systematic analysis of the X-ray imaging system demonstrates that, by employing a multi-beam X-ray tube and a detector with 18.5 μm pixels and a frame rate of 20 fps under a magnification factor of 1.04, the system achieved high-resolution imaging with resolution of 31.3 μm (16 lp/mm) for each focal spot, enabling the acquisition of seven projection angles within 1 s. The experimental results conclusively validate the clinical potential of multi-beam X-ray source in detecting various dental pathologies, demonstrating its reliability and suitability for high-resolution intraoral imaging applications.

随着口腔内牙齿健康评估需求的增加，获得更详细和信息丰富的视觉数据变得越来越重要。为了获得高分辨率的牙科成像，本研究开展了先进的x射线成像技术的研究。本研究提出采用多束x射线源实现高分辨率三维口腔内成像。系统地分析了焦斑尺寸、探测器像素尺寸、系统放大倍率和线对分辨率等关键参数。建立了x射线成像分辨率公式的理论框架，确定了影响成像分辨率的关键因素。搭建实验平台，对多束x射线管进行性能测试。结果表明，x射线管工作在70 kV的阳极电压和7 mA的电流下。测量到的焦斑尺寸范围为0.43 ~ 0.52 mm，平均为0.47 mm，标准差为0.028。线对分辨率测试证实，所有焦点都达到了16 lp/mm的目标分辨率。对x射线成像系统的系统分析表明，该系统采用多束x射线管和18.5 μm像素的探测器，在1.04的放大倍数下，帧率为20 fps，实现了每个焦斑分辨率为31.3 μm （16 lp/mm）的高分辨率成像，可在1 s内获取7个投影角度。实验结果最终验证了多束x射线源在检测各种口腔病理方面的临床潜力，证明了其在高分辨率口腔内成像应用中的可靠性和适用性。

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引用次数: 0

Comprehensive assessment of shielding performance and neutron dose escalation in high-energy LINAC vaults: lessons from a radiation safety case study 高能LINAC拱顶屏蔽性能和中子剂量增加的综合评估：来自辐射安全案例研究的经验教训。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-22 DOI: 10.1016/j.apradiso.2025.112400

Zakaria Tahiri , Hamza Sekkat , Reda Hallab , Mohammed Talbi , Hicham Harrass , M'Hamed El Mansouri

This analytical case study investigates a real-world shielding failure at a high-energy linear accelerator (LINAC) vault operating at photon energies up to 18 MV, focusing on neutron dose discrepancies observed at the maze door, a known vulnerability in radiotherapy room design. The study assesses how evolving clinical techniques, particularly Intensity-Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT), impact shielding adequacy and radiation safety. A mixed-method approach was employed, combining theoretical calculations based on NCRP Report No. 151, automated Excel-based modeling and on-site radiation measurements using neutron-sensitive probes. Pre- and post-IMRT/VMAT workloads were compared and the weekly neutron dose equivalent at the maze entrance was used as the primary performance indicator. The effectiveness of borated polyethylene (BPE) shielding was evaluated under both scenarios. Following the implementation of IMRT/VMAT, the facility's weekly workload increased from 790 Gy/week to 2310 Gy/week, with the 18 MV workload increasing from 470 Gy/week to 1222 Gy/week. This resulted in a significant rise in neutron dose equivalent at the maze door, increasing from 869.5 μSv/week (pre-IMRT/VMAT) to 2260 μSv/week, a 2.6-fold increase. To maintain a conservative design dose limit of P⁄2 = 50 μSv/week, the required BPE shielding thickness increased from 55.8 mm to 74.7 mm, exceeding the door's original structural capacity. Photon and capture gamma-ray contributions were negligible. This case revealed shielding deficiencies from underestimating clinical workload and advanced modality adoption. Findings emphasize anticipatory shielding design, periodic reassessment and safety controls, crucial for facilities in low- and middle-income countries transitioning from conventional 3D-CRT to IMRT/VMAT techniques in radiotherapy.

本分析案例研究调查了在光子能量高达18 MV的高能直线加速器（LINAC）拱顶中实际发生的屏蔽故障，重点研究了在迷宫门观察到的中子剂量差异，这是放疗室设计中的一个已知漏洞。该研究评估了不断发展的临床技术，特别是调强放射治疗（IMRT）和体积调制电弧治疗（VMAT），冲击屏蔽充分性和辐射安全性。采用混合方法，结合基于NCRP第151号报告的理论计算，基于excel的自动化建模和使用中子敏感探针的现场辐射测量。比较imrt /VMAT前后的工作量，并以迷宫入口处每周中子剂量当量作为主要绩效指标。在这两种情况下，对硼化聚乙烯（BPE）屏蔽的有效性进行了评估。在实施IMRT/VMAT后，该设施的每周工作量从790 Gy/周增加到2310 Gy/周，其中18 MV工作量从470 Gy/周增加到1222 Gy/周。这导致迷宫门口的中子剂量当量显著增加，从869.5 μSv/周（imrt /VMAT前）增加到2260 μSv/周，增加2.6倍。为了保持P / 2 = 50 μSv/周的保守设计剂量限制，所需的BPE屏蔽厚度从55.8 mm增加到74.7 mm，超过了门的原始结构容量。光子和捕获伽马射线的贡献可以忽略不计。该病例揭示了低估临床工作量和先进模式采用的屏蔽缺陷。研究结果强调了预期屏蔽设计、定期重新评估和安全控制，这对于中低收入国家的设施从传统的3D-CRT过渡到IMRT/VMAT放疗技术至关重要。

