Pub Date : 2025-01-11DOI: 10.1016/j.apradiso.2025.111670
Taiki Yoshii , Jun Kawarabayashi
In clearance measurements involving a single material type, a conversion factor was applied to convert measurement results to activity based on an assumed uniform density. However, this factor has been found to underestimate activity in material mixtures. In this study, we proposed a method to identify the location with the lowest detection sensitivity (minimum location) in a mixture and evaluated its applicability to the conversion factor. We calculated this minimum location by determining the weighted average of a two-dimensional distribution of line attenuation coefficients, obtained through X-ray computed tomography (X-ray CT). We were able to identify the angle in polar coordinates using the center of the image as the origin, but the distance remained indeterminate. However, with this method, the minimum location can be identified along any straight line passing through the center of the image. This method has the potential to enhance activity evaluation for mixtures in cases where conservative evaluation of activity was previously unfeasible.
{"title":"Development of a practical conversion factor for evaluating radioactivity in mixed metal and plastic clearance objects","authors":"Taiki Yoshii , Jun Kawarabayashi","doi":"10.1016/j.apradiso.2025.111670","DOIUrl":"10.1016/j.apradiso.2025.111670","url":null,"abstract":"<div><div>In clearance measurements involving a single material type, a conversion factor was applied to convert measurement results to activity based on an assumed uniform density. However, this factor has been found to underestimate activity in material mixtures. In this study, we proposed a method to identify the location with the lowest detection sensitivity (minimum location) in a mixture and evaluated its applicability to the conversion factor. We calculated this minimum location by determining the weighted average of a two-dimensional distribution of line attenuation coefficients, obtained through X-ray computed tomography (X-ray CT). We were able to identify the angle in polar coordinates using the center of the image as the origin, but the distance remained indeterminate. However, with this method, the minimum location can be identified along any straight line passing through the center of the image. This method has the potential to enhance activity evaluation for mixtures in cases where conservative evaluation of activity was previously unfeasible.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111670"},"PeriodicalIF":1.6,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142969398","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}
Pub Date : 2025-01-09DOI: 10.1016/j.apradiso.2025.111669
P. Vukotić , V. Radolić , R. Svrkota , D. Stanić , T. Anđelić , R. Mrdak , B. Fuštić , M. Benšić
The national radon surveys in Montenegro revealed that the highest annual average radon concentrations (CRn,ind) in ground floors of dwellings and schools were found in a rural region characterized as a typical high-karst area. In this region, spanning approximately 800 km2, CRn,ind values in 9 houses and 16 schools ranged from 219 to 2494 Bq/m3, with AM = 977 Bq/m3. To investigate the causes of these elevated indoor radon concentrations, the following parameters were measured near the 25 surveyed buildings: soil humidity, electrical conductivity, pH, activity concentrations of 226Ra, 238U, 235U, 232Th and 40K, radon concentration in soil gas (c), soil permeability for radon gas (k), and gamma dose rate in the air. The geogenic radon potential (GRP) of the location was calculated based on the measured values of c and k. As anticipated, the soil permeability in this karstic region was notably high, 1.53·10−11 m2 on average, resulting in elevated GRPs and radon indexes (RI). Therefore, 9 investigated locations were classified as having an Extremely High RI, and the other 9 as having Very High RI.
Building characteristics, such as filling, wall material, floor slab quality (FSQ), window frames, and construction period, were also assessed.
A multivariate regression analysis was performed to evaluate the relationship between CRn,ind and independent variables of geogenic origin, as well as those related to building construction. The optimal linear regression model, with predictor variables FSQ, c, k, GRP and 238U, can explain 29.1% of the variance of indoor radon concentrations.
