Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.019
Jacob G. Fantidis , Athanasia Κ. Thomoglou , Maristella Ε. Voutetaki , Bassam Tayeh , George Nikolaou
The evaluation of non-destructive neutron radiography (NR) for examining the internal composition of various structural materials, has been the focus of extensive research. This manuscript uses non-destructive testing to generate three-dimensional radiographs of three different brick structural materials: glass block, magnesia-chrome, and lead to evaluate their capability to withstand fast neutrons and gammas emitted from a source. When neutrons with thermal or epithermal spectrum are required, the optimum combination for an accelerator was simulated using a 2.8 MeV proton beam on a lithium target. The presented facility tested both thermal and fast neutron radiography. This study examined various aperture diameters and collimator lengths. It found that implementing a special fast neutron filter significantly increased the thermal neutron content (TNC) with minimal impact on the thermal neutron flux. For fast neutron radiography, the study evaluated parameters such as geometric unsharpness, fast neutron flux, and the percentage of the uncollided fast neutron reaching the object. Both neutrons and photons from the source were used to inspect faults in a glass brick.
{"title":"Bricks non-destructive simulation testing method utilizing neutron radiography facility based on a 7Li(p,n)7Be reaction","authors":"Jacob G. Fantidis , Athanasia Κ. Thomoglou , Maristella Ε. Voutetaki , Bassam Tayeh , George Nikolaou","doi":"10.1016/j.net.2024.08.019","DOIUrl":"10.1016/j.net.2024.08.019","url":null,"abstract":"<div><div>The evaluation of non-destructive neutron radiography (NR) for examining the internal composition of various structural materials, has been the focus of extensive research. This manuscript uses non-destructive testing to generate three-dimensional radiographs of three different brick structural materials: glass block, magnesia-chrome, and lead to evaluate their capability to withstand fast neutrons and gammas emitted from a source. When neutrons with thermal or epithermal spectrum are required, the optimum combination for an accelerator was simulated using a 2.8 MeV proton beam on a lithium target. The presented facility tested both thermal and fast neutron radiography. This study examined various aperture diameters and collimator lengths. It found that implementing a special fast neutron filter significantly increased the thermal neutron content (TNC) with minimal impact on the thermal neutron flux. For fast neutron radiography, the study evaluated parameters such as geometric unsharpness, fast neutron flux, and the percentage of the uncollided fast neutron reaching the object. Both neutrons and photons from the source were used to inspect faults in a glass brick.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103150"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.017
Sijiu Qi , Wei Tan , Ke Zhang , Yuancen Wang , Wenjing Lin , Peize Han , Guorui Zhu
The fluidelastic instability (FEI) in heat exchanger tubes has been of widespread concern due to its tendency to cause damage to the tubes. Generally, FEI in the transverse direction of the tube occurs earlier than in the streamwise direction, and the intrinsic frequency of the tube as well as the way of tube distribution have a great influence. The mechanisms involved in inducing FEI need to be further investigated. We set up an air-water two-phase flow water tunnel test system and adopt a normal triangular arrangement plate with a pitch-to-diameter ratio of 1.41 to conduct experiments. It was ensured that FEI could occur in the experimental flow range, by varying the intrinsic frequency of the flexible tube. The fluidelastic instability phenomenon was investigated in a single flexible tube array and a cluster of seven flexible tubes (the central cluster). Comparative analysis was conducted between the results of the two array configurations. The experiments involved concurrent streamwise and transverse directions, and an analysis of the pressure exerted on the flexible tubes. Additionally, the “transitional” state observed in flexible tubes under strongly coupled vibration in the central cluster was explored. The findings indicated that a cluster of seven flexible tubes intensified the vibration coupling between bundles, leading to a more complex flow field around the tube bundle perimeter, consequently exacerbating tube vibration. Furthermore, under the “transitional” state, enhanced stability was manifested. Additionally, instability in the streamwise direction was primarily controlled by the stiffness mechanism; a single flexible tube did not exhibit fluidelastic instability in the streamwise direction, while the central cluster did. This paper recommends an instability constant (K) value of 3.4 for the Connors formula for a normal triangular tube bundle configuration with the pitch-to-diameter ratio of 1.41, thereby providing empirical and theoretical support for the vibration analysis of tube bundles.
