Teses / dissertações sobre o tema "Caractérisation des plasmas"
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Chruszez, Olivier. "Caractérisation de matériaux plasmas pour la conception de fonctions hyperfréquences". Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/15662/1/CHRUSZEZ.pdf.
Texto completo da fonteDervieux, Vincent Nicolas Marie. "Caractérisation des plasmas chauds et denses produits par intéraction laser à ultra-haute intensité d'une cible solide". Palaiseau, Ecole polytechnique, 2015. http://www.theses.fr/2015EPXX0041.
Texto completo da fonteAstic, Dominique. "Caractérisation par spectroscopie d'émission d'un plasma créé par laser CO2 impulsionnel sur matériaux solides". Aix-Marseille 2, 1990. http://www.theses.fr/1990AIX22052.
Texto completo da fonteCadier, Benoît. "Fibres autorenforcées pour modules d'abonnés : optimisation, caractérisation". Poitiers, 1998. http://www.theses.fr/1998POIT2289.
Texto completo da fonteMartinie, Olivier. "Caractérisation physique et chimique de décharges hors équilibre : application au traitement des NOx". Orléans, 2000. http://www.theses.fr/2000ORLE2047.
Texto completo da fonteDelair, Laurent. "Caractérisation de sources plasmas dédiées à la simulation de rentrées atmosphériques et au traitement de polluants : arc soufflé basse pression et décharge de polluants". Rouen, 2004. http://www.theses.fr/2004ROUES052.
Texto completo da fonteThis work deals with the experimental study of two plasma sources : an original plasma torch (two anodic arc roots) which generates a low pressure nitrogen arcjet, and an atmospheric pressure gliding arc. The thermodynamic characteristics of the nitrogen plasma – densities and temperatures – are deduced from emission spectroscopy analysis, from its creation zone to its expansion zone. Mach number measurements are carried out at the torch exit. The study of the arc(s dynamic behaviour highlights an acoustic resonance frequency inside the arc chamber. The analysis of the gliding arc with emission spectroscopy reveals its non-equilibrium state and some abnormal ionic line broadenings in its creation zone due to plasma turbulence phenomena. Simultaneous high speed acquisitions of electrical signals and light intensity confirm its classical dynamical behaviour : ignition, lengthening, extinction. They also show the impulse behaviour of the arc column as it moves between the electrodes
Latrasse, Louis. "Conception, caractérisation et applications des plasmas micro-onde en configuration matricielle". Phd thesis, Université Joseph Fourier (Grenoble), 2006. http://tel.archives-ouvertes.fr/tel-00123911.
Texto completo da fonteBrault, Cédric. "Développement et mise en oeuvre d'un diagnostic d'imagerie ultra-rapide en magnétoplasma de laboratoire : application à la caractérisation du transport radial du plasma". Aix-Marseille 1, 2007. http://www.theses.fr/2007AIX11041.
Texto completo da fonteRanz, Xavier. "Développement et caractérisation de dépôts d'apatite obtenus par projection plasma sur prothèses orthopédiques". Toulouse, INPT, 1996. http://www.theses.fr/1996INPT005G.
Texto completo da fonteAouinti, Mohammed. "Caractérisation de la décharge microonde de CO2 et étude des interactions plasma-polyproylène". Le Mans, 2000. http://cyberdoc.univ-lemans.fr/theses/2000/2000LEMA1018.pdf.
Texto completo da fonteThe aim of the present work is focused on the synthesis of polymer materials presenting specific surface properties. Our approach consists to the characterization of CO2 microwave discharge, and then to the study at the interactions between these species and polypropylene film. We have shown that the CO2 microwave discharge is very peopled in different electronics and vibrationals excited states of CO, that the rate of these species (CO, O2 and O) varies strongly with the microwave power, but is less sensitive to the gas flow. These reactive species induce surface modifications of polypropylene as principally degradation through atomic hydrogen abstraction, functionalization through oxygenated groups attachment and crosslinking via double bounds formation. Simultaneously to these surface modifications, we have shown for certain conditions treatments (high microwave power) a structural change in polypropylene thickness, tied to radiative absorption particularly VUV which action can be effective beyond 100 µm. The short wave length radiations are probably the origin of thermal relaxation which produce locals rearrangements of chains in depth. This structural change is assigned to a total transformation of the smectic phase and partial the amorphous phase. This tansformation is expressed by an increase of the crystallinity rate and crystallites size. An increase in texture degree was also observed with preferential orientation of the crystallites in sample plan
Viel, Virginie. "Modélisation et caractérisation d'un plasma microonde". Toulouse, ENSAE, 1995. http://www.theses.fr/1995ESAE0002.
Texto completo da fonteTran, Tan Vinh. "Caractérisation et modélisation des plasmas micro-onde multi-dipolaires : application à la pulvérisation assistée par plasma multi-dipolaire". Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10287.
