Plasma Sources Science and Technology最新文献

{"title":"Trumpet-shaped diffuse plasma jet in a semi-confined environment","authors":"Weisheng Cui, Li Chai, Ruobing Zhang","doi":"10.1088/1361-6595/ad15af","DOIUrl":"https://doi.org/10.1088/1361-6595/ad15af","url":null,"abstract":"\u0000 This paper reports a unique trumpet-shaped diffuse plasma jet (TDPJ) with a caliber exceeding 30 mm in a semi-confined environment, which is larger than the diameter of existing atmospheric pressure plasma jets (APPJs) in an open environment. The morphology of the TDPJ is attributed to the influence of the electric field on the development characteristics of ionization waves in the ambient environment. High-speed ICCD camera images show that the plasma bullets in the TDPJ have a completely different propagation trajectory compared to the APPJ. Different shapes of diffuse plasma jets can also be formed by adjusting the doping gas, which is due to the Penning ionization and consistent with the impact of the electric field. This research reveals the long-neglected effect of the electric field on ionization waves and provides a way to manipulate the morphology of plasma jets efficiently. The generation mechanism of the TDPJ can provide preliminary guidance for the effective medical treatment of plasma jets in semi-confined environments, such as human internal organs.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"385 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138974203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatio-temporal dynamics of electrons and helium metastables in uniform dielectric barrier discharges formed in He/N₂","authors":"Niklas Nawrath, Ihor Korolov, N. Bibinov, P. Awakowicz, A. Gibson","doi":"10.1088/1361-6595/ad1513","DOIUrl":"https://doi.org/10.1088/1361-6595/ad1513","url":null,"abstract":"\u0000 A uniform atmospheric pressure dielectric barrier discharge is operated in helium with an admixture (0.45%) of nitrogen. The discharge is ignited in the gas gap between a driven and a grounded electrode and propagates along the dielectric surface outside the gap. Plasma conditions are characterized with current and voltage measurements and by application of absolutely calibrated optical emission spectroscopy, with a focus on nitrogen molecular emission. Plasma parameters, namely electron density and reduced electric field are determined with spatial and temporal resolution in the frame of collisional-radiative model by application of calibrated intensified CCD camera and Abel inversion of measured images. The density of helium metastable states is calculated using the measured plasma parameters and successfully compared with values measured using tunable diode laser absorption spectroscopy.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"70 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139004621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Availability and reactivity of N2(v) for NH3 synthesis by plasma catalysis","authors":"Brian N Bayer, Sai Raskar, Igor V Adamovich, Peter J Bruggeman, Aditya Bhan","doi":"10.1088/1361-6595/ad10f0","DOIUrl":"https://doi.org/10.1088/1361-6595/ad10f0","url":null,"abstract":"Production of vibrationally excited N₂ (N₂(<italic toggle=\"yes\">v</italic>)) in atmospheric pressure nonthermal plasma and loss of N₂(<italic toggle=\"yes\">v</italic>) by gas-phase reactions and reactions on catalytic surfaces are analyzed to examine the role of N₂(<italic toggle=\"yes\">v</italic>) in NH₃ formation by plasma catalysis. Vibrational state-to-state kinetic models complemented with molecular beam mass spectrometry (MBMS) measurements demonstrate that N₂(<italic toggle=\"yes\">v</italic>&gt; 0) is produced with densities 100× greater than the density of N radicals by a radiofrequency atmospheric pressure plasma jet. The experimentally measured loss of N₂(<italic toggle=\"yes\">v</italic>) corresponds with a state-to-state kinetic model that describes loss of N₂(<italic toggle=\"yes\">v</italic>) by surface-mediated vibrational relaxation without consideration of reactions that convert N₂(<italic toggle=\"yes\">v</italic>) to NH₃ over the catalyst surface. Rate constants for vibrational relaxation of N₂(<italic toggle=\"yes\">v</italic>) on catalyst surfaces exceed upper bounds on proposed rate constants for NH₃ formation reactions from N₂(<italic toggle=\"yes\">v</italic>) over Fe when <italic toggle=\"yes\">v</italic> &lt; 9, Ni when <italic toggle=\"yes\">v</italic> &lt; 18, and Ag when <italic toggle=\"yes\">v</italic> &lt; 39, which indicates that only higher vibrational levels can possibly contribute to catalytic NH₃ formation faster than they undergo vibrational relaxation on the surface. Densities of N₂(<italic toggle=\"yes\">v</italic>&gt; 8), vibrational levels that can possibly react over Fe to form NH₃ faster than they undergo vibrational relaxation, are less than or similar to N densities at the inlet