Papers by Antoine Durocher-Jean
Dépôt local de puissance et chauffage des électrons par une onde électromagnétique plane dans un plasma excité à la RCE
HAL (Le Centre pour la Communication Scientifique Directe), 2013
Plasma Processes and Polymers, Feb 13, 2020
The need to ensuring the "see-through" property of transparent materials when exposed to sudden t... more The need to ensuring the "see-through" property of transparent materials when exposed to sudden temperature changes or very humid conditions has encouraged the development of antifogging strategies, such as the deposition of (super)hydrophilic coatings. However, despite the effectiveness of these coatings in combating the effects of fogging, most of the coating techniques explored to date are typically How to cite this article: Rodríguez Durán I, Durocher-Jean A, Profili J, Stafford L, Laroche G. Atmospheric pressure Townsend discharges as a promising tool for the one-step deposition of antifogging coatings from N 2 O/TMCTS mixtures.
Influence of N<sub>2</sub>, O<sub>2</sub>, and H<sub>2</sub> admixtures on the electron power balance and neutral gas heating in microwave Ar plasmas at atmospheric pressure
Journal of Physics D, Sep 6, 2019
A combination of optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen... more A combination of optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combined with collisional-radiative (CR) modelling of argon 2p states was used to characterize microwave argon plasmas at atmospheric pressure in presence of N2, O2, and H2 admixtures. In particular, the neutral gas temperature (obtained from the broadening of argon 2p2-1s2 and 2p3-1s2 emission lines), the number density of argon 1s5 atoms (obtained from absorption spectroscopy of the argon 2p9-1s5 transition using a tunable laser diode), the electron temperature (obtained from the comparison between measured and simulated argon 2p-to-1s relative line emission intensities), and the electron density (obtained from the Stark broadening of the Hβ line and argon relative line emission intensities) were recorded as a function of the axial distance along the microwave plasma column. The results show that, for a given position in the plasma and a higher amount of admixture in the nominally pure argon plasma, the neutral gas temperature increases and the electron number density decreases, while the electron temperature and the population of argon metastable atoms first decreases and then increases at higher concentrations. With such information, a detailed analysis of the electron power balance was performed. It is found that less than 1% of the admixture in the argon plasma already absorbed more than 80% of the microwave power. Part of this energy is used for neutral gas heating, mostly through electron-impact excitation of rotational levels.
Physics of Plasmas, Jun 1, 2019
Optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combin... more Optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combined with collisional-radiative (CR) modeling of argon 2p states are developed and used to determine the neutral gas temperature, the Ar 1s number density, and the electron temperature along a microwave argon plasma column at atmospheric pressure. The CR model, designed specifically for atmosphericpressure and optically thick plasma conditions, is fully detailed and validated by comparing the relative line emission intensities of argon 2p-to-1s transitions measured experimentally with the ones predicted by the CR model using the electron temperature as the only adjustable parameter. Subsequently, the neutral gas temperature ($1300-1600 K; obtained from the broadening of argon 2p 2-1s 2 and 2p 3-1s 2 emission lines), the Ar 1s 5 number density (1-2 Â 10 18 m À3 ; obtained from absorption spectroscopy of the argon 2p 9-1s 5 transition using a tunable laser diode), and the electron temperature ($1.4 eV; obtained from the comparison between the measured and simulated 2p-to-1s emission line intensities) are reported as a function of the axial distance along the microwave plasma column. The values and behaviors reveal a good agreement with those reported in previous experimental and modeling studies.