Texto completo da fonteThe scaling up of plasma processes in the low pressure range remains a question to be solved for their rise at the industrial level. One solution is the uniform distribution of elementary plasma sources where the plasma is produced via electron cyclotron resonance (ECR) coupling. These elementary plasma sources are made up of a cylindrical permanent magnet (magnetic dipole) set at the end of a coaxial microwave line. Although of simple concept, the optimisation of these dipolar plasma sources is in fact a complex problem. It requires the knowledge , on one hand, of the configurations of static magnetic fields and microwave electric fields, and, on the other hand, of the mechanisms of plasma production in the region of high intensity magnetic field (ECR condition), and of plasma diffusion. Therefore, the experimental characterisation of the operating ranges and plasma parameters has been performed by Langmuir probes and optical emission spectroscopy on different configurations of dipolar sources. At the same time, in a first analytical approach, calculations have been made on simple magnetic field configurations, motion and trajectory of electrons in these magnetic fields, and the acceleration of electrons by ECR coupling. Then, the results have been used for the validation of the numerical modelling of the electron trajectories by using a hybrid PIC (particle-in-cell) / MC (Monte Carlo) method. The experimental study has evidenced large operating domains, between 15 and 200 W of microwave power, and from 0. 5 to 15 mTorr argon pressure. The analysis of plasma parameters has shown that the region of ECR coupling is localised near the equatorial plane of the magnet and dependent on magnet geometry. These characterisations, applied to a cylindrical reactor using 48 sources, have shown that densities between 1011 and 1012 cm-3 could be achieved in the central part of the volume at a few mTorr argon pressures. The modelling of electron trajectories near the magnet has also shown a better radial confinement with magnets exhibiting high length over diameter ratios. In addition, the numerical study corroborates the results of the experimental study, i. E. An ECR coupling region close to the equatorial plane of the magnet and not near the end of the coaxial microwave line. Finally, these results have been successfully applied to plasma assisted sputtering of targets allowing, in particular, their uniform erosion
Callebert, Franck. "Synthèse et caractérisation de couches minces organosiliciées obtenues par polymérisation assistée par plasma froid différé d'azote". Caen, 2005. http://www.theses.fr/2005CAEN2062.
Texto completo da fonteDong, Binjie. "Etude et caractérisation de plasmas destinés au contrôle actif d'écoulements gazeux subsoniques". Orléans, 2008. http://www.theses.fr/2008ORLE2055.
Texto completo da fonteDong, Binjie. "ÉTUDE ET CARACTÉRISATION DE PLASMAS DESTINÉS AU CONTRÔLE ACTIF D'ÉCOULEMENTS GAZEUX SUBSONIQUES". Phd thesis, Université d'Orléans, 2008. http://tel.archives-ouvertes.fr/tel-00360770.
Texto completo da fonteUrsu, Cristian. "Caractérisation par méthodes optiques et électriques du plasma produit par ablation laser". Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10005/document.
Texto completo da fonteThe transient plasmas generated by high-fluence laser ablation are complex phenomena involving multiple processes, as optical radiation absorption by the matter, temperature increase and phase transitions generated by the energy transfer, expanding gas hydrodynamics, electrical interactions between the charged particles, or the interaction of the laser radiation with the generated plasma. A most complete understanding of this phenomenon is therefore necessary from the fundamental point of view, but also for characterizing the behavior of high technological potential materials under intense irradiation. We have developed a multi-diagnostic approach, based on optical and electrical techniques: fast ICCD camera imaging, space- and time-resolved optical emission spectroscopy, diode laser absorption spectroscopy, Langmuir probe. These techniques have been used to characterize plasmas generated by nanosecond laser ablation of various samples, from simple Al and Cu metals, to more complicated ceramics, chalcogenide glasses or ferromagnetics. The main results have been the observation of the plasma splitting in two structures and the kinetic and energetic characterization of their constituents. These results present fundamental (development of a fractal hydrodynamic model) and applied (erosion of dielectric walls in space plasma thrusters, pulsed laser deposition of thin films) interest
Hbid, Tarik. "Modélisation et caractérisation expérimentale des décharges radiofréquence basse pression en présence de poudres". Toulouse 3, 1995. http://www.theses.fr/1995TOU30213.
Texto completo da fonteKahalerras, Mohamed Khaled. "Caractérisation des matériaux piézoélectriques dédiés à la génération des décharges plasmas pour applications biomédicales". Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0019/document.
Texto completo da fonteDue to intensive development efforts during the past decade, piezoelectric transformers havebecome an attractive alternative solution compared to the con-ventionally used technologies forcold plasma generation. Their high efficiency, thin-shaped dimensions and low voltage supplymake them serious and original candidates for numerous low power applications, particularly inbiomedical field. Operating as a plasma generator, the electromechanical conversion within thetransformer is accompanied by mechanical and dielectric losses, often converted into heat. On topof these effects, the discharge is likely to influence the electrical behavior of the device. Thedynamic and highly non-linear evolution of the dis-charge leads to an unknown behavior ofelectrical properties. Consequently, the transformer supply stage is an active research subject inthe same way as the trans-former itself. Moreover, considering the configuration of the generationprocess, which positions the piezoelectric material as the source and the spot of the plasmadischarge, it becomes necessary to consider the viability of the device. The ioniza-tion of thegaseous environment surrounding the generator causes complex elec-tronic effects, which canlead to material deposition on the surface of the generator and thus modify or even degrade it. It iswithin this framework, at the interface between electrical engineering and material science, thatthis thesis is articulated. A first part is intended to develop a setup for numerical control of thedevice using a digital phase-locked loop to ensure its continuous operation in different operatingconditions. Subsequently, a model of the plasma generator in configurations close to dielectricbarrier discharges is proposed; Simulations allow an estimation of the discharge power from anexperimental identification of the model parameters. In a second part, we seek to establish acorrelation between the material structure and its electrical properties based on a multi-scalecharacterization methodology, before and after plasma discharge. The study focuses mainly onthe surface evolution in terms of the crystalline structure and the chemical composition, related tothe over-all properties of the piezoelectric transformer before and after discharge generation.Finally, a temperature study that concerns the investigation of the effects of self-heating of thegenerator in this operating mode is performed
Fabry, Frédéric. "Etude d'un procédé plasma pour la synthèse de noirs de carbone structures par pyrolyse d'hydrocarbures à haute température et caractérisation des produits". Perpignan, 1999. http://www.theses.fr/1999PERP0336.