of the catalyst bed and measured NH₃ formation for the investigated conditions in this work, while densities of N₂(<italic toggle=\"yes\">v</italic>&gt; 17) and N₂(<italic toggle=\"yes\">v</italic>&gt; 38) are orders of magnitude below the N density at the inlet of the catalyst bed and the measured NH₃ formation. The loss of N₂(<italic toggle=\"yes\">v</italic>) by vibrational relaxation on the surface limits the ability of N₂(<italic toggle=\"yes\">v</italic>) to contribute to catalytic NH₃ formation and explains why N₂(<italic toggle=\"yes\">v</italic>) does not produce NH₃ in quantities that are comparable to NH₃ formation from N even though N₂(<italic toggle=\"yes\">v</italic> &gt; 0) is more abundantly produced by the plasma.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138682967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling the COST reference plasma jet to a microfluidic device: a computational study","authors":"Julien Bissonnette-Dulude, Pepijn Heirman, Sylvain Coulombe, Annemie Bogaerts, Thomas Gervais, Stephan Reuter","doi":"10.1088/1361-6595/ad1421","DOIUrl":"https://doi.org/10.1088/1361-6595/ad1421","url":null,"abstract":"\u0000 The use of microfluidic devices in the field of plasma-liquid interaction can unlock unique possibilities to investigate the effects of plasma-generated reactive species for environmental and biomedical applications. So far, very little simulation work has been performed on microfluidic devices in contact with a plasma source. We report on the modelling and computational simulation of physical and chemical processes taking place in a novel plasma-microfluidic platform. The main production and transport pathways of reactive species both in plasma and liquid are modelled by a novel modelling approach that combines 0D chemical kinetics and 2D transport mechanisms. This combined approach, applicable to systems where the transport of chemical species occurs in unidirectional flows at high Péclet numbers, decreases calculation times considerably compared to regular 2D simulations. It takes advantage of the low computational time of the 0D reaction models while providing spatial information through multiple plug-flow simulations to yield a quasi-2D model. The gas and liquid flow profiles are simulated entirely in 2D, together with the chemical reactions and transport of key chemical species. The model correctly predicts increased transport of hydrogen peroxide into the liquid when the microfluidic opening is placed inside the plasma effluent region, as opposed to inside the plasma region itself. Furthermore, the modelled hydrogen peroxide production and transport in the microfluidic liquid differs by less than 50% compared with experimental results. To explain this discrepancy, the limits of the 0D-2D combined approach are discussed.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"79 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138979436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a radiofrequency linear plasma device in uniform and convergent magnetic fields","authors":"Kazunori Takahashi, Yume Teranishi","doi":"10.1088/1361-6595/ad0fb0","DOIUrl":"https://doi.org/10.1088/1361-6595/ad0fb0","url":null,"abstract":"A linear radiofrequency plasma device is constructed, where a source operating at a frequency of 13.56 MHz and a maximum power of several kW is attached to a cylindrical vacuum chamber about 1 m in length. Seven solenoids are located around the source and the chamber, providing various magnetic field configurations by changing the solenoid currents. The plasma density of the radiofrequency linear plasma device is initially characterized in uniform and convergent magnetic field configurations. A blue mode argon plasma, being inherent to the helicon or high-density discharge, is observed in the chamber downstream of the source for both configurations, while the density near the antenna is lower than that in the chamber. Furthermore, the density for the convergent magnetic field configuration is found to be larger than that for the uniform case, providing a maximum density of about <inline-formula>\u0000<tex-math><?CDATA $2times10^{19}~textrm{m}^{-3}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>2</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mn>19</mml:mn></mml:mrow></mml:msup><mml:mtext> </mml:mtext><mml:msup><mml:mrow><mml:mtext>m</mml:mtext></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math>\u0000<inline-graphic xlink:href=\"psstad0fb0ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. Spatiotemporal measurements of the ion saturation current reveal that the density peak is formed near the rf antenna at the initial time of the discharge and the peripheral high-density region subsequently appears downstream of the antenna, implying that the rf power is efficiently coupled with the electrons downstream of the antenna once the initial plasma is created. A few ms after turning on the rf power, the density over the whole region reduces, which seems to be due to a neutral depletion.