{"title":"Study of fluidelastic instability in the streamwise and transverse directions through tube array under two-phase flow conditions using pressure effects","authors":"Sijiu Qi , Wei Tan , Ke Zhang , Yuancen Wang , Wenjing Lin , Peize Han , Guorui Zhu","doi":"10.1016/j.net.2024.08.017","DOIUrl":"10.1016/j.net.2024.08.017","url":null,"abstract":"<div><div>The fluidelastic instability (FEI) in heat exchanger tubes has been of widespread concern due to its tendency to cause damage to the tubes. Generally, FEI in the transverse direction of the tube occurs earlier than in the streamwise direction, and the intrinsic frequency of the tube as well as the way of tube distribution have a great influence. The mechanisms involved in inducing FEI need to be further investigated. We set up an air-water two-phase flow water tunnel test system and adopt a normal triangular arrangement plate with a pitch-to-diameter ratio of 1.41 to conduct experiments. It was ensured that FEI could occur in the experimental flow range, by varying the intrinsic frequency of the flexible tube. The fluidelastic instability phenomenon was investigated in a single flexible tube array and a cluster of seven flexible tubes (the central cluster). Comparative analysis was conducted between the results of the two array configurations. The experiments involved concurrent streamwise and transverse directions, and an analysis of the pressure exerted on the flexible tubes. Additionally, the “transitional” state observed in flexible tubes under strongly coupled vibration in the central cluster was explored. The findings indicated that a cluster of seven flexible tubes intensified the vibration coupling between bundles, leading to a more complex flow field around the tube bundle perimeter, consequently exacerbating tube vibration. Furthermore, under the “transitional” state, enhanced stability was manifested. Additionally, instability in the streamwise direction was primarily controlled by the stiffness mechanism; a single flexible tube did not exhibit fluidelastic instability in the streamwise direction, while the central cluster did. This paper recommends an instability constant (K) value of 3.4 for the Connors formula for a normal triangular tube bundle configuration with the pitch-to-diameter ratio of 1.41, thereby providing empirical and theoretical support for the vibration analysis of tube bundles.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103148"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.07.056
Qi Liu , Jinhai Li , Haitao Wang , Yan Zhang , Haisheng Chen , Renbo Wang , Shumin Zhou
In this paper, we present a new structure of capacitor-inductor discharge circuit and develop a pulsed magnetic field power supply for small size Betatron, addressing the urgent need for adjustable pulsed radiation frequencies. The proposed power supply employs insulated gate bipolar transistors (IGBTs) to control the discharge of the energy storage capacitor to the excitation winding, thus generating a pulsed current, which produces a pulsed magnetic field and accelerates the electrons. By adjusting the operating frequency of the IGBTs, the frequency of the pulsed current, and consequently the accelerator pulsed radiation frequency, can be regulated. The proposed design employs dual sustained paths, which are formed by the energy storage capacitor and the excitation winding, as well as a loss-compensation capacitor with the excitation winding. By adjusting the loss-compensation time, the problem of the pulsed current amplitude attenuation due to losses can be overcome, ensuring the stability of the pulsed magnetic field. Experimental results show that the power supply produces a pulsed current up to 220 A, which accelerates the electrons to 6.2 MeV, allowing the accelerator pulsed radiation frequency to be adjusted within a 333-Hz range. The proposed power supply makes small size Betatron suitable for a wide range of applications and provides technical knowledge for other types accelerators.
