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Background simulation of a low background gamma ray spectrometer with an array of five germanium detectors
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-27 DOI: 10.1016/j.apradiso.2025.111748
Jikai Chen , Zhi Zeng , Hao Ma , Mingkun Jing , Huaqiang Zhong , Hui Cao , Hui Zhang , Junli Li , Jianping Cheng
A new gamma ray spectrometer with an array of five germanium detectors, called ARGUS, is designed to screen and select materials used in rare-event search experiments. In this paper, we investigate the background characteristics of ARGUS using Monte Carlo simulation. The expected background count rate was found to reach the level of 10 counts per day per kg of germanium crystal (cpkd) in the energy region of 60 keV to 2700 keV. The minimum detectable activity (MDA) for germanium array was estimated via the maximum likelihood method. With an 100-day measurement of a 118.3 kg high purity copper sample, the MDA were calculated to be 28.8 μBq/kg for 212Pb (238 keV) and 32.8 μBq/kg for 214Bi (609 keV). The ARGUS is planned to be built in the China Jinping Underground Laboratory in 2025.
{"title":"Background simulation of a low background gamma ray spectrometer with an array of five germanium detectors","authors":"Jikai Chen ,&nbsp;Zhi Zeng ,&nbsp;Hao Ma ,&nbsp;Mingkun Jing ,&nbsp;Huaqiang Zhong ,&nbsp;Hui Cao ,&nbsp;Hui Zhang ,&nbsp;Junli Li ,&nbsp;Jianping Cheng","doi":"10.1016/j.apradiso.2025.111748","DOIUrl":"10.1016/j.apradiso.2025.111748","url":null,"abstract":"<div><div>A new gamma ray spectrometer with an array of five germanium detectors, called ARGUS, is designed to screen and select materials used in rare-event search experiments. In this paper, we investigate the background characteristics of ARGUS using Monte Carlo simulation. The expected background count rate was found to reach the level of 10 counts per day per kg of germanium crystal (cpkd) in the energy region of 60 keV to 2700 keV. The minimum detectable activity (MDA) for germanium array was estimated via the maximum likelihood method. With an 100-day measurement of a 118.3 kg high purity copper sample, the MDA were calculated to be 28.8 <span><math><mi>μ</mi></math></span>Bq/kg for <sup>212</sup>Pb (238 keV) and 32.8 <span><math><mi>μ</mi></math></span>Bq/kg for <sup>214</sup>Bi (609 keV). The ARGUS is planned to be built in the China Jinping Underground Laboratory in 2025.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111748"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Assessing the impact of uncertainty in a VMAT plan for H&N cancer considering patient setup error (PSE)
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-27 DOI: 10.1016/j.apradiso.2025.111757
Arvind Kumar , Kiran Sharma , C.P. Bhatt , Awanish Sharma
In radiotherapy, accurate radiation dose delivery is critical, despite the uncertainties that can cause discrepancies between the prescribed and administered doses. This study examines the influence of uncertainties caused by patient positioning errors on dose accuracy and evaluates the potential consequences if these errors remain uncorrected. The investigation involves 670 treatment plans, including 10 clinically implemented plans and 660 with artificially induced uncertainties. These plans target patients undergoing volumetric arc therapy (VMAT) for various head & neck cancers using the Halcyon™ medical linear accelerator. Two scenarios are analyzed: one reflecting actual patient positioning shifts and another involving deliberate displacements ranging from 1 to 10 mm to assess the impact of uncertainty in a VMAT plan. Dosimetric validation is performed using EPID and the Octavius 4D phantom to introduce and assess the impact of these uncertainties. Results indicate that target coverage falls below the acceptable V95% threshold along the (X+, X-), (Y+, Y-), and (Z+, Z-) axes, when positioning errors exceed 5 mm. Additionally, both parotid glands are significantly affected by positioning uncertainties. Patient-specific quality assurance (PSQA) assessments confirm that positioning errors substantially affect the accuracy of dose delivery. To minimize uncertainties, strict adherence to recommended QA, clinical guidelines, imaging protocols, and other SOPs is crucial in clinical practice. Independent dosimetric audits are essential for evaluating the accuracy of dose delivery in treatment.