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of filamentation dynamics of microwave discharge in nitrogen","authors":"A. Saifutdinov, Elena Kustova","doi":"10.1088/1361-6595/ad13a3","DOIUrl":"https://doi.org/10.1088/1361-6595/ad13a3","url":null,"abstract":"\u0000 The present study deals with numerical simulations of microwave discharges in nitrogen based on extended fluid-dynamic model. The set of governing equations for non-equilibrium gas-discharge plasma includes conservation equations for species number densities, electron energy density, Poisson equation for the electric field coupled to the multi-temperature Navier--Stokes fluid-dynamic equations taking into account thermal nonequilibrium; the power transmitted from microwave radiation to electrons is determined from the Helmholtz equation. The kinetic scheme includes 62 reactions involving neutral molecules and atoms in the ground and electronically excited states, ions and electrons. The set of equations is solved for a two-dimensional problem under conditions of experiments at a pressure of 40 and 50~Torr and different electromagnetic wave frequencies and pulse duration. The dynamics of discharge formation and transition from the diffuse to the filament form is studied. The results are compared with experimental data, and a good agreement is shown for the time larger than 10~$mu$s. The possible reasons for discrepancies at a shorter time are discussed and the effect of small oxygen impurities on the quantitative characteristics of the discharge are evaluated. The presence of a small oxygen impurity and seed electrons in the region of discharge formation yields a better agreement between numerical and experimental data.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"41 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138588731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle-in-cell simulations of high frequency capacitively coupled plasmas including spatially localised inductive-like heating","authors":"M Osca Engelbrecht, C P Ridgers, J Dedrick, R Boswell","doi":"10.1088/1361-6595/ad0fb1","DOIUrl":"https://doi.org/10.1088/1361-6595/ad0fb1","url":null,"abstract":"High frequency (HF) capacitively coupled plasmas (CCPs) are ubiquitous, having several industrial applications, especially in the semiconductor industry. Inductive heating effects within these plasmas play an important role and therefore understanding them is key to improve industrial applications. For this purpose kinetic research, using particle-in-cell (PIC) codes, offers significant opportunity to study, and improve, industrial plasma processes that operate at the atomic level. However, PIC codes commonly used for CCPs are electrostatic and thus cannot be used to simulate electromagnetically induced currents. Therefore we have developed EPOCH-LTP, a 1D PIC code with a current heating model, that enables the simulation of inductive heating effects in HF CCPs. First simulation results, from an HF CCP (60 MHz) operated at 1 mTorr of argon, show that inductive currents couple most of their power to the electrons at the interface between the bulk plasma and the sheath. Furthermore, the simulation of a dual-frequency CCP, where a HF inductive current and a low-frequency (LF) voltage waveform at 400 kHz are applied, have shown a synergy between the HF and LF waveforms that increase the inductive heating rate.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"197 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas heating by inductively coupled low-pressure chlorine process plasmas","authors":"D. Levko, V. Subramaniam, L. Raja","doi":"10.1088/1361-6595/ad12dd","DOIUrl":"https://doi.org/10.1088/1361-6595/ad12dd","url":null,"abstract":"\u0000 The mechanism of gas heating in low-pressure inductively coupled chlorine plasma is analyzed using a self-consistent two-dimensional axisymmetric fluid plasma model that is coupled with the compressible Navier-Stokes equations. For gas pressures of 10 and 20 mTorr and the discharge powers in the range 0.1 – 1.3 kW, the main reactions contributing to gas heating were the ion-ion recombination reactions and the quenching of electronically excited chlorine atoms. At the same time, the energy released by the electron impact dissociation reaction of molecular chlorine is negligible due to its high degree of dissociation within the plasma bulk. The comparison between the results of our simulations and the fitting equation proposed in the literature show qualitative agreement, although there is significant quantitative discrepancy.