Pub Date : 2026-01-22DOI: 10.1016/j.radphyschem.2026.113656
Tahir E. Adreani , Ibrahim I. Suliman , Hajo Idriss , A. Sulieman , M. Alkhorayef , D. Bradley
Artificial neural network (ANN) and multilinear regression (MLR) models are widely recognized for their effectiveness in predicting the dynamics of industrial and natural phenomena. In this study, both multiple regression and ANN were employed to forecast radioactivity levels in regions affected by gold mining in Eastern Sudan. We developed multi-regression and ANN models using Python scripts in a Linux environment. The results were tested and validated against background radiation measurements in an area with naturally occurring radioactive materials (NORM) in Eastern Sudan. These findings were compared with the activity concentrations of the soil samples measured using high-purity germanium (HPGe) gamma spectrometry. The study revealed that The ANN model demonstrated superior predictive capabilities for 226Ra and 232Th activity concentrations compared to MLR, owing to ANN's ability to model nonlinear relationships in environmental radioactivity data. Although the multilinear regression performed better at 40K because of its linear soil dependency, the ANN achieved higher correlation coefficients overall. These results confirm that ANN-based methodologies can effectively predict radionuclide distributions and improve environmental radiation assessment.
{"title":"Artificial neural network (ANN) vs multilinear regression (MLR) models to predict naturally occurring radioactivity (NORM) in the gold mining area in eastern Sudan","authors":"Tahir E. Adreani , Ibrahim I. Suliman , Hajo Idriss , A. Sulieman , M. Alkhorayef , D. Bradley","doi":"10.1016/j.radphyschem.2026.113656","DOIUrl":"10.1016/j.radphyschem.2026.113656","url":null,"abstract":"<div><div>Artificial neural network (ANN) and multilinear regression (MLR) models are widely recognized for their effectiveness in predicting the dynamics of industrial and natural phenomena. In this study, both multiple regression and ANN were employed to forecast radioactivity levels in regions affected by gold mining in Eastern Sudan. We developed multi-regression and ANN models using Python scripts in a Linux environment. The results were tested and validated against background radiation measurements in an area with naturally occurring radioactive materials (NORM) in Eastern Sudan. These findings were compared with the activity concentrations of the soil samples measured using high-purity germanium (HPGe) gamma spectrometry. The study revealed that The ANN model demonstrated superior predictive capabilities for <sup>226</sup>Ra and <sup>232</sup>Th activity concentrations compared to MLR, owing to ANN's ability to model nonlinear relationships in environmental radioactivity data. Although the multilinear regression performed better at <sup>40</sup>K because of its linear soil dependency, the ANN achieved higher correlation coefficients overall. These results confirm that ANN-based methodologies can effectively predict radionuclide distributions and improve environmental radiation assessment.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113656"},"PeriodicalIF":2.8,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-22DOI: 10.1016/j.radphyschem.2026.113661
Hui-Chao Li , Dan-Dan Su , Xiao-Bin Li , Jun-Liang Guo , Feng-Chen Li , Shu-Qi Meng
In pressurized water reactors (PWRs), neutron-induced water radiolysis is a key factor in accelerating the oxidation of zirconium alloy cladding. In this study, the neutron-induced water radiolysis process from 1 keV to 5 MeV at 573 K and 15.5 MPa was simulated using the reactive force field molecular dynamics (ReaxFF-MD) method. The results show that the G-values of molecular products (H2, H2O2) decrease with increasing neutron energy, while the G-value of free radicals (•OH, H•) increase, demonstrating the linear energy transfer (LET) effect. The analysis of the microscopic mechanism reveals that low-energy primary knock-on atoms (PKAs) forms a dense track, and the G-value evolution follows a delayed-onset rapid growth pattern. Medium energy PKAs trigger a compression-rebound effect, and forms a transition track. High-energy PKAs penetrate in an inefficient energy-transfer mode with dispersed energy, and the G-value rapidly reaches the peak and then decreases. This study elucidates the intrinsic mechanism of the LET effect from the atomic scale, and provides a theoretical basis for the study of zirconium alloy oxidation and the construction of material damage model.
