This study presents an experimental evaluation of key parameters (efficiency and sensitivity) of two detectors based on lanthanum chloride LaCl3(Ce) scintillation crystals. We performed measurements in the neutron energy range of ∼2.2–2.9 MeV using a reference neutron source at the D.I. Mendeleyev Institute for Metrology in St. Petersburg, Russia. A special feature of the source is the thin target (mitigating internal neutron attenuation), the total D-D neutron yield is ∼2 × 106 n/s. The values for the sensitivity obtained from the experiment were underestimated by a factor of several times compared to those calculated using cross-sections from the ENDF/B-VIII.0 nuclear data library. These results suggest a possible need to refine the properties of the 35Cl(n,p)35Sg.s. reaction used in the evaluation model and to supplement the database with experimental data in the neutron energy region of ∼2.5 MeV.
{"title":"Characterisation of LaCl3(Ce)-based detectors for D-D fusion neutron diagnostic","authors":"D.S. Fridrikhsen , S.Yu. Obudovsky , T.M. Kormilitsyn , A.V. Pankratenko , Yu.A. Kashchuk , N.N. Moiseev","doi":"10.1016/j.radmeas.2025.107600","DOIUrl":"10.1016/j.radmeas.2025.107600","url":null,"abstract":"<div><div>This study presents an experimental evaluation of key parameters (efficiency and sensitivity) of two detectors based on lanthanum chloride LaCl<sub>3</sub>(Ce) scintillation crystals. We performed measurements in the neutron energy range of ∼2.2–2.9 MeV using a reference neutron source at the D.I. Mendeleyev Institute for Metrology in St. Petersburg, Russia. A special feature of the source is the thin target (mitigating internal neutron attenuation), the total D-D neutron yield is ∼2 × 10<sup>6</sup> n/s. The values for the sensitivity obtained from the experiment were underestimated by a factor of several times compared to those calculated using cross-sections from the ENDF/B-VIII.0 nuclear data library. These results suggest a possible need to refine the properties of the <sup>35</sup>Cl(n,p)<sup>35</sup>S<sub>g.s.</sub> reaction used in the evaluation model and to supplement the database with experimental data in the neutron energy region of ∼2.5 MeV.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107600"},"PeriodicalIF":2.2,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840083","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 : 2025-12-18DOI: 10.1016/j.radmeas.2025.107595
Qi Liu , Benno Rohrer , Sairos Safai , Antony John Lomax , Zhiling Chen , Michele Togno
{"title":"Corrigendum to “Characterization of a Gd-based color CMOS detector for proton dosimetry” [Radiat. Meas. 164 (2023) 106945]","authors":"Qi Liu , Benno Rohrer , Sairos Safai , Antony John Lomax , Zhiling Chen , Michele Togno","doi":"10.1016/j.radmeas.2025.107595","DOIUrl":"10.1016/j.radmeas.2025.107595","url":null,"abstract":"","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107595"},"PeriodicalIF":2.2,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973278","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 : 2025-12-18DOI: 10.1016/j.radmeas.2025.107594
Zhong-Bin Hang , Chuan-Feng Liu , Yan Zhang , Zi-Wei Liang , Hai Hu , Tian-Tian Zhang , Yun-Tao Liu , Ming-Zhe Song , Ke-Xin Wei , Lin Qin , Xi-Mei Wang , Zuo-Xiang He
Background:
In the clinical application of brachytherapy, the relevant quantities of brachytherapy seed strength must be converted into absorbed dose at a reference depth of 1 cm in water. The current method of obtaining the absorbed dose in water is based on the air kerma strength and dose rate constant, which has an uncertainty of more than 10% (k=2), potentially affecting cancer treatment outcomes.
Purpose:
To ensure accurate dosimetry for 125I brachytherapy seeds, an extrapolation chamber embedded in the water-equivalent material was designed and manufactured to measure the absorbed dose in water directly.
Methods:
The mathematical model for determining the absorbed dose in water is based on radiation transport theory, where the key term conversion factor is determined using the Monte Carlo (MC) methods. In this paper, the basic structure, the measurement method, and the MC simulation of the extrapolation chamber are described. The dose rate constant of the model 6711 125I brachytherapy seed was obtained using three methods (experimental measurement, MC simulation, and AAPM recommended values), and the results was compared and analyzed.