{"title":"Development of a pulsed magnetic field power supply for small size Betatron","authors":"Qi Liu , Jinhai Li , Haitao Wang , Yan Zhang , Haisheng Chen , Renbo Wang , Shumin Zhou","doi":"10.1016/j.net.2024.07.056","DOIUrl":"10.1016/j.net.2024.07.056","url":null,"abstract":"<div><div>In this paper, we present a new structure of capacitor-inductor discharge circuit and develop a pulsed magnetic field power supply for small size Betatron, addressing the urgent need for adjustable pulsed radiation frequencies. The proposed power supply employs insulated gate bipolar transistors (IGBTs) to control the discharge of the energy storage capacitor to the excitation winding, thus generating a pulsed current, which produces a pulsed magnetic field and accelerates the electrons. By adjusting the operating frequency of the IGBTs, the frequency of the pulsed current, and consequently the accelerator pulsed radiation frequency, can be regulated. The proposed design employs dual sustained paths, which are formed by the energy storage capacitor and the excitation winding, as well as a loss-compensation capacitor with the excitation winding. By adjusting the loss-compensation time, the problem of the pulsed current amplitude attenuation due to losses can be overcome, ensuring the stability of the pulsed magnetic field. Experimental results show that the power supply produces a pulsed current up to 220 A, which accelerates the electrons to 6.2 MeV, allowing the accelerator pulsed radiation frequency to be adjusted within a 333-Hz range. The proposed power supply makes small size Betatron suitable for a wide range of applications and provides technical knowledge for other types accelerators.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103125"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.07.051
Longxian Li, Min Zhu, Yan Li, Yanru Ren, Longfei Pu, Chengxuan Peng
A first-principles approach based on density-functional theory has been used to investigate the corrosion resistance of alpha-U in the CO environment. Calculations show that O2 molecules spontaneously dissociate on the uranium surface, and the two O atoms formed by dissociation tend to adsorb on the hole sites and bind to the surface in the form of a U–O bond to emit a large amount of heat. The CO molecules occur on the surface of uranium as a non-dissociative chemical. The mechanism of CO inhibiting the adsorption of O2 molecules stems from the fact that CO molecules occupy the optimal adsorption sites. Another inhibition mechanism, the combination of C atoms and O atoms to form bonds and consume oxygen atoms, has little effect on uranium corrosion.
我们采用基于密度泛函理论的第一原理方法研究了α-U 在 CO 环境中的耐腐蚀性。计算表明，O 分子在铀表面自发解离，解离形成的两个 O 原子倾向于吸附在空穴位点上，并以 U-O 键的形式与表面结合，从而释放出大量热量。CO 分子作为一种非解离化学物质出现在铀表面。CO 抑制 O 分子吸附的机制源于 CO 分子占据了最佳吸附位点。另一种抑制机制，即 C 原子和 O 原子结合成键并消耗氧原子，对铀腐蚀的影响很小。
{"title":"The role of CO on initial oxidation behavior of α-U(001) surface: A first principles study","authors":"Longxian Li, Min Zhu, Yan Li, Yanru Ren, Longfei Pu, Chengxuan Peng","doi":"10.1016/j.net.2024.07.051","DOIUrl":"10.1016/j.net.2024.07.051","url":null,"abstract":"<div><div>A first-principles approach based on density-functional theory has been used to investigate the corrosion resistance of alpha-U in the CO environment. Calculations show that O<sub>2</sub> molecules spontaneously dissociate on the uranium surface, and the two O atoms formed by dissociation tend to adsorb on the hole sites and bind to the surface in the form of a U–O bond to emit a large amount of heat. The CO molecules occur on the surface of uranium as a non-dissociative chemical. The mechanism of CO inhibiting the adsorption of O<sub>2</sub> molecules stems from the fact that CO molecules occupy the optimal adsorption sites. Another inhibition mechanism, the combination of C atoms and O atoms to form bonds and consume oxygen atoms, has little effect on uranium corrosion.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103120"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.002
Qiang Yan , Yong Li , Guowei Wang , Zhengxin Wu , Haitao Zhang , Chuyuan Mao , Zhiqiang Long , Guoqing Liu
To develop lead-free gamma-ray shielding material, bismuth tungstate (Bi2WO6) nanocrystals were synthesized under different conditions of precursor solution by hydrothermal method and composite material based on polyurethane and bismuth tungstate nanocrystals were prepared and evaluated using gamma ray sources in this study. The effects of crystal structure and morphology on the gamma ray shielding properties of bismuth tungstate were specially investigated. Results indicated that pH value of precursors solution had significant effect on the synthesis of bismuth tungstate: orthorhombic Bi2WO6 were obtained under acidic or neutral conditions while tetragonal Bi0.875W0.125O1.6875 were obtained under strongly alkaline condition. With the increase of pH value, the morphology of bismuth tungstate changed from flower-like microspheres to persimmon-like microstructures, and then to randomly stacked nanosheets. Bismuth tungstate nanocrystals were added to polyurethane to prepare flexible gamma-ray shielding material and the gamma ray shielding properties were also tested with energy of 59.5 keV, 81.0 keV and 121.8 keV. For orthorhombic persimmon-like bismuth tungstate (Bi2WO6) which were produced under weak acidic or neutral condition (pH = 2, 5, 7), it was found that the linear attenuation coefficient of gamma ray grew by about 8 % when pH changing from 2 to 7 for all energy tested. While for tetragonal bismuth tungstate (Bi0.875W0.125O1.6875), weakly alkaline condition (pH = 9) induced significant decrease (9 %@59.5 keV, 17 %@81.0 keV and 11 %121.8 keV) of linear attenuation coefficient compared with neutral condition, which could be explained by the dramatic crystal structure change of bismuth tungstate. More alkaline synthesizing condition would make finer granularity of bismuth tungstate and the linear attenuation coefficient increased when pH change from 9 to 12. In addition, obvious differences of mechanical properties were also observed between the composites prepared using different crystalline bismuth tungstates. The results of this study provide a reference for the development of new flexible radiation shielding materials with non-toxicity, light weight and high efficiency.