{"title":"RADON in a high karst area of Montenegro – A case study","authors":"P. Vukotić , V. Radolić , R. Svrkota , D. Stanić , T. Anđelić , R. Mrdak , B. Fuštić , M. Benšić","doi":"10.1016/j.apradiso.2025.111669","DOIUrl":"10.1016/j.apradiso.2025.111669","url":null,"abstract":"<div><div>The national radon surveys in Montenegro revealed that the highest annual average radon concentrations (<em>C</em><sub><em>Rn,ind</em></sub>) in ground floors of dwellings and schools were found in a rural region characterized as a typical high-karst area. In this region, spanning approximately 800 km<sup>2</sup>, <em>C</em><sub><em>Rn,ind</em></sub> values in 9 houses and 16 schools ranged from 219 to 2494 Bq/m<sup>3</sup>, with AM = 977 Bq/m<sup>3</sup>. To investigate the causes of these elevated indoor radon concentrations, the following parameters were measured near the 25 surveyed buildings: soil humidity, electrical conductivity, pH, activity concentrations of <sup>226</sup>Ra, <sup>238</sup>U, <sup>235</sup>U, <sup>232</sup>Th and <sup>40</sup>K, radon concentration in soil gas (<em>c</em>), soil permeability for radon gas (<em>k</em>), and gamma dose rate in the air. The geogenic radon potential (<em>GRP</em>) of the location was calculated based on the measured values of <em>c</em> and <em>k</em>. As anticipated, the soil permeability in this karstic region was notably high, 1.53·10<sup>−11</sup> m<sup>2</sup> on average, resulting in elevated <em>GRP</em>s and radon indexes (<em>RI</em>). Therefore, 9 investigated locations were classified as having an Extremely High <em>RI</em>, and the other 9 as having Very High <em>RI</em>.</div><div>Building characteristics, such as filling, wall material, floor slab quality (<em>FSQ</em>), window frames, and construction period, were also assessed.</div><div>A multivariate regression analysis was performed to evaluate the relationship between <em>C</em><sub><em>Rn,ind</em></sub> and independent variables of geogenic origin, as well as those related to building construction. The optimal linear regression model, with predictor variables <em>FSQ</em>, <em>c</em>, <em>k</em>, <em>GRP</em> and <sup>238</sup>U, can explain 29.1% of the variance of indoor radon concentrations.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111669"},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982567","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}
Pub Date : 2025-01-07DOI: 10.1016/j.apradiso.2025.111663
Zhengqiu Weng , Jinlong Wang , Haqi Zhang , Luning Lin , Haiting Chen , Lili Shi
For the purpose of assessing image quality and calculating patient X-ray dosage in radiology, computed tomography (CT), fluoroscopy, mammography, and other fields, it is necessary to have prior knowledge of the X-ray energy spectrum. The main components of an X-ray tube are an electron filament, also known as the cathode, and an anode, which is often made of tungsten or rubidium and angled at a certain angle. At the point where the electrons generated by the cathode and the anode make contact, a spectrum of X-rays with energies spanning from zero to the maximum energy value of the released electrons is created. Typically, the energy distribution of X-rays depends on various parameters, including the energy of the electron beam (tube voltage) and the angle of the anode. As a result, the X-ray energy spectrum is specific to the configuration of each tube and imaging system. This study aims to develop an efficient method for rapidly determining the X-ray energy spectrum of medical imaging systems across a broad range of tube voltages and anode angles using a limited set of specific spectra. The investigation began by simulating seven different anode angles between 12° and 24° using the Monte Carlo N Particle (MCNP) method. The X-ray spectra were generated for tube voltages of 20, 30, 40, 50, 60, 70, 80, 100, 130, and 150 kV. In order to make point-by-point X-ray spectrum predictions, 150 Radial Basis Function Neural Networks (RBFNNs) were trained using tube voltage and anode angle as inputs. The RBFNNs were trained to anticipate the X-ray spectra for different target angles and tube voltages between 20 and 150 kV. This research only used Monte Carlo simulations to represent one system; however, the approach shown here is generalizable to any real-world system.
