IEEE Transactions on Plasma Science最新文献

{"title":"Thermodynamic and Pilot-Scale Assessment of Al2O3 Reduction in Nitrogen--Hydrogen RF Plasma","authors":"Igor B. Matveev","doi":"10.1109/TPS.2026.3724776","DOIUrl":"https://doi.org/10.1109/TPS.2026.3724776","url":null,"abstract":"The Hall–Héroult electrolytic process has dominated global aluminum production for nearly 140 years, but it faces hard limits in efficiency and generates significant carbon, fluorine, and hazardous solid waste emissions. This work presents a thermodynamic and pilot-scale assessment of aluminum production via direct reduction of alumina (Al₂O₃) in nitrogen–hydrogen radio frequency (RF) plasma. In contrast to the conventional Hall–Héroult process, the proposed approach eliminates carbon electrodes, cryolite, and fluorinated byproducts. A thermodynamic analysis based on hydrogen reduction of Al₂O₃ indicates a theoretical minimum energy requirement of approximately 6.5 MWh per ton of aluminum (MWh/t Al), including both reaction enthalpy and sensible heat contributions. Preliminary estimates derived from an APT-100 RF plasma system (~100 kVA) suggest a specific energy consumption (SEC) of approximately 12.1 MWh/t Al under pilot-scale conditions. Projected performance at higher power levels (~1 MW), assuming improved plasma efficiency and heat recovery, indicates the potential to approach ~6.8 MWh/t Al. These projected values are based on simplified energy balance assumptions and require experimental validation. The analysis defines key process parameters, assumptions, and scaling limitations. In addition to aluminum production, the process enables the formation of aluminum nitride (AlN) as a valuable byproduct. The results suggest that RF plasma reduction represents a promising pathway for low-emission aluminum production, subject to further experimental confirmation.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5376-5382"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149175972","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":"Experimental Study on Triggered Vacuum Arc and Its Voltage Characteristics of Butt Contacts Under the Conditions of 50- and 60-Hz Frequencies","authors":"Lijun Wang;Zhinan Chen;Qiang Ma;Tianlu Liu;Runming Zhang","doi":"10.1109/TPS.2026.3694021","DOIUrl":"https://doi.org/10.1109/TPS.2026.3694021","url":null,"abstract":"Butt contacts have simple structures and are widely employed in vacuum interruption applications. To investigate the triggered vacuum arc characteristics and arc voltage difference under different global power grid operating frequencies (50 and 60 Hz), this study conducted triggered arc experiments on 41-mm diameter butt contacts at both frequencies under a sinusoidal current with a peak value of 6.80 kA. A comparative analysis was then performed on arc morphology, arc voltage, and arc current characteristics, and anode spot behavior. The results demonstrate that for 41-mm-diameter butt contacts, significant side-arcing occurs at larger gap distances, which markedly increases the effective arc voltage <inline-formula> <tex-math>$U_{mathrm {eff}}$ </tex-math></inline-formula>. Specifically, <inline-formula> <tex-math>$U_{mathrm {eff}}$ </tex-math></inline-formula> appears to exhibit a range of fluctuations under the same <inline-formula> <tex-math>$D$ </tex-math></inline-formula>/<inline-formula> <tex-math>$g$ </tex-math></inline-formula> (the ratio of the contact diameter <inline-formula> <tex-math>$D$ </tex-math></inline-formula> to the gap distance <inline-formula> <tex-math>$g$ </tex-math></inline-formula>) condition. But at a 3-mm gap, the 60-Hz arc can stably maintain a diffused state and smooth <inline-formula> <tex-math>$U_{mathrm {eff}}$ </tex-math></inline-formula>. <inline-formula> <tex-math>$U_{mathrm {eff}}$ </tex-math></inline-formula> shows a decreasing trend as the <inline-formula> <tex-math>$D$ </tex-math></inline-formula>/<inline-formula> <tex-math>$g$ </tex-math></inline-formula> ratio increases. During this decline, the rate of decrease appears to diminish significantly between <inline-formula> <tex-math>$D$ </tex-math></inline-formula>/g values of 4.1 and 6.83, which may be attributed to the frequent occurrence of side-arcing, and this transition point can be regarded as the critical threshold for the butt contacts to effectively confine arc burning within the gap.