Pub Date : 2025-01-07DOI: 10.1109/TPS.2024.3522083
Qizheng Ye
Based on the simplified mathematical model of streamer discharge proposed in the previous work, this article first obtains the closed-form analytical solution of the electron number density in the streamer head as a function of position, which includes three types of streamers (stable streamer, avalanche, and spark streamer). Among these, the stable streamer and the spark streamer could not be described analytically in the past, while the avalanche type is consistent with Townsend’s theoretical model. Second, this article presents the polarity effect of the stable streamer, as well as the two types and conditions for streamer extinction. Finally, the closed-form analytical solution of the streamer head position changing with time is derived, whose characteristic parameters are the same as those in the spatial domain. The above results provide a unified and simplified approximate analysis method of streamer discharge.
{"title":"Approximate Analytical Method of Streamer Discharge: Solutions","authors":"Qizheng Ye","doi":"10.1109/TPS.2024.3522083","DOIUrl":"https://doi.org/10.1109/TPS.2024.3522083","url":null,"abstract":"Based on the simplified mathematical model of streamer discharge proposed in the previous work, this article first obtains the closed-form analytical solution of the electron number density in the streamer head as a function of position, which includes three types of streamers (stable streamer, avalanche, and spark streamer). Among these, the stable streamer and the spark streamer could not be described analytically in the past, while the avalanche type is consistent with Townsend’s theoretical model. Second, this article presents the polarity effect of the stable streamer, as well as the two types and conditions for streamer extinction. Finally, the closed-form analytical solution of the streamer head position changing with time is derived, whose characteristic parameters are the same as those in the spatial domain. The above results provide a unified and simplified approximate analysis method of streamer discharge.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"19-28"},"PeriodicalIF":1.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465841","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 : 2025-01-07DOI: 10.1109/TPS.2024.3520663
N. K. Bastykova;S. K. Kodanova;T. S. Ramazanov
This article investigates the binary collision between an ion and a charged dust particle in the plasma in the presence of a uniform magnetic field. The trajectories of ions are calculated using the modified Velocity Verlet algorithm designed for a reliable simulation of the charged particle dynamics in arbitrarily strong static homogeneous external magnetic fields. We consider the coupling parameter values for dusty plasma experiments and the external magnetic field with $Bleq 1~{mathrm { T}}$ . It has been revealed that at some magnetic field values, the ions are trapped around the charged dust particle. The magnetic field strength values in which the ion becomes trapped around the dust particle have been obtained for typical argon and helium gas discharge plasma parameters.
{"title":"Magnetic Field-Induced Ion Trapping Around Dust Particle in Plasma","authors":"N. K. Bastykova;S. K. Kodanova;T. S. Ramazanov","doi":"10.1109/TPS.2024.3520663","DOIUrl":"https://doi.org/10.1109/TPS.2024.3520663","url":null,"abstract":"This article investigates the binary collision between an ion and a charged dust particle in the plasma in the presence of a uniform magnetic field. The trajectories of ions are calculated using the modified Velocity Verlet algorithm designed for a reliable simulation of the charged particle dynamics in arbitrarily strong static homogeneous external magnetic fields. We consider the coupling parameter values for dusty plasma experiments and the external magnetic field with <inline-formula> <tex-math>$Bleq 1~{mathrm { T}}$ </tex-math></inline-formula>. It has been revealed that at some magnetic field values, the ions are trapped around the charged dust particle. The magnetic field strength values in which the ion becomes trapped around the dust particle have been obtained for typical argon and helium gas discharge plasma parameters.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"12-18"},"PeriodicalIF":1.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465849","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 : 2025-01-07DOI: 10.1109/TPS.2024.3521408
Yingjie Zhang;Anqi Li;Tong Yuan;Xinchun Zhang;Weili Fan
Corona effect is a critical factor in the design and construction of ultrahigh-voltage (UHV) transmission lines, since it can cause ionic wind, which induces destructive instability, such as conductor vibration and rotation. Here, we develop a 2-D unipolar ion discharge model by using electrohydrodynamic (EHD) methods coupled with Navier-Stokes (N-S) equations. The effects of conductor cross-sectional geometry and voltage levels on the distribution of electric field, characteristics of ionic wind, and distribution of EHD force during the corona discharge have been studied. It is shown that both the cross-sectional geometry and voltage level have significant influence on the aerodynamic characteristics of the conductor. A higher corona inception field strength can be produced when the conductor geometry is closer to a cylindrical shape. As the number of strands in the conductor is increased, the cross-sectional geometries become more complex, leading to greater electric field distortion, which assists the ionic wind effect and maximum composite velocity. Higher voltage levels inhibit the ionic wind speed, resulting in a reduced maximum composite velocity. Moreover, the increases in the number of conductor strands and voltage levels can enhance the EHD force, inducing the fluctuations in ionic wind velocity around the conductors. Our results provide insights into ionic wind generation from corona discharges in transmission lines and offer theoretical guidance for mitigating the corona-induced vibrations.