{"title":"Assessing the impact of uncertainty in a VMAT plan for H&N cancer considering patient setup error (PSE)","authors":"Arvind Kumar ,&nbsp;Kiran Sharma ,&nbsp;C.P. Bhatt ,&nbsp;Awanish Sharma","doi":"10.1016/j.apradiso.2025.111757","DOIUrl":"10.1016/j.apradiso.2025.111757","url":null,"abstract":"<div><div>In radiotherapy, accurate radiation dose delivery is critical, despite the uncertainties that can cause discrepancies between the prescribed and administered doses. This study examines the influence of uncertainties caused by patient positioning errors on dose accuracy and evaluates the potential consequences if these errors remain uncorrected. The investigation involves 670 treatment plans, including 10 clinically implemented plans and 660 with artificially induced uncertainties. These plans target patients undergoing volumetric arc therapy (VMAT) for various head &amp; neck cancers using the Halcyon™ medical linear accelerator. Two scenarios are analyzed: one reflecting actual patient positioning shifts and another involving deliberate displacements ranging from 1 to 10 mm to assess the impact of uncertainty in a VMAT plan. Dosimetric validation is performed using EPID and the Octavius 4D phantom to introduce and assess the impact of these uncertainties. Results indicate that target coverage falls below the acceptable V95% threshold along the (X+, X-), (Y+, Y-), and (Z+, Z-) axes, when positioning errors exceed 5 mm. Additionally, both parotid glands are significantly affected by positioning uncertainties. Patient-specific quality assurance (PSQA) assessments confirm that positioning errors substantially affect the accuracy of dose delivery. To minimize uncertainties, strict adherence to recommended QA, clinical guidelines, imaging protocols, and other SOPs is crucial in clinical practice. Independent dosimetric audits are essential for evaluating the accuracy of dose delivery in treatment.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111757"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Impact of reconstruction algorithms at different sphere-to-background ratios on PET quantification: A phantom study
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-27 DOI: 10.1016/j.apradiso.2025.111761
Ahmed A. Mohymen , Hamed I. Farag , Sameh M. Reda , Ahmed S. Monem , Said A. Ali
Using National Electrical Manufacturers Association (NEMA) phantom, the behavior of four distinct Positron Emission Tomography/Computed Tomography (PET/CT) reconstruction algorithms was investigated. These reconstruction algorithms were (Ordered Subset Expectation Maximization (OSEM), OSEM+ (Point Spread Function) PSF, OSEM + Time of Flight (TOF), and OSEM + TOF + PSF), and the focus was on sphere sizes and SBRs using recovery coefficients as a quantitation method. The obtained results demonstrated the significant effect of TOF on Gibbs artifact and Partial Volume Effect (PVE) at various Sphere-to-Background Ratios (SBRs). TOF-based algorithms improved quantification accuracy and mitigated the influence of Gibbs artifact, particularly at higher SBRs. Compared to PSF algorithm, TOF- based algorithms effectively mitigated the impact of PVE on small-sized spheres and less dependent on SBRs. In terms of Standardized Uptake Value (SUV) quantification, SUVmean was better when utilizing TOF-based algorithms at lower SBRs, whereas SUVmax at higher SBRs. The combination of TOF and PSF produced a promising outcomes in quantifying and detecting a small-sized spheres across various SBRs, ultimately resulting in a more reliable and precise diagnostic information.
{"title":"Impact of reconstruction algorithms at different sphere-to-background ratios on PET quantification: A phantom study","authors":"Ahmed A. Mohymen ,&nbsp;Hamed I. Farag ,&nbsp;Sameh M. Reda ,&nbsp;Ahmed S. Monem ,&nbsp;Said A. Ali","doi":"10.1016/j.apradiso.2025.111761","DOIUrl":"10.1016/j.apradiso.2025.111761","url":null,"abstract":"<div><div>Using National Electrical Manufacturers Association (NEMA) phantom, the behavior of four distinct Positron Emission Tomography/Computed Tomography (PET/CT) reconstruction algorithms was investigated. These reconstruction algorithms were (Ordered Subset Expectation Maximization (OSEM), OSEM+ (Point Spread Function) PSF, OSEM + Time of Flight (TOF), and OSEM + TOF + PSF), and the focus was on sphere sizes and SBRs using recovery coefficients as a quantitation method. The obtained results demonstrated the significant effect of TOF on Gibbs artifact and Partial Volume Effect (PVE) at various Sphere-to-Background Ratios (SBRs). TOF-based algorithms improved quantification accuracy and mitigated the influence of Gibbs artifact, particularly at higher SBRs. Compared to PSF algorithm, TOF- based algorithms effectively mitigated the impact of PVE on small-sized spheres and less dependent on SBRs. In terms of Standardized Uptake Value (SUV) quantification, SUVmean was better when utilizing TOF-based algorithms at lower SBRs, whereas SUVmax at higher SBRs. The combination of TOF and PSF produced a promising outcomes in quantifying and detecting a small-sized spheres across various SBRs, ultimately resulting in a more reliable and precise diagnostic information.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111761"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Radioisotope compositional analysis using Monte Carlo γ-ray simulations and regression neural network
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-25 DOI: 10.1016/j.apradiso.2025.111746
C.J. Buckton , S.M. Wyngaardt , M. Ngxande
