Pub Date : 2023-11-13DOI: 10.1088/2058-6272/ad0c21
Qiangyou He, ZhiGang Deng, Zhimeng Zhang, Yadong Xia, Bo Zhang, Lingbiao Meng, Shukai He, Hua Huang, Lei Yang, Hongjie Liu, Wei Fan, Chen Lin, Weimin Zhou, Tingshuai Li, Xueqing Yan
Abstract Giant electromagnetic pulses (EMPs) induced by high-power laser irradiating solid targets interfere with various experimental diagnoses and even damage equipment, so unveiling the evolution of EMPs inside the laser chamber is crucial for designing effective EMP shielding. In this work, the transmission characteristics of EMPs as a function of distances from the target chamber center (TCC) are studied using B-dot probes. The mean EMP amplitude generated by picosecond laser-target interaction reaches 561 kV m-1, 357 kV m-1, 395 kV m-1, and 341 kV m-1 at 0.32 m, 0.53 m, 0.76 m, and 1 m from TCC, which decreases dramatically from 0.32 m to 0.53 m. However, it shows a fluctuation from 0.53 m to 1 m. The temporal features of EMPs indicate that time-domain EMP signals near the target chamber wall have a wider full width at half maximum compared to that close to TCC, mainly due to the echo oscillation of electromagnetic waves inside the target chamber based on simulation and experimentation. The conclusions of this study will provide a new approach to mitigate strong electromagnetic pulses by decreasing the echo oscillation of electromagnetic waves inside the target chamber during laser coupling with targets.
{"title":"Spatial and temporal evolution of electromagnetic pulses from solid target irradiated with multi-hundred-terawatt laser pulse inside target chamber","authors":"Qiangyou He, ZhiGang Deng, Zhimeng Zhang, Yadong Xia, Bo Zhang, Lingbiao Meng, Shukai He, Hua Huang, Lei Yang, Hongjie Liu, Wei Fan, Chen Lin, Weimin Zhou, Tingshuai Li, Xueqing Yan","doi":"10.1088/2058-6272/ad0c21","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c21","url":null,"abstract":"Abstract Giant electromagnetic pulses (EMPs) induced by high-power laser irradiating solid targets interfere with various experimental diagnoses and even damage equipment, so unveiling the evolution of EMPs inside the laser chamber is crucial for designing effective EMP shielding. In this work, the transmission characteristics of EMPs as a function of distances from the target chamber center (TCC) are studied using B-dot probes. The mean EMP amplitude generated by picosecond laser-target interaction reaches 561 kV m-1, 357 kV m-1, 395 kV m-1, and 341 kV m-1 at 0.32 m, 0.53 m, 0.76 m, and 1 m from TCC, which decreases dramatically from 0.32 m to 0.53 m. However, it shows a fluctuation from 0.53 m to 1 m. The temporal features of EMPs indicate that time-domain EMP signals near the target chamber wall have a wider full width at half maximum compared to that close to TCC, mainly due to the echo oscillation of electromagnetic waves inside the target chamber based on simulation and experimentation. The conclusions of this study will provide a new approach to mitigate strong electromagnetic pulses by decreasing the echo oscillation of electromagnetic waves inside the target chamber during laser coupling with targets.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281628","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}
Abstract Historically, the streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis, with limited attention paid to the sphere-plane gap at high altitude analysis. In this paper, the sphere-plane gap discharge tests were carried out under the gap distance of 5m at the Qinghai Ultra High Voltage (UHV) test base at an altitude of 2200m. The experiments measured the physical parameters such as discharge current, electric field intensity and instantaneous optical power. The duration of the dark period and the critical charge of streamer-to-leader transition were obtained at high altitude. Based on radial thermal expansion of streamer stem, we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude, and calculated the stem temperature, stem radii and the duration of streamer-to-leader transition. Compared with measured duration of sphere-plane electrode discharge at an altitude of 2200m, the error rate of the modified model was 0.94%, while the classical model was 6.97%, demonstrating the effectiveness of the modified model. From the comparisons and analysis, several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception.