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma catalysis: separating plasma and surface contributions for an Ar/N2/O2 atmospheric discharge interacting with a Pt catalyst","authors":"Michael Hinshelwood, Gottlieb S Oehrlein","doi":"10.1088/1361-6595/ad0f47","DOIUrl":"https://doi.org/10.1088/1361-6595/ad0f47","url":null,"abstract":"Atmospheric pressure non-equilibrium plasmas can form nitrogen oxide (NO<italic toggle=\"yes\">\u0000_x\u0000</italic>) compounds directly from nitrogen and oxygen without a catalyst, and at lower catalyst temperatures than would be possible without plasma. In this work, the oxidation of plasma-produced NO from an Ar/N₂/O₂ non-equilibrium atmospheric-pressure plasma-jet (APPJ) over a platinum-on-alumina powder catalyst was investigated with <italic toggle=\"yes\">in-situ</italic> infrared spectroscopy. Products downstream of the catalyst bed were analyzed along with catalyst surface species. The catalyst was exposed to plasma at both constant temperature and a cyclic temperature ramp in order to study long-lasting and transient surface changes. Primary incident reactive species to the catalyst were assessed to be NO and O₃. Pt-Al₂O₃ at 350 °C increased oxidation of NO relative to Al₂O₃ or an empty chamber. The surface state of Pt-Al₂O₃ evolves during plasma-effluent exposure and requires upwards of 20 min exposure for stabilization compared to Al₂O₃. Once stable surface conditions are achieved, thermal cycling reveals a repeatable hysteresis pattern in downstream products. At low temperature, oxygen and NO<italic toggle=\"yes\">\u0000_x\u0000</italic> accumulate on the catalyst surface and react at elevated temperatures to form NO₂. Increasing plasma power and O₂:N₂ ratio increases the hysteresis of the heating relative to the cooling curves in the pattern of NO₂ formation. The limitation on NO oxidation at high temperatures was assessed to be Pt-O which is depleted as the catalyst is heated. Once stored species have been depleted, NO oxidation rates are determined by incoming reactants. Two overlapping NO oxidation patterns are identified, one determined by surface reactants formed at low temperature, and the other by reactants arriving at the surface at high temperature. The plasma is responsible for providing the reactants to the catalyst surface, while the catalyst enables reaction at high temperature or storage at low temperature for subsequent reaction.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138682965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collision integrals of electronically excited atoms in air plasmas. I. N–N and O–O interactions","authors":"Wensheng Zhao, Qizhen Hong, Chao Yang, Quanhua Sun, Yuan Hu","doi":"10.1088/1361-6595/ad0edf","DOIUrl":"https://doi.org/10.1088/1361-6595/ad0edf","url":null,"abstract":"The current work presents the collision integral data for N(⁴\u0000<italic toggle=\"yes\">S</italic>)–N(⁴\u0000<italic toggle=\"yes\">S</italic>, ²\u0000<italic toggle=\"yes\">D</italic>, ²\u0000<italic toggle=\"yes\">P</italic>) and O(³\u0000<italic toggle=\"yes\">P</italic>, ¹\u0000<italic toggle=\"yes\">D</italic>, ¹\u0000<italic toggle=\"yes\">S</italic>)–O(³\u0000<italic toggle=\"yes\">P</italic>, ¹\u0000<italic toggle=\"yes\">D</italic>, ¹\u0000<italic toggle=\"yes\">S</italic>) interactions in the temperature range of 500–50 000 K. The collision integrals are calculated based on high-quality potential energy curves (PECs) obtained from fitting the high-level <inline-formula>\u0000<tex-math><?CDATA $ab~initio$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mi>a</mml:mi><mml:mi>b</mml:mi><mml:mtext> </mml:mtext><mml:mi>i</mml:mi><mml:mi>n</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>i</mml:mi><mml:mi>o</mml:mi></mml:math>\u0000<inline-graphic xlink:href=\"psstad0edfieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> calculation data in a wide energy range to the neural network (NN) functions. In the construction of PECs, the diabatic PECs are adopted when avoided crossings exist because the diabatic paths are much more likely to be followed for such situations. Moreover, the nonadiabatic transition effects are estimated to be negligible for PECs crossings. The accuracy of traditional analytical formulas to fit PECs are also examined. It is found that the collision integral calculations are sensitive to the accuracy of PECs and the NN based PECs overwhelm the others. The contribution of inelastic excitation exchange processes to the diffusion collision integrals are also computed by using an accurate evaluation of the differences of PECs for <italic toggle=\"yes\">gerade</italic> and <italic toggle=\"yes\">ungerade</italic> pairs of excited atoms. Finally, based on the new collision integral data, we calibrate the collision model parameters suitable for the widely used particle simulation methods. The collision integrals and collision models developed in this work can be used to support high-confidence simulations of weakly ionized air plasma problems.","PeriodicalId":20192,"journal":{"name":"Plasma Sources Science and Technology","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}