{"title":"AI-enhanced X-ray spectrum reconstruction for medical imaging system","authors":"Zhengqiu Weng , Jinlong Wang , Haqi Zhang , Luning Lin , Haiting Chen , Lili Shi","doi":"10.1016/j.apradiso.2025.111663","DOIUrl":"10.1016/j.apradiso.2025.111663","url":null,"abstract":"<div><div>For the purpose of assessing image quality and calculating patient X-ray dosage in radiology, computed tomography (CT), fluoroscopy, mammography, and other fields, it is necessary to have prior knowledge of the X-ray energy spectrum. The main components of an X-ray tube are an electron filament, also known as the cathode, and an anode, which is often made of tungsten or rubidium and angled at a certain angle. At the point where the electrons generated by the cathode and the anode make contact, a spectrum of X-rays with energies spanning from zero to the maximum energy value of the released electrons is created. Typically, the energy distribution of X-rays depends on various parameters, including the energy of the electron beam (tube voltage) and the angle of the anode. As a result, the X-ray energy spectrum is specific to the configuration of each tube and imaging system. This study aims to develop an efficient method for rapidly determining the X-ray energy spectrum of medical imaging systems across a broad range of tube voltages and anode angles using a limited set of specific spectra. The investigation began by simulating seven different anode angles between 12° and 24° using the Monte Carlo N Particle (MCNP) method. The X-ray spectra were generated for tube voltages of 20, 30, 40, 50, 60, 70, 80, 100, 130, and 150 kV. In order to make point-by-point X-ray spectrum predictions, 150 Radial Basis Function Neural Networks (RBFNNs) were trained using tube voltage and anode angle as inputs. The RBFNNs were trained to anticipate the X-ray spectra for different target angles and tube voltages between 20 and 150 kV. This research only used Monte Carlo simulations to represent one system; however, the approach shown here is generalizable to any real-world system.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111663"},"PeriodicalIF":1.6,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982565","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}
Pub Date : 2025-01-07DOI: 10.1016/j.apradiso.2025.111667
Rahul Roy, Hemant K. Patni, Pradeep K. Singh, Pramilla D. Sawant
Shadow Shield Whole Body Counter (SSWBC) is used to estimate internal dose of radiation workers due to the intake of fission and activation products. The SSWBC geometry was numerically modelled in FLUKA code. The computational model was validated by comparing the experimental and simulated counting efficiencies (CEs), also known as response, using Bhabha Atomic Research Centre (BARC) reference BOttle Mannequin Absorption (BOMAB) phantom. Monte Carlo simulations were carried out in FLUKA to estimate the response for High Energy Photon emitters (HEPs, Eγ > 200 keV) using adult and paediatric (new-born, 1-year, 5-year, 10-year and 15-year) reference computational phantoms for male and female provided by International Commission on Radiation Protection. The scanning geometry of the system was simulated, scoring energy deposition in a NaI(Tl) detector at 15 static locations along the bed's length. The final response was calculated by averaging the detector responses at 15 static locations obtained from the simulations. The results highlight that the gender-averaged response at 300 keV for 5-year-olds is ∼20% higher than that for adults. For 15-year-olds and adults, female phantoms have 2.4% and 3.8% higher responses than males at 300 keV and, 3.2% and 1.1% higher responses at 1400 keV. From new-born to 10-year response is similar for both genders. The results also highlight that for any age group, response increases up to few detector locations and then it falls sharply. At any energy, the detector location for peak response is different for various age groups. These results will be useful for realistic assessment of HEPs in members of the public during any nuclear or radiological emergency scenarios.
{"title":"Counting efficiencies of shadow shield whole body counter for adult and paediatric reference computational phantoms","authors":"Rahul Roy, Hemant K. Patni, Pradeep K. Singh, Pramilla D. Sawant","doi":"10.1016/j.apradiso.2025.111667","DOIUrl":"10.1016/j.apradiso.2025.111667","url":null,"abstract":"<div><div>Shadow Shield Whole Body Counter (SSWBC) is used to estimate internal dose of radiation workers due to the intake of fission and activation products. The SSWBC geometry was numerically modelled in FLUKA code. The computational model was validated by comparing the experimental and simulated counting efficiencies (CEs), also known as response, using Bhabha Atomic Research Centre (BARC) reference BOttle Mannequin Absorption (BOMAB) phantom. Monte Carlo simulations were carried out in FLUKA to estimate the response for High Energy Photon emitters (HEPs, E<sub>γ</sub> > 200 keV) using adult and paediatric (new-born, 1-year, 5-year, 10-year and 15-year) reference computational phantoms for male and female provided by International Commission on Radiation Protection. The scanning geometry of the system was simulated, scoring energy deposition in a NaI(Tl) detector