{"title":"Modification of streamer-to-leader transition model based on radial thermal expansion in the sphere-plane gap discharge at high altitude","authors":"Jianghai Geng, Guo Lin, Ping Wang, Yujian Ding, Yang Ding, Hua Yu","doi":"10.1088/2058-6272/ad0c1c","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c1c","url":null,"abstract":"Abstract Historically, the streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis, with limited attention paid to the sphere-plane gap at high altitude analysis. In this paper, the sphere-plane gap discharge tests were carried out under the gap distance of 5m at the Qinghai Ultra High Voltage (UHV) test base at an altitude of 2200m. The experiments measured the physical parameters such as discharge current, electric field intensity and instantaneous optical power. The duration of the dark period and the critical charge of streamer-to-leader transition were obtained at high altitude. Based on radial thermal expansion of streamer stem, we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude, and calculated the stem temperature, stem radii and the duration of streamer-to-leader transition. Compared with measured duration of sphere-plane electrode discharge at an altitude of 2200m, the error rate of the modified model was 0.94%, while the classical model was 6.97%, demonstrating the effectiveness of the modified model. From the comparisons and analysis, several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"57 21","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281631","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c1d
Wangling He, Hongyu Wei, Yinlu Zhang, Yongcong Liu, Yunpeng Liu, Baoquan Wan, Yang Zhou, Yanzhao Wan, Zheyuan Gan
Abstract The corona discharge from transmission lines in high-altitude areas is more severe than that in plain areas. The radio interferences caused thereby are key factors to be considered in the design of transmission lines. To study the influence of altitude on the negative corona characteristics, a movable small corona cage experimental platform was established: experiments were conducted at four altitudes in the range of 1120‒4320m, and the corona current pulse and radio interference level of 0.8-mm diameter fine copper wire under different negative voltages were collected. The experimental results show that the average amplitude, repetition frequency, and average current of corona current pulse increase with the increase of altitude. The dispersion of pulse amplitude increases with the increase of altitude, while the randomness of pulse interval decreases continuously. Taking the average current as an intermediate variable, the relationship of radio interference level with altitude is obtained. The research has certain guiding significance for understanding the corona discharge characteristics of ultra-high voltage lines.
{"title":"The characteristics of negative corona discharge and radio interference at different altitudes based on coaxial wire-cylinder gap","authors":"Wangling He, Hongyu Wei, Yinlu Zhang, Yongcong Liu, Yunpeng Liu, Baoquan Wan, Yang Zhou, Yanzhao Wan, Zheyuan Gan","doi":"10.1088/2058-6272/ad0c1d","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c1d","url":null,"abstract":"Abstract The corona discharge from transmission lines in high-altitude areas is more severe than that in plain areas. The radio interferences caused thereby are key factors to be considered in the design of transmission lines. To study the influence of altitude on the negative corona characteristics, a movable small corona cage experimental platform was established: experiments were conducted at four altitudes in the range of 1120‒4320m, and the corona current pulse and radio interference level of 0.8-mm diameter fine copper wire under different negative voltages were collected. The experimental results show that the average amplitude, repetition frequency, and average current of corona current pulse increase with the increase of altitude. The dispersion of pulse amplitude increases with the increase of altitude, while the randomness of pulse interval decreases continuously. Taking the average current as an intermediate variable, the relationship of radio interference level with altitude is obtained. The research has certain guiding significance for understanding the corona discharge characteristics of ultra-high voltage lines.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"57 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281633","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c23
Shuailing Lu, Xuebin Ma, Songlin Liu
Abstract The supercritical CO2 cOoled Lithium-Lead (COOL) blanket has been designed as one advanced blanket candidate for the Chinese Fusion Engineering Test Reactor (CFETR). This paper focuses on the electromagnetic (EM) loads (Maxwell force and Lorentz force) acting on the COOL blanket, which are important mechanical loads in further structural analysis of the COOL blanket. In this study, a 3D electromagnetic analysis is performed using ANSYS finite element method to obtain EM force on the COOL blanket. Firstly, the magnetic scalar potential (MSP) method is used to obtain the magnetic field distribution and the Maxwell force on the COOL blanket. Then, the magnetic vector potential (MVP) method is performed during a plasma disruption event to get the eddy current distribution. At last, a multi-step method is adopted for the calculation of the Lorentz force and the torque. The maximum Lorentz force of inboard and outboard blanket structural components is 4968kN and 1786kN respectively.
