Pub Date : 2024-10-10DOI: 10.1109/TPS.2024.3469955
Yunhong Zhou;Zenan Chen;Yinfang Huang;Houwen Yang;Shuqin Li
With the extensive promotion of new energy generation in high-altitude regions, the demand for air circuit breakers (ACBs) has correspondingly increased, as they serve as essential protective devices in energy storage systems. However, the climate conditions in high-altitude areas pose challenges to the interruption performance of ACBs. This study focuses on ACBs and, based on the theory of magnetohydrodynamics (MHD), utilizes the finite element software Ansys Fluent to establish a 2-D dynamic arc simulation model. Simulation analyses are conducted at altitudes of 2, 3, 4, and 5 km. The findings reveal that as altitude increases, the average arc voltage decreases while the arcing time prolongs. In addition, the arc demonstrates faster movement before entering the arc-extinguishing splitter plates and slower movement afterward. Furthermore, through climate chamber simulation experiments, the arc current and voltage of the breaker in high-altitude environment are measured, and the erosion conditions of the arc-extinguishing splitter plates in post-test prototypes are used to validate the accuracy of the simulation model. The findings indicate that the simulation results are in good agreement with the experimental results. The construction of this simulation model helps compensate for the limitations of unclear observation of arc motion trajectories in experiments, facilitating the analysis of arc motion patterns and the identification of factors affecting the interruption performance of circuit breakers in different altitude environments. Thereby, this study can provide a theoretical basis and reference for the design of ACBs in high-altitude environment.
{"title":"Modeling and Analysis of Breaking Arc for AC Air Circuit Breakers in High-Altitude Environment","authors":"Yunhong Zhou;Zenan Chen;Yinfang Huang;Houwen Yang;Shuqin Li","doi":"10.1109/TPS.2024.3469955","DOIUrl":"https://doi.org/10.1109/TPS.2024.3469955","url":null,"abstract":"With the extensive promotion of new energy generation in high-altitude regions, the demand for air circuit breakers (ACBs) has correspondingly increased, as they serve as essential protective devices in energy storage systems. However, the climate conditions in high-altitude areas pose challenges to the interruption performance of ACBs. This study focuses on ACBs and, based on the theory of magnetohydrodynamics (MHD), utilizes the finite element software Ansys Fluent to establish a 2-D dynamic arc simulation model. Simulation analyses are conducted at altitudes of 2, 3, 4, and 5 km. The findings reveal that as altitude increases, the average arc voltage decreases while the arcing time prolongs. In addition, the arc demonstrates faster movement before entering the arc-extinguishing splitter plates and slower movement afterward. Furthermore, through climate chamber simulation experiments, the arc current and voltage of the breaker in high-altitude environment are measured, and the erosion conditions of the arc-extinguishing splitter plates in post-test prototypes are used to validate the accuracy of the simulation model. The findings indicate that the simulation results are in good agreement with the experimental results. The construction of this simulation model helps compensate for the limitations of unclear observation of arc motion trajectories in experiments, facilitating the analysis of arc motion patterns and the identification of factors affecting the interruption performance of circuit breakers in different altitude environments. Thereby, this study can provide a theoretical basis and reference for the design of ACBs in high-altitude environment.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3257-3269"},"PeriodicalIF":1.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-10DOI: 10.1109/TPS.2024.3470905
Fengyun Wang;Zhenbao Liang;Zheng Zhou;Yuhan Zhang;Xiaoxia Du;Hua Li
Inactivation of bacteria by plasma is related to its active substances; the aim of this study is to investigate the impact of active substances’ spatial distribution on inactivation efficiency. In this study, a comparative analysis of the distribution and concentration of reactive oxygen and nitrogen species (RONSs) in the cross section of the plasma jet was conducted under different discharge voltages, working gas flow rates, and treatment distances. Then the impact of RONS distribution on the inactivation efficiency against Staphylococcus aureus (ATCC 25923) biofilm was analyzed. Experimental results demonstrated an influence of gas flow rates and treatment distances on RONS distribution. For instance, at the treatment distance of 3 mm, RONS distribution showed a solid circular shape at 0.4 standard liters per minute (SLM) and below, a double ring shape at 0.5 SLM, and a ring shape at 0.6 SLM. At 5 mm, the RONS distribution showed a solid circular shape at 0.8 SLM and below, a double ring shape at 0.9 SLM, and a ring shape at 0.9 SLM and above. The total redox concentration exhibited a positive correlation with the three physical parameters. Biofilm was treated for 100 s at a vertical position of approximately 3 mm. The inactivation of biofilm by the jet was slightly more efficient at 0.4 SLM (RONS was characterized by a low concentration of solid circular shape) compared to 0.8 SLM (high concentration of ring shape). Extending the treatment time to 300 s resulted in similar inactivation efficiency at 0.8 to 0.4 SLM.