at 15 static locations along the bed's length. The final response was calculated by averaging the detector responses at 15 static locations obtained from the simulations. The results highlight that the gender-averaged response at 300 keV for 5-year-olds is ∼20% higher than that for adults. For 15-year-olds and adults, female phantoms have 2.4% and 3.8% higher responses than males at 300 keV and, 3.2% and 1.1% higher responses at 1400 keV. From new-born to 10-year response is similar for both genders. The results also highlight that for any age group, response increases up to few detector locations and then it falls sharply. At any energy, the detector location for peak response is different for various age groups. These results will be useful for realistic assessment of HEPs in members of the public during any nuclear or radiological emergency scenarios.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111667"},"PeriodicalIF":1.6,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982566","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}
Pub Date : 2025-01-06DOI: 10.1016/j.apradiso.2025.111668
Qian Zhang , Rui Shi , Rui Gou , Guang Yang , Xianguo Tuo
The three-dimensional radiation field is an important database reflecting the radioactivity distribution in a nuclear facility. It is of great significance to accurately and quickly grasp the radiation dose field distribution to implement radiation protection. Presently, majority of radiation field reconstruction algorithms concentrate on two-dimensional reconstruction and can only measure on a regular grid. With the progress of artificial intelligence technology, neural networks have great potential in radiation field reconstruction. In this work, an improved Genetic Algorithm Optimized Backpropagation (GA-BP) neural network was proposed, which can efficiently reconstruct the radiation dose rate at any given position within the three-dimensional space, even under the condition of a low sampling rate. The proposed method achieves a remarkable speed, capable of reconstructing nearly 500 spots in 0.01 s. Two Monte Carlo simulations corresponding to the shielded and unshielded cases verified the effectiveness of the proposed method. The method was further tested on datasets with equally spaced and randomly distributed data points. In both simulation scenarios, the proposed method demonstrated the ability to reconstruct the three-dimensional dose rate field using less than 6% of the data for the simulation cases with a low error level of 3% (unshielded) to 8% (shielded). In the real experimental validation, the error is at 15%, and the point error is less than 30% in most areas.
{"title":"Genetic algorithm optimized BP neural network for fast reconstruction of three-dimensional radiation field","authors":"Qian Zhang , Rui Shi , Rui Gou , Guang Yang , Xianguo Tuo","doi":"10.1016/j.apradiso.2025.111668","DOIUrl":"10.1016/j.apradiso.2025.111668","url":null,"abstract":"<div><div>The three-dimensional radiation field is an important database reflecting the radioactivity distribution in a nuclear facility. It is of great significance to accurately and quickly grasp the radiation dose field distribution to implement radiation protection. Presently, majority of radiation field reconstruction algorithms concentrate on two-dimensional reconstruction and can only measure on a regular grid. With the progress of artificial intelligence technology, neural networks have great potential in radiation field reconstruction. In this work, an improved Genetic Algorithm Optimized Backpropagation (GA-BP) neural network was proposed, which can efficiently reconstruct the radiation dose rate at any given position within the three-dimensional space, even under the condition of a low sampling rate. The proposed method achieves a remarkable speed, capable of reconstructing nearly 500 spots in 0.01 s. Two Monte Carlo simulations corresponding to the shielded and unshielded cases verified the effectiveness of the proposed method. The method was further tested on datasets with equally spaced and randomly distributed data points. In both simulation scenarios, the proposed method demonstrated the ability to reconstruct the three-dimensional dose rate field using less than 6% of the data for the simulation cases with a low error level of 3% (unshielded) to 8% (shielded). In the real experimental validation, the error is at 15%, and the point error is less than 30% in most areas.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111668"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998958","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}
Pub Date : 2025-01-06DOI: 10.1016/j.apradiso.2025.111660
Zihao Fan , Haoran Liu , Zhijie Yang , Juncheng Liang , Changhao Sun , Yifan Tian
The accuracy of measuring the activity of 177Lu is crucial for calibrating the instruments employed in clinical applications. To support the measurements of 177Lu solution, the existing TDCR-Čerenkov method has been extended for this nuclide. The contribution of β and γ transitions from 177Lu was taken into account in the extended method. Finally, the results obtained using this method, with an uncertainty of 0.62%, were found to be in good agreement with that derived from liquid scintillation counting.