{"title":"Dynamics of neutron-induced water radiolysis in high-temperature, high-pressure water relevant to PWR primary coolant","authors":"Hui-Chao Li , Dan-Dan Su , Xiao-Bin Li , Jun-Liang Guo , Feng-Chen Li , Shu-Qi Meng","doi":"10.1016/j.radphyschem.2026.113661","DOIUrl":"10.1016/j.radphyschem.2026.113661","url":null,"abstract":"<div><div>In pressurized water reactors (PWRs), neutron-induced water radiolysis is a key factor in accelerating the oxidation of zirconium alloy cladding. In this study, the neutron-induced water radiolysis process from 1 keV to 5 MeV at 573 K and 15.5 MPa was simulated using the reactive force field molecular dynamics (ReaxFF-MD) method. The results show that the <em>G</em>-values of molecular products (H<sub>2</sub>, H<sub>2</sub>O<sub>2</sub>) decrease with increasing neutron energy, while the <em>G</em>-value of free radicals (•OH, H•) increase, demonstrating the linear energy transfer (LET) effect. The analysis of the microscopic mechanism reveals that low-energy primary knock-on atoms (PKAs) forms a dense track, and the <em>G</em>-value evolution follows a delayed-onset rapid growth pattern. Medium energy PKAs trigger a compression-rebound effect, and forms a transition track. High-energy PKAs penetrate in an inefficient energy-transfer mode with dispersed energy, and the <em>G</em>-value rapidly reaches the peak and then decreases. This study elucidates the intrinsic mechanism of the LET effect from the atomic scale, and provides a theoretical basis for the study of zirconium alloy oxidation and the construction of material damage model.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113661"},"PeriodicalIF":2.8,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033170","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}
The standard-less IM-NAA approach using research reactors requires characterization of the different irradiation sites with respect to neutron flux parameters, specifically the sub-cadmium to epithermal flux ratio (f) and the epithermal neutron flux shape factor (α). The flux characterization was performed at two research reactor facilities at BARC, Mumbai: the outer core irradiation position (H7) of the Apsara-U reactor and the Pneumatic Carrier Facility (PCF) of the Dhruva reactor. The accuracy and robustness of the developed methodology was validated using certified reference materials (CRMs). The optimized IM-NAA methodology was subsequently employed for the comprehensive chemical characterization of different steel samples relevant to advanced reactor technology. The uncertainty associated with IM-NAA measurements was rigorously evaluated, accounting for nuclear data parameters (e.g., Q0, k0, ) reactor flux parameters (f, α), and other contributors often neglected in conventional analysis. The work successfully demonstrated that IM-NAA, when implemented with properly characterized flux parameters, provides a reliable, standard-less methodology for the accurate and precise compositional analysis of complex alloys, thereby strengthening quality control and material verification protocols for advanced nuclear technologies.