Results:
The absorbed dose in water of the model 6711 125I brachytherapy seed was determined, and after repeated measurements and uncertainty evaluation, the result was 12.39 mGy/h, with an uncertainty of 3.5% (k=2). In addition, the brachytherapy seed was calibrated using an absolute measurement device for the air kerma strength, and its dose rate constant was calculated, which was in good agreement with both the AAPM-recommended values and MC simulated values.
Conclusions:
We successfully developed an absolute measurement device for the absorbed dose in water, which reduced the measurement uncertainty for 125I brachytherapy seeds and achieved dose accuracy for external radiotherapy. This study contributes to the establishment of primary standards for the absorbed dose in water of 125I brachytherapy seeds.
{"title":"Absolute measurement of absorbed dose in water for 125I brachytherapy seeds","authors":"Zhong-Bin Hang , Chuan-Feng Liu , Yan Zhang , Zi-Wei Liang , Hai Hu , Tian-Tian Zhang , Yun-Tao Liu , Ming-Zhe Song , Ke-Xin Wei , Lin Qin , Xi-Mei Wang , Zuo-Xiang He","doi":"10.1016/j.radmeas.2025.107594","DOIUrl":"10.1016/j.radmeas.2025.107594","url":null,"abstract":"<div><h3>Background:</h3><div>In the clinical application of brachytherapy, the relevant quantities of brachytherapy seed strength must be converted into absorbed dose at a reference depth of 1 cm in water. The current method of obtaining the absorbed dose in water is based on the air kerma strength and dose rate constant, which has an uncertainty of more than 10% (<em>k</em>=2), potentially affecting cancer treatment outcomes.</div></div><div><h3>Purpose:</h3><div>To ensure accurate dosimetry for <sup>125</sup>I brachytherapy seeds, an extrapolation chamber embedded in the water-equivalent material was designed and manufactured to measure the absorbed dose in water directly.</div></div><div><h3>Methods:</h3><div>The mathematical model for determining the absorbed dose in water is based on radiation transport theory, where the key term conversion factor <span><math><mrow><mi>C</mi><mrow><mo>(</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>i</mi><mo>+</mo><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> is determined using the Monte Carlo (MC) methods. In this paper, the basic structure, the measurement method, and the MC simulation of the extrapolation chamber are described. The dose rate constant of the model 6711 <sup>125</sup>I brachytherapy seed was obtained using three methods (experimental measurement, MC simulation, and AAPM recommended values), and the results was compared and analyzed.</div></div><div><h3>Results:</h3><div>The absorbed dose in water of the model 6711 <sup>125</sup>I brachytherapy seed was determined, and after repeated measurements and uncertainty evaluation, the result was 12.39 mGy/h, with an uncertainty of 3.5% (<em>k</em>=2). In addition, the brachytherapy seed was calibrated using an absolute measurement device for the air kerma strength, and its dose rate constant was calculated, which was in good agreement with both the AAPM-recommended values and MC simulated values.</div></div><div><h3>Conclusions:</h3><div>We successfully developed an absolute measurement device for the absorbed dose in water, which reduced the measurement uncertainty for <sup>125</sup>I brachytherapy seeds and achieved dose accuracy for external radiotherapy. This study contributes to the establishment of primary standards for the absorbed dose in water of <sup>125</sup>I brachytherapy seeds.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107594"},"PeriodicalIF":2.2,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787322","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 : 2025-12-18DOI: 10.1016/j.radmeas.2025.107599
Jialong Yang , Xingyan Liu , Diyun Shu , Changran Geng , Xiaobin Tang , Yuan-Hao Liu
Accurate quantitative measurement of neutron non-primary radiation is crucial for the safe implementation of boron neutron capture therapy (BNCT), yet such measurement faces challenges including large measurement area and strong γ-ray interference. Indirect neutron radiography (INR) offers advantages for large-area measurement and γ resistance, but its application is limited by the low sensitivity of activation detectors and measurement errors from crosstalk. To address these challenges, dysprosium (Dy) was selected as the activation detector to enhance sensitivity, establishing a quantitative calibration relationship between its activity and imaging plate (IP) signals. For signal crosstalk during foil exposure, spatial convolution kernel was constructed using Monte Carlo simulations, and then applied with the Biconjugate Gradient Stabilized (Bi-CGSTAB) algorithm to perform spatial deconvolution of dose deposition on the IP, thereby reconstructing the actual activity of each pixel on the foil. Validation experiments demonstrated significant improvement, and the proportion of data points exceeding 5 % deviation decreased from over 60 % before correction to below 15 % after correction. Applied to clinical BNCT device, it successfully obtained the two-dimensional (2D) distribution of neutron non-primary radiation within 150–550 mm from the radiation field edge. The converted maximum skin absorbed dose rate was 1.26 × 10−4 Gy/s, located at 150 mm from the radiation field edge and decaying rapidly with increasing distance. This study achieved the quantitative measurement of 2D neutron non-primary radiation distribution in clinical BNCT devices, and provided technical support for comprehensive assessment of radiation risks and optimization of protection design.