{"title":"Numerical Investigation of Ionic Wind-Flow Characteristics in Direct-Current Transmission Conductors With Different Cross- Sectional Geometries","authors":"Yingjie Zhang;Anqi Li;Tong Yuan;Xinchun Zhang;Weili Fan","doi":"10.1109/TPS.2024.3521408","DOIUrl":"https://doi.org/10.1109/TPS.2024.3521408","url":null,"abstract":"Corona effect is a critical factor in the design and construction of ultrahigh-voltage (UHV) transmission lines, since it can cause ionic wind, which induces destructive instability, such as conductor vibration and rotation. Here, we develop a 2-D unipolar ion discharge model by using electrohydrodynamic (EHD) methods coupled with Navier-Stokes (N-S) equations. The effects of conductor cross-sectional geometry and voltage levels on the distribution of electric field, characteristics of ionic wind, and distribution of EHD force during the corona discharge have been studied. It is shown that both the cross-sectional geometry and voltage level have significant influence on the aerodynamic characteristics of the conductor. A higher corona inception field strength can be produced when the conductor geometry is closer to a cylindrical shape. As the number of strands in the conductor is increased, the cross-sectional geometries become more complex, leading to greater electric field distortion, which assists the ionic wind effect and maximum composite velocity. Higher voltage levels inhibit the ionic wind speed, resulting in a reduced maximum composite velocity. Moreover, the increases in the number of conductor strands and voltage levels can enhance the EHD force, inducing the fluctuations in ionic wind velocity around the conductors. Our results provide insights into ionic wind generation from corona discharges in transmission lines and offer theoretical guidance for mitigating the corona-induced vibrations.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"99-107"},"PeriodicalIF":1.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465837","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 : 2025-01-07DOI: 10.1109/TPS.2024.3520819
Bingyu Huang;Xuping Zhang;Hui Peng;Xuemiao Chen;Guiji Wang;Xianfeng Zhang;Fuli Tan;Jianheng Zhao;Chengwei Sun
The studies of characteristics and load configuration of an electromagnetically driven shaped liner during the collapse process are significant for understanding its physical process deeply and guiding its application. A coupled electromagnetic-mechanical–thermal physical model was established and validated for characterizing electromagnetically driven shaped liners. The parameters of the liner structure were optimized for high velocity and strong penetration jet. The outcomes demonstrated that the current and magnetic fields concentrated on the outer surface of the liner at the beginning of loading. Subsequently, they gradually diffused in the thickness direction due to magnetic diffusion. The liner was heated and even ablated by joule heat at current density with several mega-amperes per centimeter. Under a current with a peak value of 4.4 MA and a half-cycle of $1.29~mu $ s, the diffusion depth of the copper liner is 0.4 mm. Within the diffusion depth, some material near the apex vaporized, while most of the area remained in a solid or liquid state. The collapse velocity increases with decreasing thickness under the same loading conditions. The current density decreases due to the increase in the diameter, and the overall velocity of the liner with a larger cone angle is smaller than that of a smaller cone angle. The tendency and law of the current density, magnetic diffusion depth, and ablation thickness on the loading surface are similar. Furthermore, the ablation near the apex with a larger cone angle is more severe. A shaped liner with a small cone angle is suitable for obtaining a jet with high velocity and strong penetration.