{"title":"The Distribution of Active Substances and the Bacterial Inactivation Effect Induced by a Helium Microplasma","authors":"Fengyun Wang;Zhenbao Liang;Zheng Zhou;Yuhan Zhang;Xiaoxia Du;Hua Li","doi":"10.1109/TPS.2024.3470905","DOIUrl":"https://doi.org/10.1109/TPS.2024.3470905","url":null,"abstract":"Inactivation of bacteria by plasma is related to its active substances; the aim of this study is to investigate the impact of active substances’ spatial distribution on inactivation efficiency. In this study, a comparative analysis of the distribution and concentration of reactive oxygen and nitrogen species (RONSs) in the cross section of the plasma jet was conducted under different discharge voltages, working gas flow rates, and treatment distances. Then the impact of RONS distribution on the inactivation efficiency against Staphylococcus aureus (ATCC 25923) biofilm was analyzed. Experimental results demonstrated an influence of gas flow rates and treatment distances on RONS distribution. For instance, at the treatment distance of 3 mm, RONS distribution showed a solid circular shape at 0.4 standard liters per minute (SLM) and below, a double ring shape at 0.5 SLM, and a ring shape at 0.6 SLM. At 5 mm, the RONS distribution showed a solid circular shape at 0.8 SLM and below, a double ring shape at 0.9 SLM, and a ring shape at 0.9 SLM and above. The total redox concentration exhibited a positive correlation with the three physical parameters. Biofilm was treated for 100 s at a vertical position of approximately 3 mm. The inactivation of biofilm by the jet was slightly more efficient at 0.4 SLM (RONS was characterized by a low concentration of solid circular shape) compared to 0.8 SLM (high concentration of ring shape). Extending the treatment time to 300 s resulted in similar inactivation efficiency at 0.8 to 0.4 SLM.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3111-3117"},"PeriodicalIF":1.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-10DOI: 10.1109/TPS.2024.3455777
Gianluca Barone;Valerio Belardi;Mauro Dalla Palma;Damiano Paoletti;Gian Mario Polli;Francesco Vivio
The article presents the status of DTT cryostat system and illustrates the structural verification activities performed to assess its mechanical response under various design load combinations. To this purpose, an FEM shell model of the cryostat has been developed including mechanical loads on the cryostat base due to Vacuum Vessel and Magnets, modeled as equivalent point mass. Anchoring of the base columns to the Tokamak basements has also been modeled. To verify the cryostat design, simulations have been carried out for the most critical VDEs and seismic load combinations. In addition, thermo-mechanical effects induced by both Vacuum Vessel and Magnets, on the cryostat base, have been investigated, for plasma operation and baking conditions. Further, buckling condition, under external pressure, and accidental overpressure conditions, have also been investigated.
