Plasma Science & Technology最新文献

{"title":"Effect of ion stress on properties of magnetized plasma sheath","authors":"Long Chen, Zuojun Cui, Wei-fu Gao, Ping Duan, Zichen Kan, Cong-qi Tan, Jun-yu Chen","doi":"10.1088/2058-6272/ad0d4f","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0d4f","url":null,"abstract":"In the plasma sheath, there is a significant gradient in ion velocity, resulting in strong stress on ions treated as a fluid. This aspect has often been neglected in previous sheath studies. This study is based on the Braginskii plasma transport theory and establishes a 1D3V sheath fluid model that takes into account the ion stress effect. Under the assumption that ions undergo both electric and diamagnetic drift in the presheath region, self-consistent boundary conditions, including the ion Bohm velocity, are derived based on the property of the Sagdeev pseudopotential. Furthermore, assuming that the electron velocity at the wall follows a truncated Maxwellian distribution, the wall floating potential is calculated, leading to a more accurate sheath thickness estimation. The results show that ion stress significantly reduces the sheath thickness, enhances ion Bohm velocity, wall floating potential, and ion flux at the wall. It hinders the acceleration of ions within the sheath, leading to notable alterations in the particle density profiles within the sheath. Further research indicates that in ion stress, bulk viscous stress has the greatest impact on sheath properties.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139269539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Novel method for identifying the stages of discharge underwater based on impedance change characteristic","authors":"Chong Gao, Zhongjian Kang, Dajian Gong, Yang Zhang, Yufang Wang, Yiming Sun","doi":"10.1088/2058-6272/ad0d56","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0d56","url":null,"abstract":"It is difficult to determine the discharge stages in a fixed time of repetitive discharge underwater due to the arc formation process being susceptible to external environmental influences. This paper proposes a novel underwater discharge stage identification method based on the Strong Tracking Filter (STF) and impedance change characteristics. The time-varying equivalent circuit model of the discharge underwater is established based on the plasma theory analysis of the impedance change characteristics and mechanism of the discharge process. The STF is used to reduce the randomness of the impedance of repeated discharges underwater, and then the universal identification resistance data is obtained. Based on the resistance variation characteristics of the discriminating resistance of the pre-breakdown, main, and oscillatory discharge stages, the threshold values for determining the discharge stage are obtained. These include the threshold values for the resistance variation rate (K) and the moment (t). Experimental and error analysis results demonstrate the efficacy of this innovative method in discharge stage determination, with a maximum mean square deviation of Scr less than 1.761.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139270051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Simulation of ion cyclotron wave heating in the EXL-50U spherical tokamak based on dispersion relations","authors":"Haojie Ma, Huasheng Xie, Bo Li","doi":"10.1088/2058-6272/ad0d53","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0d53","url":null,"abstract":"This study investigates the single-pass absorption (SPA) of ion cyclotron range of frequency (ICRF) heating in hydrogen plasma of the EXL-50U spherical tokamak, which is an upgraded device of the EXL-50 with a central solenoid and a stronger magnetic field. The reliability of the kinetic dispersion equation is confirmed by the one-dimensional full-wave code, and the applicability of Porkolab’s simplified theoretical SPA model is discussed based on the kinetic dispersion equation. Simulations are conducted to investigate the heating effects of the fundamental and second harmonic frequencies. The results indicate that with the design parameters of the EXL-50U device, the SPA for second harmonic heating is 63%, while the SPA for fundamental heating is 13%. Additionally, the optimal injection frequencies are 23 MHz at 0.9 T and 31 MHz at 1.2 T. The wave vector of the antenna parallel to the magnetic field, with a value of k∥ = 7.5 m−1, falls within the optimal heating region. Simulations reveal that the ICRF heating system can play an important role in the ion heating of the EXL-50U.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139267756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Laser-induced plasma formation in water with up to 400 mJ double-pulse LIBS","authors":"Marion Henkel, Michelle Siemens, R. Methling, B. Emde, Jörg Hermsdorf, Steffen Franke, Diego Gonzalez","doi":"10.1088/2058-6272/ad0d59","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0d59","url":null,"abstract":"Double-pulse LIBS is a promising technique for deep-sea applications. LIBS measurements in shallow water with up to 400 mJ each pulse were done to select laser parameters which promote optimized spectral line emission from plasma even at elevated pressures, where line broadening until loss of most of the spectral information can occur. Optical emission spectroscopy, using a Czerny-Turner spectrometer, has been applied to investigate the dependence of the emitted radiation on laser parameters and hydrostatic pressure. It has been found, that higher laser pulse energies, especially with short pulse delay as required in high water pressure, can also have an adverse effect on the measured spectrum.