{"title":"Optimized quantitative indirect neutron radiography method for 2D non-primary radiation measurement in BNCT","authors":"Jialong Yang , Xingyan Liu , Diyun Shu , Changran Geng , Xiaobin Tang , Yuan-Hao Liu","doi":"10.1016/j.radmeas.2025.107599","DOIUrl":"10.1016/j.radmeas.2025.107599","url":null,"abstract":"<div><div>Accurate quantitative measurement of neutron non-primary radiation is crucial for the safe implementation of boron neutron capture therapy (BNCT), yet such measurement faces challenges including large measurement area and strong γ-ray interference. Indirect neutron radiography (INR) offers advantages for large-area measurement and γ resistance, but its application is limited by the low sensitivity of activation detectors and measurement errors from crosstalk. To address these challenges, dysprosium (Dy) was selected as the activation detector to enhance sensitivity, establishing a quantitative calibration relationship between its activity and imaging plate (IP) signals. For signal crosstalk during foil exposure, spatial convolution kernel was constructed using Monte Carlo simulations, and then applied with the Biconjugate Gradient Stabilized (Bi-CGSTAB) algorithm to perform spatial deconvolution of dose deposition on the IP, thereby reconstructing the actual activity of each pixel on the foil. Validation experiments demonstrated significant improvement, and the proportion of data points exceeding 5 % deviation decreased from over 60 % before correction to below 15 % after correction. Applied to clinical BNCT device, it successfully obtained the two-dimensional (2D) distribution of neutron non-primary radiation within 150–550 mm from the radiation field edge. The converted maximum skin absorbed dose rate was 1.26 × 10<sup>−4</sup> Gy/s, located at 150 mm from the radiation field edge and decaying rapidly with increasing distance. This study achieved the quantitative measurement of 2D neutron non-primary radiation distribution in clinical BNCT devices, and provided technical support for comprehensive assessment of radiation risks and optimization of protection design.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107599"},"PeriodicalIF":2.2,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840082","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 : 2025-12-17DOI: 10.1016/j.radmeas.2025.107597
H. Sekkat , A. Khallouqi , O. El rhazouani , A. Halimi
This study evaluates the performance of a deep learning model developed to predict organ-specific radiation doses in pediatric head CT scans. The model automates tissue segmentation and voxelization of organs for Monte Carlo (MC) simulations, which provide the ground truth for dose assessment. Using a Python-based framework, the model preprocesses DICOM images, applies HU-based thresholds for tissue classification, and refines segmentation with morphological operations. The segmented tissues, bone, brain matter, eye lens and air + fat, are reconstructed into 3D voxelized volumes, enabling precise dose predictions. A convolutional neural network (CNN) with a pre-trained VGG16 architecture was employed to predict doses based on features extracted from the CT scans and voxelized phantoms. The dataset included 982 pediatric CT scans, with data augmentation techniques applied for model robustness. The model demonstrated high performance in predicting radiation doses, closely matching the MC simulated doses for all organs, with minimal deviations in mean doses and low standard deviations. RRMSE values were low (4.84 % for bone, 6.01 % for brain matter, 8.45 % for air + fat, and 10.59 % for eye lens), indicating high precision. Additionally, the model achieved high R2 values, with bone showing the best correlation (0.95). Performance analysis across 15 random allocations revealed that bone consistently exhibited the highest prediction accuracy, with the lowest median RRMSE (7.84 %) and median MAPE (1.2 %). Although variability was higher for brain matter, eye lens, and air + fat, bone demonstrated superior consistency and accuracy. In conclusion, the deep learning model effectively predicts organ-specific radiation doses for pediatric head CT scans, with particularly high accuracy for bone tissue. While the model shows reliable performance across multiple metrics, further optimization is needed for tissues with higher variability, indicating its promising potential in enhancing radiation dose assessment in pediatric CT.