{"title":"Standard-less IM-NAA for compositional analysis of nuclear reactor materials: Flux characterization and uncertainty evaluation","authors":"S.K. Samanta , Purbali Das , Sonika Gupta , Suparna Sodaye","doi":"10.1016/j.radphyschem.2026.113657","DOIUrl":"10.1016/j.radphyschem.2026.113657","url":null,"abstract":"<div><div>The standard-less IM-NAA approach using research reactors requires characterization of the different irradiation sites with respect to neutron flux parameters, specifically the sub-cadmium to epithermal flux ratio (<em>f</em>) and the epithermal neutron flux shape factor (<em>α</em>). The flux characterization was performed at two research reactor facilities at BARC, Mumbai: the outer core irradiation position (H7) of the Apsara-U reactor and the Pneumatic Carrier Facility (PCF) of the Dhruva reactor. The accuracy and robustness of the developed methodology was validated using certified reference materials (CRMs). The optimized IM-NAA methodology was subsequently employed for the comprehensive chemical characterization of different steel samples relevant to advanced reactor technology. The uncertainty associated with IM-NAA measurements was rigorously evaluated, accounting for nuclear data parameters (e.g., <em>Q</em><sub><em>0</em></sub>, <em>k</em><sub><em>0</em></sub>, <span><math><mrow><mover><msub><mi>E</mi><mi>r</mi></msub><mo>‾</mo></mover></mrow></math></span>) reactor flux parameters (<em>f, α</em>), and other contributors often neglected in conventional analysis. The work successfully demonstrated that IM-NAA, when implemented with properly characterized flux parameters, provides a reliable, standard-less methodology for the accurate and precise compositional analysis of complex alloys, thereby strengthening quality control and material verification protocols for advanced nuclear technologies.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113657"},"PeriodicalIF":2.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-21DOI: 10.1016/j.radphyschem.2026.113658
Omar Bentiane, Omaima Khettabi, Omar Berradi, El Mehdi Sadiki, Fatimaezzahra Bouzzit, Rodouan Touti
Computed Tomography (CT) is a key diagnostic tool in medical imaging, but concerns persist regarding radiation exposure, particularly in repeat or high-dose examinations. The CTDIvol quantifies scanner output but does not accurately represent the patient dose. The Size-Specific Dose Estimate (SSDE) provides a more clinically relevant patient-specific dose estimate by accounting for body size and composition. This study aims to quantify the differences between CTDIvol and SSDE in adult thoraco-abdominopelvic and abdominopelvic CT scans, compare manual and automatic methods of patient size estimation, and evaluate organ doses. A retrospective review was conducted on 52 adult CT scans (thoraco-abdominopelvic and abdominopelvic). Four patient-size metrics were collected: the manually measured effective diameter (Deff-M), the automatically averaged z-axis effective diameter (Deff-AZ), and two water-equivalent diameters (Dw-E and Dw-AZ). The SSDE values were calculated according to AAPM TG-204 and TG-220. The organ doses were estimated with IndoseCT based on Monte Carlo-derived correlations. The mean CTDIvol was 13.0 ± 3.6 mGy, with SSDE values 31–37 % higher across all methods. Deff-AZ was 4.7 % greater than Deff-M, while Dw-E and Dw-AZ showed near-perfect agreement. The liver, kidneys, and bladder received the highest doses (>15 mGy) as they are directly irradiated, whereas radiosensitive organs outside the primary scan field, such as the thyroid and eyes, received measurable scatter doses. SSDE provides a more accurate representation of patient radiation dose than CTDIvol and should be integrated into routine CT protocols. Among the evaluated size metrics, attenuation-based Dw proved to be the most robust and reproducible. Incorporating organ-dose estimations and SSDE into clinical practice can enhance patient safety, optimize imaging protocols, and support compliance with radiation protection regulations.
