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{"title":"X-Ray Micro-Discharges Fine Dynamics in a Vacuum High Voltage Experiment","authors":"S. Spagnolo;L. Cordaro;N. Pilan;A. De Lorenzi;C. L. Fontana;A. Muraro;T. Patton;F. Pino;G. Croci;R. Gobbo;L. Lotto;I. Mario;E. Martines;D. Rigamonti;E. Spada;M. Tardocchi;M. Zuin","doi":"10.1109/TPS.2024.3485494","DOIUrl":"https://doi.org/10.1109/TPS.2024.3485494","url":null,"abstract":"The High Voltage Padova Test Facility (HVPTF) is an experimental device for investigating high voltage (HV) Direct Current insulation in a vacuum, in support of the development of the prototype of a neutral beam injector for ITER, named MITICA. Inside a high vacuum environment, two stainless steel electrodes, spaced by a few centimeters gap, can achieve a voltage difference of up to 800 kV. During the electrode conditioning process, small current bursts, known as micro-discharges (MDs) occur, accompanied by the emission of X-rays, and of an overall increase in gas emission measurement. This study focuses on the fine dynamics of the MD phenomenon measured by the current signal and by the X-ray detectors, in an attempt to provide a possible physical interpretation of this mechanism. In particular, it appears that the MD fine dynamics are related to the growing asymmetry between the MD current values collected by the anode and cathode, observed during the electrode conditioning. The role of the vacuum chamber, acting as a third electrode, is investigated by an updated toy model, which evaluates the different current contributions collected from the two polarized electrodes, particularly those generated by secondary electron (SE) emission. The ratio of anode to cathode currents computed by the toy model closely matches the experimental one. Further experimental observations supporting the hypothesis of anode gas emission and expansion are discussed. Finally, a first study about the statistical distribution of the time intervals between successive MD suggests the occurrence of almost two different trigger mechanisms, evolving during the electrode conditioning process.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4514-4519"},"PeriodicalIF":1.3,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798019","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":"Innovative Concepts in the DTT Neutral Beam Injector","authors":"P. Agostinetti;E. Benedetti;R. Bonifetto;M. Bonesso;G. Calabrò;M. Cavenago;F. Crisanti;S. Dal Bello;M. Dalla Palma;D. D’Ambrosio;R. Dima;G. Favero;A. Ferro;M. Fincato;L. Grando;G. Granucci;R. Lombroni;R. Marsilio;A. Murari;T. Patton;A. Pepato;F. Raffaelli;P. Rebesan;M. Recchia;M. Ripani;A. Romano;E. Sartori;M. Scarpari;V. Variale;G. Ventura;F. Veronese;R. Zanino;A. Zappatore;G. Zavarise","doi":"10.1109/TPS.2024.3418133","DOIUrl":"https://doi.org/10.1109/TPS.2024.3418133","url":null,"abstract":"The main purpose of the divertor tokamak test (DTT) facility is to study alternative solutions to mitigate the issue of the power exhaust, under integrated physics and technical conditions relevant to ITER and DEMO. One of the most complex and innovative subsystems of the entire project is certainly the negative-ion-based neutral beam injector (NBI), meant to inject 10 MW of auxiliary power with a beam of 510 keV deuterium neutrals. This contribution describes the conceptual design of the beamline for the DTT NBI system, with a particular focus on the innovative technical solutions adopted to fulfill the requirements and maximize the performance. The DTT NBI is required to operate with high efficiency in several operating scenarios, covering a large range of beam energies, between 10% and 100% of the nominal value (510 keV). To reach this challenging goal, an innovative accelerator design, the spherical and lemon hyperlens grids (SLHGs), has been developed. The implementation of this design concept of the accelerator has recently become possible thanks to recent improvements in additive manufacturing (AM) technology. Another original aspect of the DTT NBI, compared to existing devices, regards the vacuum pumping system, which will be based on nonevaporable getter (NEG) pumps. This will represent the first application of the NEG technology to an NBI for the heating and current drive system of a fusion experiment, with a possible simplification of the overall construction, with respect to typical solutions based on cryogenic pumps. Other innovative solutions are the cylindrical sawtooth structure (CSS) for the neutralizer panels and the stray field shielding system (SFSS) with encapsulated neutralizer. This article provides an overview of the injector for DTT NBI with a particular focus on innovative technical solutions.