<div><div>As a fundamental technique in radionuclide identification and radiation monitoring, <span><math><mi>γ</mi></math></span> spectroscopy is a common method used in risk and hazard assessment studies. Analysis in <span><math><mi>γ</mi></math></span> spectroscopy often involves identification and classification of radioactive sources. The knowledge of known <span><math><mi>γ</mi></math></span>-emitting radioisotopes allows for the distinction to be made between different species by observing certain spectral features such as photopeaks due to the specific energies of the <span><math><mi>γ</mi></math></span> emissions, Compton continuum due to photon scattering, X-ray fluorescence, etc. Each radioisotope is uniquely identified based on these features, allowing a model to be developed for comparing new spectral data with existing data. Various machine learning techniques have been used and tested to observe the performance of different algorithms on <span><math><mi>γ</mi></math></span>-ray spectra, especially in regards to species classification. More recently, deep learning methods such as deep neural networks (DNNs) have been proven to be very successful in identifying and analysing <span><math><mi>γ</mi></math></span>-ray spectra, often by use of a combination of simulated and experimental data. These networks can classify radioisotope energy spectra with high precision.</div><div>Being able to identify and also quantify contributions from isotopes in combination is challenging, especially where spectral features between multiple sources overlap, or the energy resolution is poor, causing further distortions in the spectrum. However, knowledge of the composition of a mixture of radiation sources is an ability which can be crucial in composition and elementary analysis from spectral information.</div><div>This work sees the development of a regression-based convolutional neural network (CNN) which attempts to predict the sources and proportions of each source in simulated mixed-source spectra. A comparison between the network and a traditional library least-squares algorithm is also made. A Monte Carlo based simulation is used to produce the spectral data, using the GEANT4 software package, for 6 different isotopes and a basic experimental design modelled after a NaI(Tl) scintillation detector. A comprehensive dataset is generated for these isotopes, for use in future analysis works. With scintillators being a common choice for field work in radiation monitoring and similar environmental studies, a network with high performance and efficiency can provide a promising tool for automated spectral analysis and detection. The model is highly efficient, being able to process batches of spectra in a second, with accurate predictions having mean-square error on the order of <span><math><mrow><mo>∼</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>. It also outperforms the traditional linear method
{"title":"Radioisotope compositional analysis using Monte Carlo γ-ray simulations and regression neural network","authors":"C.J. Buckton ,&nbsp;S.M. Wyngaardt ,&nbsp;M. Ngxande","doi":"10.1016/j.apradiso.2025.111746","DOIUrl":"10.1016/j.apradiso.2025.111746","url":null,"abstract":"&lt;div&gt;&lt;div&gt;As a fundamental technique in radionuclide identification and radiation monitoring, &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; spectroscopy is a common method used in risk and hazard assessment studies. Analysis in &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; spectroscopy often involves identification and classification of radioactive sources. The knowledge of known &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-emitting radioisotopes allows for the distinction to be made between different species by observing certain spectral features such as photopeaks due to the specific energies of the &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; emissions, Compton continuum due to photon scattering, X-ray fluorescence, etc. Each radioisotope is uniquely identified based on these features, allowing a model to be developed for comparing new spectral data with existing data. Various machine learning techniques have been used and tested to observe the performance of different algorithms on &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-ray spectra, especially in regards to species classification. More recently, deep learning methods such as deep neural networks (DNNs) have been proven to be very successful in identifying and analysing &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-ray spectra, often by use of a combination of simulated and experimental data. These networks can classify radioisotope energy spectra with high precision.&lt;/div&gt;&lt;div&gt;Being able to identify and also quantify contributions from isotopes in combination is challenging, especially where spectral features between multiple sources overlap, or the energy resolution is poor, causing further distortions in the spectrum. However, knowledge of the composition of a mixture of radiation sources is an ability which can be crucial in composition and elementary analysis from spectral information.&lt;/div&gt;&lt;div&gt;This work sees the development of a regression-based convolutional neural network (CNN) which attempts to predict the sources and proportions of each source in simulated mixed-source spectra. A comparison between the network and a traditional library least-squares algorithm is also made. A Monte Carlo based simulation is used to produce the spectral data, using the GEANT4 software package, for 6 different isotopes and a basic experimental design modelled after a NaI(Tl) scintillation detector. A comprehensive dataset is generated for these isotopes, for use in future analysis works. With scintillators being a common choice for field work in radiation monitoring and similar environmental studies, a network with high performance and efficiency can provide a promising tool for automated spectral analysis and detection. The model is highly efficient, being able to process batches of spectra in a second, with accurate predictions having mean-square error on the order of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. It also outperforms the traditional linear method","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111746"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Optimizing resin shielding for neutron diffractometer detectors
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-25 DOI: 10.1016/j.apradiso.2025.111755
Mohamed Hachouf, Naziha Benaskeur
In nuclear techniques, specific materials are used to shield detectors. For quick scan during kinetic analysis of materials, multi-detector systems are used in neutron diffraction where borated hydrogenated-materials are used to shield detectors from the neutron background. For shielding enhancement, the B4C powder is eventually added for better protection. Then, neutron shielding calculations play a vital role in optimizing detector system design.