{"title":"Structural Assessment of the DTT Cryostat Design","authors":"Gianluca Barone;Valerio Belardi;Mauro Dalla Palma;Damiano Paoletti;Gian Mario Polli;Francesco Vivio","doi":"10.1109/TPS.2024.3455777","DOIUrl":"https://doi.org/10.1109/TPS.2024.3455777","url":null,"abstract":"The article presents the status of DTT cryostat system and illustrates the structural verification activities performed to assess its mechanical response under various design load combinations. To this purpose, an FEM shell model of the cryostat has been developed including mechanical loads on the cryostat base due to Vacuum Vessel and Magnets, modeled as equivalent point mass. Anchoring of the base columns to the Tokamak basements has also been modeled. To verify the cryostat design, simulations have been carried out for the most critical VDEs and seismic load combinations. In addition, thermo-mechanical effects induced by both Vacuum Vessel and Magnets, on the cryostat base, have been investigated, for plasma operation and baking conditions. Further, buckling condition, under external pressure, and accidental overpressure conditions, have also been investigated.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4120-4125"},"PeriodicalIF":1.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Coplanar dielectric barrier discharge (CDBD) is widely used on the surface of materials because of its high plasma density and no requirement for the thickness of modified materials. In order to make the filamentary CDBD achieve suitable modification conditions under atmospheric pressure air conditions, a convenient and effective method for judging the macroscopic characteristics of discharge is urgently needed. In this article, a method of CDBD discharge analysis based on image processing is proposed, which characterizes the discharge uniformity by the saturation voltage obtained by binarization of the discharge image, the average pixel value, and the pixel variance of the discharge gray image. It makes up for the lack of identification of discharge uniformity by traditional diagnostic methods and can analyze discharge saturation voltage, discharge intensity, and uniformity efficiently and quickly. According to the above three parameters, we can further divide the discharge mode into fast discharge mode, slow discharge mode, and saturated discharge mode. The research in this article simplifies the process of determining the working conditions of surface modification using CDBD and provides a new idea for the scientific and quantitative study of the discharge characteristics of CDBD.
{"title":"Discharge Mode Analysis of Coplanar Dielectric Barrier Discharge Based on Image Processing","authors":"Qiaojue Liu;Mi You;Jieming Wang;Yangyang Chen;Zhanhe Guo;Shushu Zhu;Shuqun Wu","doi":"10.1109/TPS.2024.3466912","DOIUrl":"https://doi.org/10.1109/TPS.2024.3466912","url":null,"abstract":"Coplanar dielectric barrier discharge (CDBD) is widely used on the surface of materials because of its high plasma density and no requirement for the thickness of modified materials. In order to make the filamentary CDBD achieve suitable modification conditions under atmospheric pressure air conditions, a convenient and effective method for judging the macroscopic characteristics of discharge is urgently needed. In this article, a method of CDBD discharge analysis based on image processing is proposed, which characterizes the discharge uniformity by the saturation voltage obtained by binarization of the discharge image, the average pixel value, and the pixel variance of the discharge gray image. It makes up for the lack of identification of discharge uniformity by traditional diagnostic methods and can analyze discharge saturation voltage, discharge intensity, and uniformity efficiently and quickly. According to the above three parameters, we can further divide the discharge mode into fast discharge mode, slow discharge mode, and saturated discharge mode. The research in this article simplifies the process of determining the working conditions of surface modification using CDBD and provides a new idea for the scientific and quantitative study of the discharge characteristics of CDBD.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3166-3173"},"PeriodicalIF":1.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
This article introduces a new plasmonic sensor utilizing long range surface plasmon resonance (LRSPR), which is constructed from a heterostructure of thallium bromide (TlBr) along with BluePhosphorene and Tungsten diselenide (BlueP/WSe2). Through meticulous analysis, we systematically investigated the optimal sensor configuration which consists of 8 nm thick silver (Ag) metal layer, a 1900 nm thick Magnesium fluoride (MgF2) dielectric buffer laye (DBL), and a 2-nm thick TlBr layer to enhance the capabilities of the sensor. The achieved configuration of he proposed sensor claims exceptional attributes, including narrower full width at half maximum (FWHM =0.01 Deg.), higher detection accuracy [DA =100 (Deg−1)], imaging figure of merit [IFOM =4410500 (Deg. RIU)−1], imaging sensitivity, ( ${S} _{text {img.}} =44$ 105 RIU−1), and angular figure of merit (FOM $_{text {ang.}} =5814.38$ RIU−1). It exhibits significantly improved performance by achieving 38.02, 964.89, 25.39, and 61.40-times higher values of DA, IFOM, ${S} _{text {img.}}$ , and FOMang respectively, as compared to the conventional surface plasmon resonance (CSPR) sensor. Furthermore, the penetration depth (PD) of 989.45 nm of the proposed LRSPR sensor surpasses the PD (210.01 nm) of CSPR sensors, and demonstrates precise and sensitive refractive index (RI) sensing applications in biomedical. Consequently, the proposed sensor offers superior performance over existing LRSPR sensors.