{"title":"Preliminary electromagnetic analysis of the COOL blanket for CFETR","authors":"Shuailing Lu, Xuebin Ma, Songlin Liu","doi":"10.1088/2058-6272/ad0c23","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c23","url":null,"abstract":"Abstract The supercritical CO2 cOoled Lithium-Lead (COOL) blanket has been designed as one advanced blanket candidate for the Chinese Fusion Engineering Test Reactor (CFETR). This paper focuses on the electromagnetic (EM) loads (Maxwell force and Lorentz force) acting on the COOL blanket, which are important mechanical loads in further structural analysis of the COOL blanket. In this study, a 3D electromagnetic analysis is performed using ANSYS finite element method to obtain EM force on the COOL blanket. Firstly, the magnetic scalar potential (MSP) method is used to obtain the magnetic field distribution and the Maxwell force on the COOL blanket. Then, the magnetic vector potential (MVP) method is performed during a plasma disruption event to get the eddy current distribution. At last, a multi-step method is adopted for the calculation of the Lorentz force and the torque. The maximum Lorentz force of inboard and outboard blanket structural components is 4968kN and 1786kN respectively.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"58 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281762","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c1f
Yikang Jia, Tianhui Li, Rui Zhang, Pengyu Zhao, Zifeng Wang, Min Chen, Li Guo, Dingxin Liu
Abstract Plasma-activated water (PAW), as an extended form of cold atmospheric-pressure plasma, greatly expands the application of plasma-based technology. The biological effects of PAW are closely related to the aqueous reactive species, which can be regulated by the activation process. In this study, the surface plasma-activated air (SAA) and the He + O2 plasma jet (Jet) were parallelly combined (the SAA + Jet combination) or sequential combined (the SAA → Jet combination and the Jet → SAA combination) to prepare plasma-activated saline (PAS). The PAS activated by the combinations exhibited stronger bactericidal effects than that activated by the SAA or the Jet alone. The concentrations of H2O2 and NO2− were higher in the PAS activated by the Jet → SAA combination, while ONOO− were close in the three kinds of PAS and 1O2 were highest in the PAS activated by the SAA + Jet combination. The analysis of scavengers also demonstrated that H2O2, 1O2, and ONOO‒ in the PAS activated by the SAA + Jet combination, and 1O2 in the PAS activated by the Jet → SAA combination played critical roles in bactericidal effects. Further, the effective placement time of the three PAS varied and the PAS activated by the Jet → SAA combination could also inactivate 2.6-log10 of the MRSA cells after placement for more than 60 min. The regulation of reactive species in plasma-activated water through different combinations of plasma devices could improve the directional application of plasma-activated water in the biomedical field.