{"title":"Evaluation of gamma rays shielding properties of bismuth tungstate with different morphologies","authors":"Qiang Yan , Yong Li , Guowei Wang , Zhengxin Wu , Haitao Zhang , Chuyuan Mao , Zhiqiang Long , Guoqing Liu","doi":"10.1016/j.net.2024.08.002","DOIUrl":"10.1016/j.net.2024.08.002","url":null,"abstract":"<div><div>To develop lead-free gamma-ray shielding material, bismuth tungstate (Bi<sub>2</sub>WO<sub>6</sub>) nanocrystals were synthesized under different conditions of precursor solution by hydrothermal method and composite material based on polyurethane and bismuth tungstate nanocrystals were prepared and evaluated using gamma ray sources in this study. The effects of crystal structure and morphology on the gamma ray shielding properties of bismuth tungstate were specially investigated. Results indicated that pH value of precursors solution had significant effect on the synthesis of bismuth tungstate: orthorhombic Bi<sub>2</sub>WO<sub>6</sub> were obtained under acidic or neutral conditions while tetragonal Bi<sub>0.875</sub>W<sub>0.125</sub>O<sub>1.6875</sub> were obtained under strongly alkaline condition. With the increase of pH value, the morphology of bismuth tungstate changed from flower-like microspheres to persimmon-like microstructures, and then to randomly stacked nanosheets. Bismuth tungstate nanocrystals were added to polyurethane to prepare flexible gamma-ray shielding material and the gamma ray shielding properties were also tested with energy of 59.5 keV, 81.0 keV and 121.8 keV. For orthorhombic persimmon-like bismuth tungstate (Bi<sub>2</sub>WO<sub>6</sub>) which were produced under weak acidic or neutral condition (pH = 2, 5, 7), it was found that the linear attenuation coefficient of gamma ray grew by about 8 % when pH changing from 2 to 7 for all energy tested. While for tetragonal bismuth tungstate (Bi<sub>0.875</sub>W<sub>0.125</sub>O<sub>1.6875</sub>), weakly alkaline condition (pH = 9) induced significant decrease (9 %@59.5 keV, 17 %@81.0 keV and 11 %121.8 keV) of linear attenuation coefficient compared with neutral condition, which could be explained by the dramatic crystal structure change of bismuth tungstate. More alkaline synthesizing condition would make finer granularity of bismuth tungstate and the linear attenuation coefficient increased when pH change from 9 to 12. In addition, obvious differences of mechanical properties were also observed between the composites prepared using different crystalline bismuth tungstates. The results of this study provide a reference for the development of new flexible radiation shielding materials with non-toxicity, light weight and high efficiency.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103133"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.07.061
Rui Chen, Qingxian Zhang, Jian Zhang, Liangquan Ge, Yi Gu, Rui Yang, Hui Li, Qiushi Liu, Zhiqiang Cheng, Yi Lin
The X-ray spectrum of X-ray tube is crucial for radiation dose calculations. Due to the high photon flux, it is difficult to directly measure the primary spectrum of X-ray tube. Transmission measurement is one of indirect method used to determine the primary spectrum of X-ray tube. Although the method is experimentally simple, X-ray spectrum estimation from transmission method is a seriously ill-conditioned problem. In this paper, a new transmission measurement instrument with an the Al2O3:C crystal detector is proposed. Real-time dose rate attenuation data from transmission method are collected by using the radioluminescence(RL) of the Al2O3:C crystal. The expectation-maximization (EM) method is applied for X-ray spectrum estimation from transmission method. The method is demonstrated on typical simulated spectra of 80,100,120,140 and 160 kV from X-ray tubes. The X-ray spectra are simulated with the Monte Carlo code Geant4. The EM method is successfully applied to seriously ill-conditioned and under determined estimation problems. The results showed that the X-ray spectrum estimation method is a robust technique for estimating the primary spectrum of X-ray tube, and that the new instrument for transmission measurements can be used to accurately estimate X-ray spectrum.