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"3802-3808"},"PeriodicalIF":1.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797970","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 Progress of Modeling and Simulation of Vacuum Arcs Considering Multicomponents With Different Anode Modes","authors":"Lijun Wang;Jieli Chen;Zhefeng Zhang;Runming Zhang;Cong Wang;Shenli Jia","doi":"10.1109/TPS.2024.3485966","DOIUrl":"https://doi.org/10.1109/TPS.2024.3485966","url":null,"abstract":"Vacuum arc widely appears in vacuum interrupters, ion sources, thrusters, and other related application fields. Understanding the components’ characteristics in vacuum arc is very important for the above application fields. At present, modeling and numerical simulation technology is becoming more and more important for the study of vacuum arc mechanisms. In this article, multicomponent magnetohydrodynamic (MHD) models of vacuum arc with passive and active anode modes will be reviewed, and the commercial alloy electrode materials in vacuum interrupters will be considered. The influence of the spatial magnetic field generated by commercial electrodes on the arc was studied. Furthermore, transient plasma characteristics and component evolution processes of vacuum arcs with different situations (fixed gap distance and electrode movement) in vacuum interrupters are reviewed. Vacuum arc plasma jet characteristics with a ring anode under different external magnetic fields will also be introduced, and the separation mechanisms of light and heavy ions in vacuum arcs will also be studied. Finally, the challenge of vacuum arc modeling in the future is also discussed.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4402-4418"},"PeriodicalIF":1.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798018","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":"Improved Horizontal Plasma Position Control Using c-RIO-Based Real Time System in Aditya-U","authors":"Pramila Gautam;Vismaysinh Raulji;Rohit Kumar;Rachana Rajpal;Rakesh Tanna;Joydeep Ghosh;Aditya-U Team","doi":"10.1109/TPS.2024.3474713","DOIUrl":"https://doi.org/10.1109/TPS.2024.3474713","url":null,"abstract":"Real-time techniques are crucial in tokamaks to stabilize plasma position and achieve longer discharges. ADITYA-U uses real-time feedback control of the equilibrium field to stabilize the horizontal plasma position and improve plasma parameters. This innovative control system, developed using the NI-PXI-7831R card in a PXI chassis, featured an integrated PID controller. The PID controller generates control signals for the fast-feedback coils, resulting in successful control of the horizontal plasma position. However, the initial control system had some limitations. Therefore, it was upgraded using the Compact-RIO (c-RIO), for better control and flexibility in adjusting PID parameters. This upgrade allowed for longer durations of discharge of ~400 ms and improved data retrieval capabilities. The full paper will provide more details on the upgraded system and its performance in the ADITYA-U tokamak.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"3809-3813"},"PeriodicalIF":1.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797893","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":"A Clustered Routing Algorithm Based on Forwarding Mechanism Optimization","authors":"Qian Sun;Jialong Pang;Xiaoyi Wang;Zhiyao Zhao;Jing Li","doi":"10.1109/JSEN.2024.3467055","DOIUrl":"https://doi.org/10.1109/JSEN.2024.3467055","url":null,"abstract":"Given the intrinsic low energy and high consumption characteristics of sensor nodes, it is imperative to explore strategies for achieving energy-efficient routing within wireless sensor networks (WSNs). A significant body of existing research on clustered routing algorithms for WSNs has concentrated on employing heuristic optimization algorithms to facilitate the selection of routing paths. However, once the number of sensor nodes or the deployment environment changes, the algorithm’s performance can fluctuate significantly, potentially requiring redesign and retuning. In this article, we propose the clustered routing algorithm based on forwarding mechanism optimization (CRFMO), which defines separate routing rules for intracluster and intercluster communication, providing suitable communication paths for nodes. The algorithm eschews the complex procedure of parameter tuning during the routing path selection process and contributes to expediting WSN deployment and balancing node load pressure, ultimately extending the network’s operational lifespan. Simulation outcomes reveal that, in comparison to LEACH-IACA and IMP-LEACH, the CRFMO algorithm markedly enhances energy distribution balance, equalizes the burden among nodes, sustains high network coverage over an extended period, which enhances the quality of network monitoring, and significantly extends the lifetime of the network.