Applied Radiation and Isotopes最新文献

{"title":"Impact of silver nanoparticle impurity on improving LiF:Mg, Ti thermoluminescence response.","authors":"Marzieh Goli, Hamid Reza Baghani, Ehsan Koushki, Mostafa Robatjazi","doi":"10.1016/j.apradiso.2025.112070","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112070","url":null,"abstract":"<p><p>Thermoluminescence dosimeters (TLDs) are widely used for radiation dose measurement in various applications, including radiation protection, radiotherapy, and diagnostic radiology. Therefore, efforts to improve TLD response and reduce uncertainty in measurements are highly valuable. This study aims to evaluate the effect of adding silver (Ag) nanoparticles to LiF:Mg,Ti TLD in terms of their structural characteristics, thermoluminescence (TL) properties, and dosimetric performance. The TLD samples were first synthesized, and Ag nanoparticles were subsequently incorporated as a third impurity. Both prepared samples (with and without Ag nanoparticles) were irradiated with predefined dose levels of 6 MV photons and corresponding glow curves and dose-response curves were compared. XRD, FESEM, and EDS analyses confirmed the proper formation of the LiF TLD structure. The presence of Ag nanoparticles was verified without any alteration in the overall crystalline structure of LiF. The obtained elemental correction coefficient (ECC) values were close to unity, indicating a nearly uniform distribution of impurities in the LiF structure. TLD glow curve at the same dose level enhanced when Ag nanoparticles were added to the TLD. Furthermore, the dose-response curve improved in the presence of Ag nanoparticles. Based on the results, it can be concluded that incorporating Ag nanoparticles into LiF:Mg,Ti enhances its thermoluminescence response and sensitivity.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112070"},"PeriodicalIF":1.8,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144741022","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}

{"title":"Research on gamma image reconstruction method for estimating radiation source distance using the dichotomy method.","authors":"Rui Liu, Yufeng Xiao, Yicong Zhou, Zhongyi Li, Yuanshen Ma, Dong Yan, Zhenyu Ren, Bo Yang","doi":"10.1016/j.apradiso.2025.112060","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112060","url":null,"abstract":"<p><p>To enhance the precision of locating unidentified radiation sources with a coded aperture camera, this study introduces a refined Maximum Likelihood Expectation Maximization (MLEM) algorithm. This algorithm incorporates the dichotomy method to estimate the distance to the radiation source, followed by a superimposition of the calculated system response matrix to predict the source's position within the imaging area. Initially, a system response matrix table is created, listing potential distances from the radiation source to the camera in ascending order. The process involves assessing the mean square error (MSE) and the full width at half maximum (FWHM) of the current image to determine if the hypothesized distance surpasses the actual distance. Following this, a binary search is executed on the matrix table to ascertain the closest lower and upper bounds to the true distance. Subsequently, the system matrices for these boundary distances are aggregated to derive an approximate response matrix. This matrix is then employed in the MLEM algorithm to estimate the radiation source's position. Experimental outcomes indicate that the enhanced algorithm provides superior localization accuracy and a definable distance range (nearest lower and upper bounds) between the radiation source and the camera compared to the conventional MLEM algorithm, thus better facilitating the analysis of hotspots.The proposed method achieves satisfactory reconstruction for a single radiation source and for multiple sources located at the same detector distance; however, its performance in reconstructing multiple sources at differing distances remains to be improved.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112060"},"PeriodicalIF":1.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144741023","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}