{"title":"Coupled Electromagnetic–Mechanical–Thermal Characteristics and Structure Optimization of Electromagnetically Driven Shaped Liner","authors":"Bingyu Huang;Xuping Zhang;Hui Peng;Xuemiao Chen;Guiji Wang;Xianfeng Zhang;Fuli Tan;Jianheng Zhao;Chengwei Sun","doi":"10.1109/TPS.2024.3520819","DOIUrl":"https://doi.org/10.1109/TPS.2024.3520819","url":null,"abstract":"The studies of characteristics and load configuration of an electromagnetically driven shaped liner during the collapse process are significant for understanding its physical process deeply and guiding its application. A coupled electromagnetic-mechanical–thermal physical model was established and validated for characterizing electromagnetically driven shaped liners. The parameters of the liner structure were optimized for high velocity and strong penetration jet. The outcomes demonstrated that the current and magnetic fields concentrated on the outer surface of the liner at the beginning of loading. Subsequently, they gradually diffused in the thickness direction due to magnetic diffusion. The liner was heated and even ablated by joule heat at current density with several mega-amperes per centimeter. Under a current with a peak value of 4.4 MA and a half-cycle of <inline-formula> <tex-math>$1.29~mu $ </tex-math></inline-formula>s, the diffusion depth of the copper liner is 0.4 mm. Within the diffusion depth, some material near the apex vaporized, while most of the area remained in a solid or liquid state. The collapse velocity increases with decreasing thickness under the same loading conditions. The current density decreases due to the increase in the diameter, and the overall velocity of the liner with a larger cone angle is smaller than that of a smaller cone angle. The tendency and law of the current density, magnetic diffusion depth, and ablation thickness on the loading surface are similar. Furthermore, the ablation near the apex with a larger cone angle is more severe. A shaped liner with a small cone angle is suitable for obtaining a jet with high velocity and strong penetration.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5633-5640"},"PeriodicalIF":1.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106390","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 : 2025-01-06DOI: 10.1109/TPS.2024.3516487
Michael J. Johnson;David R. Boris;Tzvetelina B. Petrova;Scott G. Walton
Atmospheric pressure plasma jets operate by projecting a streamer discharge toward remote substrates. The formation and propagation of streamers is an inherently stochastic process, which leads to cycle-to-cycle variations in streamer properties. The present work quantifies these variations through electrical measurements of a plasma jet striking a conductive substrate. It was found that streamer ignition and magnitude can change substantially from cycle to cycle and thus differ from time-averaged measurements taken over many cycles. For example, the energy required to drive the plasma jet and the amount of charge delivered to the substrate during a given cycle can vary from their respective averages by a factor of 2 or more. While some of this can be due to power supply stability, several other operating characteristics of the plasma jet were found to influence repeatability. It was found that helium and argon produced plasma jets with different levels of repeatability, with the repeatability of argon strongly dependent on the feed gas flow rate. Jets driven with pulsed-DC were notably more repeatable than those driven by a high-voltage sinewave. This is attributed to the difference in voltage rise time, which promotes more consistent ignition times. Increasing the voltage and frequency of the pulsed-DC plasma jet can further improve repeatability, where voltages above 2 kV and driving frequencies above 200 Hz significantly enhance the repeatability of the plasma jet.
{"title":"Electrical Characterization of the Cycle-to-Cycle Repeatability of an Atmospheric Pressure Plasma Jet","authors":"Michael J. Johnson;David R. Boris;Tzvetelina B. Petrova;Scott G. Walton","doi":"10.1109/TPS.2024.3516487","DOIUrl":"https://doi.org/10.1109/TPS.2024.3516487","url":null,"abstract":"Atmospheric pressure plasma jets operate by projecting a streamer discharge toward remote substrates. The formation and propagation of streamers is an inherently stochastic process, which leads to cycle-to-cycle variations in streamer properties. The present work quantifies these variations through electrical measurements of a plasma jet striking a conductive substrate. It was found that streamer ignition and magnitude can change substantially from cycle to cycle and thus differ from time-averaged measurements taken over many cycles. For example, the energy required to drive the plasma jet and the amount of charge delivered to the substrate during a given cycle can vary from their respective averages by a factor of 2 or more. While some of this can be due to power supply stability, several other operating characteristics of the plasma jet were found to influence repeatability. It was found that helium and argon produced plasma jets with different levels of repeatability, with the repeatability of argon strongly dependent on the feed gas flow rate. Jets driven with pulsed-DC were notably more repeatable than those driven by a high-voltage sinewave. This is attributed to the difference in voltage rise time, which promotes more consistent ignition times. Increasing the voltage and frequency of the pulsed-DC plasma jet can further improve repeatability, where voltages above 2 kV and driving frequencies above 200 Hz significantly enhance the repeatability of the plasma jet.