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139268376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Non-thermal atmospheric pressure positive pulsating corona discharge in degradation of textile dye Reactive Blue 19 enhanced by Bi2O3 catalyst","authors":"Milica Petrović, Dragan Radivojević, Saša Rančev, Nena Velinov, Miloš Kostić, Danijela Bojić, Aleksandar Bojić","doi":"10.1088/2058-6272/ad0c9a","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c9a","url":null,"abstract":"Abstract Monoclinic Bi2O3 was applied for the first time, to the best of our knowledge, as a catalyst in a process of the dye degradation by the non-thermal atmospheric pressure positive pulsating corona discharge. The research focused on the interaction of the plasma-generated species and the catalyst, as well as its role in the degradation process. Plasma decomposition of the anthraquinone reactive dye Reactive Blue 19 (RB 19) was performed by the self- made reactor system. Bi2O3 was prepared by electrodeposition followed by thermal treatment, and characterized by XRD, SEM and EDX techniques. It was observed that the catalyst promoted decomposition of plasma-generated H2O2 into •OH radicals, the principle dye-degrading reagent, which further attacked the dye molecules. The catalyst improved the decolorization rate by 2.5 times, the energy yield by 93.4%, and the total organic carbon TOC removal by 7.1%, respectively. The excitation of the catalyst mostly occurred through the strikes of plasma-generated reactive ion and radical species from the air, accelerated by the electric field, as well as by the fast electrons with the energy of up to 15 eV, generated by the streamers reaching the liquid surface. Those strikes transferred the energy to the catalyst and created the electrons and holes which further reacted with H2O2 and water, producing the •OH radicals. This was indentified as the primary role of the catalyst in this process. Decolorization reactions followed the pseudo first order kinetics. Production of H2O2 and dye degradation rate increased with the increase of input voltage. The optimal catalyst dose was 500 mg dm-3. Decolorization rate was little lower in the river water compared to the one in deionized water due to the side reactions of •OH radicals with the organic matter and inorganic ions dissolved in the river water.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Plasma nitrogen fixation system with dual-loop enhancement for improved energy efficiency and its efficacy for lettuce cultivation","authors":"Zeyang Han, Mengxue Zhang, Di Zhang, Xin He, Tianjun Jing, Zhixuan Ge, Yuge Li, Zhu Tong, Yunhong Ren, Chongshan Zhong, Fang Ji","doi":"10.1088/2058-6272/ad0c96","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c96","url":null,"abstract":"Abstract Plasma nitrogen fixation (PNF) has been emerging as a promising technology for greenhouse gas-free and renewable energy-based agriculture. Yet, most PNF studies seldom address practical application-specific issues. In this work, we present the development of a compact and automatic PNF system for on-site agricultural applications. The system utilized a gliding-arc discharge as the plasma source and employed a dual-loop design to generate NO x - from air and water under atmospheric conditions. Experimental results showed that the system with a dual-loop design performs well in terms of energy costs and production rates. Optimal operational parameters for the system were determined through experimentation, resulting in an energy cost of 13.9 MJ mol −1 and an energy efficiency of 16 g kWh −1 for NO 3 - production, respectively. Moreover, the concentration of exhausted NO x was below the emission standards. Soilless lettuce cultivation experiments demonstrated that NO x - produced by the PNF system could serve as liquid nitrate nitrogen fertilizer. Overall, our work demonstrates the potential of the developed PNF system for on-site application in the production of green-leaf vegetables.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134954043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak","authors":"Vadim Krupin, Maxim Nurgaliev, Anton Nemets, Ivan Zemtsov, Stepan Suntsov, Tatyana Myalton, Dmitriy Sergeev, Nikita Solovev, Dmitriy Sarychev, Dmitriy Ryjakov, Sergey Tugarinov, Nikolay Naumenko","doi":"10.1088/2058-6272/ad0c9c","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c9c","url":null,"abstract":"Abstract Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating (ECRH) on second harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so the increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. EC resonance position varies from high field side to low field side by variation of toroidal magnetic field. Scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges power balance ion heat conductivity exceeds neoclassical level up to 10 times. High ion heat transport regimes are distinguished by three parameters: T e /T i ratio, normalized electron density gradient R/L n e , and ion-ion collisionality ν ii ∗ . Combination of high T e /T i , high ν ii ∗ , and R/L n e =6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in low transport scenario.