IEEE Transactions on Plasma Science最新文献

{"title":"Optimal Oscillation Region for A6 Magnetron via Mode Competition Analysis of Cross-Sectional Vector Electric Fields","authors":"Dong-Hyun Oh;Young-Wook Kim;Jung-Hoon Han","doi":"10.1109/TPS.2026.3729983","DOIUrl":"https://doi.org/10.1109/TPS.2026.3729983","url":null,"abstract":"Relativistic magnetrons (RMs), a class of high-power microwave (HPM) sources, have attracted significant attention across various industrial applications. Under specific operating conditions, RMs experience mode competition, which leads to variations in critical performance metrics such as oscillation efficiency and rise time. While optimal operating conditions have been previously proposed for strapped magnetrons, applying these formulations to unstrapped magnetrons is challenging due to inherent differences in their operational characteristics. Accordingly, this article proposes a novel optimal operating condition applicable to the A6 magnetron—a representative unstrapped RM—based on the analysis of mode competition. The proposed mathematical formulation is designed by utilizing the frequencies and electric field components, including both magnitudes and phases, of the operating mode and the adjacent competing mode. Simulation results demonstrate that the proposed formulation yields a significantly higher oscillation efficiency and a shorter 90% rise time compared to the conventional formulation.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5086-5092"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176148","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}

{"title":"Eco-Friendly Synthesis of CeO2 Nanoparticles Using Air Microdischarge Plasma for Efficient Photocatalytic Degradation of Norfloxacin","authors":"Markandesan Muthuselvan;Mani Vijay;Kalidass Suresh","doi":"10.1109/TPS.2026.3714719","DOIUrl":"https://doi.org/10.1109/TPS.2026.3714719","url":null,"abstract":"Nonthermal plasma (NTP) is an emerging technique for nanoparticle (NP) synthesis due to its ability to generate highly reactive species under mild conditions. Microdischarge plasma (MDP) is a type of NTP that offers various advantages over standard synthesis processes, including a single-step process, short processing time, atmospheric operating conditions, and elimination of surfactant or other additional chemicals. Herein, CeO₂ NPs were synthesized using air MDP in a short time without the need for high-temperature post treatment. Reactive species generated by air plasma, including hydroxyl radicals (OH•) and other reactive oxygen species (ROS), play a major role in the nucleation and growth of NPs. The as-prepared CeO₂ NPs displayed a cubic fluorite crystal structure, with a small crystallite size of 1.74 nm and spherical morphology. The optical band gap of as-synthesized CeO₂ NPs was found to be 2.6 eV, indicating that defect states introduced during the MDP process reduced the band gap, thereby enhancing the visible light absorption. The photocatalytic potential of the synthesized CeO₂ NPs was assessed by the degradation of norfloxacin. The maximum degradation efficiency of 91.91% was achieved using a low catalyst dosage of 0.1 g/L^-1, and the degradation process follows pseudo-first-order kinetics. Antibacterial assays confirmed that the photodegraded samples did not affect both gram-negative and gram-positive bacteria, indicating effective degradation of the antibiotic without inducing toxicity. Therefore, the MDP technique is a rapid and eco-friendly approach for large-scale production of functional metal oxide NPs for water treatment and environmental remediation.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5597-5605"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176170","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}

{"title":"Inverse Synthetic Aperture Radar Imaging of Reentry Target Under the Strong Interference of Plasma Sheath","authors":"Shaohui Yao;Zhenmiao Deng;Ye Ge;Gang Wu;Yuhan Hong;Xinjie Ma;Haochuan Deng","doi":"10.1109/TPS.2026.3732659","DOIUrl":"https://doi.org/10.1109/TPS.2026.3732659","url":null,"abstract":"Accurate inverse synthetic aperture radar (ISAR) imaging of a reentry target is severely challenged by the plasma sheath formed around the vehicle surface. In such environments, the plasma sheath acts not only as a lossy dispersive medium but also as a distributed parasitic scatterer with a nonuniform velocity field, which introduces additional Doppler components and distorts the 1-D range profiles (ODRPs) after pulse compression. This article investigates the fundamental failure mechanism of conventional envelope-based ISAR motion compensation methods under plasma sheath interference. Furthermore, this article reveals the intrinsic limitation of dechirped signals for ISAR imaging under plasma sheath interference and clarifies the necessity of employing intermediate-frequency (IF) direct-sampled signals. To overcome this limitation, a coherent motion compensation (CMC) framework is proposed for sheath-contaminated radar echoes. The proposed method is validated using both a simplified scatterer model and a multiphysics simulation framework combining Fluent-based plasma-flow modeling and FEKO-based electromagnetic scattering analysis. Results demonstrate that the proposed approach effectively suppresses the impact of sheath-induced parasitic echoes and produces well-focused ISAR images under severe plasma sheath interference.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5227-5241"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176205","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}