{"title":"Different bactericidal abilities of plasma-activated saline with varied reactive species prepared by the combinations of surface plasma-activated air and plasma jet","authors":"Yikang Jia, Tianhui Li, Rui Zhang, Pengyu Zhao, Zifeng Wang, Min Chen, Li Guo, Dingxin Liu","doi":"10.1088/2058-6272/ad0c1f","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c1f","url":null,"abstract":"Abstract Plasma-activated water (PAW), as an extended form of cold atmospheric-pressure plasma, greatly expands the application of plasma-based technology. The biological effects of PAW are closely related to the aqueous reactive species, which can be regulated by the activation process. In this study, the surface plasma-activated air (SAA) and the He + O2 plasma jet (Jet) were parallelly combined (the SAA + Jet combination) or sequential combined (the SAA → Jet combination and the Jet → SAA combination) to prepare plasma-activated saline (PAS). The PAS activated by the combinations exhibited stronger bactericidal effects than that activated by the SAA or the Jet alone. The concentrations of H2O2 and NO2− were higher in the PAS activated by the Jet → SAA combination, while ONOO− were close in the three kinds of PAS and 1O2 were highest in the PAS activated by the SAA + Jet combination. The analysis of scavengers also demonstrated that H2O2, 1O2, and ONOO‒ in the PAS activated by the SAA + Jet combination, and 1O2 in the PAS activated by the Jet → SAA combination played critical roles in bactericidal effects. Further, the effective placement time of the three PAS varied and the PAS activated by the Jet → SAA combination could also inactivate 2.6-log10 of the MRSA cells after placement for more than 60 min. The regulation of reactive species in plasma-activated water through different combinations of plasma devices could improve the directional application of plasma-activated water in the biomedical field.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"58 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281626","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c1e
Cunkai Li, Yunfeng Liang, Zhonghe Jiang, Song Zhou, Jiankun Hua, Jie Yang, Qinghu Yang, Alexander Knieps, Philipp Drews, Xin Xu, Feiyue Mao, Wei Xie, Yutong Yang, Jinlong Guo, Yangbo Li, Zhengkang Ren, Zhipeng Chen, Nengchao Wang
Abstract Accurate measurements of the edge plasma equilibrium profiles, including the temperature and density of electrons and ions, are critical to understanding the characteristics of the scrape-off layer (SOL) and divertor plasma transport in magnetically confined fusion research. On the J-TEXT tokamak, a multi-channel retarding field analyzer (RFA) probe has been developed to study edge plasma equilibrium profiles under various poloidal divertor and island divertor configurations. The edge radial profile of the ion-to-electron temperature ratio, τ_{i/e}, has been determined, which gradually decreases as the SOL ion self-collisionality, ν_{SOL}^*, increases. This is widely consistent with what has been observed previously from various tokamak experiments. However, the comparison of experimental results under different configurations shows that in the poloidal divertor configuration, even under the same ν_{SOL}^*, τ_{i/e} in the SOL region becomes smaller as the distance from the X-point to the target plate increases. In the island divertor configuration, τ_{i/e} near the O-point is higher than that near the X-point at the same ν_{SOL}^*, and both are higher than the limiter configuration. These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.
{"title":"Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations","authors":"Cunkai Li, Yunfeng Liang, Zhonghe Jiang, Song Zhou, Jiankun Hua, Jie Yang, Qinghu Yang, Alexander Knieps, Philipp Drews, Xin Xu, Feiyue Mao, Wei Xie, Yutong Yang, Jinlong Guo, Yangbo Li, Zhengkang Ren, Zhipeng Chen, Nengchao Wang","doi":"10.1088/2058-6272/ad0c1e","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c1e","url":null,"abstract":"Abstract Accurate measurements of the edge plasma equilibrium profiles, including the temperature and density of electrons and ions, are critical to understanding the characteristics of the scrape-off layer (SOL) and divertor plasma transport in magnetically confined fusion research. On the J-TEXT tokamak, a multi-channel retarding field analyzer (RFA) probe has been developed to study edge plasma equilibrium profiles under various poloidal divertor and island divertor configurations. The edge radial profile of the ion-to-electron temperature ratio, τ_{i/e}, has been determined, which gradually decreases as the SOL ion self-collisionality, ν_{SOL}^*, increases. This is widely consistent with what has been observed previously from various tokamak experiments. However, the comparison of experimental results under different configurations shows that in the poloidal divertor configuration, even under the same ν_{SOL}^*, τ_{i/e} in the SOL region becomes smaller as the distance from the X-point to the target plate increases. In the island divertor configuration, τ_{i/e} near the O-point is higher than that near the X-point at the same ν_{SOL}^*, and both are higher than the limiter configuration. These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"57 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281632","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c22