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5597-5607"},"PeriodicalIF":1.3,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106537","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 : 2024-12-30DOI: 10.1109/TPS.2024.3512522
Tian-Ze Bai;Chang-Hong Peng
The accident diagnosis of fusion blanket is one of the important issues of fusion reactor safety. In this study, the water-cooled blanket system of China Fusion Engineering Test Reactor (CFETR) is modeled using the RELAP5 code. On the basis of steady-state initialization, several design basis accidents were calculated, including in-vessel loss of coolant accident (LOCA), in-box LOCA, ex-vessel LOCA, and loss of flow accident (LOFA). The RELAP5 calculation results are used as training and validation sets for accident diagnosis. A CFETR water-cooled blanket accident diagnosis method was constructed using a deep neural network based on long short-term memory (LSTM). The 34 blanket parameters simulated by the program within 60 s of the accident occurrence are used as inputs to the model. Diagnostic analysis is conducted on the types, locations, and severity of accidents in the water-cooled blanket. The results indicate that the model can accurately diagnose and obtain detailed information about accidents. Even if a random error of ±10% is added to the input data, the accuracy of the accident classification model is not less than 99.3%, and the errors of the LOCA break size and LOFA pump speed do not exceed 3%. The model has been validated as an effective method for fusion blanket accident diagnosis.
{"title":"An Accident Diagnosis Method of CFETR Water-Cooled Blanket Based on Deep Neural Network","authors":"Tian-Ze Bai;Chang-Hong Peng","doi":"10.1109/TPS.2024.3512522","DOIUrl":"https://doi.org/10.1109/TPS.2024.3512522","url":null,"abstract":"The accident diagnosis of fusion blanket is one of the important issues of fusion reactor safety. In this study, the water-cooled blanket system of China Fusion Engineering Test Reactor (CFETR) is modeled using the RELAP5 code. On the basis of steady-state initialization, several design basis accidents were calculated, including in-vessel loss of coolant accident (LOCA), in-box LOCA, ex-vessel LOCA, and loss of flow accident (LOFA). The RELAP5 calculation results are used as training and validation sets for accident diagnosis. A CFETR water-cooled blanket accident diagnosis method was constructed using a deep neural network based on long short-term memory (LSTM). The 34 blanket parameters simulated by the program within 60 s of the accident occurrence are used as inputs to the model. Diagnostic analysis is conducted on the types, locations, and severity of accidents in the water-cooled blanket. The results indicate that the model can accurately diagnose and obtain detailed information about accidents. Even if a random error of ±10% is added to the input data, the accuracy of the accident classification model is not less than 99.3%, and the errors of the LOCA break size and LOFA pump speed do not exceed 3%. The model has been validated as an effective method for fusion blanket accident diagnosis.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"161-166"},"PeriodicalIF":1.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465811","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 : 2024-12-30DOI: 10.1109/TPS.2024.3519036
P.-A. Gourdain;A. Bachmann;I. N. Erez;F. Garrett;J. Hraki;S. McGaffigan;I. West-Abdallah;J. R. Young
Magnetic fields play an important role in plasma dynamics, yet it is a quantity difficult to measure accurately with physical probes, whose presence disturbs the very field they measure. The Faraday rotation (FR) of a polarized beam of light provides a mechanism to measure the magnetic field without disturbing the dynamics and has been used with great success in astrophysics and high-energy-density plasma science, where physical probes cannot be used. However, the rotation is typically small, which degrades the accuracy of the measurement. Since polarization cannot be measured directly, detectors rely on a polarizer to measure a small change in beam intensity instead. In this work, we show how beam shaping can improve FR measurements using an optical derivative setup. Since the rotation measurement is now strictly proportional to the beam shape and intensity, the system allows to improve the measurement accuracy simply by increasing the laser beam power.
