Article
Chemistry, Analytical
Youngseok Lee, Sijun Kim, Jangjae Lee, Chulhee Cho, Inho Seong, Shinjae You
Summary: This paper investigates the causes of shifts in plasma conditions during plasma etching using various plasma diagnostic tools. The results show that an increase in ion energy flux, a decrease in fluorocarbon radical flux, and an increase in input power all result in the breaking of the process window.
Article
Physics, Applied
Ram Krushna Mohanta, Devilal Kumawat, G. Ravi
Summary: This study examines the effects of chamber pressure on the electrical and thermodynamic characteristics of a low-pressure thermal plasma jet. The research investigates various factors, including current-voltage characteristics, arc voltage fluctuations, plasma jet temperature, electron density, and velocity under different chamber pressure conditions. The findings reveal the influence of chamber pressure on different frequencies in the arc voltage spectrum and demonstrate the changes in the plasma jet's temperature, density, and velocity due to the varying chamber pressures.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
I Adamovich, S. Agarwal, E. Ahedo, L. L. Alves, S. Baalrud, N. Babaeva, A. Bogaerts, A. Bourdon, P. J. Bruggeman, C. Canal, E. H. Choi, S. Coulombe, Z. Donko, D. B. Graves, S. Hamaguchi, D. Hegemann, M. Hori, H-H Kim, G. M. W. Kroesen, M. J. Kushner, A. Laricchiuta, X. Li, T. E. Magin, S. Mededovic Thagard, V Miller, A. B. Murphy, G. S. Oehrlein, N. Puac, R. M. Sankaran, S. Samukawa, M. Shiratani, M. Simek, N. Tarasenko, K. Terashima, E. Thomas, J. Trieschmann, S. Tsikata, M. M. Turner, I. J. van der Walt, M. C. M. van de Sanden, T. von Woedtke
Summary: The 2022 Roadmap is a publication that aims to identify important challenges in the field of low-temperature plasma (LTP) physics and technology. It includes visions from 41 leading experts representing 21 countries and five continents, with a focus on new topics and areas of interest in the field. The roadmap is expected to contribute to the continued development of LTP science and technology in the next 5-10 years.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Spectroscopy
T. Gajo, Z. Mijatovic, S. Djurovic
Summary: A method for determining the electron temperature of a plasma based on the ratio of electron densities obtained from hydrogen H alpha and H beta spectral lines is discussed. The method was applied to wall stabilized DC and pulsed arc plasmas, and compared with three other methods. The results showed a good agreement with the newer theories of Stark broadening of hydrogen spectral lines.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2022)
Article
Engineering, Chemical
Georg Mauer
Summary: Hydrogen is widely used as a working gas in plasma spraying, impacting plasma jet characteristics even in small percentages, particularly under low pressure conditions. Addition of hydrogen increases plasma enthalpy and expands the jet radially, while promoting fast recombination of electrons and ions. The presence of hydrogen also leads to lower temperatures in the core of the jet due to energy consumption from dissociation.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2021)
Article
Engineering, Aerospace
Guangchuan Zhang, Junxue Ren, Haibin Tang, Yibai Wang, Zhongkai Zhang, Jiubin Liu, Ruojian Pan, Zun Zhang, Jinbin Cao
Summary: This paper presents an optical diagnostics study on a low-power Hall thruster operating with Xe/Kr mixtures. It is found that the excitation of atoms and ionization of ions are spatially separated in different regions near the channel exit. The presence of xenon increases the density of krypton atoms in metastable state and promotes their ionization. Increasing the mixture flowrate and Kr fraction shifts the ionization zone downstream, while increasing the discharge voltage and channel length shifts it upstream. A longer discharge channel improves the overall performance of the thruster by enhancing thrust efficiency, current efficiency, and reducing electron current.