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"24 22","pages":"38071-38081"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Porcine Corneal Injuries and Investigation of Damage Thresholds of High-Frequency Terahertz Wave","authors":"Hao Lin;Pan Liu;Wenzai An;Xin Yan;Shen Wu;Ningli Wang","doi":"10.1109/TPS.2024.3403722","DOIUrl":"https://doi.org/10.1109/TPS.2024.3403722","url":null,"abstract":"The objective was to investigate immediate ocular damage in exposed to 34.5-terahertz (THz) electromagnetic wave generated by quantum cascade laser (QCL). This research developed the damage porcine model for THz exposure, and its damage occurrence threshold values of time dimension and energy dimension were obtained. The right eyes were exposed to 34.5-THz spot from fiber, and the contralateral eyes were used as control eyes. Slit-lamp examination 5 min after THz exposure revealed a semicircular area of opacity characterized by fluorescein staining, indicating damaged corneal epithelial cells in the irradiated area and encircling by corneal edema. Hematoxylin-eosin (HE) staining suggested the irradiated corneas over 2 min exposure contained fewer epithelial cell layers with vacuolated cells, swollen endothelium, and edematous stroma, compared to contralateral corneas. In vivo evidence suggested exposure time over 6 min or energy over 40 mW leaded to full-thickness detachment of the corneal epithelium. The damage was present when the energy of THz wave was greater than 20 mW or the exposure time was longer than 2 min.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4735-4738"},"PeriodicalIF":1.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797921","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-Emission Properties of Vertically Aligned Carbon Nanotube Cathodes of Varying Geometries","authors":"Connor Gunter;Scott D. Kovaleski;Junyoung Shin;Elizabeth Bellott;Matthew Maschmann;Brandon Weatherford","doi":"10.1109/TPS.2024.3487079","DOIUrl":"https://doi.org/10.1109/TPS.2024.3487079","url":null,"abstract":"This work characterizes the bulk emission properties of carbon nanotube (CNT) forest cathodes fabricated with various geometries. Geometries explored include dense nanotube forests of varying height grown on \u0000<inline-formula> <tex-math>$5times 5$ </tex-math></inline-formula>\u0000 mm silicon (Si) substrates and discrete, patterned CNT pillars fabricated using UV photolithography. Dense forests heights ranged from \u0000<inline-formula> <tex-math>$526~mu text { m}$ </tex-math></inline-formula>\u0000 to 1.41 mm, with packing fraction for dense forest calculated to be 4e10 nanotubes/cm2 based on an average nanotube separation distance of 100 nm for fixed growth dense forests. Patterned sample micro pillar heights ranged from 47 to \u0000<inline-formula> <tex-math>$393~mu text { m}$ </tex-math></inline-formula>\u0000 with pillar widths on tested samples ranging from 250 to \u0000<inline-formula> <tex-math>$270~mu text { m}$ </tex-math></inline-formula>\u0000. Properties explored include emission current, turn-on field, and emission current performance over time. A parallel plate electron beam diode with a 100-\u0000<inline-formula> <tex-math>$mu text { m}$ </tex-math></inline-formula>\u0000 A-K gap and an automated test apparatus were developed to provide a configurable experiment that provides accurate and repeatable measurements for dc, dc sweep, and timed performance testing. Operating voltages for the voltage sweeps spanned from 0 to −350 V. Testing has shown evidence of a hysteresis effect on the emission current tied to the applied field history as well as shifting of the turn-on field magnitude throughout the testing period, suggesting a conditioning effect during use. Three separate emission regions in the I–V curves during sweep testing have also been observed. In the geometric study, dense forests and patterned samples were sweep tested up to a peak applied voltage of −250 V, with the taller samples generally performing better. Currents produced in the geometric study from the dense forest emitters ranged from 36.8 to \u0000<inline-formula> <tex-math>$572.34~mu text { A}$ </tex-math></inline-formula>\u0000, with current densities ranging from 15 to 2.29 mA/cm2. Currents produced from the patterned micropillar emitters ranged from 39.4 to \u0000<inline-formula> <tex-math>$317.51~mu text { A}$ </tex-math></inline-formula>\u0000, with current densities ranging from 67 to 3 mA/cm2. DC time testing showed a relatively stable output current over a 4.5-h testing period. The findings of this work aim to explore CNT emitters as a viable alternative to thermionic cathodes used in large RF systems and to characterize connection between CNT emitter geometry and the resulting emission performance. The insights gained from this work will be used for informed design and optimization of future emitters.