Plasma Sources Science and Technology最新文献_第7页

On the wave mode transition of argon helicon plasma 关于氩氦等离子体的波模转换

Plasma Sources Science and Technology Pub Date : 2024-02-09 DOI: 10.1088/1361-6595/ad27eb

Ruilin Cui, Tianliang Zhang, Feng He, Bocong Zheng, J. Ouyang

引用次数: 0

On the wave mode transition of argon helicon plasma 关于氩氦等离子体的波模转换

Plasma Sources Science and Technology Pub Date : 2024-02-09 DOI: 10.1088/1361-6595/ad27eb

Ruilin Cui, Tianliang Zhang, Feng He, Bocong Zheng, J. Ouyang

引用次数: 0

Electrical characterization and imaging of discharge morphology in a small-scale packed bed dielectric barrier discharge 小规模填料床介质势垒放电中放电形态的电学表征和成像

Plasma Sources Science and Technology Pub Date : 2024-02-09 DOI: 10.1088/1361-6595/ad27ed

Rezvan Hosseini Rad, Volker Brüser, Ronny Brandenburg

{"title":"Electrical characterization and imaging of discharge morphology in a small-scale packed bed dielectric barrier discharge","authors":"Rezvan Hosseini Rad, Volker Brüser, Ronny Brandenburg","doi":"10.1088/1361-6595/ad27ed","DOIUrl":"https://doi.org/10.1088/1361-6595/ad27ed","url":null,"abstract":"\u0000 Packed bed dielectric barrier discharges exhibit an improved energy efficiency and selectivity in nonthermal plasma based gas conversion. They enable the direct interaction between plasma and catalyst. In this contribution a compact coaxial DBD reactor enabling the end-on imaging of the discharge with and without packed beds is constructed and studied. The discharge morphology is correlated with electrical measurements such as V-Q plots. The studies are performed for different packed bed materials, binary gas compositions of argon and carbon dioxide, voltage amplitudes, average powers, and pressures. The analysis points outs the role of parasitic capacitances and parasitic discharges as often overlooked aspects. The introduction of the packed bed material into the coaxial barrier discharge arrangement increases the total capacitance, but the barrier of the outer glass tube mostly determines the maximum effective dielectric capacitance. The choice of the packed bed material determines the voltage threshold and the average discharge power. The investigations leads to a revision of the equivalent circuit for packed bed barrier discharge reactors, which also accounts the properties of different filling materials.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139788584","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}

引用次数: 0

Fine structure resolved excitation cross sections of singly ionized Ga for the modeling and diagnostics of Ga plasmas 用于镓等离子体建模和诊断的单电离镓的精细结构解析激发截面

Plasma Sources Science and Technology Pub Date : 2024-02-09 DOI: 10.1088/1361-6595/ad27ec

Indhu Suresh, Priti Priti, R. Srivastava, R. Gangwar

{"title":"Fine structure resolved excitation cross sections of singly ionized Ga for the modeling and diagnostics of Ga plasmas","authors":"Indhu Suresh, Priti Priti, R. Srivastava, R. Gangwar","doi":"10.1088/1361-6595/ad27ec","DOIUrl":"https://doi.org/10.1088/1361-6595/ad27ec","url":null,"abstract":"\u0000 Calculation of electron impact excitation cross sections for singly charged Ga ions plays a crucial role in plasma modeling, facilitating the comprehension of plasma behavior, characteristics, and dynamics in diverse domains, such as astrophysics, fusion research, the semiconductor industry, etc. In the available literature, there is a notable scarcity of, or even a complete absence of, these cross sections. Hence, in the present work, electron impact excitation cross sections are calculated for the transitions from the fine structure resolved energy levels of the configurations 4s2 and 4s4p to the fine structure resolved energy levels of the configurations 4s4p, 4s5s, 4p2 and 4s4d of the singly charged Ga ion (Ga+) using the relativistic distorted wave approximation theory with the target states represented by multi configurational Dirac Fock wavefunctions. The cross sections are calculated for projectile electron energy varying from threshold to 500 eV. Furthermore, the electron impact excitation rate coefficients for all the transitions under investigation are also calculated for electron temperatures ranging from 0.5 to 5 eV. In addition, analytic fitting of the rate coefficients is also performed, providing a practical resource for directly utilizing in plasma modeling applications.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":" 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790318","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}

引用次数: 0

Hybrid simulation of instabilities in capacitively coupled RF CF4/Ar plasmas driven by a dual frequency source 双频源驱动的电容耦合射频 CF4/Ar 等离子体不稳定性的混合模拟