{"title":"Deep learning-based organ dose prediction in pediatric head CT using fully automated tissue segmentation and newly developed voxelized phantoms in GATE/Geant4 simulation toolkit","authors":"H. Sekkat , A. Khallouqi , O. El rhazouani , A. Halimi","doi":"10.1016/j.radmeas.2025.107597","DOIUrl":"10.1016/j.radmeas.2025.107597","url":null,"abstract":"<div><div>This study evaluates the performance of a deep learning model developed to predict organ-specific radiation doses in pediatric head CT scans. The model automates tissue segmentation and voxelization of organs for Monte Carlo (MC) simulations, which provide the ground truth for dose assessment. Using a Python-based framework, the model preprocesses DICOM images, applies HU-based thresholds for tissue classification, and refines segmentation with morphological operations. The segmented tissues, bone, brain matter, eye lens and air + fat, are reconstructed into 3D voxelized volumes, enabling precise dose predictions. A convolutional neural network (CNN) with a pre-trained VGG16 architecture was employed to predict doses based on features extracted from the CT scans and voxelized phantoms. The dataset included 982 pediatric CT scans, with data augmentation techniques applied for model robustness. The model demonstrated high performance in predicting radiation doses, closely matching the MC simulated doses for all organs, with minimal deviations in mean doses and low standard deviations. RRMSE values were low (4.84 % for bone, 6.01 % for brain matter, 8.45 % for air + fat, and 10.59 % for eye lens), indicating high precision. Additionally, the model achieved high R<sup>2</sup> values, with bone showing the best correlation (0.95). Performance analysis across 15 random allocations revealed that bone consistently exhibited the highest prediction accuracy, with the lowest median RRMSE (7.84 %) and median MAPE (1.2 %). Although variability was higher for brain matter, eye lens, and air + fat, bone demonstrated superior consistency and accuracy. In conclusion, the deep learning model effectively predicts organ-specific radiation doses for pediatric head CT scans, with particularly high accuracy for bone tissue. While the model shows reliable performance across multiple metrics, further optimization is needed for tissues with higher variability, indicating its promising potential in enhancing radiation dose assessment in pediatric CT.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107597"},"PeriodicalIF":2.2,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790517","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 : 2025-12-17DOI: 10.1016/j.radmeas.2025.107598
A. Romanyukha , J.L. Saunders , J.A. Delzer , A. Smolinski , K. Riley , A. Guynn , A. Tsioplaya , A. Cook
Alanine Electron Paramagnetic Resonance (EPR) dosimetry can measure the total (neutron + photon) dose from a neutron source. Commercially available optically stimulated luminescence (OSL) dosimeters and readers can accurately measure photon doses. An independent measurement of the photon dose contribution is vital because alanine has a different sensitivity to neutrons and photons when calibrated in terms of tissue kerma from 60Co gamma radiation. Therefore, OSL dosimetry can be used to separate neutron and photon dose contributions from the total dose measured by alanine. The Armed Forces Radiobiology Research Institute (AFRRI) research reactor produces varied neutron-photon mixtures, primarily used for radiobiology experiments. Many phantoms at AFRRI are used to measure the accuracy of dose delivery in animal experiments. In the present work, standard and 3D-printed rat phantoms equipped with OSL and alanine dosimeters were used. A special holder capable of securing four alanine pellets and four OSL NanoDot dosimeters was designed and 3D-printed and inserted into the rat phantoms during irradiation. This work was aimed at comparing 3D-printed rat phantoms with the standard PMMA phantom. The results of neutron and photon dose measurements after irradiation in different photon and neutron mixtures are presented. Based on these measurements, the relative neutron sensitivity of alanine was determined to be 0.35 ± 0.11 Gy. Alanine neutron dose measurements were validated using other dosimetry techniques, and further applications of the developed approach are discussed.