{"title":"Faraday Rotation Measurements in High-Energy-Density Plasmas Using Shaped Laser Beams","authors":"P.-A. Gourdain;A. Bachmann;I. N. Erez;F. Garrett;J. Hraki;S. McGaffigan;I. West-Abdallah;J. R. Young","doi":"10.1109/TPS.2024.3519036","DOIUrl":"https://doi.org/10.1109/TPS.2024.3519036","url":null,"abstract":"Magnetic fields play an important role in plasma dynamics, yet it is a quantity difficult to measure accurately with physical probes, whose presence disturbs the very field they measure. The Faraday rotation (FR) of a polarized beam of light provides a mechanism to measure the magnetic field without disturbing the dynamics and has been used with great success in astrophysics and high-energy-density plasma science, where physical probes cannot be used. However, the rotation is typically small, which degrades the accuracy of the measurement. Since polarization cannot be measured directly, detectors rely on a polarizer to measure a small change in beam intensity instead. In this work, we show how beam shaping can improve FR measurements using an optical derivative setup. Since the rotation measurement is now strictly proportional to the beam shape and intensity, the system allows to improve the measurement accuracy simply by increasing the laser beam power.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5608-5614"},"PeriodicalIF":1.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106388","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 : 2024-12-30DOI: 10.1109/TPS.2024.3515047
Qianyu Wang;Kama Huang
Plasma consists of a collection of ions, electrons, and bound neutral particles, and the whole is a neutral state of matter. Plasma can be divided into two types: high-temperature plasma and low-temperature plasma. Low-temperature plasma is plasma that occurs at room temperature, although the temperature of the electrons is very high. Low-temperature plasma can be used for welding, sterilization, melting, and other applications. In this article, an arrow-shaped microwave low-temperature plasma jet based on a coaxial structure is proposed. The device has the advantages of small volume, low power consumption, high stability, and self-excitation. The plasma length can be varied by changing the velocity of the plasma jet or the microwave power. The argon discharge can be excited at atmospheric pressure with a microwave power of 3.2 W, and its minimum maintenance power is 1.57 W. The optical emission spectra of the plasma show that it contains highly active OH radicals and a large number of energetic particles. Under proper operating conditions, the flame tail treatment of human fingers only heats up to $36.7~^{circ }$ C for 30 s. This portable device can be efficiently used in medical cosmetology and material surface treatment.
{"title":"An Arrowhead-Type Microwave Low-Temperature Plasma Jet at Atmospheric Pressure","authors":"Qianyu Wang;Kama Huang","doi":"10.1109/TPS.2024.3515047","DOIUrl":"https://doi.org/10.1109/TPS.2024.3515047","url":null,"abstract":"Plasma consists of a collection of ions, electrons, and bound neutral particles, and the whole is a neutral state of matter. Plasma can be divided into two types: high-temperature plasma and low-temperature plasma. Low-temperature plasma is plasma that occurs at room temperature, although the temperature of the electrons is very high. Low-temperature plasma can be used for welding, sterilization, melting, and other applications. In this article, an arrow-shaped microwave low-temperature plasma jet based on a coaxial structure is proposed. The device has the advantages of small volume, low power consumption, high stability, and self-excitation. The plasma length can be varied by changing the velocity of the plasma jet or the microwave power. The argon discharge can be excited at atmospheric pressure with a microwave power of 3.2 W, and its minimum maintenance power is 1.57 W. The optical emission spectra of the plasma show that it contains highly active OH radicals and a large number of energetic particles. Under proper operating conditions, the flame tail treatment of human fingers only heats up to <inline-formula> <tex-math>$36.7~^{circ }$ </tex-math></inline-formula>C for 30 s. This portable device can be efficiently used in medical cosmetology and material surface treatment.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5533-5537"},"PeriodicalIF":1.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106499","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 : 2024-12-30DOI: 10.1109/TPS.2024.3519166
Yuting Zhang;Zhenchun Wang;Yan Hu;Wenlai Zhang
The stability of armature velocity is one of the crucial indicators for evaluating the performance of electromagnetic launch systems. A multistage control method for armature muzzle velocity is proposed based on the discharge time and quantity of the power module. By analyzing the pulse power supply model, the relationship between the discharge time, quantity, and armature velocity of the pulse power supply module is established. A multistage feedback control algorithm based on pulse discharge is introduced, which includes steps such as stride selection, adjustment of pulse power supply discharge time, and velocity calculation. By adjusting the discharge time and quantity of the pulse power supply according to the difference between the measured velocity at a reference position and the expected velocity, precise control of the armature velocity is achieved. When the armature muzzle velocity reaches 595.85 m/s, the proposed multistage feedback control method can maintain the accuracy of the armature muzzle velocity within 0.83%. The effectiveness of the control method is verified, providing a theoretical foundation for the precise control of armature muzzle velocity in practical launch experiments.