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4731-4738"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176122","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":"X-Ray Radiation in 126-kV Vacuum Interrupters During Sequential Power--Frequency Conditioning and Comparative Analysis of Conditioning Methods","authors":"Wei Sun;Huantong Shi;Xingwen Li","doi":"10.1109/TPS.2026.3688798","DOIUrl":"https://doi.org/10.1109/TPS.2026.3688798","url":null,"abstract":"The pursuit of high-voltage, ecofriendly vacuum circuit breakers (VCBs) as alternatives to SF<inline-formula> <tex-math>${}_{mathbf {6}}$ </tex-math></inline-formula>-insulated apparatus brings to the fore the challenge of X-ray radiation generated during the conditioning of vacuum interrupters (VIs). This article presents an experimental and simulation study on the X-ray emission characteristics of a 126-kV VI. The temporal evolution of radiation during sequential power–frequency voltage conditioning cycles is investigated, and the effectiveness of three conditioning methods is comparatively evaluated from a radiation perspective. A self-designed absorption spectrometer was employed to measure the X-ray dose and spectrum. Results from five consecutive conditioning experiments revealed a progressive reduction in the total X-ray dose alongside significant spectral hardening, indicating a saturation of the conditioning effect after 4–5 cycles. Comparative analysis demonstrates that, while laser preconditioning has a minimal impact (~5% dose reduction), high-current preconditioning substantially reduces the subsequent power–frequency conditioning dose rate by approximately 35% compared to the conventional method. Crucially, high-current conditioning also results in a softer X-ray spectrum, characterized by a lower proportion of high-energy photons, which implies reduced penetration capability and a lower radiation threat. These findings provide insights for optimizing conditioning protocols, enhancing personnel safety, and guiding the design of radiation shielding for high-voltage VI testing and manufacturing.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4848-4855"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176140","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":"Field Energy Evolution and Contact Optimization of 27.5-kV Vacuum Interrupter During Interruption Process Based on DBM-MOPSO","authors":"J. Y. Zheng;X. M. Liu;H. Chen;J. J. Yang;Y. N. You;X. W. Wang","doi":"10.1109/TPS.2026.3714476","DOIUrl":"https://doi.org/10.1109/TPS.2026.3714476","url":null,"abstract":"The coupled effect of long-term current-carrying thermal stability, electromagnetic force on the arc during fault interruption, and post-arc dynamic insulation performance is the decisive factor for the operating performance of the vacuum circuit breaker (VCB). This article takes a <inline-formula> <tex-math>$2 times 27.5$ </tex-math></inline-formula>/T2500-31.5 environmentally friendly cubicle-type gas-insulated switch (C-GIS) as the research object, combining with the short-circuit interruption test of the prototype, modeling and simulation are carried out on the field energy and the spatiotemporal evolution process during the interruption process of the VCB. The characteristic values of temperature rise, magnetic arc-blowing, and breakdown withstand performance under the multiphysics field coupling effect of the VCB have been determined. Moreover, the effect of the key structural parameters (contact electrode diameter, slot width, and slot deflection angle) on the field energy evolution during the interruption process has been investigated. To improve the design efficiency of the VCB, a deep Boltzmann machine (DBM) is adopted to construct a surrogate model that can describe the effect of contact structure on the multiphysics performance characteristic values, and compared with a convolutional neural network (CNN) and support vector machine regression (SVR) to verify its prediction accuracy. Aiming at enhancing the energy bearing, utilization, and dissipation capacity of the VCB, the multiobjective particle swarm optimization (MOPSO) algorithm is applied for the parametric design of the contact structure. And the results show that the changes in contact structural parameters can significantly affect the multiphysics performance of the VCB. Compared with the initial design, the contact structure obtained by the optimized design method proposed in this article reduces the average temperature rise on the surface of the outlet terminals at both the movable and static sides of the VCB by 11.80%, and decreases the average electric field intensity at the contact edge by 1.31%, without compromising the magnetic arc-blowing performance. The method proposed in this article is applied to a 2.2 kV/5000 A–60 kA low-voltage high-current vacuum contactor and a 36 kV/2500 A–25 kA ring main unit (RMU) to verify the effectiveness of the method.