Plasma Sources Science and Technology Pub Date : 2024-02-07 DOI: 10.1088/1361-6595/ad270e

Wan Dong, Yifan Zhang, Julian Schulze, Yuan-Hong Song

{"title":"Hybrid simulation of instabilities in capacitively coupled RF CF4/Ar plasmas driven by a dual frequency source","authors":"Wan Dong, Yifan Zhang, Julian Schulze, Yuan-Hong Song","doi":"10.1088/1361-6595/ad270e","DOIUrl":"https://doi.org/10.1088/1361-6595/ad270e","url":null,"abstract":"\u0000 Instabilities in capacitively coupled Ar/CF4 plasma discharges driven by dual frequency sources are investigated using a one-dimensional fluid/electron Monte Carlo (MC) hybrid model. Periodic oscillations of the electron density and temperature on the timescale of multiple low frequency periods are observed. As the electron density increases, an intense oscillation of the electron temperature within each high frequency period is initiated. This causes a fluctuation of the electron density and results in a discharge instability. This phenomenon is consistent with the discharge behavior observed in scenarios with single-frequency (SF) sources, as reported by Dong et al. [PSST 31 (2022) 025006]. However, unlike the single-frequency case, plasma parameters such as the electron density, electric field, electron power absorption and ionization rate exhibit not only periodic fluctuations but also a spatial asymmetry under the influence of the dual-frequency source. This spatial asymmetry leads to a non-uniform distribution of the electron density between the electrodes, which is related to a spatially asymmetric electric field, electron heating, and ionization around a region of minimum electron density (inside the bulk). This region of minimum electron density is shifted back and forth through the entire plasma bulk from one electrode to the other within multiple low frequency period. The above phenomena are related to superposition effect between the instabilities and the dual-frequency source. Moreover, the time averaged electric field influences the spatio-temporal evolution of ion fluxes. The ion fluxes at the electrodes, which play an important role in etching processes, are affected by both the high and low frequency components of the driving voltage waveform as well as the observed instabilities. As the high frequency increases, the electronegativity and electron temperature are reduced and the electron density increases, resulting in a gradual disappearance of the instabilities.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"68 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139794909","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}

引用次数: 0

Absolute calibration of the ratio of Xe/O two-photon absorption cross-sections for O-TALIF applications 用于 O-TALIF 的 Xe/O 双光子吸收截面比的绝对校准

Plasma Sources Science and Technology Pub Date : 2024-02-07 DOI: 10.1088/1361-6595/ad270f

Zhan Shu, N. Popov, S. Starikovskaia

{"title":"Absolute calibration of the ratio of Xe/O two-photon absorption cross-sections for O-TALIF applications","authors":"Zhan Shu, N. Popov, S. Starikovskaia","doi":"10.1088/1361-6595/ad270f","DOIUrl":"https://doi.org/10.1088/1361-6595/ad270f","url":null,"abstract":"\u0000 The paper presents a calibration of the ratio of two-photon absorption cross sections, $sigma^{(2)}_{Xe}/ sigma^{(2)}_O$, necessary for the absolute O-atom density measurements by two-photon absorption laser-induced fluorescence (TALIF) technique. To calibrate the ratio of the cross-sections, a special discharge with 100% dissociation of molecular oxygen, and so with a known “reference” density of O-atom [O]$_{ref}$=2$cdot$[O$_2$] was suggested. This is a nanosecond capillary discharge in N$_2$: O$_2$ mixtures with a few percent of oxygen at a reduced electric field of a few hundred of Td and specific deposited energy of about 1 eV/molecule. Voltage at the electrodes, electrical current in the plasma, longitudinal electric field and energy delivered to the gas were measured with 0.2~ns synchronisation. Additionally, radial distribution of emission of excited nitrogen molecules and gas temperature in the discharge and afterglow were obtained experimentally. Detailed 1D kinetic modeling was suggested to confirm complete O$_2$ dissociation and to analyse the main reactions. By comparing the data measured by TALIF technique with the ``reference'' density of oxygen atoms [O]$_{ref}$, the ratio of the two-photon absorption cross-sections $sigma^{(2)}_{Xe}/ sigma^{(2)}_O$ was determined.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139857951","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}

引用次数: 0

Hybrid simulation of instabilities in capacitively coupled RF CF4/Ar plasmas driven by a dual frequency source 双频源驱动的电容耦合射频 CF4/Ar 等离子体不稳定性的混合模拟

Plasma Sources Science and Technology Pub Date : 2024-02-07 DOI: 10.1088/1361-6595/ad270e