The present work aims to establish, by SCALE6.1 code simulation, some neutron shielding parameters of borated and non-borated resin. For an eventual use in the newly designed multi-detector system for Es-Salam neutron diffractometer, the simulation has been done for different monochromatic neutron-beams that can be used to investigate different structural properties of materials.
The neutron behavior of the C57H65O10 resin without and with 5 wt% boron has been studied for different monochromatic neutron-beam. The backscattered neutron flux, the backscattering depth and the transmission-off thickness are analyzed and evaluated. They are reduced following the B4C addition for each studied neutron-energy and a good diffraction data can be obtained. The obtained results permit to establish the corresponding shielding condition for an optimized design with the lowest mechanical loading on any neutron-scattering instrument detection-system.
{"title":"Optimizing resin shielding for neutron diffractometer detectors","authors":"Mohamed Hachouf,&nbsp;Naziha Benaskeur","doi":"10.1016/j.apradiso.2025.111755","DOIUrl":"10.1016/j.apradiso.2025.111755","url":null,"abstract":"<div><div>In nuclear techniques, specific materials are used to shield detectors. For quick scan during kinetic analysis of materials, multi-detector systems are used in neutron diffraction where borated hydrogenated-materials are used to shield detectors from the neutron background. For shielding enhancement, the B<sub>4</sub>C powder is eventually added for better protection. Then, neutron shielding calculations play a vital role in optimizing detector system design.</div><div>The present work aims to establish, by SCALE6.1 code simulation, some neutron shielding parameters of borated and non-borated resin. For an eventual use in the newly designed multi-detector system for Es-Salam neutron diffractometer, the simulation has been done for different monochromatic neutron-beams that can be used to investigate different structural properties of materials.</div><div>The neutron behavior of the C<sub>57</sub>H<sub>65</sub>O<sub>10</sub> resin without and with 5 wt% boron has been studied for different monochromatic neutron-beam. The backscattered neutron flux, the backscattering depth and the transmission-off thickness are analyzed and evaluated. They are reduced following the B<sub>4</sub>C addition for each studied neutron-energy and a good diffraction data can be obtained. The obtained results permit to establish the corresponding shielding condition for an optimized design with the lowest mechanical loading on any neutron-scattering instrument detection-system.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111755"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Health risk assessment of natural radionuclides through the consumption of fish species in Pazhaverkadu Lagoon, Southeast Coast of India
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-25 DOI: 10.1016/j.apradiso.2025.111753
Olimuhammed Basith , Raju Krishnamoorthy , Marckasagayam Priyadharshini , Van-Hao Duong , Mohamed Saiyad Musthafa
Radionuclides can bioaccumulate in the bodies of aquatic creatures, albeit to trace amounts in the surrounding water. Due of its importance as a fishing destination in South India, the current study is being conducted in the Pazhaverkadu lagoon. For 20 distinct edible fish species, the average fish bone gross alpha and beta activity were 13.25 Bq/kg and 33.10 Bq/kg. The mean values of gross alpha and gross beta activity of fish muscle were 21.98 and 63.56 Bq/kg respectively. Using the alpha and beta emitters, the Annual Effective Dose Equivalent (AED) of 0.52 mSv/y was calculated; this value is below the recommended limit. The mean values of the radiological risk metrics Excessive lifetime cancer risk (ELCR) and Annual Gonadal Dose Equivalent (AGDE) are 0.001 μSv/y and 0.22 μSv/y, respectively. The bioaccumulation of 210Po and 210Pb for more than 20 fish species was investigated. The mean activity in water samples is therefore 1.42 mBq/l and 2.44 mBq/l, respectively. In contrast, sediment samples have average activity values of 6.51 Bq/kg and 3.16 Bq/kg, respectively. Fish muscle had mean 210Po and 210Pb activities of 41.58 and 2.61 Bq/kg, respectively, whereas bone had mean activities of 3.005 and 4.51 Bq/kg. The committed effective dose equivalent (CEDE) values for the 210Po and 210Pb samples in this study varied from 0.04 to 0.22 mSv/y and 0.003–0.027 mSv/y and 8.82 mSv/y, respectively. Fish bones had a concentration ratio of 2.9 × 103 to 6.5 × 103 and muscles 1.9 × 104 to 5.2 × 104; similarly, for 210Pb, the range was 1.5 × 103 to 4.0 × 103 and 1.6 × 103 to 3.5 × 103. The results of this investigation show that the values are below the global average and that there is no assessment of the radiological risk to the fish consumers in the Pazhaverkadu lagoon.