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4817-4825"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176174","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":"Self-Similar Elliptical Plasmonic Metasurface for Midinfrared Sensing","authors":"Fatemeh Kazemi;Zahra Sadat Tabatabaeian;Ferdows B. Zarrabi;Mohammad Reza Rakhshani","doi":"10.1109/TPS.2026.3734024","DOIUrl":"https://doi.org/10.1109/TPS.2026.3734024","url":null,"abstract":"Optical metasurfaces have emerged as promising platforms for tailoring light-matter interactions at the nanoscale. In this article, a novel self-similar metasurface is developed, comprising two rows of elliptical gold elements on a silicon dioxide (SiO<inline-formula> <tex-math>${}_{2}$ </tex-math></inline-formula>) substrate serving as the optical layer. These elements are arranged radially on concentric rings, enabling a dual-band response. Two distinct resonances are observed at wavelengths of 4.9 and <inline-formula> <tex-math>$9.8~mu $ </tex-math></inline-formula>m, respectively. The specific arrangement of the metasurface structure provides a Fano response at the second resonance. At the first resonance, the metasurface exhibits a Q-factor of approximately 47, while the Q-factor increases to around 885 at the second resonance. The metasurface structure is further explored for sensing applications, demonstrating high sensitivity at the first and second resonances, with sensitivity values of 1088 and 340 (nm/RIU), respectively. In addition, figures of merit (FOM) are calculated to quantify the overall performance of the metasurface. The FOM values obtained for the first and second resonances are 10.88 and 30.90 (RIU⁻¹), respectively. This study showcases the potential of the proposed optical metasurface design for efficient dual-band and sensing applications.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5319-5326"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176223","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":"Direct Reduction of Iron Ore Pellets With High-Potential Reducing Gas Obtained by Plasma-Steam Gasification of Solid Fuel","authors":"Vladimir E. Messerle;Alexandr B. Ustimenko;Sestager Kh. Aknazarov;Magzhan N. Orynbasar","doi":"10.1109/TPS.2026.3684580","DOIUrl":"https://doi.org/10.1109/TPS.2026.3684580","url":null,"abstract":"A thermodynamic analysis of plasma-steam gasification of noncoking low-grade high-ash brown coal and reduction of iron ore pellets using the obtained synthesis gas was performed. In equilibrium, coal carbon and sulfur gasification rates were achieved at 100% at temperatures of 1300 and 1700 K, respectively. The degree of iron reduction reaches its maximum (99.999%) at T = 1040 K. Experimental studies of the specified processes were carried out in a plasma installation with a combined-type reactor with a rated power of 100 kW. The maximum concentration of synthesis gas (95.8%) is achieved at a temperature of 2300 K. The degree of coal gasification and desulfurization at moderate energy consumption (2.83 kWh/kg) reaches 93.5% and 90.8%, respectively. The reduction rate of iron ore pellets using synthesis gas reached 90.5% at a process temperature of 1200 K. The reduced metal contained no more than 0.14% carbon and 0.014% sulfur. The discrepancy between experimental and calculated data did not exceed 12%. Research has demonstrated the feasibility of producing low-carbon iron using synthesis gas from low-grade coal as a high-potential reducing agent.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5383-5389"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176234","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":"Effect of Annealing Temperature on the Sheet Resistance and Secondary Electron Emission Yield of Chromium Oxide-Coated Alumina","authors":"Akio Ogura;Souichi Katagiri;Ryu Hasunuma","doi":"10.1109/TPS.2026.3722511","DOIUrl":"https://doi.org/10.1109/TPS.2026.3722511","url":null,"abstract":"A flashover along the surface of a solid insulator in vacuum is a discharge phenomenon that can result in device damage, and this issue limits, for example, the applicable maximum voltage of charged-particle