{"title":"Dose-dependent X-ray irradiation-induced bystander effects in MCF-7 breast cancer cells.","authors":"Beatriz Allyne D Carandang, Teresa Sy-Ortin, John Paul C Cabahug, Chitho P Feliciano","doi":"10.1016/j.apradiso.2025.112065","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112065","url":null,"abstract":"<p><p>Emerging evidence shows that exposure of cancer cells to ionizing radiation may trigger signal-mediated events in unirradiated cells called the radiation-induced bystander effects (RIBE). Manifestation of the effect is highly variable, dependent on the treatment parameters such as methodology, radiation type, LET, or cell lines. This study aims to investigate RIBE in MCF-7 after irradiation using an X-ray benchtop irradiator. MCF-7 cells were cultured at 2 × 10⁵ cells per T25 flask and irradiated using a CellRad™ bench-top irradiator at 130 kV, 5 mA, with an additional 0.5 mm aluminum filter. The irradiation setup placed the flask within a circular field size of 19.8 cm, delivering a dose rate of 2.096 Gy/min. Acute doses investigated included 0 Gy (sham), 0.5 Gy, 1.5 Gy, 3.36 Gy, 8 Gy, and 12 Gy. Twenty-four hours post-irradiation, medium transfer from irradiated cells (ICM) was performed to initiate radiation-induced bystander effects in non-irradiated cells. Subsequent assessments included viability assays and colony formation assays to validate observed effects, with relative survival calculated relative to sham-irradiated cells. Results show that exposure of the cells to the irradiated cell medium resulted in a significant decrease in cell viability and clonogenic ability, demonstrating bystander effects. This decrease in survival is dose-dependent where the effect is more significant at higher doses 3.36 Gy-12 Gy.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112065"},"PeriodicalIF":1.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144717343","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}

{"title":"Concentration and distribution characteristics of gross alpha, ²³⁸U, ²³⁴U and ²²⁶Ra in freshwater of some rivers and artificial lakes in southeast Vietnam.","authors":"Minh An Dinh, Nhut Tan Tran, Van Thang Nguyen, Xuan Anh Dao Lam, Truc Phuong Huynh, Cong Hao Le","doi":"10.1016/j.apradiso.2025.112064","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112064","url":null,"abstract":"<p><p>Rivers and artificial lakes are the major sources that supply freshwater to communities, cities, agriculture, and industry. However, this water type is normally polluted by radionuclides, which are from groundwater discharge, surface soil runoff, or Naturally Occurring Radionuclides (NOR) effluents. In this study, gross alpha and alpha-emitting radionuclides (²³⁴U, ²³⁸U and ²²⁶Ra) were analysed in freshwater samples collected in 31 sites in two rivers and four quarry lakes in Southeast Vietnam. The analyses were conducted in two separate parts of water: suspended matter and filtered water. The mean gross alpha, ²³⁴U, ²³⁸U and ²²⁶Ra activities in unfiltered water were 52.9, 8.2, 7.9, and 6.1 mBq L^-1, respectively. These values remain within the recommendations of the United States Environmental Protection Agency (USEPA) and World Health Organization (WHO) for the contamination of radionuclides in drinking water. High activities were found in the water of the Sai Gon River due to the impact of pollutants from the densely populated and industrial zones. Ratios of ²³⁴U/²³⁸U were found to be slightly >1, while ratios of ²²⁶Ra/²³⁴U and ²²⁶Ra/²³⁸U were found to be < 1. Radionuclides ²³⁴U, ²³⁸U and ²²⁶Ra contribute significantly to the gross alpha in both rivers and artificial lakes. Strong linear correlations were found between the activities of alpha-emitting radionuclides and gross alpha in quarry lake water (Pearson correlation coefficient p > 0.7). For two types of freshwater, a significant amount of gross alpha, alpha-emitting radionuclides, was found in the suspended solids of water. The suspended matter/water partition coefficients (K_sw) for two types of water were 1.23 × 10⁵, 1.66 × 10⁴, 1.55 × 10⁴, and 9.7 × 10³ L kg^-1 for gross alpha, ²³⁴U, ²³⁸U and ²²⁶Ra, respectively. K_sw values of the gross alpha and radionuclides for river water are significantly higher than those in quarry lake water.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112064"},"PeriodicalIF":1.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697492","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}