Texto completo da fonteEscarguel, Alexandre. "Caractérisation spatio-temporelle de plasmas crées par impulsion laserdans un liquide : application à l'étude de l'élargissement Stark de la raie Balmer alpha de l'hydrogène". Aix-Marseille 1, 1998. http://www.theses.fr/1998AIX11080.
Texto completo da fonteGuiffard, Benoît. "Elaboration et caractérisation de céramiques ferroélectriques de type PZT fluorure". Lyon, INSA, 1999. http://theses.insa-lyon.fr/publication/1999ISAL0074/these.pdf.
Texto completo da fonteFerroelectric ceramics with general formula Pb(ZrxTi1-x)O3) (PZT) are intensively used in many industrial domains like medecine or aeronautics owing to their dielectric and electromechanical properties. The aim of the study is the search of hard PZT ceramics with stable and reproductible characteristics versus temperature and under mechanical uniaxial stress. A non hysteretic behaviour versus both types of sollicitations is also needed. These specificities are required for strongly spinned devices like vibratory gyroscopes in which ceramics undergo large mechanical stresses. Besides, the material must exhibit low dielectric constant and high mechanical quality factor. In order to reach these objectives, new Fluorine-doped PZT materials have been prepared by a wet method and characterized. The partial fluorine - oxygen substitution has been realized on a nominal composition Pb0. 89(Ba, Sr)0. 11(ZrxTi1-x)O3 doped with magnesium
Kontogiannopoulos, Nikolaos. "Caractérisation par spectroscopie X de plasmas chauds et denses créés par lasers de puissance". Phd thesis, Ecole Polytechnique X, 2007. http://pastel.archives-ouvertes.fr/pastel-00003578.
Texto completo da fonteChambettaz, Florentin. "Caractérisation et développement d'un procédé de gravure séquentiel contrôlé à l'échelle nanométrique". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT023/document.
Texto completo da fonteThe miniaturization of microelectronics devices requires the development of ever more accurate etching processes. The subject of this thesis is part of this problematic: a controlled sequential etching process at the nanoscale has been developed to overcome the inherent defects of direct plasma etching. This etching process intended in our case for the etching for SiN spacers, is divided in two steps. The first step is a light atom implantation. The implantation of light chemical species such as Hydrogen or Helium has the advantage of modifying the structure of the material without inducing a damaging sputtering for the device to be etched. In the second step, the layer modified by the implantation is etched selectively regarding the pristine material via a remote plasma.Hydrogen implantation was mainly studied during this work: different characterizations to quantify the implanted hydrogen as well as the modified thickness were carried out. X-ray reflectometry measurements were used to determine the modified thickness as a function of the self-polarization power and the duration of implantation. Hydrogen implant profiles on SiN were also carried out through electrical characterizations. The charge density profiles observed were compared to Si-H and N-H bond profiles obtained from infrared spectroscopic measurements in multiple reflections. These measurements were also compared to secondary ionization mass spectrometry profiles. These profiles make it possible to quantify implanted hydrogen as a function of depth, and have also provided information regarding the influence of UV radiation and the chemical configuration of the implanted material. A significant presence of oxide on the surface of the implanted material has also been observed through X-ray photoelectron spectroscopic measurements.The removal step was mainly studied via kinetic ellipsometric in situ measurements and X-ray photoelectron spectroscopic measurements for different temperature conditions and for different chemical mixtures. The ellipsometric measurements made it possible to observe the formation of salts during etching, whereas the X-ray photoelectron spectroscopic analysis showed that the surface of the material was deoxidized by the remote plasma, while a large quantity of fluorine was measured at the same time on the material surface. The studies carried out on the implantation and removal steps made it possible to succesfully etch patterned samples under the appropriate conditions
Hernandez, Karina. "Caractérisation expérimentale de l'interaction arc-matériau : application à l'optimisation des appareils de coupure". Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2412/.
Texto completo da fonteQuantification of energy transfer is an essential theme for optimization of many systems and processes such as low-voltage circuit breakers. The AEPPT team investigates this topic over many years, both from an experimental and theoretical point of view by developing experimental devices and numerical models. To this day, experimental studies have been made on a transferred arc configuration for current values about a hundred amperes. In this work, a new experimental device has been carried out to generate a pulsed arc of several kilo amperes. Two complementary approaches were considered to quantify time-resolved energy transfer: to study the interaction of the arc with the electrode material and to characterize the plasma created. High-speed video analysis has been used, thermographic and spectroscopy measurements were carried out
Bertrand-Duchesne, Marie-Pierre. "Caractérisation et rôle des facteurs de croissance libérés par les plasmas riches en plaquettes". Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23797/23797.pdf.
Texto completo da fonteBertrand-Duchesne, Marie-Pierre. "Caractérisation et rôle des facteurs de croissance libérés par les plasmas riches en plaquette". Master's thesis, Université Laval, 2006. http://hdl.handle.net/20.500.11794/18345.
Texto completo da fonteGhrab, Mounir. "Caractérisation de jets de plasmas créés par laser à CO2 impulsionnel sur matériaux solides". Aix-Marseille 2, 1993. http://www.theses.fr/1993AIX22075.
Texto completo da fonteVillemant, Marc. "Modélisation et caractérisation expérimentale de l’influence de l’émission électronique sur le fonctionnement des propulseurs à courant de Hall". Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0038.