Article
Optics
Safa Algoraini, Zhiwei Sun, Bassam B. B. Dally, Zeyad T. T. Alwahabi
Summary: This study experimentally investigates the structure of laminar premixed ethylene/air flat flames at low pressure. The aim is to understand the conditions and precursors affecting soot particle inception. Laser-induced incandescence and emission spectroscopy techniques were used to measure the profiles of soot volume fraction, CH* and C-2* radicals, and temperatures. The study reveals the spatial distribution of these variables as a function of height above the burner and their relationship with pressure.
APPLIED PHYSICS B-LASERS AND OPTICS
(2023)
Article
Chemistry, Physical
Inho Seong, Si-jun Kim, Youngseok Lee, Chulhee Cho, Wonnyoung Jeong, Yebin You, Minsu Choi, Byeongyeop Choi, Shinjae You
Summary: Investigating the quenching of electron temperature in plasma processing is crucial for controlling electron temperature and improving the efficiency of plasma material processing.
Article
Nuclear Science & Technology
P. Balazs, O. Asztalos, G. Anda, M. Vecsei, S. Zoletnik, S. T. A. Kumar, G. I. Pokol
Summary: Beam emission spectroscopy (BES) is a powerful plasma diagnostic method for measuring plasma density and its fluctuations. This paper utilizes synthetic BES codes to analyze a hypothetical alkali BES system on the HSX stellarator, and explores the unusual tendencies of BES in low ion temperature and low plasma density conditions.
FUSION ENGINEERING AND DESIGN
(2023)
Article
Physics, Applied
Asad Masood, Ayesha Zaman, N. U. Rehman, M. Aniq, M. Ibrahim Khan, M. Ali
Summary: Plasma-based sterilization in the atmospheric pressure plasma needle configuration is a developing technique with diverse applications. This study characterizes the plasma of capacitively coupled He-O-2/Ar and He-N-2/Ar mixtures, and determines the optimal conditions for plasma-based sterilization. The use of optical emission spectroscopy and actinometry allows the estimation of atomic densities and the calculation of rotational temperatures. The results suggest that the optimal conditions for plasma-based sterilization in the needle configuration are 4% oxygen and nitrogen concentration at 4 kV applied pulsing voltage and 100SCCM flow rate.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Mechanics
Sihan Fang, Xin Lin, Hui Zeng, Xingying Zhu, Fa Zhou, Junna Yang, Fei Li, Dongbin Ou, Xilong Yu
Summary: This study proposes an optical diagnostic method based on optical emission spectroscopy and laser absorption spectroscopy to investigate gas-surface interactions within the boundary layer. The results show that this method is reliable for deep investigation of gas-surface interactions in harsh aerothermal environments.
Article
Energy & Fuels
Xu Liu, Wenjun Zhong, Peng Jiang, Liming Dai, Zhixia He, Qian Wang
Summary: The objective of this study is to explore the challenges associated with the RCCI concept under low loads and to investigate the effects of low-reactivity fuel and direct injection timing. The increase in ethanol content results in longer ignition delay and a displacement of the ignition kernels towards the downstream of the fuel stream. Delaying the DI timing of HCB reduces ignition delay time and creates a higher concentration gradient of the combustible mixture, resulting in a higher apparent heat release rate and shorter combustion duration. Delaying the DI timing substantially impacts the characteristics of flame kernels generation and propagation.
Article
Thermodynamics
Dandan Qi, Kaixuan Yang, Xuan Zhao, Danhua Mei, Yaoyao Ying, Lei Xu, Xin Tu, Dong Liu
Summary: This study presents comprehensive optical diagnostics for flame behavior and soot emission under direct plasma coupling. The experimental results demonstrate the influence of plasma interaction on flame morphology, temperature, and soot emission. The study also reveals the relationships between flame morphological and electrical parameters. The findings contribute to a better understanding of flame combustion and soot emission.