{"title":"Application of combined EPR alanine/OSL Al2O3:C dosimetry for neutron and photon dose measurements","authors":"A. Romanyukha , J.L. Saunders , J.A. Delzer , A. Smolinski , K. Riley , A. Guynn , A. Tsioplaya , A. Cook","doi":"10.1016/j.radmeas.2025.107598","DOIUrl":"10.1016/j.radmeas.2025.107598","url":null,"abstract":"<div><div>Alanine Electron Paramagnetic Resonance (EPR) dosimetry can measure the total (neutron + photon) dose from a neutron source. Commercially available optically stimulated luminescence (OSL) dosimeters and readers can accurately measure photon doses. An independent measurement of the photon dose contribution is vital because alanine has a different sensitivity to neutrons and photons when calibrated in terms of tissue kerma from <sup>60</sup>Co gamma radiation. Therefore, OSL dosimetry can be used to separate neutron and photon dose contributions from the total dose measured by alanine. The Armed Forces Radiobiology Research Institute (AFRRI) research reactor produces varied neutron-photon mixtures, primarily used for radiobiology experiments. Many phantoms at AFRRI are used to measure the accuracy of dose delivery in animal experiments. In the present work, standard and 3D-printed rat phantoms equipped with OSL and alanine dosimeters were used. A special holder capable of securing four alanine pellets and four OSL NanoDot dosimeters was designed and 3D-printed and inserted into the rat phantoms during irradiation. This work was aimed at comparing 3D-printed rat phantoms with the standard PMMA phantom. The results of neutron and photon dose measurements after irradiation in different photon and neutron mixtures are presented. Based on these measurements, the relative neutron sensitivity of alanine was determined to be 0.35 ± 0.11 Gy. Alanine neutron dose measurements were validated using other dosimetry techniques, and further applications of the developed approach are discussed.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107598"},"PeriodicalIF":2.2,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790518","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 : 2025-12-16DOI: 10.1016/j.radmeas.2025.107596
Svenja Riedesel , Christina Ankjærgaard
Time-resolved luminescence measurements provide a powerful means of investigating luminescence processes across timescales, ranging from picoseconds to seconds. These measurements are typically enabled by pulsed stimulation, where light pulses of fixed durations are applied to a sample. Luminescence can then be recorded both during and after the pulsed light stimulation, allowing discrimination between stimulation and emission, as well as isolation of luminescence components with different lifetimes.
Quartz and feldspar minerals are the two natural minerals most commonly used in luminescence studies. Time-resolved luminescence of feldspars has been investigated since the early 1990s, while quartz time-resolved signals has come into focus since around 2000. Over the past three decades, the extensive research into time-resolved and pulsed luminescence properties of these two minerals has provided insights into the lifetime of recombination and relaxation processes of various emissions in these minerals. These differences in the luminescence decay of quartz and feldspar offers a practical solution for discriminating their luminescence.
This review is aimed at researchers specialising in the field of luminescence dating, who embark on their first pulsed and time-resolved luminescence journeys. It provides practical information on measurement techniques for conducting time-resolved luminescence measurements and presents an overview of research findings, accumulated over the past 3.5 decades highlighting both the fundamental processes revealed and the applications enabled by these methods.