{"title":"Health risk assessment of natural radionuclides through the consumption of fish species in Pazhaverkadu Lagoon, Southeast Coast of India","authors":"Olimuhammed Basith ,&nbsp;Raju Krishnamoorthy ,&nbsp;Marckasagayam Priyadharshini ,&nbsp;Van-Hao Duong ,&nbsp;Mohamed Saiyad Musthafa","doi":"10.1016/j.apradiso.2025.111753","DOIUrl":"10.1016/j.apradiso.2025.111753","url":null,"abstract":"<div><div>Radionuclides can bioaccumulate in the bodies of aquatic creatures, albeit to trace amounts in the surrounding water. Due of its importance as a fishing destination in South India, the current study is being conducted in the Pazhaverkadu lagoon. For 20 distinct edible fish species, the average fish bone gross alpha and beta activity were 13.25 Bq/kg and 33.10 Bq/kg. The mean values of gross alpha and gross beta activity of fish muscle were 21.98 and 63.56 Bq/kg respectively. Using the alpha and beta emitters, the Annual Effective Dose Equivalent (AED) of 0.52 mSv/y was calculated; this value is below the recommended limit. The mean values of the radiological risk metrics Excessive lifetime cancer risk (ELCR) and Annual Gonadal Dose Equivalent (AGDE) are 0.001 μSv/y and 0.22 μSv/y, respectively. The bioaccumulation of <sup>210</sup>Po and <sup>210</sup>Pb for more than 20 fish species was investigated. The mean activity in water samples is therefore 1.42 mBq/l and 2.44 mBq/l, respectively. In contrast, sediment samples have average activity values of 6.51 Bq/kg and 3.16 Bq/kg, respectively. Fish muscle had mean <sup>210</sup>Po and <sup>210</sup>Pb activities of 41.58 and 2.61 Bq/kg, respectively, whereas bone had mean activities of 3.005 and 4.51 Bq/kg. The committed effective dose equivalent (CEDE) values for the <sup>210</sup>Po and <sup>210</sup>Pb samples in this study varied from 0.04 to 0.22 mSv/y and 0.003–0.027 mSv/y and 8.82 mSv/y, respectively. Fish bones had a concentration ratio of 2.9 × 10<sup>3</sup> to 6.5 × 10<sup>3</sup> and muscles 1.9 × 10<sup>4</sup> to 5.2 × 10<sup>4</sup>; similarly, for <sup>210</sup>Pb, the range was 1.5 × 10<sup>3</sup> to 4.0 × 10<sup>3</sup> and 1.6 × 10<sup>3</sup> to 3.5 × 10<sup>3</sup>. The results of this investigation show that the values are below the global average and that there is no assessment of the radiological risk to the fish consumers in the Pazhaverkadu lagoon.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111753"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A new background discrimination method using support vector machine (SVM) with gaussian kernel in low-level 3H liquid scintillation measurement
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-25 DOI: 10.1016/j.apradiso.2025.111754
Yifan Tian , Haoran Liu , Zhijie Yang , Juncheng Liang , Hao Yang , Zihao Fan , Cong Chen , Qisheng Zhang
In this study, a new background discrimination method using SVM with gaussian kernel in low-level 3H liquid scintillation measurement is developed. Dimensionality reduction techniques were employed to process the full waveform data of each event following time discrimination. The reduced-dimensional data were then used to construct the classification model. To ensure a fair comparison with traditional method, the advantages of offline processing were employed to systematically traverse all possible parameter configurations within reasonable ranges, enabling the determination of the optimal parameters. In machine learning-based background event discrimination, the high-quality labeled datasets are obtained through long-term measurements of blank samples and short-term measurements of medium-activity 3H samples. Additionally, a series of low-activity 3H samples with activity levels of approximately 1 Bq, 3 Bq, and 5 Bq were prepared through quantitative dilution. The results demonstrate that the proposed method achieves a significant improvement in discrimination capability compared to traditional method. It effectively minimizes background levels across the entire energy range while preserving detection efficiency, significantly enhancing the measurement capability for low-activity 3H samples.