{"title":"On the Feasibility of Thallium Bromide in Long-Range Plasmonic Sensing for Enhancement of Performance","authors":"Virendra Kumar;Sarika Pal;Vivek Singh;Bela Goyal;Lalit Kumar Awasthi;Yogendra Kumar Prajapati","doi":"10.1109/TPS.2024.3468954","DOIUrl":"https://doi.org/10.1109/TPS.2024.3468954","url":null,"abstract":"This article introduces a new plasmonic sensor utilizing long range surface plasmon resonance (LRSPR), which is constructed from a heterostructure of thallium bromide (TlBr) along with BluePhosphorene and Tungsten diselenide (BlueP/WSe2). Through meticulous analysis, we systematically investigated the optimal sensor configuration which consists of 8 nm thick silver (Ag) metal layer, a 1900 nm thick Magnesium fluoride (MgF2) dielectric buffer laye (DBL), and a 2-nm thick TlBr layer to enhance the capabilities of the sensor. The achieved configuration of he proposed sensor claims exceptional attributes, including narrower full width at half maximum (FWHM =0.01 Deg.), higher detection accuracy [DA =100 (Deg−1)], imaging figure of merit [IFOM =4410500 (Deg. RIU)−1], imaging sensitivity, (\u0000<inline-formula> <tex-math>${S} _{text {img.}} =44$ </tex-math></inline-formula>\u0000105 RIU−1), and angular figure of merit (FOM\u0000<inline-formula> <tex-math>$_{text {ang.}} =5814.38$ </tex-math></inline-formula>\u0000 RIU−1). It exhibits significantly improved performance by achieving 38.02, 964.89, 25.39, and 61.40-times higher values of DA, IFOM, \u0000<inline-formula> <tex-math>${S} _{text {img.}}$ </tex-math></inline-formula>\u0000, and FOMang respectively, as compared to the conventional surface plasmon resonance (CSPR) sensor. Furthermore, the penetration depth (PD) of 989.45 nm of the proposed LRSPR sensor surpasses the PD (210.01 nm) of CSPR sensors, and demonstrates precise and sensitive refractive index (RI) sensing applications in biomedical. Consequently, the proposed sensor offers superior performance over existing LRSPR sensors.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4598-4605"},"PeriodicalIF":1.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-04DOI: 10.1109/TPS.2024.3465611
J. Goswami;S. S. Kausik
Dusty plasma can exist in a wide range, from the laboratory to Saturn’s rings. The coupling parameter plays a crucial role in diagnosing dusty plasma. There are two ways to deal analytically with the effect of coupling in plasma. First, where the coupling parameter is represented with the help of viscoelastic relaxation time $(tau _{m})$ and, second, where the electrostatic temperature $(d)$ represents the coupling parameters, in this work, we have used both techniques in a strongly coupled four-component plasma in which we have considered the dynamics of negatively charged dust grains and $q-$ nonextensive distribution for electrons, ions, and positrons. The main focus of this particular work is to find out the operational regions and validity of these two techniques. The result of this article will give future researchers an idea of how coupling would be encountered in a dusty plasma system.