{"title":"X-ray spectrum estimation from the transmission method using the radioluminescence of an Al2O3:C crystal","authors":"Rui Chen, Qingxian Zhang, Jian Zhang, Liangquan Ge, Yi Gu, Rui Yang, Hui Li, Qiushi Liu, Zhiqiang Cheng, Yi Lin","doi":"10.1016/j.net.2024.07.061","DOIUrl":"10.1016/j.net.2024.07.061","url":null,"abstract":"<div><div>The X-ray spectrum of X-ray tube is crucial for radiation dose calculations. Due to the high photon flux, it is difficult to directly measure the primary spectrum of X-ray tube. Transmission measurement is one of indirect method used to determine the primary spectrum of X-ray tube. Although the method is experimentally simple, X-ray spectrum estimation from transmission method is a seriously ill-conditioned problem. In this paper, a new transmission measurement instrument with an the Al<sub>2</sub>O<sub>3</sub>:C crystal detector is proposed. Real-time dose rate attenuation data from transmission method are collected by using the radioluminescence(RL) of the Al<sub>2</sub>O<sub>3</sub>:C crystal. The expectation-maximization (EM) method is applied for X-ray spectrum estimation from transmission method. The method is demonstrated on typical simulated spectra of 80,100,120,140 and 160 kV from X-ray tubes. The X-ray spectra are simulated with the Monte Carlo code Geant4. The EM method is successfully applied to seriously ill-conditioned and under determined estimation problems. The results showed that the X-ray spectrum estimation method is a robust technique for estimating the primary spectrum of X-ray tube, and that the new instrument for transmission measurements can be used to accurately estimate X-ray spectrum.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103130"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.008
Guoguang Li , Liang Sheng , Baojun Duan , Yang Li , Dongwei Hei , Qingzi Xing
Thick pinhole imaging system is widely used for diagnosing intense pulsed radiation sources. However, owing to the trade-off among spatial resolution, field of view (FOV) and signal-to-noise ratio (SNR), the imaging system normally falls short in achieving high-precision spatial diagnosis. In this paper, we propose an unsupervised deep learning method for single image super-resolution (SISR) of the thick pinhole imaging system. The point spread function (PSF) of the imaging system is obtained by analytical calculation and Monte Carlo simulation methods, and the mathematical model of the imaging system is established using a linear equation. To solve the ill-posed inverse problem, we adopt randomly initialized deep convolutional neural networks (DCNNs) as an image prior without pre-training, which is named deep image prior (DIP). The results demonstrate that, by utilizing the SISR technique to increase the number of pixels in reconstructed images, the proposed DIP algorithm can mitigate the spatial resolution degradation caused by an insufficient spatial sampling frequency of the camera. Compared with various classical algorithms, the proposed DIP algorithm exhibits superior capabilities in recovering high-frequency signals and suppressing ringing artifacts. Furthermore, the convergence and robustness of the proposed DIP algorithm under different random seeds and SNR conditions are also verified.