Deposition of anti‐fog coatings on glass substrates using the jet of an open‐to‐air microwave argon plasma at atmospheric pressure
Plasma Processes and Polymers, Apr 22, 2020
This study reports a one‐step process for the formation of anti‐fog coatings on commercial glass ... more This study reports a one‐step process for the formation of anti‐fog coatings on commercial glass substrates using the jet of an open‐to‐air microwave argon plasma at atmospheric pressure with hexamethyldisiloxane (HMDSO) as the precursor for plasma‐enhanced chemical vapor deposition. Optical microscopy and broadband light transmittance measurements revealed significant precursor fragmentation and gas phase association reactions when HMDSO was injected close to the tube outlet, resulting in powder‐like, hydrophobic, and semiopaque glass surfaces. On the contrary, injection of HMDSO close to the substrate led to smoother, homogeneous, hydrophilic, and transparent glass surfaces. In addition, transmittance measurements at 590 nm in humid air according to American Society for Testing and Materials standard tests revealed superior anti‐fogging properties to plasma‐treated glass substrates. On the basis of the optical emission and absorption spectroscopy measurements, electrons, metastable argon atoms, and hot neutral argon atoms were mostly responsible for the significant precursor fragmentation close to the tube outlet, whereas the contribution of hot neutrals and ultraviolet photons became important close to the substrate.
Evidence of local power deposition and electron heating by standing electromagnetic wave in electron cyclotron resonance plasmas
HAL (Le Centre pour la Communication Scientifique Directe), 2013
Atoms, Dec 6, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Atoms
Pulsed gas injection in a plasma can affect many fundamentals, including electron heating and los... more Pulsed gas injection in a plasma can affect many fundamentals, including electron heating and losses. The case of an asymmetric RF magnetron plasma with a pulsed argon injection is analyzed by optical emission spectroscopy of argon 2p-to-1s transitions coupled with collisional-radiative modeling. For a fully detailed population model of argon 2p levels accounting for direct and stepwise electron-impact excitation in optically thick conditions, a rapid decrease in the electron temperature, Te, is observed during each gas injection with the sudden pressure rise. The opposite trend, with unrealistic Te values before and after each pulse, is observed for analysis based on simple corona models, thus emphasizing the importance of stepwise excitation processes and radiation trapping. Time-resolved electron temperature variations are directly linked to the operating parameters of the pulsed gas injection, in particular the injection frequency. Based on the complete set of data, it is shown ...
Diagnostics spectroscopiques de plasmas d'argon à la pression atmosphérique en présence d'espèces réactives
Les travaux réalisés dans le cadre de cette thèse de doctorat caractérisent de manière cohérente ... more Les travaux réalisés dans le cadre de cette thèse de doctorat caractérisent de manière cohérente la physique des plasmas d'argon à la pression atmosphérique en présence d'espèces réactives. Ces travaux sont motivés par les lacunes manifestes de la compréhension des plasmas froids à la pression atmosphérique, celles-ci étant en grande partie dues au nombre restreint de techniques de diagnostic permettant de les caractériser. Dans ce contexte, des diagnostics optiques permettant l'obtention des propriétés fondamentales (température du gaz et des électrons, densité d'états excités) sont d'abord développés et validés tant pour les plasmas microonde que pour les décharges à barrière diélectriques d'argon à la pression atmosphérique. En particulier, une méthode couplant des mesures d'émission optique des transitions 2p-1s de l'argon à un modèle collisionnel-radiatif décrivant la population des niveaux émetteurs 2p permettant d'obtenir la température des électrons est présentée, de même qu'un moyen d'obtenir la température du gaz à l'aide de mesures d'élargissement spectral de raies et la densité d'états métastables de l'argon à l'aide de mesures de spectroscopie d'absorption par diode laser accordable en longueur d'onde. Par la suite, ces diagnostics optiques sont employés pour étudier l'influence de l'ajout