{"title":"Optimization of a Micromegas-based fission chamber for application to intensive thermal neutron measurement.","authors":"Qi-An Wei, Xiu-Liang Zhao, Song Feng, Li-Yan Liu, Xin-Chun Xiao, Zhi-Chao Tang, Yan-Xi Ye, Zhe-Xu Li, Yu-Chen Liu, Meng-Jia Chen, Jin Tian, Yang Wu, San-Jun He","doi":"10.1016/j.apradiso.2025.112040","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112040","url":null,"abstract":"<p><p>The use of Micromegas to construct fission chambers offers advantages of wide range and high sensitivity, providing significant application value in high-intensity thermal neutron measurements, such as reactor neutron flux rate monitoring. However, the pad array readout method of detectors can lead to multiple-triggering from a single signal, which increases the burden on the electronics and limiting the detector's counting capacity. Therefore, it is necessary to optimize the detector structure and operating conditions to restrict the transverse migration and diffusion of charged particles. It is crucial to reduce the multi-channel response and improve the count range of the detector. This study utilized Monte Carlo simulations to investigate detector performance, focusing on conversion efficiency, detection efficiency, emitted energy spectrum, and average energy deposition, as well as the transverse migration and diffusion characteristics of charged particles. The results indicate that the drift region width significantly impacts the spatial distribution of primary electrons. Using a noble gas with a higher atomic number, such as Xe, or increasing gas pressure can effectively reduce the spread of primary electron positions. With a gas mixture of 70 % Xe and 30 % CF₄ and a drift region electric field of 1000 V/cm, the transverse diffusion of electrons is minimized, with a full width at half maximum (FWHM) of 0.13 mm. Experiments on neutron count rate and repeated count ratio with different drift region widths confirmed that limiting the drift region width could effectively reduce repeated counts caused by multi-channel responses. With a conversion layer thickness of 1.4 mg/cm² and a drift width of 2 mm, the mean neutron count rate is 0.079, and the repeated count ratio is only 21.09 %. This study provides theoretical and reference foundations for enhancing the count rate range of this new fission chamber and developing it into a high-count-rate detector for measuring high-intensity thermal neutrons.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112040"},"PeriodicalIF":1.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144706074","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}

{"title":"Determination of (p, n) reaction cross-section for various nuclei at 7.5 MeV by using machine learning models.","authors":"Naima Amrani, Serkan Akkoyun","doi":"10.1016/j.apradiso.2025.112059","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112059","url":null,"abstract":"<p><p>This study investigates the prediction of (p, n) reaction cross-sections for various nuclei at 7.5 MeV using machine learning models. A dataset of 91 instances, containing key nuclear properties such as mass number (A), proton number (Z), neutron number (N), and the asymmetry term ((N-Z)/A²), was utilized. Various machine learning techniques, including Random Forest, Support Vector Regression (SVR), Gradient Boosting, Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), K-Nearest Neighbours, Multiple Linear Regression and Ensemble Model were employed. Model performances were evaluated using Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and R² metrics. Among the models, ensemble methods, SVR, and boosting-based approaches demonstrated superior predictive capabilities, effectively capturing nonlinear relationships between nuclear properties and cross-sections. Results highlight the significance of the asymmetry term in enhancing prediction accuracy. This study underscores the potential of machine learning as a robust tool for nuclear physics applications, particularly in understanding and predicting nuclear reaction cross-sections.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112059"},"PeriodicalIF":1.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144717342","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}

{"title":"A novel dual-chamber cyclotron target for simultaneous production of F-18 and P-32","authors":"Fabian Yoga Prastha ,&nbsp;Zaki Su'ud ,&nbsp;Imam Kambali","doi":"10.1016/j.apradiso.2025.112058","DOIUrl":"10.1016/j.apradiso.2025.112058","url":null,"abstract":"<div><div>This study presents a novel cyclotron-based method for the simultaneous production of fluorine-18 (F-18) and phosphorus-32 (P-32) using a dual-chamber target system. Monte Carlo simulations with PHITS and DCHAIN were employed to model F-18 production via the ¹⁸O(p,n)¹⁸F reaction in an H₂¹⁸O target and secondary P-32 production through the ³²S(n,p)³²P reaction in a sulfur-filled chamber. Four geometric configurations were analyzed to optimize neutron flux and isotope yields. The most effective design (0.75 cm × 1.20 cm) yielded 2.2342 ± 0.0008 GBq/μAh of F-18 and 0.0261 ± 0.0026 MBq/μAh of P-32, with radionuclidic impurities remaining below 0.1 %. A conservative ±10 % uncertainty was applied to P-32 yields to account for modeling variation in secondary neutron flux, while F-18 uncertainties reflect PHITS statistical precision. Additional simulations at 8–13 MeV confirmed 13 MeV as the optimal energy within the DECY-13 cyclotron's capabilities. Thermal and structural analyses using ANSYS confirmed safe operation at 25 μA for 1 h, without exceeding material or target limits. The proposed system provides a compact and efficient solution for co-producing F-18 and P-32, potentially enhancing radioisotope production workflows in medical and research settings.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"Article 112058"},"PeriodicalIF":1.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670684","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}