{"title":"Activity determination of 177Lu using TDCR-Čerenkov method","authors":"Zihao Fan , Haoran Liu , Zhijie Yang , Juncheng Liang , Changhao Sun , Yifan Tian","doi":"10.1016/j.apradiso.2025.111660","DOIUrl":"10.1016/j.apradiso.2025.111660","url":null,"abstract":"<div><div>The accuracy of measuring the activity of <sup>177</sup>Lu is crucial for calibrating the instruments employed in clinical applications. To support the measurements of <sup>177</sup>Lu solution, the existing TDCR-Čerenkov method has been extended for this nuclide. The contribution of β and γ transitions from <sup>177</sup>Lu was taken into account in the extended method. Finally, the results obtained using this method, with an uncertainty of 0.62%, were found to be in good agreement with that derived from liquid scintillation counting.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111660"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963470","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}
Pub Date : 2025-01-04DOI: 10.1016/j.apradiso.2025.111662
N.A. Kotb , A.H.M. Solieman , T. El-Zakla , T.Z. Amer , S. Elmeniawi , M.N.H. Comsan
Neutron and gamma-ray shielding design for a 30Ci (1.11TBq) 241Am-Be irradiation facility is studied using MCNP5 Monte Carlo simulation code. The study focuses on the optimization of the shielding layers of the previously planned neutron irradiation facility. The shielding design aims at reducing the effective dose rate down to 10 μSv/h for occupationally exposed workers as recommended by the International Commission on Radiological Protection (ICRP) (20 mSv per year for workers). The dose rate calculations consider not only 241Am-Be produced neutrons but also gamma rays from the 241Am decay, 12C∗ de-excitation, and neutron interaction with source and facility materials. Different materials (paraffin, borated-paraffin, beryllium, copper, tantalum, tungsten, zinc, bismuth, and lead) have been investigated as neutron and gamma shields. The choice of the shielding materials is based on their effectiveness (the total weight of the facility and the cost). Among several configurations, shielding layers consisting of 10 cm paraffin wax, 2.5 cm lead, and 31.5 cm borated-paraffin wax are found sufficient to meet the safety requirements, leading to a cubic facility of 104.2 cm overall length. Some irradiation parameters are estimated for the final design; namely neutron and gamma spectra as well as flux and absorbed dose components. In addition, the occupational exposure is assessed considering ICRP exposure conditions to calculate the effective dose rate along with the isodose distribution.
{"title":"Multi-layer shielding optimization of a high activity 241Am-Be mixed field irradiation facility","authors":"N.A. Kotb , A.H.M. Solieman , T. El-Zakla , T.Z. Amer , S. Elmeniawi , M.N.H. Comsan","doi":"10.1016/j.apradiso.2025.111662","DOIUrl":"10.1016/j.apradiso.2025.111662","url":null,"abstract":"<div><div>Neutron and gamma-ray shielding design for a 30Ci (1.11TBq) <sup>241</sup>Am-Be irradiation facility is studied using MCNP5 Monte Carlo simulation code. The study focuses on the optimization of the shielding layers of the previously planned neutron irradiation facility. The shielding design aims at reducing the effective dose rate down to 10 μSv/h for occupationally exposed workers as recommended by the International Commission on Radiological Protection (ICRP) (20 mSv per year for workers). The dose rate calculations consider not only <sup>241</sup>Am-Be produced neutrons but also gamma rays from the <sup>241</sup>Am decay, <sup>12</sup>C∗ de-excitation, and neutron interaction with source and facility materials. Different materials (paraffin, borated-paraffin, beryllium, copper, tantalum, tungsten, zinc, bismuth, and lead) have been investigated as neutron and gamma shields. The choice of the shielding materials is based on their effectiveness (the total weight of the facility and the cost). Among several configurations, shielding layers consisting of 10 cm paraffin wax, 2.5 cm lead, and 31.5 cm borated-paraffin wax are found sufficient to meet the safety requirements, leading to a cubic facility of 104.2 cm overall length. Some irradiation parameters are estimated for the final design; namely neutron and gamma spectra as well as flux and absorbed dose components. In addition, the occupational exposure is assessed considering ICRP exposure conditions to calculate the effective dose rate along with the isodose distribution.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111662"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998961","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}
This study examines the impact of the Westcott g-factor on the concentration of elements like In, Ir, Re, Yb, Eu and Lu, measured using neutron capture reactions (n,γ), specifically focusing on those reactions, whose thermal neutron capture cross-sections (σ (n,γ)) deviate from the conventional '1/v' behaviour. These measurements are quantified using k₀-based neutron activation analysis. The Westcott g-factor for the non-1/v nuclides was calculated using the characterized neutron temperature (Tn) at PFTS irradiation channel of KAMINI reactor. This computation involved establishing a correlation between g(Tn) Vs Tn, spanning a range from 0 to 100 °C, derived from the latest ENDF/B-VIII.0 nuclear data library. NJOY21 code package modules like RECONR (Resonance Reconstruction) and BROADR (Doppler Broadening) were used to process the neutron capture cross-section at different temperatures. The impact of g(Tn) on the Lu concentration was found to be highest at 81% and least for the Re at 0.2% using 185Re isotope.