{"title":"Miniaturized Conventional Collector for Next-Generation High-Efficiency TWTs","authors":"Deepali Yadav;A. Mercy Latha;Meenu Kaushik;Sanjay Kumar Ghosh;Vishant Gahlaut","doi":"10.1109/TPS.2026.3725851","DOIUrl":"https://doi.org/10.1109/TPS.2026.3725851","url":null,"abstract":"The collector in a traveling wave tube (TWT) plays a crucial role in determining the tube’s overall efficiency while also contributing significantly to its size and weight. In tubes requiring very high efficiencies, multistage depressed collectors (MDCs) are widely employed, as they aid in sorting and collecting the electron beam at its lowest kinetic energy, thereby achieving high collector efficiency. TWTs used for airborne and spaceborne applications must be compact and lightweight. Hence, the MDC should be designed with a small diameter, reduced length, and less weight. Here, a miniaturized MDC has been designed with a conventional electrode geometry for a high-electronic-efficiency space TWT, with a high-power operation of 900 W. Here, as a conventional electrode geometry has been adopted, avoiding complicated electrode geometries, this collector allows ease of fabrication and does not prolong the development cycle. Size reduction has been attempted by optimizing the conventional electrode geometries and the corresponding depressed electrode potentials in order to maximize the collector efficiency with negligible backstreaming and body currents. The optimized MDC offers a radial size reduction of up to 35% and longitudinal length reduction of up to 19% relative to the full-sized conventional collector, without compromising collector performance. Detailed studies of the high-voltage breakdown limit, geometrical and potential sensitivity analyses, and thermal steady-state analysis indicate that the MDC performs well electrically and thermally, in addition to providing size and weight benefits.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5111-5117"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176251","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}

{"title":"Research on Integrated Charging and Discharging Technology of Cascaded Power Supply Based on Battery Energy Storage","authors":"Jinpu Cai;Yaohong Sun;Yinghui Gao;Jing Han;Ping Yan","doi":"10.1109/TPS.2026.3722523","DOIUrl":"https://doi.org/10.1109/TPS.2026.3722523","url":null,"abstract":"To meet the requirements of electromagnetic launch devices, this article proposes a cascaded high-voltage power supply topology based on integrated charging and discharging of lithium batteries for pulsed capacitor charging. Lithium batteries are used as long-term energy storage units to meet the mobility requirements of electromagnetic launch devices, and only one charger module is used to fully charge all battery power to realize the lightweight of electromagnetic launch devices. A multistage constant current charging (CC Charge) strategy is proposed based on this topology, which can fully charge all batteries at the same time. In addition, for the discharge of the battery to the pulsed capacitor, a double closed-loop PI control strategy with outer-loop output limiting is proposed to realize stable and CC Charge of the pulsed capacitor to 7000 V, which improves the operational stability of electromagnetic launch devices. A MATLAB/Simulink simulation model is built to verify the charging and discharging control strategy, and the results show the effectiveness of the proposed circuit topology and control strategy, which can reduce the complexity of electromagnetic launch devices and control the batteries to discharge stably at constant current.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5163-5171"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176312","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}

{"title":"Extended FEM Simulation and Experimental Validation of Magnetic Fields in AMF Contacts for Vacuum Circuit Breakers","authors":"David Cziumplik;Thierry Delachaux;Michael Kurrat","doi":"10.1109/TPS.2026.3718200","DOIUrl":"https://doi.org/10.1109/TPS.2026.3718200","url":null,"abstract":"This work presents an expanded experimental and numerical investigation of the magnetic field distribution in axial-magnetic-field (AMF) contact systems under static conditions for large gaps. AMF contacts are used in vacuum circuit breakers (VCBs). Building on an earlier study, a finite-element-method (FEM) model and a physical test method using copper rods as a metal-vapor replacement are employed to characterize the axial magnetic flux density within the contact gap. A calibrated Hall sensor enables magnetic-field measurements, which are compared directly with FEM results. Additional measurements, conducted under revised rod configurations and sensor positions, further validate the repeatability of the method. Beyond validating the simulation against measurements at gap distances of 20, 30, and 40 mm, the present work extends the analysis by examining the spatial distribution of the axial magnetic flux density <inline-formula> <tex-math>$B_{mathrm {z}}$ </tex-math></inline-formula> for a 40-mm contact gap in greater detail. Instead of restricting the evaluation to the mid-gap plane or the centerline, the magnetic-field profiles are extracted radially on the lower contact surface and at axial positions 5–20 mm above it. This approach captures the characteristic field distribution across the whole gap. The resulting field distributions are compared with published plasma-simulation data, demonstrating that the simplified static model reproduces key trends of more complex metal-vapor arc simulations. This agreement indicates that the method can provide meaningful insight into AMF behavior and enables qualitative conclusions regarding expected erosion patterns and contact-design implications.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4873-4881"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149175986","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}