{"title":"Determination of the half-life of 127Sb using the reference source method","authors":"Jianfeng Liang ,&nbsp;Guowei Chen ,&nbsp;Xiaolin Zhang ,&nbsp;Qingdi Guan ,&nbsp;Xiangbo Zhang ,&nbsp;Jinlong Fan ,&nbsp;Yunhe Zhang ,&nbsp;Yue Ma ,&nbsp;Feng Xie ,&nbsp;Jiang Xu","doi":"10.1016/j.apradiso.2025.112056","DOIUrl":"10.1016/j.apradiso.2025.112056","url":null,"abstract":"<div><div>¹²⁷Sb is a helpful radionuclide in nuclear forensics, yet discrepancies in previous measurements have led to a 1.8 % uncertainty in its recommended half-life value, compromising accurate activity determination. In this study, ¹²⁷Sb samples were chemically separated from the fission products of ²³⁵U following thermal neutron irradiation at Xi'an Pulsed Reactor. The decay of ¹²⁷Sb was monitored using the reference source method with two High-Purity Germanium (HPGe) detectors, acquiring gamma spectra at equidistant intervals over 25 days (about 6.5 half-lives). A weighted least-squares fit of the decay curve yielded a half-life of 3.877 (24) days, deviating by 0.7 % from the latest recommended value of 3.85 (7) days. Our result reduces the uncertainty significantly compared to prior measurements, enhancing reliability for nuclear forensic applications.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"Article 112056"},"PeriodicalIF":1.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670729","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}

{"title":"Boron nanodrugs for boron neutron capture therapy","authors":"Jiaxin Wan ,&nbsp;Linwen Lv ,&nbsp;Yanan Chang ,&nbsp;Juan Li ,&nbsp;Gengmei Xing ,&nbsp;Kui Chen","doi":"10.1016/j.apradiso.2025.112044","DOIUrl":"10.1016/j.apradiso.2025.112044","url":null,"abstract":"<div><div>Boron neutron capture therapy (BNCT) is a promising therapeutic method for malignant tumors, capable of selectively killing tumor cells through nuclear reactions at the single-cell level without damaging surrounding normal cells. With the rapid development of nano-delivery systems in recent years, boron nanodrugs have improved the efficiency of intra-tumor boron delivery and enhanced the therapeutic efficacy of BNCT. In this paper, we first review the clinically approved boron drugs and their limitations, followed by highlighting the design strategies of different boron nanodrugs. The discussion conclude with the advantages and limitations of carrier-free boron nanodrugs and boron nanodrugs utilizing carriers.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"Article 112044"},"PeriodicalIF":1.6,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670728","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}

{"title":"Hospital-cyclotrons production of high-purity ¹⁵⁵Tb via ¹⁵⁵Gd(p,n).","authors":"Francesca Barbaro, Luciano Canton, Nikolay Uzunov, Laura De Nardo, Laura Meléndez-Alafort","doi":"10.1016/j.apradiso.2025.112026","DOIUrl":"https://doi.org/10.1016/j.apradiso.2025.112026","url":null,"abstract":"<p><p>Terbium radionuclides are gaining prominence in theranostics, with ¹⁵⁵Tb emerging as promising SPECT imaging agent due to its γ emissions (87 keV, 32%; 105 keV, 25%) and favorable half-life (T_1/2=5.32 days), allowing extended biodistribution monitoring. However, efficient production via hospital cyclotrons is challenging, particularly in reducing ¹⁵⁶Tb contamination, which affects image quality and increases patient dose. This study investigates the ¹⁵⁵Gd(p,n)¹⁵⁵Tb reaction, highlighting the importance of ¹⁵⁵Gd target enrichment.</p>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"225 ","pages":"112026"},"PeriodicalIF":1.8,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144741021","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}