Texto completo da fonteNowadays, plasma Hall thrusters are used in space industry for satellites orbit rising and satellites attitude control. Nonetheless, the comprehension their physical functioning remains patchy. Several phenomena such as abnormal electron mobility or the thrusters performance dependency to wall material are still not understood. Consequently the current process to improve and qualify Hall thrusters are involving expansive and time-consuming experimental validation which, in the end, does not ensure the release of an operational thruster. Consequently, plasma behaviour in Hall thruster is a key topic of research, which could lead to non-negligible improvement in Hall thruster technology development.This Ph.D. consists in the modelling and characterization of plasma/wall interaction in Hall thrusters and its impact on Hall thruster’s performance. This Ph.D. has focused on the influence of the electron emission under electron impact on Hall thruster’s performances. It has been divided into three parts. Firstly, an experimental investigation has been carried out in order to obtain reference data on materials commonly used as plasma thruster wall (bore nitride and silicon dioxide). A literature review has been made in order to find a theoretical basis fitted to the elaboration of an electron emission model fitting the requirement of a particle in cell simulation of a Hall thruster. In second part, a detailed electron emission model based on this literature review and validated by comparison to experimental data and to a Monte-Carlo model developed in ONERA (called OSMOSEE) has been developed. This model offers the possibility to describe electron emission yield, angular and energy distribution of emitted electrons depending on various physical parameters (e.g. incident electron energy, incident electron angle, impinged material, etc.). Besides, as it is an analytical model, it computes in a reduced time (a few minutes to one hour). In a third and last part, this electron emission model has been implemented in a Particle-In-Cell (PIC) simulation of Hall thruster’s plasma and a parametric study has been carried out in order to characterize the influence of electron emission phenomenon on global plasma behaviour. This parametric study has shown that electron emission has a non-negligible impact on energy balance at plasma/wall interface and on electron distribution function in the plasma, which can’t be considered as Maxwellian
Ayrault, Sophie. "Dépôts de céramiques sur polymères (thermoplastiques ou thermodurcissables) assistés par laser ou plasmc : Faisabilité, caractérisation mécanique et physico-chimique". Ecully, Ecole centrale de Lyon, 1995. http://www.theses.fr/1995ECDL0026.
Texto completo da fonteThe aim of this work was to deposit thick ceramic coatings on polymer substrates (thermoplastics of thermosets) assisted by laser (CO2, =10,6 M) or plasma. Alumina powder has been deposited on polyethylene teraphtalate (PET) and on epoxy resin substrates. Since both these materials have different behaviours towards temperature, two adhesion mechanisms can be observed. For the thermoplastic polymer an adhesion of the ceramic particules on the substrate has been observed by mechanical anchorage which is due to the incrustation of the alumina grains on the melted polymer whatever the technique used. However, some differences between plasma or laser coatings have appeared. Using plasma coating, a grey and dense coating with appearence of a new γ crystallographic structure in addition to the original corundum structure has been obtained. Using laser coating, according to the different treatment parameters, a brown and inhomogeneous as well as rough deposit which shows the same crystallographic structure as the initial ceramic powder has been obtained. Therefore, different mechanical comportements have been shown using different techniques (tribology, erosion, microhardness, traction). As far as PET is concerned some morphological modifications inside the polymer have been observed during the treatment. Techniques have demonstrated a crystallinity gradient in the bulk of the substrate, a strong dependence of the microhardness but an unchanged morphology as a function of the treatment duration (which was shown by "finite elements" silumation). The behavior of the thermoset polymer since its own infusible porperty does not allow a direct mechanical anchorage seems different. Despite the strong interaction beam/polymer likely to create polar groups in the case of plasma treatment no adhesion with the ceramic coating occurs. It is therefore necessary to create an intermediate layer favorizing an anchorage with both substrate and alumina powder. Trials with industrial materials have shown promising results as regards quality of deposit a swell as adherence
Escaich, David. "Caractérisation et élaboration de couches de carbones amorphes hydrogènes à propriétés optiques par procédés plasmas". Toulouse 3, 2006. http://www.theses.fr/2006TOU30074.
Texto completo da fonteEsmiller, Bruno. "Caractérisation par spectroscopie d'émission de plasmas induits par laser verre-néodyme déclenché sur matériaux solides". Aix-Marseille 2, 1993. http://www.theses.fr/1993AIX22080.
Texto completo da fonteThouin, Julien. "Caractérisation expérimentale et théorique d'un arc électrique impulsionnel éclatant dans un liquide". Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30317.
Texto completo da fonteThe applications of pulsed arc discharges in water are numerous: electrohydraulic forming of metal parts, rock fracturing, or water treatment. Many of these pulsed power applications require intense pressure waves with energy deposition in times shorter than a millisecond. Consequently, there are numerous technological constraints and challenges, both electrical in nature due to the use of often high-voltage power supplies and associated equipment wear, particularly electrode erosion. In this context, the characterisation of pulsed electric arcs in water and their associated mechanisms are essential for optimising these devices. The primary phenomena associated with such discharges are pressure waves and intense radiation emission. However, the mechanisms and their dependence on discharge parameters remain poorly understood. To address this, experimental means have been implemented, initially characterising a discharge with a characteristic time in the range of ten milliseconds. This is aimed at better understanding the experimental setup and obtaining characterisation data that can be used to comprehend the environment and validate potential simulation models. The electric arc is generated by discharging capacitors charged to several hundred volts, with an energy stored of the order of kilojoules. Measurements of plasma temperature using the Boltzmann plot method on atomic oxygen lines have been carried out. Additionally, electron density of the plasma was measured from the Stark broadening of Halpha and Hbeta emission lines. These measurements are temporally resolved over the duration of the discharge, allowing for an estimation of the pressure in the thermal plasma. Rapid camera acquisitions of the generated vapour bubble's dynamics and thermal plasma with a band-pass optical filter have also been performed. In a second stage, to better approach typical experimental conditions of pulsed electrohydraulic discharge applications (similar energies but shorter times), a high-voltage, low inductance experimental setup has been developed. This setup enables discharge initiation through voltage surges in water. The power supply and discharge have been electrically characterised, and, for the electric arc, based on the measurements set up for longer times, rapid imaging and a survey of the emitted spectrum have been carried out
Kaeppelin, Vincent. "Caractérisation d'une source de plasma hélicon et application à l'implantation ionique par immersion plasma". Aix-Marseille 1, 2002. http://www.theses.fr/2002AIX11027.