Haoxi Cong, Yuxuan Wang, Lipan Qiao, Wenjing Su, Qingmin Li
The initial shape of the secondary arc considerably influences its subsequent shape. To establish the model for the arcing time of the secondary arc and modify the single-phase reclosing sequence, theoretically and experimentally analyzing the evolution process of the short-circuit arc to the secondary arc is critical. In this study, an improved charge simulation method was used to develop the internal space electric field model of the short-circuit arc. The intensity of the electric field was used as an independent variable to describe the initial shape of the secondary arc. A secondary arc evolution model was developed based on this model. Moreover, the accuracy of the model was evaluated by comparing with physical experimental results. When the secondary arc current increased, the arcing time and dispersion increased. There is an overall trend of increasing arc length with increasing arcing time. Nevertheless, there is a reduction in arc length during arc ignition due to short circuits between the arc columns. Furthermore, the arcing time decreased in the range of 0°–90° as the angle between the wind direction and the x-axis increased. This study investigated the method by which short-circuit arcs evolve into secondary arcs. The results can be used to develop the secondary arc evolution model and provide both a technical and theoretical basis for secondary arc suppression.
{"title":"Spatiotemporal evolution of short-circuit arc to secondary arc based on the improved charge model","authors":"Haoxi Cong, Yuxuan Wang, Lipan Qiao, Wenjing Su, Qingmin Li","doi":"10.1088/2058-6272/ad0c22","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c22","url":null,"abstract":"The initial shape of the secondary arc considerably influences its subsequent shape. To establish the model for the arcing time of the secondary arc and modify the single-phase reclosing sequence, theoretically and experimentally analyzing the evolution process of the short-circuit arc to the secondary arc is critical. In this study, an improved charge simulation method was used to develop the internal space electric field model of the short-circuit arc. The intensity of the electric field was used as an independent variable to describe the initial shape of the secondary arc. A secondary arc evolution model was developed based on this model. Moreover, the accuracy of the model was evaluated by comparing with physical experimental results. When the secondary arc current increased, the arcing time and dispersion increased. There is an overall trend of increasing arc length with increasing arcing time. Nevertheless, there is a reduction in arc length during arc ignition due to short circuits between the arc columns. Furthermore, the arcing time decreased in the range of 0°–90° as the angle between the wind direction and the x-axis increased. This study investigated the method by which short-circuit arcs evolve into secondary arcs. The results can be used to develop the secondary arc evolution model and provide both a technical and theoretical basis for secondary arc suppression.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"58 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281759","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 : 2023-11-13DOI: 10.1088/2058-6272/ad0c24
Letian Li, Shaocheng Liu, Ning Yan, Xiaoju Liu, Xiang Gao
Abstract The gas puff imaging (GPI) diagnostic has been developed and operated on EAST since 2012, and the time-delay estimation (TDE) method is used to derive the propagation velocity of fluctuations from the two-dimensional GPI data. However, the TDE method is difficult to analyze the data with fast transient events, such as edge-localized mode (ELM). In consequence, a method called the spatial displacement estimation (SDE) algorithm is developed to estimate the turbulence velocity with high temporal resolution. Based on the SDE algorithm, we make some improvements, including an adaptive median filter and super-resolution technology. After the development of the algorithm, a straight-line movement and a curved-line movement are used to test the accuracy of the algorithm, and the calculated speed agrees well with preset speed. This SDE algorithm is applied to the EAST GPI data analysis, and the derived propagation velocity of turbulence is consistent with that from the TDE method, but with much higher temporal resolution.