{"title":"A new background discrimination method using support vector machine (SVM) with gaussian kernel in low-level 3H liquid scintillation measurement","authors":"Yifan Tian ,&nbsp;Haoran Liu ,&nbsp;Zhijie Yang ,&nbsp;Juncheng Liang ,&nbsp;Hao Yang ,&nbsp;Zihao Fan ,&nbsp;Cong Chen ,&nbsp;Qisheng Zhang","doi":"10.1016/j.apradiso.2025.111754","DOIUrl":"10.1016/j.apradiso.2025.111754","url":null,"abstract":"<div><div>In this study, a new background discrimination method using SVM with gaussian kernel in low-level <sup>3</sup>H liquid scintillation measurement is developed. Dimensionality reduction techniques were employed to process the full waveform data of each event following time discrimination. The reduced-dimensional data were then used to construct the classification model. To ensure a fair comparison with traditional method, the advantages of offline processing were employed to systematically traverse all possible parameter configurations within reasonable ranges, enabling the determination of the optimal parameters. In machine learning-based background event discrimination, the high-quality labeled datasets are obtained through long-term measurements of blank samples and short-term measurements of medium-activity <sup>3</sup>H samples. Additionally, a series of low-activity <sup>3</sup>H samples with activity levels of approximately 1 Bq, 3 Bq, and 5 Bq were prepared through quantitative dilution. The results demonstrate that the proposed method achieves a significant improvement in discrimination capability compared to traditional method. It effectively minimizes background levels across the entire energy range while preserving detection efficiency, significantly enhancing the measurement capability for low-activity <sup>3</sup>H samples.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111754"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
In silico Monte Carlo with novel particle tagging: Assessing gold radiosensitivity in voxelized scenario of brachytherapy
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-24 DOI: 10.1016/j.apradiso.2025.111745
L.F. Araujo , T.C.F. Fonseca
Radiotherapy is widely acknowledged as one of the most effective treatments for solid and metastatic tumors. The sensitivity of tissues or cells to radiation is typically estimated using survival curves derived from laboratory experiments with in vitro cell culture models. However, some radioresistant cancer cells can pose significant treatment challenges. High atomic number (Z) nanoparticles, known as radiosensitizing agents, can induce substantial radiosensitization when positioned near therapeutic targets, resulting in a dose increase unattainable by conventional methods. This effect is associated with the emission of secondary electrons by high atomic number materials, effectively transforming them into secondary radiation sources. This study utilized a high-resolution voxelized computational model of an in vitro culture medium to investigate the insertion and impact of gold particles. Monte Carlo code (MCNP6.2) was used to model and simulate a brachytherapy scenario with a High Dose Rate (HDR) 192Ir source in a matrix of stop positions. The radiosensitivity of gold particles was evaluated using the dose enhancement factor (DEF), calculated based on the concentration of gold nanoparticle (AuNP) clusters in the culture medium (mg-AuNP/g) and the energy dependence in the in vitro samples. Simulations demonstrated a proportional relationship between DEF and concentration, enabling the creation of a predictive equation for DEF values, which was validated against published data. Additionally, energy was found to significantly influence DEF values. The DEF versus energy curve obtained exhibits similarities to the curve of the Sensitizer Enhancement Ratio (SER) versus dose, though the two differ in their determinants. SER is determined through various radiobiological mathematical models based on the biological effect derived from the fractional survival curve as a function of dose response. Furthermore, a special TAG tally was employed to identify the types of secondary electron (photoelectrons, Auger electrons and knock-on electrons and Compton scattering) production in the medium, their physical contributions, and their behavior at different energy sources of 100 keV, 192Ir and 1 MeV.