Wan Dong, Yifan Zhang, Julian Schulze, Yuan-Hong Song

{"title":"Hybrid simulation of instabilities in capacitively coupled RF CF4/Ar plasmas driven by a dual frequency source","authors":"Wan Dong, Yifan Zhang, Julian Schulze, Yuan-Hong Song","doi":"10.1088/1361-6595/ad270e","DOIUrl":"https://doi.org/10.1088/1361-6595/ad270e","url":null,"abstract":"\u0000 Instabilities in capacitively coupled Ar/CF4 plasma discharges driven by dual frequency sources are investigated using a one-dimensional fluid/electron Monte Carlo (MC) hybrid model. Periodic oscillations of the electron density and temperature on the timescale of multiple low frequency periods are observed. As the electron density increases, an intense oscillation of the electron temperature within each high frequency period is initiated. This causes a fluctuation of the electron density and results in a discharge instability. This phenomenon is consistent with the discharge behavior observed in scenarios with single-frequency (SF) sources, as reported by Dong et al. [PSST 31 (2022) 025006]. However, unlike the single-frequency case, plasma parameters such as the electron density, electric field, electron power absorption and ionization rate exhibit not only periodic fluctuations but also a spatial asymmetry under the influence of the dual-frequency source. This spatial asymmetry leads to a non-uniform distribution of the electron density between the electrodes, which is related to a spatially asymmetric electric field, electron heating, and ionization around a region of minimum electron density (inside the bulk). This region of minimum electron density is shifted back and forth through the entire plasma bulk from one electrode to the other within multiple low frequency period. The above phenomena are related to superposition effect between the instabilities and the dual-frequency source. Moreover, the time averaged electric field influences the spatio-temporal evolution of ion fluxes. The ion fluxes at the electrodes, which play an important role in etching processes, are affected by both the high and low frequency components of the driving voltage waveform as well as the observed instabilities. As the high frequency increases, the electronegativity and electron temperature are reduced and the electron density increases, resulting in a gradual disappearance of the instabilities.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"16 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139854928","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}

引用次数: 0

Absolute calibration of the ratio of Xe/O two-photon absorption cross-sections for O-TALIF applications 用于 O-TALIF 的 Xe/O 双光子吸收截面比的绝对校准

Plasma Sources Science and Technology Pub Date : 2024-02-07 DOI: 10.1088/1361-6595/ad270f

Zhan Shu, N. Popov, S. Starikovskaia

{"title":"Absolute calibration of the ratio of Xe/O two-photon absorption cross-sections for O-TALIF applications","authors":"Zhan Shu, N. Popov, S. Starikovskaia","doi":"10.1088/1361-6595/ad270f","DOIUrl":"https://doi.org/10.1088/1361-6595/ad270f","url":null,"abstract":"\u0000 The paper presents a calibration of the ratio of two-photon absorption cross sections, $sigma^{(2)}_{Xe}/ sigma^{(2)}_O$, necessary for the absolute O-atom density measurements by two-photon absorption laser-induced fluorescence (TALIF) technique. To calibrate the ratio of the cross-sections, a special discharge with 100% dissociation of molecular oxygen, and so with a known “reference” density of O-atom [O]$_{ref}$=2$cdot$[O$_2$] was suggested. This is a nanosecond capillary discharge in N$_2$: O$_2$ mixtures with a few percent of oxygen at a reduced electric field of a few hundred of Td and specific deposited energy of about 1 eV/molecule. Voltage at the electrodes, electrical current in the plasma, longitudinal electric field and energy delivered to the gas were measured with 0.2~ns synchronisation. Additionally, radial distribution of emission of excited nitrogen molecules and gas temperature in the discharge and afterglow were obtained experimentally. Detailed 1D kinetic modeling was suggested to confirm complete O$_2$ dissociation and to analyse the main reactions. By comparing the data measured by TALIF technique with the ``reference'' density of oxygen atoms [O]$_{ref}$, the ratio of the two-photon absorption cross-sections $sigma^{(2)}_{Xe}/ sigma^{(2)}_O$ was determined.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"48 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139798099","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}

引用次数: 0

An experimental and computational study on the ignition process of a pulse modulated dual-RF capacitively coupled plasma operated at various low-frequency voltage amplitudes 关于在不同低频电压振幅下运行的脉冲调制双射频电容耦合等离子体点火过程的实验和计算研究

Plasma Sources Science and Technology Pub Date : 2024-02-02 DOI: 10.1088/1361-6595/ad257f