de gaz diatomiques dans un plasma microonde, mettant en évidence l'efficacité avec laquelle ils en viennent à dominer la cinétique de la décharge en absorbant la majorité de la puissance fournie au plasma. Une comparaison entre le bilan de puissance des électrons qu'ils permettent de calculer à celui d'un diagnostic électrique est également effectué dans le cas d'une décharge à barrière diélectrique d'argon en présence de précurseurs d'anhydrides. Finalement, les propriétés fondamentales de deux conffgurations de jets de plasmas s'écoulant dans l'air ambiant, l'une radiofréquence, l'autre microonde, sont également examinées. Dans le premier cas, les effets de l'air ambiant sur ces propriétés sont mis de l'avant, alors que dans le second cas, la position d'injection du précurseur organosilicié HMDSO dans le jet de plasma est évaluée pour le dépôt de revêtements fonctionnels sur des substrats de verre. Ces derniers travaux révèlent l'obtention d'un revêtement antibuée dans des conditions opératoires spécifiques, un résultat fort prometteur pour l'industrie du verre.The research done in this Ph.D. thesis consistently characterizes the physics of argon plasmas at atmospheric pressure in the presence of reactive species. This work is motivated by the obvious deficiencies in the understanding of cold plasmas at atmospheric pressure, which are largely due to the limited number of diagnostic techniques used to characterize them. In this context, optical diagnostics allowing the obtaining of fundamental properties (gas and electron temperature, number density of excited species) are first developed and validated in a microwave argon plasma as well as in a dielectric barrier discharge in argon at atmospheric pressure. In particular, a method coupling optical emission measurements of argon 2p-1s transitions to collisional-radiative modelling of the emitting 2p levels is presented in order to get the electron temperature, as well as a means to obtain the gas temperature by the spectral broadening of emission lines and the number density of argon metastable states from tunable laser diode absorption spectroscopy measurements. Subsequently, these optical diagnostics are used to study the influence adding diatomic gases in microwave argon plasmas, highlighting the efficiency with which they start dominating the discharge kinetics by absorbing most of the supplied power. A comparison between the electron power balance calculated from such optical diagnostics to that obtained from electrical diagnostics is also made in the case of an argon-based dielectric barrier discharge with anhydride precursors. Finally, the fundamental properties of two plasmas jet configurations (one radiofrequency, the other microwave) expanding in ambient air are also examined. In the first case, the effects of ambient air on these properties are featured, while in the second case, the injection position of the organosilicon precursor HMDSO in the plasma jet is studied for the deposition of functionnal coatings on glass substrates. The latter reveals the obtaining of an antifog coating under specific operating conditions, a very promising result for the glass industry
On the rotational–translational equilibrium in non-thermal argon plasmas at atmospheric pressure
Plasma Sources Science and Technology, 2021
This work examines the rotational–translational equilibrium in non-thermal, argon-based plasmas a... more This work examines the rotational–translational equilibrium in non-thermal, argon-based plasmas at atmospheric pressure. In particular, rotational temperatures (T rot) and neutral gas temperatures (T g) are compared along the axis of plasma columns sustained by either radiofrequency (RF) or microwave (MW) electromagnetic fields. Water vapours or N2 admixtures are added to the high-purity argon plasmas to record the rotational temperatures from the emission spectra of either the OH(A2Σ + − X2Π i ) or the N2 +(B2Σ u + − X2Σ g + ) rovibrational systems. T g values are also deduced from the line broadening of selected Ar emission lines using an hyperfine spectrometer. In the MW Ar/H2O plasma, T g decreases from ∼2100 K close to the wave launcher to ∼1600 K near the end of the plasma column, while T rot is mostly constant in the 1500 K range. In presence of N2 admixtures instead of water vapours, T g is higher by about 300 K (from ∼2400 K to ∼1900 K), while T rot decreases from ∼3200 K t...