Texto completo da fonteGoujon, Marjorie. "Modélisation et caractérisation expérimentale d'un procédé de dépôt de couches minces d'oxyde de silicium en plasma radiofréquence O2/HMDSO à basse pression". Vandoeuvre-les-Nancy, INPL, 2004. http://docnum.univ-lorraine.fr/public/INPL_T_2004_GOUJON_M.pdf.
Texto completo da fonteThe presented works deal with the investigation of a low pressure oxygen-hexamethyldisiloxane radio- frequency plasma assisting a chemical vapour deposition process used to deposit silicon oxide thin films onto metallic substrates. The first step consists in developing a fluid model to describe the plasma behaviour over a RF period. A particular attention is pa id to the time variation of the electric field and the charged particle densities. Moreover, the relative influence of the electrode ion bombardment and the wave-riding process on the secondary electron creation is pointed out and helps determine working conditions where ion impingement on the electrodes is reduced. Ln a second step, the plasma is studied by means of optical emission spectroscopy and Fourier transform infra-red absorption spectroscopy (FTIR). From the experimental results, the dissociatio~ rate of the organo-silicon monomer is estimated and valuable insights into the dissociation mechanisms of the organic precursor are obtained. FTIR analyses of the deposited films are carried out and coupled with the gas phase characterization, providing correlations between the film and the plasma compositions. These results are completed by a kinetic modelling of the neutral species in the 02/HMDSO plasma. This numerical simulation corn putes the variation of the main species density over the inter-electrode space and especially in the close vicinity of the substrate, allowing prediction of the carbon incorporation in the films
Bouaziz, Moez. "Caractérisation d'un plasma d'arc à la pression atmosphérique au voisinage de l'anode". Toulouse 3, 1996. http://www.theses.fr/1996TOU30306.
Texto completo da fonteCourrege, Maeva. "Caractérisation des interactions plasma/parois dans un disjoncteur haute tension". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30162/document.
Texto completo da fonteHigh-voltage circuit breakers, present in the power grid, ensure in safety the electricity distribution. When an error is detected, or for a maintenance operation, the opening of the electrical contacts within the circuit breaker causes the appearance of an electric arc at its terminals. Protection and cut-off will only be effective if the electrical arc cut off. Many parameters, geometric and physical, are involved in the breaking capacity of a circuit breaker. The aim of this work is to analyze the impact of plasma on the various materials making up the circuit breaker. A purely theoretical approach is tackled through the use of the commercial software ANSYS Fluent. This work is carried out in collaboration with Siemens, which provides the experimental data necessary for the discussion and validation of the model. In this work, we first consider the ablation of teflon nozzles. This phenomenon is taken into account in our study, using an ablation model based on the theory of T. Christen. The ablation of the walls plays a fundamental role on the rise in pressure in the heating volumes, and has a direct effect on the cut-off realization. Thus, the role and quantification of C2F4 vapors are discussed and detailed. The second plasma / material interaction that should be studied is that with the mobile electrode made of a tungsten copper mixture. This interaction is rarely studied in the literature. The implementation requires the development of sub-layers models in the vicinity of the electrode, based on energy and flux balances, which make it possible to determine by non-equilibrium approaches the temperature of the electrodes and the rate of vapor production. On a real circuit breaker configuration, the temporal characteristics of the physical (temperature, velocities, pressure) and electrical (current, voltage) quantities are presented and discussed in the high current phase. We conclude on the need to consider the ablation of C2F4 for a good description of the rise in pressure in the heating volumes because they condition the blowing at the moment of current-zero and on the need to take into account the copper vapors because these are present at the zero crossing of the current and then condition the breaking capacity of the circuit breaker
Koné, Aboubakar. "Développement, caractérisation et optimisation d'une source plasma pour la décontamination microbiologique". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30142/document.