Article
Physics, Fluids & Plasmas
A. Ahmed, S. Singha, S. Borthakur, N. K. Neog, T. K. Borthakur, J. Ghosh
Summary: Time-integrated spectroscopic measurements of argon plasma in a coaxial pulsed plasma accelerator revealed the temporal evolution of plasma stream characteristics, including changes in density, excitation temperature, and energy density over time. The study showed a decrease in plasma densities and excitation temperature, as well as a time-dependent decreasing trend in energy density, providing valuable insights for optimizing pulsed plasma accelerators.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Applied
Jian He, Zhiqiang Zhen
Summary: The study utilized the collision-excitation model for Sulfur plasma to accurately diagnose electron temperature, revealing that specific transitions of Sulfur III can be utilized for temperature calculation, with the line ratio of transitions affecting electron temperature. This has significance for plasma electron temperature diagnostics.
MODERN PHYSICS LETTERS B
(2021)
Article
Physics, Fluids & Plasmas
Tat Loon Chng, David Z. Pai, Olivier Guaitella, Svetlana M. Starikovskaia, Anne Bourdon
Summary: Electric field induced second harmonic (E-FISH) generation is a versatile tool for measuring electric field strengths in plasmas and gas discharges. This study investigates the dependence of the E-FISH signal on the length and shape of the electric field profile. The results show that the accuracy of an E-FISH measurement is generally high in the first and third phases of the electric field evolution, but poorer in the second phase. However, the overall shape of the field evolution curve can still be captured by E-FISH.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Elmar Slikboer, Olivier Guaitella, Enrique Garcia-Caurel, Ana Sobota
Summary: Electric field and surface charge measurements were used to study the dynamics in the plasma-surface interaction. It was found that the periodic charging is directly dependent on the pulse length regardless of the control potential. Uncontrolled floating potential surface prevents a sustained plasma plume. Imposed DC bias can lead to higher electric fields and surface charge. These findings have important implications for surface treatment applications.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Pedro Viegas, Elmar Slikboer, Zdenek Bonaventura, Enric Garcia-Caurel, Olivier Guaitella, Ana Sobota, Anne Bourdon
Summary: This study examines and compares positive and negative ionization waves (IWs) in pulsed plasma jets and demonstrates the existence of a surface charging memory effect. The memory effect directly impacts the dynamics of IWs, especially when using negative electric polarity.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Fluids & Plasmas
Maik Budde, Luca Matteo Martini, Matteo Ceppelli, Sara Quercetti, Richard Engeln
Summary: Time-resolved absolute OH density measurements in a millisecond-pulsed DC glow discharge from carbon dioxide with water admixture were conducted using laser-induced fluorescence spectroscopy. A novel technique was used to calibrate the OH LIF setup and the time evolution of CO2 conversion and rotational temperature of OH were obtained.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
S. C. L. Vervloedt, M. Budde, R. Engeln
Summary: Storing excess renewable energy in hydrocarbons produced from CO2 can solve the intermittency issue of renewable energy sources in an environmentally friendly way. The reduction of CO2 to CO can be efficiently achieved using non-equilibrium plasma conversion. The effects of oxygen, an impurity abundant in air and a product of the reduction reaction, on the ro-vibrational kinetics of a pulsed DC CO2 glow discharge are studied in this research.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
C. Fromentin, T. Silva, T. C. Dias, A. S. Morillo-Candas, O. Biondo, O. Guaitella, V Guerra
Summary: This work investigates the impact of O-2 addition on CO2 dissociation and the vibrational kinetics of CO2 and CO in non-equilibrium plasma. The study utilizes a self-consistent model that includes the vibrational kinetics of CO, incorporating e-V, V-T, and V-V processes. The model is validated using experimental data from pure CO2 and CO2-O-2 discharges. The results show changes in vibrational temperature and dissociation fraction due to the addition of O-2, attributed to V-T collisions and two main mechanisms: back reaction and recombinative detachment.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Ana Sofia Morillo-Candas, Bart L. M. Klarenaar, Vasco Guerra, Olivier Guaitella