Ultra-high-resolution optical absorption spectroscopy of DC plasmas at low pressure using a supercontinuum laser combined with a laser line tunable filter and a HyperFine spectrometer
Journal of Physics D: Applied Physics, 2020
Optical absorption spectroscopy of non-equilibrium plasmas using a supercontinuum laser combined ... more Optical absorption spectroscopy of non-equilibrium plasmas using a supercontinuum laser combined with a laser line tunable filter and a HyperFine spectrometer is examined. Owing to the <2 pm spectral resolution of the HyperFine system, details on the absorption line intensity, position and width can be obtained with very high precision using a broadband light emission source. As an example, absorption spectroscopy measurements were recorded in a reduced-pressure, nominally pure argon DC plasma column and allowed for the determination of the neutral gas temperature and the Ar 1s2 and Ar 1s4 (Paschen notation) number densities. At a pressure of 1 Torr, a discharge current of 20 mA, and an absorption length of 18 cm, the analysis of the Ar 2p3-1s2 and Ar 2p8-1s4 absorption lines at respectively 840.8 nm and 842.5 nm resulted in number densities of n 1 s 2 = 5.5 × 1015 m−3 and n 1 s 4 = 1.1 × 1016 m−3 and a neutral gas temperature of T g = 340 K. These values are typical of DC discha...
Deposition of anti‐fog coatings on glass substrates using the jet of an open‐to‐air microwave argon plasma at atmospheric pressure
Plasma Processes and Polymers, 2020
This study reports a one‐step process for the formation of anti‐fog coatings on commercial glass ... more This study reports a one‐step process for the formation of anti‐fog coatings on commercial glass substrates using the jet of an open‐to‐air microwave argon plasma at atmospheric pressure with hexamethyldisiloxane (HMDSO) as the precursor for plasma‐enhanced chemical vapor deposition. Optical microscopy and broadband light transmittance measurements revealed significant precursor fragmentation and gas phase association reactions when HMDSO was injected close to the tube outlet, resulting in powder‐like, hydrophobic, and semiopaque glass surfaces. On the contrary, injection of HMDSO close to the substrate led to smoother, homogeneous, hydrophilic, and transparent glass surfaces. In addition, transmittance measurements at 590 nm in humid air according to American Society for Testing and Materials standard tests revealed superior anti‐fogging properties to plasma‐treated glass substrates. On the basis of the optical emission and absorption spectroscopy measurements, electrons, metastabl...
Plasma Processes and Polymers, 2020
The need to ensuring the "see-through" property of transparent materials when exposed to sudden t... more The need to ensuring the "see-through" property of transparent materials when exposed to sudden temperature changes or very humid conditions has encouraged the development of antifogging strategies, such as the deposition of (super)hydrophilic coatings. However, despite the effectiveness of these coatings in combating the effects of fogging, most of the coating techniques explored to date are typically How to cite this article: Rodríguez Durán I, Durocher-Jean A, Profili J, Stafford L, Laroche G. Atmospheric pressure Townsend discharges as a promising tool for the one-step deposition of antifogging coatings from N 2 O/TMCTS mixtures.
Influence of N2, O2, and H2 admixtures on the electron power balance and neutral gas heating in microwave Ar plasmas at atmospheric pressure
Journal of Physics D: Applied Physics, 2019
A combination of optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen... more A combination of optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combined with collisional-radiative (CR) modelling of argon 2p states was used to characterize microwave argon plasmas at atmospheric pressure in presence of N2, O2, and H2 admixtures. In particular, the neutral gas temperature (obtained from the broadening of argon 2p2-1s2 and 2p3-1s2 emission lines), the number density of argon 1s5 atoms (obtained from absorption spectroscopy of the argon 2p9-1s5 transition using a tunable laser diode), the electron temperature (obtained from the comparison between measured and simulated argon 2p-to-1s relative line emission intensities), and the electron density (obtained from the Stark broadening of the Hβ line and argon relative line emission intensities) were recorded as a function of the axial distance along the microwave plasma column. The results show that, for a given position in the plasma and a higher amount of admixture in the nominally pure argon plasma, the neutral gas temperature increases and the electron number density decreases, while the electron temperature and the population of argon metastable atoms first decreases and then increases at higher concentrations. With such information, a detailed analysis of the electron power balance was performed. It is found that less than 1% of the admixture in the argon plasma already absorbed more than 80% of the microwave power. Part of this energy is used for neutral gas heating, mostly through electron-impact excitation of rotational levels.