{"title":"Development of 2D spatial displacement estimation method for turbulence velocimetry of gas puff imaging system on EAST","authors":"Letian Li, Shaocheng Liu, Ning Yan, Xiaoju Liu, Xiang Gao","doi":"10.1088/2058-6272/ad0c24","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c24","url":null,"abstract":"Abstract The gas puff imaging (GPI) diagnostic has been developed and operated on EAST since 2012, and the time-delay estimation (TDE) method is used to derive the propagation velocity of fluctuations from the two-dimensional GPI data. However, the TDE method is difficult to analyze the data with fast transient events, such as edge-localized mode (ELM). In consequence, a method called the spatial displacement estimation (SDE) algorithm is developed to estimate the turbulence velocity with high temporal resolution. Based on the SDE algorithm, we make some improvements, including an adaptive median filter and super-resolution technology. After the development of the algorithm, a straight-line movement and a curved-line movement are used to test the accuracy of the algorithm, and the calculated speed agrees well with preset speed. This SDE algorithm is applied to the EAST GPI data analysis, and the derived propagation velocity of turbulence is consistent with that from the TDE method, but with much higher temporal resolution.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"58 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281621","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}
Abstract Rapid online analysis of liquid slag is essential for optimizing the quality and energy 
efficiency of steel production. To investigate the key factors that affect the online measurement of 
refined slag using laser-induced breakdown spectroscopy (LIBS), this study examined the effects 
of slag composition and temperature on the intensity and stability of the LIBS spectra. The 
experimental temperature was controlled at three levels: 1350, 1400, and 1450 °C. The results 
showed that slag composition and temperature significantly affected the intensity and stability of 
the LIBS spectra. Increasing the Fe content and temperature in the slag reduces its viscosity, 
resulting in an enhanced intensity and stability of the LIBS spectra. Additionally, 42 refined slag 
samples were quantitatively analyzed for Fe, Si, Ca, Mg, Al, and Mn at 1350, 1400, and 1450 °C. 
The normalized full spectrum combined with partial least squares (PLS) quantification modeling 
was used, using the Ca II 317.91 nm spectral line as an internal standard. The results show that using the internal standard normalization method can significantly reduce the influence of spectral 
fluctuations. Meanwhile, a temperature of 1450 °C has been found to yield superior results 
compared to both 1350 and 1400 °C, and it is advantageous to conduct a quantitative analysis of 
the slag when it is in a water-like state with low viscosity.
摘要快速在线分析液渣对优化钢铁生产质量和能源效率至关重要。为了研究影响激光诱导击穿光谱(LIBS)在线测量精渣的关键因素，本研究考察了渣成分和温度对LIBS光谱强度和稳定性的影响。实验温度控制在1350、1400和1450°C三个水平。结果表明，炉渣成分和温度显著影响LIBS谱的强度和稳定性。随着炉渣中铁含量和温度的升高，炉渣的黏度降低，LIBS光谱的强度和稳定性增强。此外，42个精炼矿渣样品在1350、1400和1450°C下定量分析了Fe、Si、Ca、Mg、Al和Mn。采用归一化全光谱结合偏最小二乘(PLS)定量建模
，以Ca II 317.91 nm谱线为内标。结果表明，采用内标归一化方法可以显著降低光谱波动的影响。同时，发现温度在1450℃时比在1350℃和1400℃时效果更好，有利于在渣处于低粘度的水态时进行定量分析。
{"title":"Characteristics of laser-induced breakdown spectroscopy of liquid slag","authors":"Changyan Dong, Hongxia Yu, Lanxiang Sun, Yang Li, Xiuye Liu, Ping Zhou, Shaowen Huang","doi":"10.1088/2058-6272/ad0c25","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c25","url":null,"abstract":"Abstract Rapid online analysis of liquid slag is essential for optimizing the quality and energy 
efficiency of steel production. To investigate the key factors that affect the online measurement of 
refined slag using laser-induced breakdown spectroscopy (LIBS), this study examined the effects 
of slag composition and temperature on the intensity and stability of the LIBS spectra. The 
experimental temperature was controlled at three levels: 1350, 1400, and 1450 °C. The results 
showed that slag composition and temperature significantly affected the intensity and stability of 
the LIBS spectra. Increasing the Fe content and temperature in the slag reduces its viscosity, 
resulting in an enhanced intensity and stability of the LIBS spectra. Additionally, 42 refined slag 
samples were quantitatively analyzed for Fe, Si, Ca, Mg, Al, and Mn at 1350, 1400, and 1450 °C. 