{"title":"Design Methodology and Simulation Studies of a Compact Trifunctional Metasurface for Wideband Terahertz Applications","authors":"Akhilendra Pratap Singh;Shriman Narayana;Vineet Singh;Sivavenkateswara Rao V.","doi":"10.1109/TPS.2026.3733219","DOIUrl":"https://doi.org/10.1109/TPS.2026.3733219","url":null,"abstract":"This article presents a systematic two-stage design approach for the implementation of small trifunctional VO₂-based metasurfaces. The vanadium dioxide (VO<inline-formula> <tex-math>${}_{2}$ </tex-math></inline-formula>)-based compact trifunctional terahertz (THz) metasurface is proposed for dynamic manipulation of electromagnetic waves. The proposed metasurface takes advantage of the thermally induced insulator-to-metal phase change of VO₂ to perform three different functionalities in a single compact unit cell of <inline-formula> <tex-math>$30times ~30~times ~17 0.6~mu $ </tex-math></inline-formula>m³. The polarization-insensitive broadband absorption in the metallic state (<inline-formula> <tex-math>$sigma = 2~times ~105$ </tex-math></inline-formula> S/m, above <inline-formula> <tex-math>$68~^{circ }$ </tex-math></inline-formula>C) results in a 3-dB absorption bandwidth of 4.61 THz with an absorption coefficient exceeding 90% over the range of 3.06–7.67 THz. The VO₂ works as a linear-to-cross polarization converter with a polarization-conversion ratio (PCR) larger than 0.9 at 2.63–7.25 THz and as a linear-to-circular polarization converter (LP–CPC) at 1.73–2.36, 7.60–7.61, 8.06–8.27, and 8.77–8.80 THz with an axial ratio (AR) below 3 dB. The obtained PCR bandwidth is 4.62 THz, and the total AR bandwidth is 0.63 THz. The absorption mechanism is explained by the impedance matching between the metasurface and free space in the operating band, which has been verified by the normalized impedance analysis. The anisotropic resonance of the gold elliptical split-ring resonator (ESRR) and the rectangular patch leads to polarization conversion. Compared to previously reported VO₂-based multifunctional metasurfaces, the proposed structure has a smaller footprint of the unit cell, and it is characterized by improved absorption and polarization-conversion bandwidths. The design proposed is a promising candidate for advanced THz sensing, imaging, polarization manipulation, and next-generation wireless communication systems due to its compactness, temperature-driven tunability, and multifunctionality.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5348-5359"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176008","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}