{"title":"In silico Monte Carlo with novel particle tagging: Assessing gold radiosensitivity in voxelized scenario of brachytherapy","authors":"L.F. Araujo ,&nbsp;T.C.F. Fonseca","doi":"10.1016/j.apradiso.2025.111745","DOIUrl":"10.1016/j.apradiso.2025.111745","url":null,"abstract":"<div><div>Radiotherapy is widely acknowledged as one of the most effective treatments for solid and metastatic tumors. The sensitivity of tissues or cells to radiation is typically estimated using survival curves derived from laboratory experiments with <em>in vitro</em> cell culture models. However, some radioresistant cancer cells can pose significant treatment challenges. High atomic number (Z) nanoparticles, known as radiosensitizing agents, can induce substantial radiosensitization when positioned near therapeutic targets, resulting in a dose increase unattainable by conventional methods. This effect is associated with the emission of secondary electrons by high atomic number materials, effectively transforming them into secondary radiation sources. This study utilized a high-resolution voxelized computational model of an <em>in vitro</em> culture medium to investigate the insertion and impact of gold particles. Monte Carlo code (MCNP6.2) was used to model and simulate a brachytherapy scenario with a High Dose Rate (HDR) <sup>192</sup>Ir source in a matrix of stop positions. The radiosensitivity of gold particles was evaluated using the dose enhancement factor (DEF), calculated based on the concentration of gold nanoparticle (AuNP) clusters in the culture medium (mg-AuNP/g) and the energy dependence in the <em>in vitro</em> samples. Simulations demonstrated a proportional relationship between DEF and concentration, enabling the creation of a predictive equation for DEF values, which was validated against published data. Additionally, energy was found to significantly influence DEF values. The DEF versus energy curve obtained exhibits similarities to the curve of the Sensitizer Enhancement Ratio (SER) versus dose, though the two differ in their determinants. SER is determined through various radiobiological mathematical models based on the biological effect derived from the fractional survival curve as a function of dose response. Furthermore, a special TAG tally was employed to identify the types of secondary electron (photoelectrons, Auger electrons and knock-on electrons and Compton scattering) production in the medium, their physical contributions, and their behavior at different energy sources of 100 keV, <sup>192</sup>Ir and 1 MeV.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111745"},"PeriodicalIF":1.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Radon in water measurements by sampling with sunflower oil
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-24 DOI: 10.1016/j.apradiso.2025.111752
S. Georgiev, V. Todorov, H. Stoycheva, K. Mitev
A novel method for measuring radon in water is proposed. This method involves sampling radon from water into sunflower oil and subsequently measuring the radon in the oil using either Cherenkov counting or Liquid Scintillation (LS) counting. The high partition coefficient of radon between oil and water enables radon preconcentration in the oil, significantly improving the Minimum Detectable Activity Concentration (MDAC) compared to direct Cherenkov or LS measurements in water. The estimated MDACs for the method are 0.20 Bq/l using Cherenkov counting and 0.04 Bq/l using gross alpha/beta LS counting.
The MDAC achieved with Cherenkov counting allows for radon-in-water measurements for the purposes of radiation protection, ecology, hydrology, and earth sciences without requiring LS cocktails.
The MDAC for LS counting facilitates radium-in-water measurements (via radon measurement) for radiation protection without chemical pretreatment of the water sample.
Additionally, the method enables direct estimation of the radon partition coefficient between water and oils. The partition coefficient of radon between sunflower oil and water at 20 °C is estimated at Koil/w = 23.2(16).
{"title":"Radon in water measurements by sampling with sunflower oil","authors":"S. Georgiev,&nbsp;V. Todorov,&nbsp;H. Stoycheva,&nbsp;K. Mitev","doi":"10.1016/j.apradiso.2025.111752","DOIUrl":"10.1016/j.apradiso.2025.111752","url":null,"abstract":"<div><div>A novel method for measuring radon in water is proposed. This method involves sampling radon from water into sunflower oil and subsequently measuring the radon in the oil using either Cherenkov counting or Liquid Scintillation (LS) counting. The high partition coefficient of radon between oil and water enables radon preconcentration in the oil, significantly improving the Minimum Detectable Activity Concentration (MDAC) compared to direct Cherenkov or LS measurements in water. The estimated MDACs for the method are 0.20 Bq/l using Cherenkov counting and 0.04 Bq/l using gross alpha/beta LS counting.</div><div>The MDAC achieved with Cherenkov counting allows for radon-in-water measurements for the purposes of radiation protection, ecology, hydrology, and earth sciences without requiring LS cocktails.</div><div>The MDAC for LS counting facilitates radium-in-water measurements (via radon measurement) for radiation protection without chemical pretreatment of the water sample.</div><div>Additionally, the method enables direct estimation of the radon partition coefficient between water and oils. The partition coefficient of radon between sunflower oil and water at 20 °C is estimated at <em>K</em><sub><em>oil/w</em></sub> = 23.2(16).</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111752"},"PeriodicalIF":1.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A GATE Monte Carlo study on ICRP110 phantoms for BNCT dosimetry evaluation