Summary: Oxygen exchange kinetics in CO2-O2 and CO-O2 low-temperature RF plasmas were investigated using isotope tracing, revealing fast exchange processes that can be explained by collisions of electronically excited atomic oxygen. Isotope labeling emerges as a potential tool to trace O(1D) states and assess the efficiency of the CO2 dissociation process. The exchange of oxygen atoms between ground-state atomic oxygen and vibrationally excited CO is another important path for isotope incorporation in nonequilibrium CO2-CO-O2 gas mixtures and may contribute to anomalous isotope enrichment in other out-of-equilibrium conditions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Physics, Fluids & Plasmas
C. Bajon, S. Dap, A. Belinger, O. Guaitella, T. Hoder, N. Naude
Summary: This study investigates dielectric barrier discharges in CO2 at atmospheric pressure. It is demonstrated for the first time that a diffuse CO2 discharge can also be obtained under these conditions, contrary to previous beliefs that discharges only work in the filamentary regime. The diffuse regime is found to be related to a memory effect mechanism occurring at the dielectric surface. Electrical measurements, intensified charged coupled device (iCCD) imaging, and optical emission spectroscopy were used to compare the filamentary and diffuse regimes and discuss their differences.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
C. Douat, S. Ponduri, T. Boumans, O. Guaitella, S. Welzel, E. Carbone, R. Engeln
Summary: This study investigates the dissociation of CO2 in a symmetric pin-to-pin dielectric barrier discharge (DBD). The number of filaments per half cycle follows a power-law as a function of the injected power and remains constant regardless of pressure or other process parameters. The CO2 conversion is found to be proportional to specific energy input (SEI) even at the single filament level.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
C. Fromentin, T. Silva, T. C. Dias, E. Baratte, O. Guaitella, V Guerra
Summary: This work investigates the impact of N-2 addition on CO2 dissociation and vibrational kinetics of CO2 and CO in non-equilibrium plasma conditions. A kinetic model is extended to include the N-2 kinetics and is validated with experimental data. The results show that the addition of N-2 increases the vibrational temperature and dissociation fraction of CO2, which is attributed to vibration-to-vibration energy exchange processes and the decrease in atomic oxygen concentration.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Audrey Chatain, Ana Sofia Morillo-Candas, Ludovic Vettier, Nathalie Carrasco, Guy Cernogora, Olivier Guaitella
Summary: The addition of small amounts of H-2 in a DC glow discharge in N-2 at low pressure and low power was studied. The presence of H-2 greatly affects the N-2 plasma discharges, increasing the electric field and electron energy. It also leads to the formation of new species, including ammonia and hydrogen-bearing ions. This research provides insights into the plasma species in the ionosphere of Titan.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
J-P Booth, O. Guaitella, S. Zhang, D. Lopaev, S. Zyryanov, T. Rakhimova, D. Voloshin, A. Chukalovsky, A. Volynets, Yu Mankelevich
Summary: The chemical kinetics of oxygen atoms and ozone molecules in pure oxygen gas were studied using cavity ringdown spectroscopy. The afterglow period was observed, with non-exponential decay of oxygen atom density and slow decay of ozone density. A modified model was used to explain these behaviors.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Chemical
Carolina A. Garcia-Soto, Edmond Baratte, Tiago Silva, Vasco Guerra, Vasile I. Parvulescu, Olivier Guaitella
Summary: In situ FTIR transmission experiments were conducted to study the interaction between CO2 and CO2-CH4 plasma with cerium oxide (CeO2) as the catalytic surface. The results showed that CO2 gas adsorbs on the CeO2 surface, forming carbonates and hydrogen carbonates. When CO2-CH4 plasma is ignited, formate species are formed while carbonate species disappear. The role of gas composition at the exit of CO2-CH4 plasma on CeO2 was also observed, and the effect of water on surface phenomena was investigated.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