{"title":"Pulsed and time-resolved optically stimulated luminescence of natural minerals – A review","authors":"Svenja Riedesel , Christina Ankjærgaard","doi":"10.1016/j.radmeas.2025.107596","DOIUrl":"10.1016/j.radmeas.2025.107596","url":null,"abstract":"<div><div>Time-resolved luminescence measurements provide a powerful means of investigating luminescence processes across timescales, ranging from picoseconds to seconds. These measurements are typically enabled by pulsed stimulation, where light pulses of fixed durations are applied to a sample. Luminescence can then be recorded both during and after the pulsed light stimulation, allowing discrimination between stimulation and emission, as well as isolation of luminescence components with different lifetimes.</div><div>Quartz and feldspar minerals are the two natural minerals most commonly used in luminescence studies. Time-resolved luminescence of feldspars has been investigated since the early 1990s, while quartz time-resolved signals has come into focus since around 2000. Over the past three decades, the extensive research into time-resolved and pulsed luminescence properties of these two minerals has provided insights into the lifetime of recombination and relaxation processes of various emissions in these minerals. These differences in the luminescence decay of quartz and feldspar offers a practical solution for discriminating their luminescence.</div><div>This review is aimed at researchers specialising in the field of luminescence dating, who embark on their first pulsed and time-resolved luminescence journeys. It provides practical information on measurement techniques for conducting time-resolved luminescence measurements and presents an overview of research findings, accumulated over the past 3.5 decades highlighting both the fundamental processes revealed and the applications enabled by these methods.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107596"},"PeriodicalIF":2.2,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790519","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 determination of absorbed dose rate to water at the surface of 90Sr-90Y medical β applicators is essential for clinical safety and quality assurance. However, existing methods have inherent limitations: extrapolation chambers are complex and not routinely available in clinical practice, radiochromic films exhibit pronounced energy dependence, and thermoluminescent dosimeters (TLDs) show relatively high measurement uncertainty. In this study, we proposed and validated a practical and traceable method for absorbed dose rate to water measurement using a commercially available parallel-plate ionization chamber (PTW34045). The chamber was calibrated using a certified β radiation standard facility in terms of absorbed dose rate to water at the surface, and its performance was evaluated. A high-precision movable platform was developed to vary the source-to-detector distance with 0.1 mm accuracy. The measured values were corrected for calibrations, environmental conditions, and air-to-water dose conversion. A custom fitting function combining a second-order polynomial and an exponential decay term was employed to extrapolate the absorbed dose rate to water at zero distance. The extrapolated absorbed dose rate values were compared with those provided by manufacturers and independently verified using TLDs calibrated with the same β standard facility. The ionization chamber and TLD measurements agreed within 3–6 %, which is consistent with their combined expanded uncertainties of 5.4 % (k = 2) and 8.8 % (k = 2), while in some cases, significant differences were observed when compared with the values used by the hospitals. Furthermore, Monte Carlo simulations were performed to model the chamber response and validate the measured dose–distance relationship. This approach offers a reliable and clinically applicable solution for β applicator dosimetry, with potential for standardization in routine quality control.
{"title":"Absorbed dose rate to water at the surface of 90Sr-90Y medical β applicators using a parallel-plate ionization Chamber: Towards establishing a traceable method for clinical β applicator dosimetry","authors":"Feixu Ren , Zhonglin Li , Chuan Wu , Ping Huang , Dongkun Xu , Lijuan Feng , Dan Hao , Qingfeng Tang , Songlin Wen , Yuxuan Zhao , Yue Huo","doi":"10.1016/j.radmeas.2025.107590","DOIUrl":"10.1016/j.radmeas.2025.107590","url":null,"abstract":"<div><div>Accurate determination of absorbed dose rate to water at the surface of <sup>90</sup>Sr-<sup>90</sup>Y medical β applicators is essential for clinical safety and quality assurance. However, existing methods have inherent limitations: extrapolation chambers are complex and not routinely available in clinical practice, radiochromic films exhibit pronounced energy dependence, and thermoluminescent dosimeters (TLDs) show relatively high measurement uncertainty. In this study, we proposed and validated a practical and traceable method for absorbed dose rate to water measurement using a commercially