{"title":"Beyond CTDIvol: Patient-specific SSDE and organ dose assessment in routine adult CT practice","authors":"Omar Bentiane, Omaima Khettabi, Omar Berradi, El Mehdi Sadiki, Fatimaezzahra Bouzzit, Rodouan Touti","doi":"10.1016/j.radphyschem.2026.113658","DOIUrl":"10.1016/j.radphyschem.2026.113658","url":null,"abstract":"<div><div>Computed Tomography (CT) is a key diagnostic tool in medical imaging, but concerns persist regarding radiation exposure, particularly in repeat or high-dose examinations. The CTDI<sub>vol</sub> quantifies scanner output but does not accurately represent the patient dose. The Size-Specific Dose Estimate (SSDE) provides a more clinically relevant patient-specific dose estimate by accounting for body size and composition. This study aims to quantify the differences between CTDI<sub>vol</sub> and SSDE in adult thoraco-abdominopelvic and abdominopelvic CT scans, compare manual and automatic methods of patient size estimation, and evaluate organ doses. A retrospective review was conducted on 52 adult CT scans (thoraco-abdominopelvic and abdominopelvic). Four patient-size metrics were collected: the manually measured effective diameter (D<sub>eff-M</sub>), the automatically averaged z-axis effective diameter (D<sub>eff-AZ</sub>), and two water-equivalent diameters (D<sub>w-E</sub> and D<sub>w-AZ</sub>). The SSDE values were calculated according to AAPM TG-204 and TG-220. The organ doses were estimated with <em>IndoseCT</em> based on Monte Carlo-derived correlations. The mean CTDI<sub>vol</sub> was 13.0 ± 3.6 mGy, with SSDE values 31–37 % higher across all methods. D<sub>eff-AZ</sub> was 4.7 % greater than D<sub>eff-M</sub>, while D<sub>w-E</sub> and D<sub>w-AZ</sub> showed near-perfect agreement. The liver, kidneys, and bladder received the highest doses (>15 mGy) as they are directly irradiated, whereas radiosensitive organs outside the primary scan field, such as the thyroid and eyes, received measurable scatter doses. SSDE provides a more accurate representation of patient radiation dose than CTDI<sub>vol</sub> and should be integrated into routine CT protocols. Among the evaluated size metrics, attenuation-based D<sub>w</sub> proved to be the most robust and reproducible. Incorporating organ-dose estimations and SSDE into clinical practice can enhance patient safety, optimize imaging protocols, and support compliance with radiation protection regulations.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113658"},"PeriodicalIF":2.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-21DOI: 10.1016/j.radphyschem.2026.113640
Ahmed A. Abdou Elabbasy , Ahmed M. El-Khayatt , Mahmoud Elsayed , Hesham M.H. Zakaly , A. Alkaoud , Islam M. Nabil , Islam N. Fathy , Alaa M. Rashad , Manar Ali
This study examined the mechanical properties and γ-ray radiation shielding performance of different ultra high-performance concrete (UHPC) mixes incorporating individual and hybrid combinations of steel (SF), polyvinyl alcohol (PVA), polypropylene (PP), and natural jute fibers (JF). Radiation attenuation was assessed through experimental testing and validated using Monte Carlo (MC) simulations and Phy-X software. Results indicated that the control UHPC mix with steel fibers alone achieved the highest compressive strength of 140 MPa at curing age of 28 days. In comparison with this SF-reinforced control mix, the hybrid fiber mixtures (SF + PVA, SF + PP, SF + JF, and SF + PP + PVA + JF) exhibited reductions in compressive strength of approximately 12.4 %, 11.6 %, 15.7 %, and 21.1 %, respectively, at the same age. Tensile and flexural strengths followed a similar trend of reduction with hybrid fiber incorporation. Relative to the tensile strength value of the control mix (10 MPa), hybrid fiber combinations (SF + PVA, SF + PP, SF + JF, and SF + PP + PVA + JF) resulted in tensile strength reductions of approximately 4 %, 5 %, 8 %, and 8 %. Similarly, their flexural strengths were notably decreased by about 9.6 %, 18.4 %, 22 %, and 24.4 %, respectively, when compared to the control mix that achieved 25 MPa with only SF. While steel fibers remain the most effective, incorporating natural or synthetic fibers like jute and polypropylene can provide acceptable γ-attenuation performance, with potential advantages in cost, flexibility, and sustainability. Hybrid combinations offer a promising balance, especially when multi-functionality (e.g., mechanical strength and γ-radiation shielding) is desired. The key novelty aspect of this work lies in examining fiber type as the main affecting variable on the radiation shielding behavior of UHPC, while combining experimental testing with MC simulation and Phy-X software for radiation shielding assessment.