{"title":"Investigating the Effects of Coupling in Strongly Coupled Dusty Plasma: A Comparative Study of Coupling Parameter Representations","authors":"J. Goswami;S. S. Kausik","doi":"10.1109/TPS.2024.3465611","DOIUrl":"https://doi.org/10.1109/TPS.2024.3465611","url":null,"abstract":"Dusty plasma can exist in a wide range, from the laboratory to Saturn’s rings. The coupling parameter plays a crucial role in diagnosing dusty plasma. There are two ways to deal analytically with the effect of coupling in plasma. First, where the coupling parameter is represented with the help of viscoelastic relaxation time \u0000<inline-formula> <tex-math>$(tau _{m})$ </tex-math></inline-formula>\u0000 and, second, where the electrostatic temperature \u0000<inline-formula> <tex-math>$(d)$ </tex-math></inline-formula>\u0000 represents the coupling parameters, in this work, we have used both techniques in a strongly coupled four-component plasma in which we have considered the dynamics of negatively charged dust grains and \u0000<inline-formula> <tex-math>$q-$ </tex-math></inline-formula>\u0000 nonextensive distribution for electrons, ions, and positrons. The main focus of this particular work is to find out the operational regions and validity of these two techniques. The result of this article will give future researchers an idea of how coupling would be encountered in a dusty plasma system.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4694-4704"},"PeriodicalIF":1.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of Extended Reality (XR) technologies virtual and augmented reality (AR) is establishing itself more and more in design, construction and operation applications in industrial and research sectors that aim to employ digital technologies with a human-centered design approach. At ITER, a methodology that includes these technologies is applied in the design study of test blanket module (TBM) port cell (PC) components and replacement operation. The use of virtual prototyping at early design phases permits anticipating issues related to human operation and accessibility. Therefore, design optimization is performed before manufacturing the actual feasibility mock-ups. XR sessions are organized involving several design experts interacting with the various components 3-D models at the same time to facilitate the design decisions and to optimize the procedures. The main asset of this XR approach is to offer different means to support the decisions and onboard all participants. The simulations are prepared by building a virtual mock-up based on native CAD models available in databases for the different systems integrated into the Tokamak building. The complexity of the systems and the large amount of data to display require data preprocessing in order to ensure a reliable representation of the scenarios to be simulated. The reliability of the 3-D data and the consideration of the risks and the environmental conditions of the areas to be simulated are essential for making applicable and sound decisions. The aim of this article is to provide a method to realize reliable XR simulations following a documented workflow usable across the ITER project. The method is based on the realization of an XR-maintenance verification plan as an input for the XR simulation and of a maintainability verification document based on the results available from XR simulations. The experience and the results gained from the TBM PC design activities involving virtual reality (VR) simulations are also discussed.
{"title":"Methodology for Applying Extended Reality Simulations for ITER Design and Hands-On Interventions Verification","authors":"Chiara Di Paolo;Stéphane Gazzotti;Jean-Pierre Martins;Benoit Manfreo;Lucas Scherrer;Mathieu Regad;Sandrine Pascal;Jean-Pierre Friconneau;Luciano Giancarli;Margherita Peruzzini;Cyril Kharoua","doi":"10.1109/TPS.2024.3435355","DOIUrl":"https://doi.org/10.1109/TPS.2024.3435355","url":null,"abstract":"The use of Extended Reality (XR) technologies virtual and augmented reality (AR) is establishing itself more and more in design, construction and operation applications in industrial and research sectors that aim to employ digital technologies with a human-centered design approach. At ITER, a methodology that includes these technologies is applied in the design study of test blanket module (TBM) port cell (PC) components and replacement operation. The use of virtual prototyping at early design phases permits anticipating issues related to human operation and accessibility. Therefore, design optimization is performed before manufacturing the actual feasibility mock-ups. XR sessions are organized involving several design experts interacting with the various components 3-D models at the same time to facilitate the design decisions and to optimize the procedures. The main asset of this XR approach