available parallel-plate ionization chamber (PTW34045). The chamber was calibrated using a certified β radiation standard facility in terms of absorbed dose rate to water at the surface, and its performance was evaluated. A high-precision movable platform was developed to vary the source-to-detector distance with 0.1 mm accuracy. The measured values were corrected for calibrations, environmental conditions, and air-to-water dose conversion. A custom fitting function combining a second-order polynomial and an exponential decay term was employed to extrapolate the absorbed dose rate to water at zero distance. The extrapolated absorbed dose rate values were compared with those provided by manufacturers and independently verified using TLDs calibrated with the same β standard facility. The ionization chamber and TLD measurements agreed within 3–6 %, which is consistent with their combined expanded uncertainties of 5.4 % (<em>k</em> = 2) and 8.8 % (<em>k</em> = 2), while in some cases, significant differences were observed when compared with the values used by the hospitals. Furthermore, Monte Carlo simulations were performed to model the chamber response and validate the measured dose–distance relationship. This approach offers a reliable and clinically applicable solution for β applicator dosimetry, with potential for standardization in routine quality control.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107590"},"PeriodicalIF":2.2,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738028","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 : 2025-12-13DOI: 10.1016/j.radmeas.2025.107591
Bruno Winicius Borsoi , Rodrigo Oliveira Bastos , Angelo Zanona Neto , Duvan Gil Rodríguez , João Marcos Fávaro Lopes , Avacir Casanova Andrello , Marcelo Marques Lopes Muller , Cristiano André Pott , Fábio Luiz Melquiades
7Be is a cosmogenic radionuclide used in gamma-ray spectrometry to trace short-term sediment movements, such as soil mobilization. Gamma-ray detectors with low resolution cannot distinguish photons with similar energies, making it challenging to detect 7Be using these instruments. When 7Be decays, it emits gamma rays with an energy of 477 keV, similar to those of other radioisotopes (228Ac, 462 keV; 208Tl, 511 keV) and of the annihilation effect (511 keV). For this reason, high-resolution detectors, such as HPGe, are typically used, as they can differentiate photons and distinguish the mentioned radionuclides which emit similar energies. However, unlike low-resolution detectors, HPGe detectors are much more expensive than other gamma detectors, both in purchase and maintenance costs. These constraints make the widespread use of 7Be measurements for soil erosion studies impractical on a global scale. In this study, we propose a method for analyzing 7Be using a low-resolution scintillation detector, specifically a NaI(Tl) detector. The method eliminates the influences on the 7Be energy window using reference from other spectral regions. The approach was applied to evaluate soil mobilization in two agricultural plots, one with terraces and the other without terraces. The results of 7Be were supported by the measurement of its half-life. Most of the 7Be activity in agricultural soil samples was above the minimum detectable activity, allowing an assessment of the spatial distribution of erosion and deposition rates across the landscape. Soil redistribution was quantitatively evaluated, indicating that terraced soil experiences less erosion than nonterraced soil.
{"title":"7Be measurements in agricultural soil using a low resolution NaI(Tl) detector","authors":"Bruno Winicius Borsoi , Rodrigo Oliveira Bastos , Angelo Zanona Neto , Duvan Gil Rodríguez , João Marcos Fávaro Lopes , Avacir Casanova Andrello , Marcelo Marques Lopes Muller , Cristiano André Pott , Fábio Luiz Melquiades","doi":"10.1016/j.radmeas.2025.107591","DOIUrl":"10.1016/j.radmeas.2025.107591","url":null,"abstract":"<div><div><sup>7</sup>Be is a cosmogenic radionuclide used in gamma-ray spectrometry to trace short-term sediment movements, such as soil mobilization. Gamma-ray detectors with low resolution cannot distinguish photons with similar energies, making it challenging to detect <sup>7</sup>Be using these instruments. When <sup>7</sup>Be decays, it emits gamma rays with an energy of 477 keV, similar to those of other radioisotopes (<sup>228</sup>Ac, 462 keV; <sup>208</sup>Tl, 511 keV) and of the annihilation effect (511 keV). For this reason, high-resolution detectors, such as HPGe, are typically used, as they can differentiate photons and distinguish the mentioned radionuclides which emit similar energies. However, unlike low-resolution detectors, HPGe detectors are much more expensive than other gamma detectors, both in purchase and maintenance costs. These constraints make the widespread use of <sup>7</sup>Be measurements for soil erosion studies impractical on a global scale. In this study, we propose a method for analyzing <sup>7</sup>Be using a low-resolution scintillation detector, specifically a NaI(Tl) detector. The method eliminates the influences on the <sup>7</sup>Be energy window using reference from other spectral regions. The approach was applied to evaluate soil mobilization in two agricultural plots, one with terraces and the other without terraces. The results of <sup>7</sup>Be were supported by the measurement of its half-life. Most of the <sup>7</sup>Be activity in agricultural soil samples was above the minimum detectable activity, allowing an assessment of the spatial distribution of erosion and deposition rates across the landscape. Soil redistribution was quantitatively evaluated, indicating that terraced soil experiences less erosion than nonterraced soil.