本研究考察了Westcott g因子对In， Ir, Re, Yb， Eu和Lu等元素浓度的影响，使用中子俘获反应（n,γ）测量，特别关注那些热中子俘获截面（σ (n,γ)）偏离传统“1/v”行为的反应。这些测量使用基于k 0的中子活化分析进行量化。利用KAMINI反应堆PFTS辐照通道的特征中子温度（Tn）计算了非1/v核素的Westcott g因子。该计算涉及建立g(Tn) Vs Tn之间的相关性，跨越0到100°C的范围，来自最新的ENDF/B-VIII。0核数据库。采用RECONR （Resonance Reconstruction）和BROADR （Doppler broadband）等NJOY21码包模块对不同温度下的中子俘获截面进行处理。利用185Re同位素，发现g（Tn）对Lu浓度的影响最大（81%），对Re浓度的影响最小（0.2%）。
{"title":"Determination of Westcott g-factors for the assay of non-1/v nuclides using k0-NAA","authors":"Manish Chand , Subhrojit Bagchi , Bilal Hassan Khan","doi":"10.1016/j.apradiso.2025.111666","DOIUrl":"10.1016/j.apradiso.2025.111666","url":null,"abstract":"<div><div>This study examines the impact of the Westcott g-factor on the concentration of elements like In, Ir, Re, Yb, Eu and Lu, measured using neutron capture reactions (n,γ), specifically focusing on those reactions, whose thermal neutron capture cross-sections (σ <sub>(n,γ)</sub>) deviate from the conventional '1/<em>v</em>' behaviour. These measurements are quantified using <em>k</em>₀-based neutron activation analysis. The Westcott g-factor for the non-1/<em>v</em> nuclides was calculated using the characterized neutron temperature (T<sub>n</sub>) at PFTS irradiation channel of KAMINI reactor. This computation involved establishing a correlation between g(T<sub>n</sub>) Vs T<sub>n</sub>, spanning a range from 0 to 100 °C, derived from the latest ENDF/B-VIII.0 nuclear data library. NJOY21 code package modules like RECONR (Resonance Reconstruction) and BROADR (Doppler Broadening) were used to process the neutron capture cross-section at different temperatures. The impact of g(T<sub>n</sub>) on the Lu concentration was found to be highest at 81% and least for the Re at 0.2% using <sup>185</sup>Re isotope.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111666"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142943319","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}
Pub Date : 2025-01-04DOI: 10.1016/j.apradiso.2025.111665
Jie Li , Xiangli Cui , Lingling Liu , Bingbing Li , Zhenle Fei , Wei Han
This study investigated the influence of tissue electron density on proton beam dose distribution using TOPAS Monte Carlo simulation. Heterogeneous tissue models composed of 14 materials were constructed to simulate the dose deposition process of a 169.23 MeV proton beam. The study analyzed the relationships between electron density and key parameters such as maximum dose, total dose, and dose distribution. Results showed that increasing electron density led to higher local maximum dose, lower total dose, and decreased Bragg peak depth, range, penumbra width, and full width at half maximum (FWHM). High-density tissues caused a sharp, concentrated Bragg peak at shallower depths, while low-density tissues caused a backward shift and widening of the Bragg peak. Differences in proton energy deposition in various tissues were the fundamental reasons for dose distribution variations. This study quantified the relationship between electron density and proton beam dose distribution, providing a reference for accurate dose calculation and optimization in proton therapy.