{"title":"Assessment of mechanical properties and radiation shielding efficiency of fiber-reinforced ultra high-performance concrete: Experimental and simulation analysis","authors":"Ahmed A. Abdou Elabbasy , Ahmed M. El-Khayatt , Mahmoud Elsayed , Hesham M.H. Zakaly , A. Alkaoud , Islam M. Nabil , Islam N. Fathy , Alaa M. Rashad , Manar Ali","doi":"10.1016/j.radphyschem.2026.113640","DOIUrl":"10.1016/j.radphyschem.2026.113640","url":null,"abstract":"<div><div>This study examined the mechanical properties and γ-ray radiation shielding performance of different ultra high-performance concrete (UHPC) mixes incorporating individual and hybrid combinations of steel (SF), polyvinyl alcohol (PVA), polypropylene (PP), and natural jute fibers (JF). Radiation attenuation was assessed through experimental testing and validated using Monte Carlo (MC) simulations and Phy-X software. Results indicated that the control UHPC mix with steel fibers alone achieved the highest compressive strength of 140 MPa at curing age of 28 days. In comparison with this SF-reinforced control mix, the hybrid fiber mixtures (SF + PVA, SF + PP, SF + JF, and SF + PP + PVA + JF) exhibited reductions in compressive strength of approximately 12.4 %, 11.6 %, 15.7 %, and 21.1 %, respectively, at the same age. Tensile and flexural strengths followed a similar trend of reduction with hybrid fiber incorporation. Relative to the tensile strength value of the control mix (10 MPa), hybrid fiber combinations (SF + PVA, SF + PP, SF + JF, and SF + PP + PVA + JF) resulted in tensile strength reductions of approximately 4 %, 5 %, 8 %, and 8 %. Similarly, their flexural strengths were notably decreased by about 9.6 %, 18.4 %, 22 %, and 24.4 %, respectively, when compared to the control mix that achieved 25 MPa with only SF. While steel fibers remain the most effective, incorporating natural or synthetic fibers like jute and polypropylene can provide acceptable γ-attenuation performance, with potential advantages in cost, flexibility, and sustainability. Hybrid combinations offer a promising balance, especially when multi-functionality (e.g., mechanical strength and γ-radiation shielding) is desired. The key novelty aspect of this work lies in examining fiber type as the main affecting variable on the radiation shielding behavior of UHPC, while combining experimental testing with MC simulation and Phy-X software for radiation shielding assessment.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113640"},"PeriodicalIF":2.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014443","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}
South Africa has seven uranium provinces scattered across different national provinces and consisting of different ore deposits. As a signatory to the Pelindaba NPT Treaty, the country is required by the International Atomic Energy Agency (IAEA) to develop its own National Nuclear Forensics Library (NNFL). Nuclear forensic science provides an essential tool to examine nuclear and other radioactive materials, as well as provide evidence that the material was out of regulatory control and was being trafficked. Once the nuclear or radioactive material is seized, the identification of the material and determination of its source is of prime importance. One of the key signatures in nuclear forensics is the isotopic analysis of lead (Pb), which can serve as a fingerprint for nuclear materials. The lead isotopic composition varies between the mining locations, depending on the geological settings. In this study, samples were collected from different mines of Mpumalanga Province. Lead isotopic ratios of the uranium ore were determined using inductively coupled plasma mass spectrometer (ICP-MS) PerkinElmer NexION 2000. According to the results of the lead-lead (Pb–Pb) geochemistry, detrital pyrites make up the mineralization of the uranium ore. The isotopic ratios differed among various ore bodies, which could act as their distinct fingerprints. Additionally, this study provided compelling evidence of the differences between BT and ET, and BT and WT samples. But for the ET-WT pair, it suggested that samples were most likely taken from the same mine shaft.