is to offer different means to support the decisions and onboard all participants. The simulations are prepared by building a virtual mock-up based on native CAD models available in databases for the different systems integrated into the Tokamak building. The complexity of the systems and the large amount of data to display require data preprocessing in order to ensure a reliable representation of the scenarios to be simulated. The reliability of the 3-D data and the consideration of the risks and the environmental conditions of the areas to be simulated are essential for making applicable and sound decisions. The aim of this article is to provide a method to realize reliable XR simulations following a documented workflow usable across the ITER project. The method is based on the realization of an XR-maintenance verification plan as an input for the XR simulation and of a maintainability verification document based on the results available from XR simulations. The experience and the results gained from the TBM PC design activities involving virtual reality (VR) simulations are also discussed.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4154-4160"},"PeriodicalIF":1.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-04DOI: 10.1109/TPS.2024.3382229
A. Schmidt;E. Anaya;M. Anderson;J. Angus;P. C. Campbell;S. F. Chapman;C. M. Cooper;O. B. Drury;L. Frausto;C. Goyon;S. Jiang;A. Jibodu;E. Koh;A. Link;D. Max;J. Park;S. R. Rocco;J. K. Walters;A. E. Youmans
A dense plasma focus (DPF) is a co-axial plasma railgun, whose discharge ends in a z-pinch phase. The MegaJOuLe neutron imaging radiography (MJOLNIR) DPF is a Lawrence Livermore National Laboratory (LLNL) experiment to demonstrate feasibility of flash neutron radiography using the DPF as a neutron source and a neutron camera to record an image. The MJOLNIR team is in the process of commissioning the DPF to full stored energy and current, 2 MJ/4.5 MA, with 1.3-MJ stored energy and 3.8-MA peak currents achieved as of October 2023. A recent redesign/rebuild of the MJOLNIR DPF has enabled robust operations, supporting >900 high voltage/plasma shots, 570+ on a single hardware setup, over the course of 11 months. Neutron yields in excess of $1times 10^{{12}}$ have been achieved on the highest current shots with deuterium gas fill. Successful high current operation requires interleaving of high current shots with lower current (~2.8-MA peak) shots. Neutron spot sizes have been measured as a function of voltage, pressure, anode implosion radius, and gas dopant levels. We document an overview of the MJOLNIR redesign and high-current experimental results.
{"title":"MegaJOuLe Neutron Imaging Radiography (MJOLNIR) Dense Plasma Focus Rebuild and High Current Experiments","authors":"A. Schmidt;E. Anaya;M. Anderson;J. Angus;P. C. Campbell;S. F. Chapman;C. M. Cooper;O. B. Drury;L. Frausto;C. Goyon;S. Jiang;A. Jibodu;E. Koh;A. Link;D. Max;J. Park;S. R. Rocco;J. K. Walters;A. E. Youmans","doi":"10.1109/TPS.2024.3382229","DOIUrl":"https://doi.org/10.1109/TPS.2024.3382229","url":null,"abstract":"A dense plasma focus (DPF) is a co-axial plasma railgun, whose discharge ends in a z-pinch phase. The MegaJOuLe neutron imaging radiography (MJOLNIR) DPF is a Lawrence Livermore National Laboratory (LLNL) experiment to demonstrate feasibility of flash neutron radiography using the DPF as a neutron source and a neutron camera to record an image. The MJOLNIR team is in the process of commissioning the DPF to full stored energy and current, 2 MJ/4.5 MA, with 1.3-MJ stored energy and 3.8-MA peak currents achieved as of October 2023. A recent redesign/rebuild of the MJOLNIR DPF has enabled robust operations, supporting >900 high voltage/plasma shots, 570+ on a single hardware setup, over the course of 11 months. Neutron yields in excess of \u0000<inline-formula> <tex-math>$1times 10^{{12}}$ </tex-math></inline-formula>\u0000 have been achieved on the highest current shots with deuterium gas fill. Successful high current operation requires interleaving of high current shots with lower current (~2.8-MA peak) shots. Neutron spot sizes have been measured as a function of voltage, pressure, anode implosion radius, and gas dopant levels. We document an overview of the MJOLNIR redesign and high-current experimental results.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 10","pages":"4906-4915"},"PeriodicalIF":1.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-04DOI: 10.1109/TPS.2024.3464615
Pasquale Lucibello