{"title":"Proton dose deposition in heterogeneous media: A TOPAS Monte Carlo simulation study","authors":"Jie Li , Xiangli Cui , Lingling Liu , Bingbing Li , Zhenle Fei , Wei Han","doi":"10.1016/j.apradiso.2025.111665","DOIUrl":"10.1016/j.apradiso.2025.111665","url":null,"abstract":"<div><div>This study investigated the influence of tissue electron density on proton beam dose distribution using TOPAS Monte Carlo simulation. Heterogeneous tissue models composed of 14 materials were constructed to simulate the dose deposition process of a 169.23 MeV proton beam. The study analyzed the relationships between electron density and key parameters such as maximum dose, total dose, and dose distribution. Results showed that increasing electron density led to higher local maximum dose, lower total dose, and decreased Bragg peak depth, range, penumbra width, and full width at half maximum (FWHM). High-density tissues caused a sharp, concentrated Bragg peak at shallower depths, while low-density tissues caused a backward shift and widening of the Bragg peak. Differences in proton energy deposition in various tissues were the fundamental reasons for dose distribution variations. This study quantified the relationship between electron density and proton beam dose distribution, providing a reference for accurate dose calculation and optimization in proton therapy.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111665"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142969406","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}
Pub Date : 2025-01-04DOI: 10.1016/j.apradiso.2025.111664
Lama Mukhled Aljuaid , Sarah Faiz Althobaiti , Asmaa Abdullah Althobaiti , Amani Hameed Alsufyani , Manal Helal Alotaibi , Bahaaedin A. Elkhader , Hamid Osman , Mohammed Meshal Althoibe , Bassem M. Raafat , Haytham A. Dahlawi , Mayeen Uddin Khandaker
This review explores the establishment of diagnostic reference levels (DRLs) for pediatric brain computed tomography (CT) examinations in Saudi Arabia and compares them with nine other countries. An extensive search strategy was employed across various databases, resulting in the inclusion of 9 studies. The studies included patient-based and phantom-based investigations into DRLs, highlighting variations across age groups and countries. Findings suggest notable differences in CT dose index (CTDI mGy) and dose length product (DLP mGy.cm) values. There was a difference in the classification of age group between Saudi food and drug administration (SFDA) and literature. For the age groups 0–5 years and 6–15 years, the DRLs for the SFDA were as follows: CTDI (28 and 42 mGy) and DLP (482 and 697 mGy cm). The discussion emphasizes the importance of age-specific DRLs to optimize radiation doses while ensuring patient safety and diagnostic efficacy. Recommendations include adopting globally accepted standards for dose optimization and continued research into factors influencing DRL variations. Limitations include varying age groupings among studies and limited access to some relevant literature. Overall, this study underscores the importance of standardizing DRLs for pediatric CT to improve patient care and safety.
{"title":"Age-specific DRLs for pediatric brain CT: A review for exploring the practices in Saudi Arabia","authors":"Lama Mukhled Aljuaid , Sarah Faiz Althobaiti , Asmaa Abdullah Althobaiti , Amani Hameed Alsufyani , Manal Helal Alotaibi , Bahaaedin A. Elkhader , Hamid Osman , Mohammed Meshal Althoibe , Bassem M. Raafat , Haytham A. Dahlawi , Mayeen Uddin Khandaker","doi":"10.1016/j.apradiso.2025.111664","DOIUrl":"10.1016/j.apradiso.2025.111664","url":null,"abstract":"<div><div>This review explores the establishment of diagnostic reference levels (DRLs) for pediatric brain computed tomography (CT) examinations in Saudi Arabia and compares them with nine other countries. An extensive search strategy was employed across various databases, resulting in the inclusion of 9 studies. The studies included patient-based and phantom-based investigations into DRLs, highlighting variations across age groups and countries. Findings suggest notable differences in CT dose index (CTDI mGy) and dose length product (DLP mGy.cm) values. There was a difference in the classification of age group between Saudi food and drug administration (SFDA) and literature. For the age groups 0–5 years and 6–15 years, the DRLs for the SFDA were as follows: CTDI (28 and 42 mGy) and DLP (482 and 697 mGy cm). The discussion emphasizes the importance of age-specific DRLs to optimize radiation doses while ensuring patient safety and diagnostic efficacy. Recommendations include adopting globally accepted standards for dose optimization and continued research into factors influencing DRL variations. Limitations include varying age groupings among studies and limited access to some relevant literature. Overall, this study underscores the importance of standardizing DRLs for pediatric CT to improve patient care and safety.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111664"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021731","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}
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