{"title":"Unsupervised deep learning method for single image super-resolution of the thick pinhole imaging system using deep image prior","authors":"Guoguang Li , Liang Sheng , Baojun Duan , Yang Li , Dongwei Hei , Qingzi Xing","doi":"10.1016/j.net.2024.08.008","DOIUrl":"10.1016/j.net.2024.08.008","url":null,"abstract":"<div><div>Thick pinhole imaging system is widely used for diagnosing intense pulsed radiation sources. However, owing to the trade-off among spatial resolution, field of view (FOV) and signal-to-noise ratio (SNR), the imaging system normally falls short in achieving high-precision spatial diagnosis. In this paper, we propose an unsupervised deep learning method for single image super-resolution (SISR) of the thick pinhole imaging system. The point spread function (PSF) of the imaging system is obtained by analytical calculation and Monte Carlo simulation methods, and the mathematical model of the imaging system is established using a linear equation. To solve the ill-posed inverse problem, we adopt randomly initialized deep convolutional neural networks (DCNNs) as an image prior without pre-training, which is named deep image prior (DIP). The results demonstrate that, by utilizing the SISR technique to increase the number of pixels in reconstructed images, the proposed DIP algorithm can mitigate the spatial resolution degradation caused by an insufficient spatial sampling frequency of the camera. Compared with various classical algorithms, the proposed DIP algorithm exhibits superior capabilities in recovering high-frequency signals and suppressing ringing artifacts. Furthermore, the convergence and robustness of the proposed DIP algorithm under different random seeds and SNR conditions are also verified.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103139"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.011
Mumtaz Ali , Ahmed Samour , Suhaib Ahmed Soomro , Waqar Khalid , Turgut Tursoy
Nuclear energy is considered an effective means of enhancing environmental sustainability. Considering this point, this study aims to explore the impact of nuclear energy, financial globalization, technological innovation, and economic growth on ecological sustainability in the top-10 nuclear energy-consuming economies from 1995 to 2020. The load capacity factor is used as a novel proxy for ecological sustainability, explaining how human actions affect ecological sustainability and how nature compensates for human-induced damage. The study employs a novel non-parametric MMQR approach to obtain coefficients across heterogeneous quantiles. The MMQR estimation findings indicate that: (i) nuclear and renewable energy consumption and financial globalization promote environmental sustainability by increasing the LCF; (ii) economic growth degrades ecological sustainability by decreasing the LCF; and (iii) the results from Granger causality suggest a causal link among economic growth, technological innovation, nuclear energy, and LCF. The study recommends that the governments of the top-10 nuclear energy-consuming countries facilitate more investment in green technologies and green energy to achieve environmental sustainability.
{"title":"A step towards a sustainable environment in top-10 nuclear energy consumer countries: The role of financial globalization and nuclear energy","authors":"Mumtaz Ali , Ahmed Samour , Suhaib Ahmed Soomro , Waqar Khalid , Turgut Tursoy","doi":"10.1016/j.net.2024.08.011","DOIUrl":"10.1016/j.net.2024.08.011","url":null,"abstract":"<div><div>Nuclear energy is considered an effective means of enhancing environmental sustainability. Considering this point, this study aims to explore the impact of nuclear energy, financial globalization, technological innovation, and economic growth on ecological sustainability in the top-10 nuclear energy-consuming economies from 1995 to 2020. The load capacity factor is used as a novel proxy for ecological sustainability, explaining how human actions affect ecological sustainability and how nature compensates for human-induced damage. The study employs a novel non-parametric MMQR approach to obtain coefficients across heterogeneous quantiles. The MMQR estimation findings indicate that: (i) nuclear and renewable energy consumption and financial globalization promote environmental sustainability by increasing the LCF; (ii) economic growth degrades ecological sustainability by decreasing the LCF; and (iii) the results from Granger causality suggest a causal link among economic growth, technological innovation, nuclear energy, and LCF. The study recommends that the governments of the top-10 nuclear energy-consuming countries facilitate more investment in green technologies and green energy to achieve environmental sustainability.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103142"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.001
Yin Qiu, Ming Li, Xiaolong Liu, Qinghua Ren, Tao Lin, Jian Liu
The TF coil of HL-3 consists of 20 D-shaped demountable bundles, and all their L-shaped center sections are bonded together as the center-post. To increase its overall rigidity to resist torsional loads and avoid de-bonding failure, the center-post is wrapped by an insulation cylinder with enough prestress. Additionally, the insulation cylinder needs to be of good dimensional precision because the CS coil is winded around it. This paper describes the results of the technical studies carried out during the development of the insulation cylinder, including material selection, parameter calculation, enlacing tests and curing tests.