We present an approach for the induction of the plasma axial current in a pinching device, that consists in the use of apertures in the external tubular conductor that surrounds the plasma itself. These apertures are spaced at regular intervals along the axis of the device and a radial parallel plate waveguide is coupled to each of them. To the end of each waveguide, a time-varying power source is connected and operated synchronously with all the others. We analyze the stability of the plasma motion in this device by using a model, the ideal device, in which the actual electromagnetic field is approximated by that generated by a time-varying azimuthal current distributed on the internal surface of the external conductor and a time-varying axial current flowing on the surface of the plasma. The desired or reference plasma motion inside the ideal device is a sequence of cylindrical equilibrium configurations coaxial with the external conductor that extends indefinitely. We analyze the stability of a reference trajectory, along which the plasma is compressed and expanded under the action of a screw magnetic field, by using a simplified set of linear equations of motion, based on the quasi 1-D flow of a gas, with electromagnetic forces complying with the quasi static approximation. Under the hypothesis that the azimuthal and axial currents are not perturbed, we show that an axial magnetic flux frozen in the plasma and an external conductor are necessary for stability. We also show that an axial magnetic field external to the plasma is not necessary for stability, so that, in a real device, its role could be limited to that of replenishing the embedded one, while the plasma is in contact or nearly in contact with the wall of its container. As opposed to previous theoretical investigations, we do not use the energy principle to prove stability/instability of a steady-state pinch without computing the eigenvalues of the linear equations of motion. On the contrary, for the cylindrical configuration analyzed, after decomposing the plasma motion in its main components, that is, massless, fluid, and string modes (the sausage and kink modes in previous different models), we compute the generalized masses and stiffnesses of the fluid and string modes. In the steady-state case, this allows us to compute their eigenvalues as a function of the geometric and magnetic parameters and then ascertain stability or instability of a specific pinch. By using these expressions, we also formulate necessary and/or sufficient conditions for stability, on the basis of which we are able to show the consistency of our results with the ones obtained in previous investigations. In particular, we derive a sufficient stability condition which is similar to the Kruskal-Shafronov necessary stability condition. We also formulate stability conditions in the time-varying case, which seems to be a novelty, except for what was done by this author in a recently published paper.
{"title":"On Axial Current Induction and Stability of a Pinch","authors":"Pasquale Lucibello","doi":"10.1109/TPS.2024.3464615","DOIUrl":"https://doi.org/10.1109/TPS.2024.3464615","url":null,"abstract":"We present an approach for the induction of the plasma axial current in a pinching device, that consists in the use of apertures in the external tubular conductor that surrounds the plasma itself. These apertures are spaced at regular intervals along the axis of the device and a radial parallel plate waveguide is coupled to each of them. To the end of each waveguide, a time-varying power source is connected and operated synchronously with all the others. We analyze the stability of the plasma motion in this device by using a model, the ideal device, in which the actual electromagnetic field is approximated by that generated by a time-varying azimuthal current distributed on the internal surface of the external conductor and a time-varying axial current flowing on the surface of the plasma. The desired or reference plasma motion inside the ideal device is a sequence of cylindrical equilibrium configurations coaxial with the external conductor that extends indefinitely. We analyze the stability of a reference trajectory, along which the plasma is compressed and expanded under the action of a screw magnetic field, by using a simplified set of linear equations of motion, based on the quasi 1-D flow of a gas, with electromagnetic forces complying with the quasi static approximation. Under the hypothesis that the azimuthal and axial currents are not perturbed, we show that an axial magnetic flux frozen in the plasma and an external conductor are necessary for stability. We also show that an axial magnetic field external to the plasma is not necessary for stability, so that, in a real device, its role could be limited to that of replenishing the embedded one, while the plasma is in contact or nearly in contact with the wall of its container. As opposed to previous theoretical investigations, we do not use the energy principle to prove stability/instability of a steady-state pinch without computing the eigenvalues of the linear equations of motion. On the contrary, for the cylindrical configuration analyzed, after