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 dual-route optical emission spectroscopy diagnostic with wide spectral range and high wavelength resolution on HL-2A tokamak","authors":"Yue Chen, Jikun Gao, Ting Long, Lin Nie, Jinming Gao, Yao Ma, Yuan Huang, Wenjing Tian, Yanmin Liu, Xiaodong Zhu, Ge Zhuang, Wulyu Zhong, Min Xu","doi":"10.1088/2058-6272/ad0c95","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c95","url":null,"abstract":"Abstract A dual-route optical emission spectroscopy (D-OES) diagnostic is newly developed to monitor the optical emission from X-point plasma region on the HL-2A tokamak. This diagnostic is composed of imaging system, beam splitting system for dual-route measurements, fiber bundles, spectrometer system, control and acquisition system. One route is used to obtain wide-spectral-range spectra, and the other route is used to acquire high-wavelength-resolution line shapes. The spectral resolution of the wide-range spectrometers is 0.8 nm with a coverage of 800 nm (@200-1000 nm). The spectral resolution of the high-resolution spectrometer is 0.01 nm with a coverage of 6 nm (@200-660 nm). The spatial resolution of each route of D-OES is about 4 cm with 11 channels. The temporal resolution is 16 ms at maximum in the single-channel mode. Wide-range spectra (containing Balmer series and Fulcher band) and highly resolved H_α line shapes are obtained by D-OES in the hydrogen glow discharge in the lab. D-OES measurements are carried out in the high-density deuterium experiments of HL-2A. The electron density n_e and deuterium temperature T_D in the X-point MARFE region are derived simultaneously by fitting the measured D_α shape. The density n_e is observed to increase from ~8.7×10^18 m^(-3) to ~7.8×10^19 m^(-3) and the temperature T_D drops from ~14.4 eV to ~2.3 eV after the onset of MARFE in the discharge #38260.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134954206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Gyro-Landau-fluid simulations of impurity effects on ion temperature gradient driven turbulence transport","authors":"Yifei Liu, Jiquan Li","doi":"10.1088/2058-6272/ad0c9b","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c9b","url":null,"abstract":"Abstract The impurity effects on ion temperature gradient (ITG) driven turbulence transport in tokamak core plasmas are investigated numerically via global simulations of microturbulence with carbon impurities and adiabatic electrons using extended fluid code (ExFC) based on a four-field gyro-Landau-fluid (GLF) model. The multispecies form of the normalized GLF equations guaranteeing self-consistent evolution of both bulk ions and impurities is presented. With parametric profiles of the cyclone base case (CBC), well-benchmarked ExFC is employed to perform simulations focusing on different impurity density profiles. For fixed temperature profile, it is found that the turbulent heat diffusivity of bulk ions in quasi-steady state is usually lower than that without impurity, which is contrary to the linear and quasi-linear predictions. The evolutions of the temperature gradient and heat diffusivity exhibit a fast relaxation process, indicating that the destabilization of the outwardly peaked impurity profile is a transient state response. Furthermore, the impurity effects of different profiles can obviously influence the nonlinear critical temperature gradient, which are likely to be dominated by linear effects. These results may evidence the plasma confinement improvement by the impurities probably through adjusting both heat diffusivity and critical temperature gradient.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Influence of the position relationship between cathode and magnetic separatrix on the discharge process of Hall thruster","authors":"Xifeng Cao, Hongning Ma, Guojun Xia, Hui Liu, Fangzhou Zhao, Yuhang Wang, Juhui Chen","doi":"10.1088/2058-6272/ad0c9d","DOIUrl":"https://doi.org/10.1088/2058-6272/ad0c9d","url":null,"abstract":"Abstract Previous studies have shown that there is an obvious coupling relationship between the installation location of the external cathode and the magnetic separatrix in the plume region of Hall thruter. In this paper, the particle-in-cell simulation method is used to compare the thruster discharge process under the conditions of different position relationships between the cathode and the magnetic separatrix. By comparing the distribution of electron conduction, potential, plasma density, and other microscopic parameters, we try to explain the formation mechanism of the discharge difference. The simulation results show that the cathode inside and outside the magnetic separatrix has a significant effect on the distribution of potential and plasma density. When the cathode is located outer side of the magnetic separatrix, the potential above the plume region is relatively low, and there is a strong potential gradient above the plume region. This potential gradient is more conducive to the radial diffusion of ions above the plume, which is the main reason for the strong divergence of the plume. The distribution of ion density is also consistent with the distribution of potential. When the cathode is located outer side of the magnetic separatrix, the radial diffusion of ions in the plume region is enhanced. Meanwhile, by comparing the results of electron conduction, it is found that the trajectories of electrons emitted from the cathode are significantly different inner and outer sides of the magnetic separatrix. This is mainly because the electrons are affected by the magnetic mirror effect of the magnetic tip, which makes it difficult for the electrons to move across the magnetic separatrix. It is the main reason for the difference in potential distribution. In this paper, the simulation results of macroscopic parameters under several conditions are also compared, which are consistent with the experimental results. The cathode is located inner side of the magnetic separatrix, which can effectively reduce the plume divergence angle and improve the thrust. In this paper, the cathode moves from R = 50 mm to R = 35 mm along the radial direction, the thrust increases by 3.6 mN, and the plume divergence angle decreases by 23.77%. Combined with the comparison of the ionization region and the peak ion density, it can be found that the main reason for the change in thrust is the change in the radial diffusion of ions in the plume region.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}