{"title":"Determination of lead isotopic ratios for nuclear forensic signatures from Mpumalanga Province, South Africa","authors":"Murorunkwere Beatrice, Noxolo Manyoba, Manny Mathuthu","doi":"10.1016/j.radphyschem.2026.113659","DOIUrl":"10.1016/j.radphyschem.2026.113659","url":null,"abstract":"<div><div>South Africa has seven uranium provinces scattered across different national provinces and consisting of different ore deposits. As a signatory to the Pelindaba NPT Treaty, the country is required by the International Atomic Energy Agency (IAEA) to develop its own National Nuclear Forensics Library (NNFL). Nuclear forensic science provides an essential tool to examine nuclear and other radioactive materials, as well as provide evidence that the material was out of regulatory control and was being trafficked. Once the nuclear or radioactive material is seized, the identification of the material and determination of its source is of prime importance. One of the key signatures in nuclear forensics is the isotopic analysis of lead (Pb), which can serve as a fingerprint for nuclear materials. The lead isotopic composition varies between the mining locations, depending on the geological settings. In this study, samples were collected from different mines of Mpumalanga Province. Lead isotopic ratios of the uranium ore were determined using inductively coupled plasma mass spectrometer (ICP-MS) PerkinElmer NexION 2000. According to the results of the lead-lead (Pb–Pb) geochemistry, detrital pyrites make up the mineralization of the uranium ore. The isotopic ratios differed among various ore bodies, which could act as their distinct fingerprints. Additionally, this study provided compelling evidence of the differences between BT and ET, and BT and WT samples. But for the ET-WT pair, it suggested that samples were most likely taken from the same mine shaft.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113659"},"PeriodicalIF":2.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014447","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}
The impedance characteristics of a cylindrical waveguide with a two-layer wall are compared with similar characteristics both an open dielectric waveguide and a waveguide with a perfectly conducting wall inside coated by a dielectric layer. Based on the analysis, a conclusion is made about their interchangeability, and in some important cases – about the preference for using an open dielectric waveguide when solving problems of particle radiation in waveguides and their application.
{"title":"On equivalence of metal-dielectric and single-layer dielectric waveguides in the problems of accelerator physics","authors":"M.I. Ivanyan , B.A. Grigoryan , A.H. Grigoryan , L.V. Aslyan , A.S. Vardanyan , V.G. Khachatryan , M.Z. Karalyan , V. Sh Avagyan","doi":"10.1016/j.radphyschem.2026.113644","DOIUrl":"10.1016/j.radphyschem.2026.113644","url":null,"abstract":"<div><div>The impedance characteristics of a cylindrical waveguide with a two-layer wall are compared with similar characteristics both an open dielectric waveguide and a waveguide with a perfectly conducting wall inside coated by a dielectric layer. Based on the analysis, a conclusion is made about their interchangeability, and in some important cases – about the preference for using an open dielectric waveguide when solving problems of particle radiation in waveguides and their application.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113644"},"PeriodicalIF":2.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.radphyschem.2026.113653
D.A. Bradley , A. Basaif , A. Oresegun , H.T. Zubair , H.M. Zin , K.Y. Choo , S.A. Ibrahim , F. Moradi , M. Alkhorayef , Tingyu Wang , Jianxiang Wen , E. Lewis , H.A. Abdul-Rashid
Examination is made of the temporal pattern of 6–15 MeV electrons, specifically at the dose-rates familiar in use of conventional linacs. The observed intra-pulse sub-structure variations are a manifestation of linac power modifications (modulation occurring within the duration of a single accelerator pulse) and inter-bunch electron repulsion. The measurement system, focal in providing sub-μs temporal resolution as well as capability in covering the dose per pulse dynamic range, comprises an in-house fabricated Ge-doped fiber-sensor, a photon-counting circuit, a multi-pixel photon counter (MPPC), and a fast digital oscilloscope. Together with the observed pulse decay-time and magnitude of afterglow, the variations in intra-pulse sub-structure captured by the system can be expected to have influence upon the accuracy of dose deposition. The measurement capability of the optical fiber scintillator system is shown to be sufficient to serve present needs, largely negating a desire for more sophisticated systems offering superior temporal resolution.