Texto completo da fonteStudies in the plasma-biology field have demonstrated the biocidal effect of atmospheric pressure plasma jets (JPPAs), making these devices an alternative to conventional biological decontamination treatments. The gas (or gas mixture) used and the power injected into the plasma were identified as the parameters influencing the biocidal efficacy of plasma jets. Recently, it has been reported that another factor may influence the biocidal effect of plasma jets: the nature of the target in interaction with the jet. This thesis proposes to study the influence of the nature of a target on the biocidal properties of plasma jets. Initially, the plasma jet was characterized in the absence of a target using electrical (voltage probe, current probe, oscilloscope) and optical (ICCD camera, optical spectrometer) diagnostic tools. The ICCD camera allowed the observation of the propagation of an ionization wave at very high velocities (of the order of km.s-1). Secondly, the characterization focused on the interaction of the plasma jet with a dielectric target (10-10 S.m-1) and a conductive target (6.0 107 S.m-1). The results show that when the ionization wave reaches the dielectric target, it propagates radially on the surface of the target forming a surface ionization wave. For the conductive target, a channel is established between the plasma source and the target surface, possibly followed by propagation of a secondary ionization wave from the target surface towards the plasma source outlet. Finally, the influence of the target nature on the biocidal efficacy of the plasma jet was studied. Endospores suspensions of Bacillus atrophaeus and Escherichia coli bacteria were used as biological indicator. Endospores and bacteria were inoculated on the surface of the dielectric and conductive target and exposed to the plasma jet. The results show different changes on the spores coat's and higher biocidal efficiency for the conductive target compared to the dielectric target. In summary, this thesis shows that the biocide effects of plasma jets should be evaluated under the experimental conditions corresponding to the intended applications
Mecuson, Jaspard Flore. "Oxydation des alliages d'aluminium aéronautiques par plasma électrolytique : caractérisation optique du procédé et étude des cinétiques de croissance des couches". Vandoeuvre-les-Nancy, INPL, 2005. http://docnum.univ-lorraine.fr/public/INPL/2005_MECUSON_F.pdf.
Texto completo da fontePlasma electrolytic oxidation (PEO) or micro-arc oxidation (MAO) is a process through which aluminium oxide layer may be grown onto aluminium substrate. Optical characterization of discharges is carried out using fast video imaging and optical emission spectroscopy, allowing us to distinguish between two different kinds of treatment, depending on the current waveform zand especially on the ratio of positive to negative charge quantity applied to the systeme. The characteristics (morphology, thickness, corrosion resistance) and growth kinetics of the coatings are studied. Growth mechanisms for the different sublayers are proposed for each type of treatment. Electric measurements are carried out allowing us to propose an electric modelling of the system. From these studies, criteria are established that enable coatings with the required properties (in terms of thickness and corrosion resistance) to be grown
Sarroukh, Ouassima. "Caractérisation d'une source de rayonnement extrême-ultraviolet (EUV) par décharge capillaire : mise en évidence du seuil d'ablation des parois". Orléans, 2005. http://www.theses.fr/2005ORLE2009.
Texto completo da fonteMage, Lucile. "Caractérisation d'un réacteur plasma de type résonance cyclotronique électronique à antenne longue : évaluation du réacteur pour un processus de dépôt". Toulouse 3, 1997. http://www.theses.fr/1997TOU30174.
Texto completo da fonteRodrigues, Anthony. "Caractérisation des interactions entre un plasma non-thermique et des matériaux". Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2288.
Texto completo da fonteThe interactions between the active species generated by a non thermal plasma and various material surfaces have been studied in this work. In a first part, biopolymers coming from biomass have been the subject of our investigations as they offer a great reservoir for a platform molecule, glucose, from which valuable chemicals can be generated. More specifically, the effects of a dielectric barrier discharge plasma on the structure and depolymerization of inulin, cellulose and starch were evaluated. For that purpose, the electrical and chemical characteristics of the plasma discharge were varied and their effects on the biopolymers evaluated in order to understand the reaction mechanisms. Our results showed that a plasma pre-treatment increased considerably the final monomer yield (in glucose and fructose) compared to the untreated starting material (84 and 54 % yield in glucose from plasma treated starch and cellulose, instead of 65 and 1 % for the same untreated samples). This effect could be partly explained by the depolymerization of the amorphous areas of the polymers by and acid attack within the plasma discharge.In a second part, the study focused on the removal of VOCs by coupling non-thermal plasma and inorganic materials. For this purpose, we designed and implemented an innovative apparatus. It consists of a plasma-catalyst reactor with controlled atmosphere that allows the analysis of the catalyst surface by IR spectroscopy (DRIFT). The decomposition of four VOCs (isopropanol, acetone, ethanol and toluene) adsorbed on different metallic oxides (y-Al2O3, CeO2 and TiO2) placed within the discharge area have been studied in situ using this method. The first results have enlightened the decomposition pathways of the different VOCs
Soulier, Manon. "Caractérisation et optimisation d'une source plasma pour le traitement de semences dans le domaine agroalimentaire". Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30278.
Texto completo da fonteAgri-food industry issues concern food products storage, and yields increase. Since the 1950's, intensive agriculture, chemical pesticides based, and massive irrigation are means used to confront increasing population needs. However, these practices have shown adverse effects on biodiversity and farmers health. Several studies have shown relevant results on cold plasmas fungicidal properties, action on seed germination and on chemicals degradation. A low-pressure air plasma (1 pascal) process was used and optimized for seed treatment. Seeds were placed onto a grounded grid inside an 80 liters reaction chamber exposed to two kinds of plasma. The main source was an electron cyclotron resonance microwave plasma applicator (MW-ECR). Plasma fundamental properties (emitted species, electron densities and temperatures) were measured to map the discharge. This characterization allowed to define two plasma regimes considering the injected power. High species density was generated inside the ECR area. At low-powers, species were diffused inside the plasma volume whereas by exceeding 100 W, they were carried towards the walls. The secondary source was a capacitively coupled radiofrequency plasma source (RF-CCP). The previous plasma parametric study was completed by varying the radiofrequency power. RF power greater than MW power results in higher reactive species density and a volume uniformization of plasma. These species are likely to interact with the seeds. This process efficiency in the agricultural issues of fungal contamination and seed yield optimization was established through two separate studies carried out on seeds which have been certified chemical treatment free. - Seeds represent the first step of the food production chain, constituting most of food products. Fungal contaminants have negative effects on seeds from field to consumer. They are crops spoilers, impacting production yields and food stocks. Molds, such as Fusarium spp. may produce mycotoxins during their metabolism process, responsible on health hazards (e.g. deoxynivalenol: DON or vomitoxin). Plasma discharges fungicidal properties were evaluated on bread wheat seeds (Triticum aestivum L.). Wheat seeds native fungal flora was identified before quantifying their inactivation by the plasma process. The microwave plasma process can face to the substrate matrix effect. This phenomenon was studied by comparing DON degradation onto plate glass carriers and wheat carriers. Post-treated seeds conformity for bread making was evaluated by physicochemical properties such as moisture and gluten contents. Germination yields were also evaluated in order to be consistent with a sustainable agriculture approach. [...]