Physics of Plasmas, 2019
Optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combin... more Optical emission and absorption spectroscopy of argon 2p-1s transitions (Paschen notation) combined with collisional-radiative (CR) modeling of argon 2p states are developed and used to determine the neutral gas temperature, the Ar 1s number density, and the electron temperature along a microwave argon plasma column at atmospheric pressure. The CR model, designed specifically for atmospheric-pressure and optically thick plasma conditions, is fully detailed and validated by comparing the relative line emission intensities of argon 2p-to-1s transitions measured experimentally with the ones predicted by the CR model using the electron temperature as the only adjustable parameter. Subsequently, the neutral gas temperature (∼1300–1600 K; obtained from the broadening of argon 2p2-1s2 and 2p3-1s2 emission lines), the Ar 1s5 number density (1–2 × 1018 m−3; obtained from absorption spectroscopy of the argon 2p9-1s5 transition using a tunable laser diode), and the electron temperature (∼1.4 e...
Time-resolved study of the electron temperature and number density of argon metastable atoms in argon-based dielectric barrier discharges
Plasma Sources Science and Technology, 2018
A combination of optical emission spectroscopy and collisional-radiative modelling is used to det... more A combination of optical emission spectroscopy and collisional-radiative modelling is used to determine the time-resolved electron temperature (assuming Maxwellian electron energy distribution function) and number density of Ar 1s states in atmospheric pressure Ar-based dielectric barrier discharges in presence of either NH3 or ethyl lactate. In both cases, T e values were higher early in the discharge cycle (around 0.8 eV), decreased down to about 0.35 eV with the rise of the discharge current, and then remained fairly constant during discharge extinction. The opposite behaviour was observed for Ar 1s states, with cycle-averaged values in the 1017 m−3 range. Based on these findings, a link was established between the discharge ionization kinetics (and thus the electron temperature) and the number density of Ar 1s state.
Physical Review E, 2014
Microwave plasmas excited at electron-cyclotron resonance were studied in the 0.5-15 mTorr pressu... more Microwave plasmas excited at electron-cyclotron resonance were studied in the 0.5-15 mTorr pressure range. In contrast with low-limit pressure conditions where the plasma emission highlights a fairly homogeneous spatial structure, a periodic spatial modulation (period ß6.2 cm) appeared as pressure increased. This feature is ascribed to a local power deposition (related to the electron density) due to the presence of a standing electromagnetic wave created by the feed electromagnetic field (2.45 GHz) in the cavity formed by the reactor walls. Analysis of the electron energy probability function by Langmuir probe and optical emission spectroscopy further revealed the presence of a high-energy tail that showed strong periodic spatial modulation at higher pressure. The spatial evolution of the electron density and of the characteristic temperature of these high-energy electrons coincides with the nodes (maximum) and antinodes (minimum) of the standing wave. These spatially-modulated power deposition and electron heating mechanisms are then discussed.
Diagnostics of microwave plasmas at atmospheric pressure applied to the growth of organosilicon nanopowders, (Available online: (http://www.icpig2015.net/Content/Papers/Topical_Invited_Speakers/TL10.pdf))
Spatially Modulated Emission of ECR Plasmas in Helium
IEEE Transactions on Plasma Science, 2014
ABSTRACT Space modulation of the optical emission is observed in electron cyclotron resonance pla... more ABSTRACT Space modulation of the optical emission is observed in electron cyclotron resonance plasmas depending on the operating pressure. In contrast with low-pressure condition, where the plasma emission highlights a fairly homogeneous spatial structure, a spatial modulation appeared as the pressure increased: both color and intensity modulations were observed. This phenomenon is attributed to the establishment of a standing wave that modulate the plasma characteristics.
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Papers by Antoine Durocher-Jean