HL-3 的 TF 线圈由 20 个 D 型可拆卸线束组成，其所有 L 型中心部分粘结在一起作为中柱。为了提高其整体刚度以抵抗扭转载荷，并避免脱粘失效，中柱由具有足够预应力的绝缘圆筒包裹。此外，由于希尔思线圈是缠绕在绝缘圆筒上的，因此绝缘圆筒需要有良好的尺寸精度。本文介绍了在绝缘筒开发过程中进行的技术研究结果，包括材料选择、参数计算、铺设试验和固化试验。
{"title":"Technical studies about the prestressed insulation cylinder of HL-3 tokamak's center-post","authors":"Yin Qiu, Ming Li, Xiaolong Liu, Qinghua Ren, Tao Lin, Jian Liu","doi":"10.1016/j.net.2024.08.001","DOIUrl":"10.1016/j.net.2024.08.001","url":null,"abstract":"<div><div>The TF coil of HL-3 consists of 20 D-shaped demountable bundles, and all their L-shaped center sections are bonded together as the center-post. To increase its overall rigidity to resist torsional loads and avoid de-bonding failure, the center-post is wrapped by an insulation cylinder with enough prestress. Additionally, the insulation cylinder needs to be of good dimensional precision because the CS coil is winded around it. This paper describes the results of the technical studies carried out during the development of the insulation cylinder, including material selection, parameter calculation, enlacing tests and curing tests.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103132"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.net.2024.08.024
Hui-hui Hong , Li-zhen Liang , Yuan-lai Xie , Qian-xu Wang , Zhuo Pan , Yao Jiang
Neutral beam injection is one of the effective heating methods in the field of magnetic confinement fusion, and neutralization is the most crucial link in the case of negative ions. To further increase the neutral beam injection power, improve the long pulse operation capability, and optimize the efficiency of the NNBI system, further research and verification about the neutralization mode are needed. Theoretically, photoneutralization can achieve more than 90 % neutralization efficiency. However, maintaining stable operation of the megawatt laser cavity over extended periods poses corresponding challenges. Additionally, the cost associated with laser target surpasses the benefit gained from increased neutralization efficiency, leading to its lack of practical application thus far. This paper proposes a solution to these issues by designing a single-channel, multi-fold photoneutralization verification system utilizing the CRAFT NNBI one-quarter and one-half size negative source test equipment. An outline of the system's test and diagnostics approach is provided. Key parameters such as laser target thickness, negative ion energy, beam shape and efficiency of the photoneutralization system are numerically calculated. Combined with the experimental data of the negative source test platform, theoretical calculations show that the neutralization efficiency can achieve 63 % with the system efficiency exceeding 40 %. Even by increasing the incident laser power or the number of reflections, neutralization efficiency can be increased to 95 %, with a simultaneous increase in system efficiency to 60 %. Maintaining efficiency while increasing incident laser power could reduce the number of reflections to approximately ten, reaching an acceptable threshold. However, this adjustment will increase the irradiation density of a single mirror from 660W/mm2 increases to 3000W/mm2. This paper methodically designs a practical laser neutralization verification platform, which is expected to substantially improve the neutralization efficiency, and facilitate practical application and validation.
{"title":"Conceptional design of photoneutralization test system for negative ion-based neutral beam injection","authors":"Hui-hui Hong , Li-zhen Liang , Yuan-lai Xie , Qian-xu Wang , Zhuo Pan , Yao Jiang","doi":"10.1016/j.net.2024.08.024","DOIUrl":"10.1016/j.net.2024.08.024","url":null,"abstract":"<div><div>Neutral beam injection is one of the effective heating methods in the field of magnetic confinement fusion, and neutralization is the most crucial link in the case of negative ions. To further increase the neutral beam injection power, improve the long pulse operation capability, and optimize the efficiency of the NNBI system, further research and verification about the neutralization mode are needed. Theoretically, photoneutralization can achieve more than 90 % neutralization efficiency. However, maintaining stable operation of the megawatt laser cavity over extended periods poses corresponding challenges. Additionally, the cost associated with laser target surpasses the benefit gained from increased neutralization efficiency, leading to its lack of practical application thus far. This paper proposes a solution to these issues by designing a single-channel, multi-fold photoneutralization verification system utilizing the CRAFT NNBI one-quarter and one-half size negative source test equipment. An outline of the system's test and diagnostics approach is provided. Key parameters such as laser target thickness, negative ion energy, beam shape and efficiency of the photoneutralization system are numerically calculated. Combined with the experimental data of the negative source test platform, theoretical calculations show that the neutralization efficiency can achieve 63 % with the system efficiency exceeding 40 %. Even by increasing the incident laser power or the number of reflections, neutralization efficiency can be increased to 95 %, with a simultaneous increase in system efficiency to 60 %. Maintaining efficiency while increasing incident laser power could reduce the number of reflections to approximately ten, reaching an acceptable threshold. However, this adjustment will increase the irradiation density of a single mirror from 660W/mm<sup>2</sup> increases to 3000W/mm<sup>2</sup>. This paper methodically designs a practical laser neutralization verification platform, which is expected to substantially improve the neutralization efficiency, and facilitate practical application and validation.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"57 1","pages":"Article 103155"},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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