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4576-4582"},"PeriodicalIF":1.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797941","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":"IEEE Sensors Council","authors":"","doi":"10.1109/JSEN.2024.3490979","DOIUrl":"https://doi.org/10.1109/JSEN.2024.3490979","url":null,"abstract":"","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"24 22","pages":"C3-C3"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10752818","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ridge-Loaded S-Band MILO Using Drift Tube and Dual Extraction Cavity","authors":"Bilawal Ali;Yubin Gong;Shaomeng Wang;Muhammad Khawar Nadeem;Jibran Latif;Atif Jameel;Yang Dong;Zhanliang Wang","doi":"10.1109/TPS.2024.3481153","DOIUrl":"https://doi.org/10.1109/TPS.2024.3481153","url":null,"abstract":"A magnetically insulated line oscillator (MILO) is a unique high-power microwave (HPM) device distinct by its inherent ability to generate a self-insulating magnetic field. In this article, an S-band ridge-loaded MILO is studied. The current design incorporates a drift section in a region of slow wave structure (SWS), resulting in a reduction of the axial velocity (\u0000<inline-formula> <tex-math>$v_{z}$ </tex-math></inline-formula>\u0000) spread of the modulated beam. Another, a dual extraction cavity is designed in the extraction region. So, the axial electric field is enhanced, and beam-wave interaction is lengthened in this region; consequently, efficiency is increased. Dispersion characteristic is obtained in eigenmode analysis. In 3-D particle-in-cell simulation, the presented MILO generates a 4.5-GW average output power at 2.56-GHz frequency with an application of 500-kV voltage and a current of 42 kA. The average efficiency is elevated to 21.4%, while it is only 15.7% for conventional ridge-loaded MILO for the same input parameters, so the net increase in efficiency is 36%.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 9","pages":"4553-4561"},"PeriodicalIF":1.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797940","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":"Highly Efficient and Controlled Thermomechanical Transfer of Electrospun PVDF Nanofiber on Flexible and Transparent PDMS Substrate","authors":"Ariba Siddiqui;Mitradip Bhattacharjee","doi":"10.1109/TNANO.2024.3496487","DOIUrl":"https://doi.org/10.1109/TNANO.2024.3496487","url":null,"abstract":"The growing interest in sensors and microdevices in different applications has led to the exploration of the most efficient and appropriate synthesis methods for flexible device development. In this direction, nanofibers have gained significant attention. However, in many cases, efficient and controlled transfer of nanofibers plays an important role in various device developments. In this study, thermomechanical i.e., temperature and pressure-induced transfer of poly(vinylidene fluoride) (PVDF) electrospun nanofibers on flexible poly(dimethylsiloxane) (PDMS) substrate has been explored. The average diameter of the transferred nanofibers is 169.78 nm. The d\u0000₃₃\u0000 of PVDF nanofibers was 25 pC/N and F(β) was found to be 80.84%. The synthesized nanofibers have effectively been transferred onto a flexible PDMS substrate with more than 92% retention of optical transparency. It is observed that the transfer of the fibers depends on the applied pressure and adhesion between the materials. Further, it was found that fully cured PDMS substrate heated at 120 °C showed better transfer efficiency (12.544%) with higher stability. The use of PVDF nanofibers along with the inherent flexibility and transparency of PDMS, renders the produced substrate highly promising for the development of low-cost, lightweight, and easily constructed flexible sensors. Moreover, the fabricated nanofibrous mat generated a maximum voltage of 2.78 V on continuous tapping.","PeriodicalId":449,"journal":{"name":"IEEE Transactions on Nanotechnology","volume":"23 ","pages":"786-793"},"PeriodicalIF":2.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142777846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}