{"title":"Arc Behavior and Surface Evolution Under Targeted Current Conditioning","authors":"Chaozheng Peng;Xiaoshe Zhai;Zhichao Chen;Haojie Jia;Shaoming Shi;Xiangzhe Li;Jianhua Wang","doi":"10.1109/TPS.2026.3695275","DOIUrl":"https://doi.org/10.1109/TPS.2026.3695275","url":null,"abstract":"The conditioning of vacuum interrupters (VIs) essentially involves a secondary metallurgical effect on contact surfaces induced by arc energy. The achievement of the following two objectives determines the final metallographic characteristics and conditioning efficacy: precise localization of insulation-weak areas on the contact surfaces to achieve uniform distribution of arc energy, and accurate regulation of energy deposition within the targeted regions to beneficially modify the contact surface. Since the breakdown conditions of the contact gap and the energy-injection conditions are coupled in conventional single-power-source modes, it is difficult to independently and effectively adjust the corresponding spatial and temporal parameters, thereby constraining further exploration of conditioning methodologies. To address the above issues, this article proposes a targeted current conditioning (TCC) technology that accurately locates and breaks down insulation weak spots using low-energy, high-voltage pulses. Subsequently, conditioning is realized by applying a high-current arc with specific amplitude and time constant to the identified region. This method overcomes the bottlenecks of uncontrollable arc energy and uneven energy distribution during conditioning, which can significantly enhance the insulation performance of VIs. Building on this foundation, this study uses high-speed imaging to observe the arc’s transfer characteristics and spatial distribution, which are correlated with field-emission characteristics to analyze the evolution of electrode surface properties. The main objectives of this study are: validating the feasibility of localization during targeted conditioning, revealing the intrinsic mechanisms underlying the evolution of surface features, and performing an in-depth investigation into the physical mechanisms responsible for insulation improvement under targeted current action.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4780-4790"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11552885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PlasmaAura: A Multimodal LLM-Based Agent for WEST Tokamak Data Analysis","authors":"Florian Baud;Feda Almuhisen;Ludovic Fleury;Dorian Midou;Philippe Moreau;Jorge Morales;Xavier Litaudon;WEST Team","doi":"10.1109/TPS.2026.3700720","DOIUrl":"https://doi.org/10.1109/TPS.2026.3700720","url":null,"abstract":"Tokamak operations generate large volumes of diagnostic data needed for plasma control and for analyzing complex plasma dynamics. During experimental sessions, session leaders and researchers must review the previous pulse and define the next experimental configuration within a 10–15-min interval, making rapid access to relevant information essential. Effective decision support often relies on dedicated tools for retrieving information from operational data systems, typically based on SQL databases or flat files. However, the manual query interfaces to these data sources often present a steep learning curve, thereby offering limited flexibility for session leaders and physics operators in the dynamic environment of tokamak operations. Recent advancements in artificial intelligence (AI), particularly in large language models (LLMs), offer a promising approach for interacting with scientific data through natural language. This work introduces PlasmaAura, a conversational agent based on a multimodal LLM (MLLM) informed with tokamak-specific knowledge through prompt engineering. This agent is capable of interpreting natural language queries to retrieve, correlate, and visualize both diagnostic and contextual tokamak data, producing executable code, figures, and textual explanations as verifiable outputs. In the present work, multimodality refers to the joint reasoning of the MLLM over textual context, generated code, and visual outputs, while the input data considered remain time-series diagnostics. We present case studies covering data retrieval, event detection, and descriptive analysis, with measured response times confirming suitability for interpulse use. This work represents a first step toward integrating AI agent tools into tokamak operation preparation, with the aim of enhancing decision-making workflows and supporting ITER objectives.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5474-5479"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176129","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}

{"title":"Impact of Obliqueness of Ambient Magnetic Field and Electron Inertia on Magnetosonic Solitons in Plasmas With Two-Fluid Approach","authors":"Sajjad Hussain;Shahzad Mahmood","doi":"10.1109/TPS.2026.3732379","DOIUrl":"https://doi.org/10.1109/TPS.2026.3732379","url":null,"abstract":"A two-fluid magnetized plasma approach is used to investigate magnetosonic waves in the presence of an oblique ambient magnetic field and electron inertia, in which the ion temperature is ignored (cold) while isothermal electron pressure is considered. In the linear limit, a dispersion relation is obtained containing both slow magnetosonic waves (SMSW) and fast magnetosonic waves (FMSW), in which dispersion effects appear due to the electron inertial wavelength included in the model. The limiting cases of SMSWs and FMSWs are also discussed. In nonlinear analysis, the Korteweg–De Vries (KdV) equation for magnetosonic solitons is derived, and its solution in terms of compressive electron density structures is obtained. It is found that both the oblique angle of the ambient magnetic field and electron inertia have a strong impact on the dispersive coefficient of the KdV equation and the formation of solitons. It is also found that the plasma model for magnetosonic wave solitons remains valid for the obliqueness of the ambient magnetic field, which lies in the range <inline-formula> <tex-math>$0^{circ }lt theta lt 90^{circ }$ </tex-math></inline-formula> for both FMSW and SMSW, respectively. The corresponding nonlinear bipolar structures of the perturbed electric field component along the direction of the wave propagation are found, while compressive and rarefactive soliton structures of the perturbed electric and magnetic field components in the perpendicular directions of the wave propagation for FMSW and SMSW, respectively, are also obtained. Our findings are general and applicable to magnetosonic wave observations in space and laboratory plasmas.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4981-4992"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176150","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}