IF 1.6 3区 工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR Pub Date : 2025-02-22 DOI: 10.1016/j.apradiso.2025.111724
Daniele Pistone , Silva Bortolussi , Setareh Fatemi , Barbara Marcaccio , Laura Bagnale , Cristina Pezzi , Marco Paganelli , Ricardo Luis Ramos , Emilia Formicola , Rosa Sica , Raffaele Buompane , Giuseppe Porzio , Lorenzo Manti , Lucio Gialanella , Valerio Vercesi , Ian Postuma
Boron Neutron Capture Therapy (BNCT) is attracting renewed attention due to advancements in compact proton accelerators for the production of neutron beams, and new BNCT facilities are being planned all around the world. A key aspect in BNCT treatments will be patient dosimetry, particularly given the complex radiation field created by neutron interactions with biological tissues. This study aimed at developing a prototype of BNCT dosimetry workflow based on Monte Carlo (MC) simulations for the GATE toolkit. Investigating the feasibility of performing voxel-level dosimetry through full MC transport in terms of simulation time and statistical uncertainties, the ICRP110 male and female adult voxelized phantoms were used to model the human body, adding the possibility to set in their organs user-defined concentrations of 10B. Irradiation simulations of the head district with two monoenergetic neutron beams and with a realistic clinical neutron spectrum were carried out. The absorbed dose matrices for each simulation, assuming both no 10B and then a systemic distribution of 15 ppm, were scored separating the contributions from 7Li, alpha particles, protons and photons. Results showed the expected increase, in presence of 10B distribution, of the 7Li and alpha average dose components in organs of interest of the head, such as brain, reaching in it about 1.3 and 2.3 fGy/evt, respectively, in presence of 15 ppm of 10B. The present prototype of dosimetric workflow, whose macros and files are freely shared for interested users and developers, will serve as a basis for future studies aiming at simulating similar BNCT scenarios with larger statistics, for example by exploiting high computing resources, to verify the obtained results with lower statistical uncertainties and possibly optimize the workflow to reduce simulation times while ensuring suitable dosimetric accuracy.
{"title":"A GATE Monte Carlo study on ICRP110 phantoms for BNCT dosimetry evaluation","authors":"Daniele Pistone ,&nbsp;Silva Bortolussi ,&nbsp;Setareh Fatemi ,&nbsp;Barbara Marcaccio ,&nbsp;Laura Bagnale ,&nbsp;Cristina Pezzi ,&nbsp;Marco Paganelli ,&nbsp;Ricardo Luis Ramos ,&nbsp;Emilia Formicola ,&nbsp;Rosa Sica ,&nbsp;Raffaele Buompane ,&nbsp;Giuseppe Porzio ,&nbsp;Lorenzo Manti ,&nbsp;Lucio Gialanella ,&nbsp;Valerio Vercesi ,&nbsp;Ian Postuma","doi":"10.1016/j.apradiso.2025.111724","DOIUrl":"10.1016/j.apradiso.2025.111724","url":null,"abstract":"<div><div>Boron Neutron Capture Therapy (BNCT) is attracting renewed attention due to advancements in compact proton accelerators for the production of neutron beams, and new BNCT facilities are being planned all around the world. A key aspect in BNCT treatments will be patient dosimetry, particularly given the complex radiation field created by neutron interactions with biological tissues. This study aimed at developing a prototype of BNCT dosimetry workflow based on Monte Carlo (MC) simulations for the GATE toolkit. Investigating the feasibility of performing voxel-level dosimetry through full MC transport in terms of simulation time and statistical uncertainties, the ICRP110 male and female adult voxelized phantoms were used to model the human body, adding the possibility to set in their organs user-defined concentrations of <sup>10</sup>B. Irradiation simulations of the head district with two monoenergetic neutron beams and with a realistic clinical neutron spectrum were carried out. The absorbed dose matrices for each simulation, assuming both no <sup>10</sup>B and then a systemic distribution of 15 ppm, were scored separating the contributions from <sup>7</sup>Li, alpha particles, protons and photons. Results showed the expected increase, in presence of <sup>10</sup>B distribution, of the <sup>7</sup>Li and alpha average dose components in organs of interest of the head, such as brain, reaching in it about 1.3 and 2.3 fGy/evt, respectively, in presence of 15 ppm of <sup>10</sup>B. The present prototype of dosimetric workflow, whose macros and files are freely shared for interested users and developers, will serve as a basis for future studies aiming at simulating similar BNCT scenarios with larger statistics, for example by exploiting high computing resources, to verify the obtained results with lower statistical uncertainties and possibly optimize the workflow to reduce simulation times while ensuring suitable dosimetric accuracy.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"220 ","pages":"Article 111724"},"PeriodicalIF":1.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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Applied Radiation and Isotopes
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