{"title":"Intra-pulse sub-structure sensing of accelerated electrons","authors":"D.A. Bradley , A. Basaif , A. Oresegun , H.T. Zubair , H.M. Zin , K.Y. Choo , S.A. Ibrahim , F. Moradi , M. Alkhorayef , Tingyu Wang , Jianxiang Wen , E. Lewis , H.A. Abdul-Rashid","doi":"10.1016/j.radphyschem.2026.113653","DOIUrl":"10.1016/j.radphyschem.2026.113653","url":null,"abstract":"<div><div>Examination is made of the temporal pattern of 6–15 MeV electrons, specifically at the dose-rates familiar in use of conventional linacs. The observed intra-pulse sub-structure variations are a manifestation of linac power modifications (modulation occurring within the duration of a single accelerator pulse) and inter-bunch electron repulsion. The measurement system, focal in providing sub-μs temporal resolution as well as capability in covering the dose per pulse dynamic range, comprises an in-house fabricated Ge-doped fiber-sensor, a photon-counting circuit, a multi-pixel photon counter (MPPC), and a fast digital oscilloscope. Together with the observed pulse decay-time and magnitude of afterglow, the variations in intra-pulse sub-structure captured by the system can be expected to have influence upon the accuracy of dose deposition. The measurement capability of the optical fiber scintillator system is shown to be sufficient to serve present needs, largely negating a desire for more sophisticated systems offering superior temporal resolution.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113653"},"PeriodicalIF":2.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.radphyschem.2026.113655
Longxing Zheng , Linchao Mei , Zhaojie Zhu , Yizhi Huang , Chaoyang Tu , G. Lakshminarayana , Qianqian Lin , Yan Wang
In response to the environmental concerns and limited stability of traditional scintillators for current-mode radiation detectors, which are often used in computed tomography, baggage screening, and non-destructive testing, this study used the Czochralski method to successfully grow YAG-based crystals doped with trivalent rare-earth ions, including Tb/Dy: YAG, Tb/Dy/Ce: YAG, and Tb/Dy/Lu: YAG crystals. Their X-ray scintillation properties and imaging performance were comprehensively investigated. The results reveal that Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG exhibit radioluminescence intensities exceeding those of commercial Ce: GAGG and Ce: LuAG crystals, demonstrating high sensitivity to X-ray irradiation. The minimum detectable doses for Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG were measured to be as low as 173.65 nGy s−1 and 211 nGy s−1, respectively—both significantly below the typical diagnostic dose of 5.5 μGy s−1. Moreover, these crystals exhibit excellent radiation stability. X-ray imaging tests further confirm that Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG offer high spatial resolution limits of 10.17 lp mm−1 and 19.4 lp mm−1, respectively, delivering high-quality imaging results. These findings underscore the superior scintillation performance of Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG crystals, and highlight their strong potential for advanced X-ray detection and imaging applications.