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引用次数: 0

Effective shielding elements and oxides for medical X-ray applications 医用x射线应用的有效屏蔽元件和氧化物。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-22 DOI: 10.1016/j.apradiso.2025.112402

H.M. Badran , M.M. Mourad , T. Sharshar

This study explores the potential of elements with atomic numbers 55–83 and their prevalent oxides as substitutes for lead in X-ray shielding applications, focusing on reducing mass and thickness while maintaining effectiveness across energies from 10 keV to 500 keV. The Pb-equivalent mass and thickness ratios were calculated for these elements and oxides, revealing significant variations in attenuation properties. To demonstrate the differences between broad-beam and narrow-beam attenuation as well as between mono-energetic photons and X-ray tube-generated spectra, measurements and calculations for 0.5 mm Pb were compared. Ta and W, as well as Pb and Bi oxides, are suitable substitutes at 15 keV, making them ideal for mammography. Sm, Nd, and Bi, as well as several oxides, are advisable alternatives near 50 keV, making them suitable for dental X-ray shielding. Pb and Bi oxides are preferred for CT applications, along with others, whereas Bi and W are appropriate for high-energy X-rays. The study also reveals that at low photon energies, PbO, Pb₃O₄, PbO₂, and Bi₂O₃ demonstrate optimal Pb-equivalent ratios slightly above unity. Alternatives such as WO₂ and YbO exhibit potential at elevated energies. Calculations performed using X-ray tube spectra generated at varying X-ray tube voltages indicated that PbO outperforms other oxides at lower tube voltages, while YbO excels at energies greater than its K-edge. These findings provide valuable insights for the development of Pb-free X-ray shielding solutions that can meet the demands of various medical imaging modalities, enhancing safety and efficiency.

本研究探索了原子序数为55-83的元素及其普遍的氧化物在x射线屏蔽应用中作为铅替代品的潜力，重点是减少质量和厚度，同时保持能量从10 keV到500 keV的有效性。计算了这些元素和氧化物的pb当量质量和厚度比，揭示了衰减特性的显著变化。为了证明宽光束和窄光束衰减以及单能量光子和x射线管产生的光谱之间的差异，对0.5 mm Pb的测量和计算进行了比较。Ta和W，以及Pb和Bi的氧化物，在15 keV下是合适的替代品，使它们成为乳房x光检查的理想选择。Sm， Nd和Bi，以及几种氧化物，在50 keV附近是可取的替代品，使它们适合用于牙科x射线屏蔽。铅和铋氧化物是CT应用的首选，而Bi和W则适用于高能x射线。研究还表明，在低光子能量下，PbO、Pb3O4、PbO2和Bi2O3表现出略高于1的最佳pb当量比。WO2和YbO等替代品在高能量下表现出潜力。利用不同x射线管电压下生成的x射线管光谱进行的计算表明，PbO在较低的管电压下优于其他氧化物，而YbO在能量大于其k边时表现优异。这些发现为开发无铅x射线屏蔽解决方案提供了有价值的见解，可以满足各种医学成像模式的需求，提高安全性和效率。

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引用次数: 0

Quality control assessment and establishment of local diagnostic reference levels in two radiological centres in Osogbo, Nigeria 在尼日利亚奥索博的两个放射中心进行质量控制评估和建立当地诊断参考水平。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-22 DOI: 10.1016/j.apradiso.2025.112403

Idowu Richard Akomolafe , Joel Olaniyi Onijingin , Jesutomisin Enoch Alegbeleye , Christopher Jimoh Olowookere , Naven Chetty , Uchechukwu Enyim Vincent

This study aims to assess Quality Control (QC) tests, determine the Entrance Surface Dose (ESD), and establish Local Diagnostic Reference Levels (LDRLs) for patients undergoing X-ray examinations at the University of Osun Teaching Hospital (UniOsun) and Union Diagnostic Centre (UDC), Osogbo, Nigeria. Demographic data from 334 patients, along with exposure parameters (kVp, mAs, FFD, and FSD), were recorded using a specially designed questionnaire with the assistance of radiographers. A one-time QC assessment test was conducted to verify the compliance of the X-ray machine with the international standard using a Gammex 330 Digital kV, dose, and time meter obtained from the National Institute for Radiation Protection and Research at the University of Ibadan, Nigeria. As referenced in the literature, a mathematical model was used to calculate the ESD (mGy) for various X-ray examinations conducted at UniOsun and UDC. Statistical analysis of the results was performed, and the 75th percentile for ESD was calculated. The results indicated that the mean highest ESD belonged to the Skull (0.047 ± 0.001) mGy and Lumbar spine (1.76 ± 0.48) mGy, and the lowest ESD belonged to the Elbow (0.012 ± 0.002) mGy and Elbow, Hand, Wrist (0.39 ± 0.06) mGy for UniOsun and UDC, respectively. The LDRL of the ESD ranged from (0.014–0.048) mGy to (0.42–2.29) mGy at UniOsun and UDC, respectively. In conclusion, the findings revealed a significant variation in ESD across different examinations and centres, highlighting the necessity for tailored dose optimisation strategies to ensure patient safety while maintaining diagnostic quality.