Kassir, Abdel Majid. "Spectres radiatifs de plasmas d'air, N2, Ar-N2-H2 à l'équilibre et en déséquilibre thermique : étude théorique et caractérisation d'une décharge micro-ondes". Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30140.
Texto completo da fontePlasma radiation plays an important role in many applications, ranging from surface modification to aerospace sciences. In a medium constituted of atoms and molecules, such as a plasma, the spectral emission analysis of these species allows one to calculate the medium's characteristic temperatures and electron number density. This study aims to characterize a plasma through its radiation in both thermal equilibrium and weak non-equilibrium conditions. To achieve this goal, a radiative spectra simulation code was developed to study the plasma radiation as a function of the medium's characteristic temperature(s). Additionally, a microwave plasma torch experimental setup was assembled allowing the generation of a weak non-equilibrium plasma, which was then characterized by means of optical emission spectroscopy. First, the context of this study will be positioned in respect to the literature and scientific project of the team. The physical laws governing equilibrium and non-equilibrium plasma will be detailed, and optical emission spectroscopy diagnostic methods normally used to probe these plasmas will be presented. In addition, radiative spectra simulation software, such as LIFBASE, SPECAIR, and SPARTAN, will be described at the end of the first chapter; spectra calculated via these software serve as a reference and comparison basis for the code developed for this work. The second part of this study focuses on the radiative spectra simulation of equilibrium and non-equilibrium plasmas. The theory of molecular radiation will be thoroughly reviewed, as will the diatomic molecules energy levels calculation. The selection rules allowing the radiative transitions between these states and leading to the particular structure of molecular spectra will be discussed, and the spectra simulated by our code will be compared to the reference spectra for the molecular systems of an air plasma and an argon-nitrogen-hydrogen plasma. The agreements and discrepancies noted during these comparisons will be underlined, as well as the necessity to compare the calculated spectra with experimental spectra in order to judge the validity of our model and those implemented in the software used as references. The third part of this work presents the experimental study that was led at the LAPLACE laboratory on the characterization of the radiation emitted by a microwave plasma torch operating at atmospheric pressure. The theory of microwaves propagation along a waveguide and the energy coupling efficiency between the microwaves and the plasma will be briefly reviewed. The experimental setup will then be detailed, and the physical conditions for generating and sustaining the discharge will be discussed. [...]
Bruno, Paola. "Dépôt de films carbonés par des plasmas CVD Argon/Méthane : étude du procédé et caractérisation du matériau". Paris 13, 2005. http://www.theses.fr/2005PA132045.
Texto completo da fonteBenmouffok, Malyk. "Caractérisation théorique du plasma lors de l'application d'un courant impulsionnel : application à l'allumage des moteurs". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30159/document.
Texto completo da fonteThe economic/ecological context and the CO2 regulation by the "euro" standards lead the automotive industry to improve the spark ignited engines. A way of improvement is the admission of a lean mixture or of a diluted mixture by recirculation of exhaust gases in the combustion chamber. The main difficulty in these conditions is to start the combustion. To overcome this problem, the ignition systems are studied and more particularly the spark. This discharge leads to the apparition of plasma and the understanding of the energy transfer mechanisms between this plasma and the reactive mixture is essential. This work is focus on the modeling of a spark during its electrical arc phase in order to predict the hydrodynamic behavior of the arc and the shock wave propagation. The 2D and 3D transient models are based on ANSYS Fluent coupled with user defined functions developed by the AEPPT team. First, the simulation is based on data from literature review in order to understand the general behavior of the discharge. Then, the model uses experimental configuration developed during the ANR FAMAC project. Simulations are mainly realized in air using simplified configurations (pin-to-pin configurations) in order to valid the model. Then, a study is done in a vessel configuration using real sparkplug geometry. This model allows us to show the role of each initial parameter as well as their impact on the plasma flow. The magnetic field influence is also determined for a nanosecond arc discharge. Finally, the model is used in order to determine the role of a cross flow on a discharge generated by a conventional Audi ignition coil. All these results could be the beginning of an energetic study on ignition systems and could lead to a discussion on the understanding of initiation of the combustion process
Laurent, Christopher. "Caractérisation expérimentale et optimisation de procédés plasma pour la décontamination de l'AMC (Contamination Moléculaire Aéroportée)". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30285.