The normalized full spectrum combined with partial least squares (PLS) quantification modeling 
was used, using the Ca II 317.91 nm spectral line as an internal standard. The results show that using the internal standard normalization method can significantly reduce the influence of spectral 
fluctuations. Meanwhile, a temperature of 1450 °C has been found to yield superior results 
compared to both 1350 and 1400 °C, and it is advantageous to conduct a quantitative analysis of 
the slag when it is in a water-like state with low viscosity.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"34 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281950","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 : 2023-11-10DOI: 10.1088/2058-6272/ad0b78
Gongshun Li, Tao Zhang, Kangning Geng, Fei Wen, Kaixuan Ye, Liqing Xu, Xiang Zhu, Xuexi Zhang, Fubin Zhong, Zhen Zhou, Shuqi Yang, Ziqiang Zhou, Lin Yu, Ting Lan, Shouxin Wang, Ang Ti, Shoubiao Zhang, Haiqing Liu, Guoqiang Li, Xiang Gao
Abstract In this paper, a new experimental observation will be presented by using a conventional reflectometry, called poloidal correlation reflectometry (PCR) on experimental advanced superconducting tokamak (EAST). The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_D during internal kink mode (IKM) rotation phase. This Doppler shift f_D is the target measurement of Doppler reflectometry, but captured by conventional reflectometry. Results show that the Doppler shift f_D is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal, but not by plasma turbulence. Fishbone mode and saturated long-live mode (LLM) are typical IKMs, and this modulation phenomenon is observed in both cases. Moreover, the value of Doppler shift f_D is positively correlated with the amplitude of IKM, even when the latter is small. However, the positive and negative frequency components of the Doppler shift f_D can be asymmetric, which is related to the plasma configuration. A simulated analysis is performed by ray-tracing to verify these observations. These results establish a clear link between the Doppler shift f_D and IKM rotation, and are beneficial to study the characteristics of IKM and related physical phenomena.
{"title":"Observation of Doppler shift f_D modulated by internal kink mode using conventional reflectometry on EAST tokamak","authors":"Gongshun Li, Tao Zhang, Kangning Geng, Fei Wen, Kaixuan Ye, Liqing Xu, Xiang Zhu, Xuexi Zhang, Fubin Zhong, Zhen Zhou, Shuqi Yang, Ziqiang Zhou, Lin Yu, Ting Lan, Shouxin Wang, Ang Ti, Shoubiao Zhang, Haiqing Liu, Guoqiang Li, Xiang Gao","doi":"10.1088/2058-6272/ad0b78","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0b78","url":null,"abstract":"Abstract In this paper, a new experimental observation will be presented by using a conventional reflectometry, called poloidal correlation reflectometry (PCR) on experimental advanced superconducting tokamak (EAST). The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_D during internal kink mode (IKM) rotation phase. This Doppler shift f_D is the target measurement of Doppler reflectometry, but captured by conventional reflectometry. Results show that the Doppler shift f_D is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal, but not by plasma turbulence. Fishbone mode and saturated long-live mode (LLM) are typical IKMs, and this modulation phenomenon is observed in both cases. Moreover, the value of Doppler shift f_D is positively correlated with the amplitude of IKM, even when the latter is small. However, the positive and negative frequency components of the Doppler shift f_D can be asymmetric, which is related to the plasma configuration. A simulated analysis is performed by ray-tracing to verify these observations. These results establish a clear link between the Doppler shift f_D and IKM rotation, and are beneficial to study the characteristics of IKM and related physical phenomena.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":"120 45","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135136364","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}
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