{"title":"Growth and scintillation performance of Tb/Dy: YAG, Tb/Dy/Lu: YAG and Tb/Dy/Ce: YAG crystals for X-ray imaging applications","authors":"Longxing Zheng , Linchao Mei , Zhaojie Zhu , Yizhi Huang , Chaoyang Tu , G. Lakshminarayana , Qianqian Lin , Yan Wang","doi":"10.1016/j.radphyschem.2026.113655","DOIUrl":"10.1016/j.radphyschem.2026.113655","url":null,"abstract":"<div><div>In response to the environmental concerns and limited stability of traditional scintillators for current-mode radiation detectors, which are often used in computed tomography, baggage screening, and non-destructive testing, this study used the Czochralski method to successfully grow YAG-based crystals doped with trivalent rare-earth ions, including Tb/Dy: YAG, Tb/Dy/Ce: YAG, and Tb/Dy/Lu: YAG crystals. Their X-ray scintillation properties and imaging performance were comprehensively investigated. The results reveal that Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG exhibit radioluminescence intensities exceeding those of commercial Ce: GAGG and Ce: LuAG crystals, demonstrating high sensitivity to X-ray irradiation. The minimum detectable doses for Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG were measured to be as low as 173.65 nGy s<sup>−1</sup> and 211 nGy s<sup>−1</sup>, respectively—both significantly below the typical diagnostic dose of 5.5 μGy s<sup>−1</sup>. Moreover, these crystals exhibit excellent radiation stability. X-ray imaging tests further confirm that Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG offer high spatial resolution limits of 10.17 lp mm<sup>−1</sup> and 19.4 lp mm<sup>−1</sup>, respectively, delivering high-quality imaging results. These findings underscore the superior scintillation performance of Tb/Dy/Ce: YAG and Tb/Dy/Lu: YAG crystals, and highlight their strong potential for advanced X-ray detection and imaging applications.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"242 ","pages":"Article 113655"},"PeriodicalIF":2.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.radphyschem.2026.113652
Beomjun Park , Jiwon Seo , Ill Hyuk Han , Jihwan Boo , Jangwon Byun , Seungho Song , Dakyoung Lee , Joo-Hong Lee , Jin-Wook Lee , Jung-Yeol Yeom , Geehyun Kim
Thallium bromide (TlBr) is a promising room-temperature gamma-ray detector material owing to its high atomic number, wide bandgap, and relatively simpler crystal growth process than CdTe-based crystals. However, its practical application is hindered by ionic migration and polarization effects that degrade long-term stability under high bias voltages. In this work, we present a quantitative methodology to evaluate ionic transport in TlBr detectors through temperature-dependent conductivity measurements in the 193–323 K range. By separating electronic and ionic contributions under both current- and voltage-bias conditions, we extracted ionic conductivity values and determined the activation energy of ion migration. The activation energy varied with the vertical position of zone-refined TlBr ingots. These values were correlated with device performance, including photocurrent degradation under X-ray irradiation and peak channel shifts in gamma-ray spectra. The results reveal that ionic migration critically impacts charge collecting ability and spectral stability. This study proposed a standardized framework for quantifying ionic migration in TlBr detectors, offering valuable guidance for evaluating the operational stability in TlBr detectors. The activation energy of ion migration can serve as a robust metric for quantitatively comparing compound semiconductor detectors, whose ions migrate.
{"title":"Quantification of ionic migration in TlBr gamma-ray detector via temperature-dependent conductivity measurements","authors":"Beomjun Park , Jiwon Seo , Ill Hyuk Han , Jihwan Boo , Jangwon Byun , Seungho Song , Dakyoung Lee , Joo-Hong Lee , Jin-Wook Lee , Jung-Yeol Yeom , Geehyun Kim","doi":"10.1016/j.radphyschem.2026.113652","DOIUrl":"10.1016/j.radphyschem.2026.113652","url":null,"abstract":"<div><div>Thallium bromide (TlBr) is a promising room-temperature gamma-ray detector material owing to its high atomic number, wide bandgap, and relatively simpler crystal growth process than CdTe-based crystals. However, its practical application is hindered by ionic migration and polarization effects that degrade long-term stability under high bias voltages. In this work, we present a quantitative methodology to evaluate ionic transport in TlBr detectors through temperature-dependent conductivity measurements in the 193–323 K range. By separating electronic and ionic contributions under both current- and voltage-bias conditions, we extracted ionic conductivity values and determined the activation energy of ion migration. The activation energy varied with the vertical position of zone-refined TlBr ingots. These values were correlated with device performance, including photocurrent degradation under X-ray irradiation and peak channel shifts in gamma-ray spectra. The results reveal that ionic migration critically impacts charge collecting ability and spectral stability. This study proposed a standardized framework for quantifying ionic migration in TlBr detectors, offering valuable guidance for evaluating the operational stability in TlBr detectors. The activation energy of ion migration can serve as a robust metric for quantitatively comparing compound semiconductor detectors, whose ions migrate.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113652"},"PeriodicalIF":2.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014449","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号