decomposing the plasma motion in its main components, that is, massless, fluid, and string modes (the sausage and kink modes in previous different models), we compute the generalized masses and stiffnesses of the fluid and string modes. In the steady-state case, this allows us to compute their eigenvalues as a function of the geometric and magnetic parameters and then ascertain stability or instability of a specific pinch. By using these expressions, we also formulate necessary and/or sufficient conditions for stability, on the basis of which we are able to show the consistency of our results with the ones obtained in previous investigations. In particular, we derive a sufficient stability condition which is similar to the Kruskal-Shafronov necessary stability condition. We also formulate stability conditions in the time-varying case, which seems to be a novelty, except for what was done by this author in a recently published paper.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3270-3284"},"PeriodicalIF":1.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-04DOI: 10.1109/TPS.2024.3467190
Afshin Shaygani;Kazimierz Adamiak;Mehrdad R. Kermani
A dielectric barrier discharge (DBD) plasma actuator for controlling airflow is proposed. It consists of diverging and converging nozzles, two concentric cylinders, and an actuator mounted in between the two cylinders. The actuator employs electrohydrodynamic (EHD) body force to induce an air jet within the air gap between the two cylinders, effectively creating a suction area while passing through the diverging nozzle, due to the Coanda effect. While merging with the air stream inside the inner cylinder, the Coanda jet effectively enhances the amplification of the airflow. The outflow rate is measured by a velocity sensor at the outlet and controlled by the plasma actuator. The control strategy is based on the active disturbance rejection control (ADRC) and compared to the baseline PID controller. The actuator was modeled by seamlessly linking two modeling platforms for a co-simulation study. The computational fluid dynamic (CFD) simulation of the plasma and airflow was carried out in the COMSOL multiphysics commercial software, and the control was implemented in Simulink. The DBD plasma model was based on the two-species model of discharge, and the electric body force, calculated from the plasma simulation, was used in the Navier-Stokes equation (NS) for the turbulent flow simulation using $k-omega $ model. The plasma-airflow system was analyzed using the input (the actuator voltage) and output (the outlet flow rate) data for the control design. Finally, the performance of the system of airflow control device was tested and discussed in the co-simulation process.
{"title":"Precision Airflow Control via EHD Actuator: A Co-Simulation and Control Design Case Study","authors":"Afshin Shaygani;Kazimierz Adamiak;Mehrdad R. Kermani","doi":"10.1109/TPS.2024.3467190","DOIUrl":"https://doi.org/10.1109/TPS.2024.3467190","url":null,"abstract":"A dielectric barrier discharge (DBD) plasma actuator for controlling airflow is proposed. It consists of diverging and converging nozzles, two concentric cylinders, and an actuator mounted in between the two cylinders. The actuator employs electrohydrodynamic (EHD) body force to induce an air jet within the air gap between the two cylinders, effectively creating a suction area while passing through the diverging nozzle, due to the Coanda effect. While merging with the air stream inside the inner cylinder, the Coanda jet effectively enhances the amplification of the airflow. The outflow rate is measured by a velocity sensor at the outlet and controlled by the plasma actuator. The control strategy is based on the active disturbance rejection control (ADRC) and compared to the baseline PID controller. The actuator was modeled by seamlessly linking two modeling platforms for a co-simulation study. The computational fluid dynamic (CFD) simulation of the plasma and airflow was carried out in the COMSOL multiphysics commercial software, and the control was implemented in Simulink. The DBD plasma model was based on the two-species model of discharge, and the electric body force, calculated from the plasma simulation, was used in the Navier-Stokes equation (NS) for the turbulent flow simulation using \u0000<inline-formula> <tex-math>$k-omega $ </tex-math></inline-formula>\u0000 model. The plasma-airflow system was analyzed using the input (the actuator voltage) and output (the outlet flow rate) data for the control design. Finally, the performance of the system of airflow control device was tested and discussed in the co-simulation process.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3153-3165"},"PeriodicalIF":1.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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