accelerators. One effective approach to improve the withstand voltage of the insulator is to coat it with a slightly electrically conductive film. In this study, we evaluated the impact of the annealing temperature on the sheet resistance and the secondary electron emission yield (SEEY) of alumina substrates coated with an about 10-nm-thick chromium oxide film. To identify the origin of the observed trend in the SEEY data, we evaluated the oxidation state of the chromium atoms in the film by X-ray photoelectron spectroscopy (XPS), and we also measured the surface morphologies of chromium coatings on silicon prepared in the same way. The results indicate that the SEEY strongly depends on the grain size and the residual metallic chromium content.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"4758-4764"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176325","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":"Blank Page","authors":"","doi":"10.1109/TPS.2026.3739645","DOIUrl":"https://doi.org/10.1109/TPS.2026.3739645","url":null,"abstract":"","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"C4-C4"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11735312","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149175960","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":"Transactions on Plasma Science","authors":"","doi":"10.1109/TPS.2026.3739641","DOIUrl":"https://doi.org/10.1109/TPS.2026.3739641","url":null,"abstract":"","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"C2-C2"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11735334","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149175991","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":"Virtual Integration Platform for Engineering and Remote Handling (VIPER)","authors":"Gazzotti Stéphane;Huc Killian;Friconneau Jean-Pierre","doi":"10.1109/TPS.2026.3700733","DOIUrl":"https://doi.org/10.1109/TPS.2026.3700733","url":null,"abstract":"Maintaining and installing equipment in nuclear confined environments present significant challenges, demanding precise planning and advanced technologies to ensure worker safety and reduce radiation exposure. The virtual integration platform for engineering and remote handling (VIPER) offers an innovative framework to enhance the design, simulation, and operational efficiency of fusion energy projects. The platform’s immersive simulation capabilities offer realistic virtual environments for validating complex engineering processes. These capabilities are crucial for high-stakes nuclear operations, where precision and safety are critical. VIPER focuses on four interconnected domains: digital continuity, scale one immersive simulation, nuclear applications, and remote handling, leveraging state-of-the-art tools and methodologies. This abstract highlights VIPER’s application in key fusion use cases, including WEST tokamak component assembly [e.g., plasma facing units and ion cyclotron resonance heating (ICRH) antennas], ITER Tokamak maintenance and decommissioning activities and DEMO remote maintenance. The objective of this article is to describe the methodology and available functionalities of a stand-alone 4-D viewer developed by the platform. It integrates functionalities, such as sequence management, including the temporal dimension. By automating coupling to model-based system engineering (MBSE) principles and robust metadata management, the application guarantees data accuracy and consistency throughout the design and operation phases. In addition, the coupling with the XDE physics engine modules enables the integration of physical analyses of operational feasibility, accessibility, and ergonomics, as well as collision detection and path-finding algorithms. Fully integrated into the engineering design process, it significantly reduces information access times and improves team communication. VIPER evolution demonstrates the transformative potential in fusion energy projects. It embraces emerging technologies, including investigations with new standards for enhanced interoperability, real-time collaboration, and scalability. With a forward-looking roadmap, VIPER is poised to advance digital engineering methodologies, solidifying its role as a cornerstone for the next generation of fusion energy systems.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 10","pages":"5461-5465"},"PeriodicalIF":1.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149176016","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}