De-Hua Shi, Xiao-Kun Wang, Yong-Xin Liu, Zoltán Donkó, Julian Schulze, You-Nian Wang

{"title":"An experimental and computational study on the ignition process of a pulse modulated dual-RF capacitively coupled plasma operated at various low-frequency voltage amplitudes","authors":"De-Hua Shi, Xiao-Kun Wang, Yong-Xin Liu, Zoltán Donkó, Julian Schulze, You-Nian Wang","doi":"10.1088/1361-6595/ad257f","DOIUrl":"https://doi.org/10.1088/1361-6595/ad257f","url":null,"abstract":"\u0000 The ignition process of a pulse modulated capacitively coupled argon discharge driven simultaneously by two different radio frequency voltages (12.5 MHz (high frequency, HF) and 2.5 MHz (low frequwncy, LF)) is investigated by multifold experimental diagnostics and particle in cell / Monte Carlo collision (PIC/MCC) simulations. In particular, (i) the effects of the low frequency voltage amplitude measured at the end of the pulse-on period, V\u0000 L,end, on the spatiotemporal distribution of the electron impact excitation rate determined by phase resolved optical emission spectroscopy, and (ii) the electrical parameters acquired by analyzing the measured waveforms of the plasma current and voltage, are studied. Computed spatiotemporal distributions of the electron impact excitation rate and electrical parameters show a good qualitative agreement with the experimental results. Generally, the HF and LF electrical parameters (amplitudes and relative phase of the voltage and the current) change with time in a similar manner during the ignition process for each V\u0000 L,end. However, various scenarios of the breakdown mechanism are found as a function of V\u0000 L,end. At low values of V\u0000 L,end, the “RF-avalanche” mode dominates the electron multiplication process. By increasing V\u0000 L,end, the ionization caused by the volume electrons is suppressed and the electron loss at the electrodes is enhanced, leading to a delayed ignition. At higher values of V\u0000 L,end, the avalanche ionization is significantly enhanced by ion-induced secondary electron emission at the electrodes.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"68 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810952","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}

引用次数: 0

An experimental and computational study on the ignition process of a pulse modulated dual-RF capacitively coupled plasma operated at various low-frequency voltage amplitudes 关于在不同低频电压振幅下运行的脉冲调制双射频电容耦合等离子体点火过程的实验和计算研究

Plasma Sources Science and Technology Pub Date : 2024-02-02 DOI: 10.1088/1361-6595/ad257f

De-Hua Shi, Xiao-Kun Wang, Yong-Xin Liu, Zoltán Donkó, Julian Schulze, You-Nian Wang

{"title":"An experimental and computational study on the ignition process of a pulse modulated dual-RF capacitively coupled plasma operated at various low-frequency voltage amplitudes","authors":"De-Hua Shi, Xiao-Kun Wang, Yong-Xin Liu, Zoltán Donkó, Julian Schulze, You-Nian Wang","doi":"10.1088/1361-6595/ad257f","DOIUrl":"https://doi.org/10.1088/1361-6595/ad257f","url":null,"abstract":"\u0000 The ignition process of a pulse modulated capacitively coupled argon discharge driven simultaneously by two different radio frequency voltages (12.5 MHz (high frequency, HF) and 2.5 MHz (low frequwncy, LF)) is investigated by multifold experimental diagnostics and particle in cell / Monte Carlo collision (PIC/MCC) simulations. In particular, (i) the effects of the low frequency voltage amplitude measured at the end of the pulse-on period, V\u0000 L,end, on the spatiotemporal distribution of the electron impact excitation rate determined by phase resolved optical emission spectroscopy, and (ii) the electrical parameters acquired by analyzing the measured waveforms of the plasma current and voltage, are studied. Computed spatiotemporal distributions of the electron impact excitation rate and electrical parameters show a good qualitative agreement with the experimental results. Generally, the HF and LF electrical parameters (amplitudes and relative phase of the voltage and the current) change with time in a similar manner during the ignition process for each V\u0000 L,end. However, various scenarios of the breakdown mechanism are found as a function of V\u0000 L,end. At low values of V\u0000 L,end, the “RF-avalanche” mode dominates the electron multiplication process. By increasing V\u0000 L,end, the ionization caused by the volume electrons is suppressed and the electron loss at the electrodes is enhanced, leading to a delayed ignition. At higher values of V\u0000 L,end, the avalanche ionization is significantly enhanced by ion-induced secondary electron emission at the electrodes.","PeriodicalId":508056,"journal":{"name":"Plasma Sources Science and Technology","volume":"61 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139870584","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}

引用次数: 0