{"title":"Multistage Feedback Control Method for Armature Velocity in Electromagnetic Rail Launch","authors":"Yuting Zhang;Zhenchun Wang;Yan Hu;Wenlai Zhang","doi":"10.1109/TPS.2024.3519166","DOIUrl":"https://doi.org/10.1109/TPS.2024.3519166","url":null,"abstract":"The stability of armature velocity is one of the crucial indicators for evaluating the performance of electromagnetic launch systems. A multistage control method for armature muzzle velocity is proposed based on the discharge time and quantity of the power module. By analyzing the pulse power supply model, the relationship between the discharge time, quantity, and armature velocity of the pulse power supply module is established. A multistage feedback control algorithm based on pulse discharge is introduced, which includes steps such as stride selection, adjustment of pulse power supply discharge time, and velocity calculation. By adjusting the discharge time and quantity of the pulse power supply according to the difference between the measured velocity at a reference position and the expected velocity, precise control of the armature velocity is achieved. When the armature muzzle velocity reaches 595.85 m/s, the proposed multistage feedback control method can maintain the accuracy of the armature muzzle velocity within 0.83%. The effectiveness of the control method is verified, providing a theoretical foundation for the precise control of armature muzzle velocity in practical launch experiments.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5649-5656"},"PeriodicalIF":1.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106392","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 : 2024-12-30DOI: 10.1109/TPS.2024.3519032
P.-A. Gourdain;A. Bachmann
Interferometry can accurately measure the electron density of a high energy density plasma by comparing the phase shift between a laser beam passing through the plasma and a reference beam. While the actual phase shift is continuous, the measured shift has discontinuities, since its measurement is constrained between $-pi $ and $pi $ , an effect called “wrapping.” Although many methods have been developed to recover the original, “unwrapped” phase shift, noise and under-sampling often hinder their effectiveness, requiring advanced algorithms to handle imperfect data. Analyzing an interferogram is essentially a pattern recognition task, where radial basis function neural networks (RBFNNs) excel. This work proposes a network architecture designed to unwrap the phase interferograms, even in the presence of significant aliasing and noise. Key aspects of this approach include a three-stage learning process that sequentially eliminates phase discontinuities, the ability to learn directly from the data without requiring a large training set, the ability to mask regions with missing or corrupted data trivially, and a parallel Levenberg-Marquardt algorithm (LMA) that uses local network clustering and global synchronization to accelerate computations.
{"title":"Neural Network Reconstruction of the Electron Density of High Energy Density Plasmas From Under-Resolved Interferograms","authors":"P.-A. Gourdain;A. Bachmann","doi":"10.1109/TPS.2024.3519032","DOIUrl":"https://doi.org/10.1109/TPS.2024.3519032","url":null,"abstract":"Interferometry can accurately measure the electron density of a high energy density plasma by comparing the phase shift between a laser beam passing through the plasma and a reference beam. While the actual phase shift is continuous, the measured shift has discontinuities, since its measurement is constrained between <inline-formula> <tex-math>$-pi $ </tex-math></inline-formula> and <inline-formula> <tex-math>$pi $ </tex-math></inline-formula>, an effect called “wrapping.” Although many methods have been developed to recover the original, “unwrapped” phase shift, noise and under-sampling often hinder their effectiveness, requiring advanced algorithms to handle imperfect data. Analyzing an interferogram is essentially a pattern recognition task, where radial basis function neural networks (RBFNNs) excel. This work proposes a network architecture designed to unwrap the phase interferograms, even in the presence of significant aliasing and noise. Key aspects of this approach include a three-stage learning process that sequentially eliminates phase discontinuities, the ability to learn directly from the data without requiring a large training set, the ability to mask regions with missing or corrupted data trivially, and a parallel Levenberg-Marquardt algorithm (LMA) that uses local network clustering and global synchronization to accelerate computations.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 12","pages":"5581-5596"},"PeriodicalIF":1.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106539","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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