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107591"},"PeriodicalIF":2.2,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790455","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}
When performing real-time dosimetry using an active-type dosimeter during clinical fluoroscopic procedures, angular dependence of dosimeter response should be taken into account. Our research group addressed this issue and proposed a triple-type dosimeter that can determine the incident angle of scattered X-rays. The triple-type detector consists of three active dosimeters. The two side dosimeters have slope filters to enhance the angular dependence and are intentionally tilted. The central dosimeter faces forward. The incident angle of X-rays () is estimated using the signal differences between the central dosimeter and the left and/or right dosimeters. Then, the absolute dose is determined by correcting the angular dependence of the central dosimeter based on the estimated . In order to verify the concept of the triple-type dosimeter, we conducted a proof-of-concept experiment using clinical X-ray fluoroscopic equipment. Scattered X-rays were generated by irradiating an elliptical cylindrical water phantom. The response of the triple-type dosimeter was evaluated by rotating it to vary the incident angle of scattered X-rays generated by the water phantom. The proposed dosimetry system could estimate the over an angular range of ±80° (with uncertainty of 1.35°), which is 30° wider than the previous version, and successfully determined the absolute doses after correction for the angular dependence of the dosimeter. Although the active-type dosimeter had a systematic uncertainty related to the angular dependence of ±15.2 %, our system succeeded in reducing the systematic uncertainty to ±3.2 %.
{"title":"A novel wearable dosimeter system that can analyze the incident direction of X-rays for medical dosimetry – Improvements to the detector arrangements and analysis algorithm –","authors":"Takashi Asahara , Rina Nishigami , Daiki Kobayashi , Natsumi Kimoto , Sota Goto , Kazuki Takegami , Rin Ishii , Mana Mitani , Mitsugi Honda , Toshihiro Iguchi , Hiroaki Hayashi","doi":"10.1016/j.radmeas.2025.107592","DOIUrl":"10.1016/j.radmeas.2025.107592","url":null,"abstract":"<div><div>When performing real-time dosimetry using an active-type dosimeter during clinical fluoroscopic procedures, angular dependence of dosimeter response should be taken into account. Our research group addressed this issue and proposed a triple-type dosimeter that can determine the incident angle of scattered X-rays. The triple-type detector consists of three active dosimeters. The two side dosimeters have slope filters to enhance the angular dependence and are intentionally tilted. The central dosimeter faces forward. The incident angle of X-rays (<span><math><mrow><msub><mi>θ</mi><mtext>in</mtext></msub></mrow></math></span>) is estimated using the signal differences between the central dosimeter and the left and/or right dosimeters. Then, the absolute dose is determined by correcting the angular dependence of the central dosimeter based on the estimated <span><math><mrow><msub><mi>θ</mi><mtext>in</mtext></msub></mrow></math></span>. In order to verify the concept of the triple-type dosimeter, we conducted a proof-of-concept experiment using clinical X-ray fluoroscopic equipment. Scattered X-rays were generated by irradiating an elliptical cylindrical water phantom. The response of the triple-type dosimeter was evaluated by rotating it to vary the incident angle of scattered X-rays generated by the water phantom. The proposed dosimetry system could estimate the <span><math><mrow><msub><mi>θ</mi><mtext>in</mtext></msub></mrow></math></span> over an angular range of ±80° (with uncertainty of 1.35°), which is 30° wider than the previous version, and successfully determined the absolute doses after correction for the angular dependence of the dosimeter. Although the active-type dosimeter had a systematic uncertainty related to the angular dependence of ±15.2 %, our system succeeded in reducing the systematic uncertainty to ±3.2 %.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"191 ","pages":"Article 107592"},"PeriodicalIF":2.2,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790520","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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