本研究旨在评估质量控制（QC）测试，确定入口表面剂量（ESD），并为在尼日利亚奥索博奥逊大学教学医院（UniOsun）和联合诊断中心（UDC）接受x射线检查的患者建立当地诊断参考水平（LDRLs）。在放射技师的协助下，使用专门设计的问卷记录了334名患者的人口统计数据以及暴露参数（kVp、mAs、FFD和FSD）。使用从尼日利亚伊巴丹大学国家辐射防护与研究所获得的Gammex 330数字千伏、剂量和时间计，进行了一次性QC评估测试，以验证x射线机是否符合国际标准。参考文献，使用数学模型计算在UniOsun和UDC进行的各种x射线检查的ESD （mGy）。对结果进行统计分析，计算ESD的第75百分位。结果显示，UniOsun和UDC的平均ESD最高为颅骨（0.047±0.001）mGy，腰椎（1.76±0.48）mGy，最低为肘部（0.012±0.002）mGy，肘部、手、腕部（0.39±0.06）mGy。在UniOsun和UDC下，ESD的LDRL分别为（0.014-0.048）mGy至（0.42-2.29）mGy。总之，研究结果显示，不同检查方式和不同中心的ESD存在显著差异，强调有必要制定量身定制的剂量优化策略，以确保患者安全，同时保持诊断质量。

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引用次数: 0

Influence of titanium dioxide on Fricke dosimetry under gamma radiation: adsorption effects of iron ions 伽马辐射下二氧化钛对Fricke剂量测定的影响：铁离子的吸附效应

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2025-12-22 DOI: 10.1016/j.apradiso.2025.112401

W. Villacis , R. Santos , M.N. Piol , P. Vargas-Jentzsch , C. Vázquez

Fricke dosimetry is the most established water-equivalent chemical dosimeter; however, its performance may be altered in heterogeneous systems containing solid materials. Understanding such interferences is crucial for applications of radiation processing and radiocatalysis, where semiconductors like TiO₂ are often present. This study presents the first systematic evaluation of TiO₂ interference in Fricke dosimetry under γ-irradiation from a Co⁶⁰ source. Adsorption experiments for Fe²⁺ and Fe³⁺ ions were performed to determine equilibrium and kinetic parameters, complemented by irradiation assays at doses up to 500 Gy and a dose rate of approximately 96 Gy/h. The TiO₂ material (anatase, 111.2 m² g⁻¹, agglomerated particles 1.4–2.4 μm) showed adsorption capacities of 0.007 mmol/g for Fe²⁺ and 0.008 mmol/g for Fe³⁺, following a pseudo-second-order kinetic behavior and Freundlich-type equilibrium isotherms. Under irradiation, a measurable interference was observed, resulting in a 6.8 % reduction at 5 mg/mL TiO₂ and 8.1 % at 10 mg/mL in the Fricke dosimetric response at 500 Gy compared with TiO₂-free reference solutions. The findings demonstrate that TiO₂ can adsorb dosimetric ions and perturb radical recombination pathways, thus affecting the chemical yield of Fe³⁺ formation. These results highlight the need for dose-mapping corrections and reference measurements when Fricke dosimetry is applied in heterogeneous systems or in the presence of oxide nanoparticles.

弗里克剂量计是最成熟的水当量化学剂量计；然而，在含有固体材料的非均相体系中，其性能可能会发生变化。了解这种干扰对于辐射处理和辐射催化的应用至关重要，在这些应用中，像TiO2这样的半导体经常存在。本研究首次系统评价了Co60源γ辐照下Fricke剂量法中TiO2的干扰。对Fe2+和Fe3+离子进行了吸附实验，以确定平衡和动力学参数，并辅以剂量高达500 Gy，剂量率约为96 Gy/h的辐照试验。TiO2材料（锐钛矿，111.2 m2 g−1，团聚颗粒1.4 ~ 2.4 μm）对Fe2+和Fe3+的吸附量分别为0.007 mmol/g和0.008 mmol/g，符合准二级动力学行为和freundlich型平衡等温线。在辐照下，观察到可测量的干扰，在500 Gy下，与不含TiO2的参考溶液相比，在5 mg/mL TiO2下，Fricke剂量学响应降低了6.8%，在10 mg/mL下降低了8.1%。研究结果表明，TiO2可以吸附剂量离子，扰乱自由基重组途径，从而影响Fe3+生成的化学产率。这些结果强调，当Fricke剂量法应用于非均相体系或氧化物纳米颗粒存在时，需要进行剂量图校正和参考测量。

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