Texto completo da fonteUn problème majeur en microélectronique est la contamination moléculaire aéroportée qui dégrade les substrats et les masques diminuant le rendement de production des composants. L'utilisation de boîtes de transport en polymères pour le stockage des substrats favorise la contamination moléculaire croisée entre les deux éléments. Il est alors primordial d'avoir un procédé de décontamination des boîtes efficace et rapide. Dans le cadre de cette thèse, plusieurs solutions de décontamination par plasmas ont été étudiées. Les plasmas étaient générés selon quatre couplages énergétiques en utilisant des excitations radiofréquence (13,56 MHz) et micro-onde (2,45 GHz). Ils étaient caractérisés avec une sonde de Langmuir et un spectromètre optique sous différentes conditions expérimentales. Enfin, un protocole de contamination au fluorure d'hydrogène a été développé pour évaluer et comparer l'efficacité de décontamination des procédés plasma à ceux utilisés actuellement en microélectronique
Bouts, Nicolas. "Synthèse, caractérisation, et propriétés de couches minces nanocomposites nickel/carbone et cuivre/carbone déposées par procédés plasmas". Nantes, 2014. https://archive.bu.univ-nantes.fr/pollux/show/show?id=eb3adf1f-744e-4804-b413-fa80c472e4d1.
Texto completo da fonteNanocomposite metal/carbon thin films, consisting of metal rich nanoparticles embedded in an amorphous carbon matrix, present specific and tunable physicochemical properties, depending on the chemical composition of thin films. The morphology and the microstructure of these materials have been explored on a wide range of chemical composition using electronic microscopy, EDX, XPS, XRD, and Raman spectroscopy. The influence of the metal nature on the nanocomposite metal/carbon thin film microstructure and electrical properties was studied for two metals : nickel and copper. The thin films were deposited using two different plasma processes : a first one combining the magnetron sputtering of the metal target (nickel or copper) and the plasma enhanced chemical vapour deposition in an argon/methane gas mixture, and the other one consisting in the cosputtering of metal and graphite targets. The study of the electrical properties highlighted an electrical percolation phenomenon. The catalytic properties for the carbon nanotubes growth and the piezoresistive behavior of nickel based thin films were studies. In addition, an original method based on the selective etching of copper nanoparticles contained in nc-Cu/C thin films was developed, leading to the synthesis of nanoporous carbon electrodes
Begou, Thomas. "Conception, réalisation et caractérisation de composants photoniques intégrés à base de matériaux diélectriques élaborés par procédés plasmas". Nantes, 2008. http://www.theses.fr/2008NANT2109.
Texto completo da fonteThis work is devoted to the design, fabrication and characterization of integrated photonic devices based on dielectric materials grown at low temperature, on silicon substrate, by plasma enhanced chemical vapor deposition (PECVD). The functional property mainly aimed is the waveguiding in monomode configuration. Waveguides have been designed and simulated by the way of analytical approaches derived from the Maxwell electromagnetic wave formalism. This step leads to the core and cladding sizing for multi or monomode devices. A first class of Si/SiO2/SiOxCyHz waveguides is developed from organosilicon materials deposited in oxygen/hexamethylidisiloxane plasma. Optical characterization of these thin films is performed by spectroscopic ellipsometry. Optical losses corresponding to a monomode transverse electrical (TE) or transverse magnetical (TM) propagation are measured through a micronic injection bench equipped a 670 nm laser. New materials, close to titanium dioxide, well suited to the development of highly integrated photonics (high value of the refractive index) have been synthesized from titanium isopropoxide (TIPT) used with a carrier gas and diluted in oxygen. Potentially interesting properties have been obtained when the titanium precursor is highly diluted. A significant improvement of the optical properties (nTiO2=2. 36 à 633 nm) and a densification of the layers are observed when the samples are elaborated with a low radiofrequency polarization at the level of the substrate holder
Magistrini, Catherine. "Caractérisation in-situ par ESCA de surfaces de polyethylène téréphtalate (PET) traitées dans la post-décharge d'un plasma oxygène de type micro-onde et caractérisation du vieillissement des surfaces après traitement". Lyon 1, 1992. http://www.theses.fr/1992LYO10117.
Texto completo da fonteGarcia, barros Maxime. "Développement et caractérisation de procédés de gravure des espaceurs Si3N4 et SiCO pour la technologie FDSOI 14nm". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT028/document.
Texto completo da fontePlasma etching for sub 14nm technological nodes require a precise control of the etching of thin nanometer-sized layers, while controlling the lateral dimension of nanometer-scale structures. For spacers etching, the 3 mains challenges appear. The first is to obtain high selectivity of the spacer’s materials with respect to silicon or silicon germanium. The use of a chemistry with a stop layer on silicon is prohibited because of the dimensional constraints. The order of the layers to be etched is of 5nm to 6nm and the thickness of the reactive layer is of 3nm. The second challenge is the control of the damaged induced by the plasma on the silicon layer and their effects on the electrical performances. Moreover, an epitaxial growth is used differentiate the NMOS and PMOS zones. This technique is very sensitive to the surface state condition and the contamination. The silicon layer should be as intact as possible. The last challenge is the control of the hard mask consumption or the spacer height. It can lead to an epitaxial growth preventing the transistors realization.Preliminary studies have shown that the use of a bias pulsed plasma coupled with the adding of tetrachlorosilane SiCl4 allows to reduce the consumption and the damaged induced of the silicon layer. We will study the new process window obtained, as well as the impact of this new process on the electrical performances of the integrated circuits.A second part of the study will focus on a new approach for the spacers etching. It consists initially in modifying the layer that we want to remove by a light ion plasma in a conventional etching reactor. The modified layer is then remove selectively to the unmodified layer by a hydrofluoric acid. We performed FTIR, XPS et SIMS analyses to characterize the modified materials and to understand the etching mechanisms.Finally, we will evaluate the compatibility of these processes with the etching of a low-k material: SiCO