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Peterschmitt, Simon. "Development of a Stable and Efficient Electron Cyclotron Resonance Thruster with Magnetic Nozzle." Thesis, Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAX053.
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Les propulseurs plasmas sont le sujet d’un intérêt grandissant pour équiper de petits satellites. Des miniaturisations de technologies matures ont été proposées ainsi que des concepts innovants, tels le propulseur à résonance cyclotron électronique muni d’une tuyère magnétique (ECRT). Ce propulseur pourrait réaliser une rupture technologique car il est sans grilles, sans neutraliseur et n’a besoin que d’un seul générateur. Le présent travail consiste à développer un ECRT accompagné du dispositif expérimental nécessaire, capable de démontrer avec précision une grande efficacité durant un fonctionnement prolongé en régime permanent. Les précédentes études sur l’ECRT étaient limitées par un manque de précision sur des mesures clés, en raison du dispositif et des technologies nécessaires à l’étude de ce propulseur. La procédure et le dispositif expérimentaux sont donc largement améliorés pour augmenter la précision des mesures. Toutefois, des spécificités dues à la tuyère magnétique compliquent l’interprétation des mesures de densité de courant d’ion. Notre analyse s’appuie donc principalement sur des mesures de poussées obtenues avec une balance. Par ailleurs, nous montrons que les performances du propulseur augmentent significativement quand on diminue la pression dans le caisson de test jusqu’à 10-7 mbar Xénon. En outre, d’éventuels effets de caisson sont explorés en testant le propulseur à l’ONERA (Palaiseau, France) et à JLU (Giessen, Allemagne). En prenant en considération ces difficultés expérimentales, nous étudions l’efficacité du propulseur en fonction de la géométrie de l’injection de gaz neutre, de la topologie du champ magnétique, et des conditions aux limites de la tuyère magnétique. De plus, nous abordons la question de l’érosion du propulseur, de deux manières : premièrement par une modification des matériaux et deuxièmement par une modification de la structure de couplage (coaxiale, ou guide d’onde circulaire). Le couplage de type guide d’onde produit des ions à des énergies trop faibles pour les exigences de la propulsion spatiale ; en revanche, une structure de couplage coaxiale usinée en graphite semble diminuer substantiellement l’érosion sans compromettre l’efficacité. Ces résultats permettent de concevoir et de tester un propulseur ~ 30 W et un propulseur ~ 200 W dont les performances sont répétables dans le temps. L’efficacité et la durée de vie sont considérablement augmentées : une première campagne de test indique une efficacité allant jusqu’à ~ 50% et une durée de vie estimée de un à quelques milliers d’heures. Pour éclairer les résultats expérimentaux, nous proposons une nouvelle démarche de modélisation, fondée sur l’étude des trajectoires des électrons et sur une approche du chauffage électronique au moyen d’une équation de Fokker-Planck. Cette démarche débouche sur le calcul de la fonction de distribution en énergie des électrons dans le propulseur ; celle-ci détermine le courant d’ions extrait et l’énergie des ionsPlasma thrusters are the subject of growing interest as a means for small satellite propulsion. Miniaturizations of mature technologies as well as innovative concepts have been proposed such as the electron-cyclotron resonance thruster with magnetic nozzle (ECRT). This thruster appears as a potentially disruptive technology because it is gridless, neutralizerless, and only requires one power supply. This work consists in the development of an ECRT with magnetic nozzle and its accompanying experimental test bench, able to accurately demonstrate high thruster efficiency during prolonged steady state operation. Previous studies on the ECRT were limited by a significant lack of accuracy on key measurements, due to the specific setup and technology needed for this thruster. The experimental procedure and the setup are thus heavily upgraded to improve the accuracy of experimental data. However, peculiarities of the magnetic nozzle complicate the interpretation of the ion current density measurements, thus our analysis of performance is mainly based on thrust balance measurements. Besides, thruster performance is shown to significantly increase when decreasing vacuum tank pressure down to 10-7 mbar Xenon, and facility effects are investigated by testing the thruster both at ONERA (France) and at JLU (Germany). Well aware of these experimental difficulties, we study the efficiency of the thruster as a function of neutral gas injection, magnetic field topology, and boundary conditions of the magnetic nozzle. In addition, we address erosion issues in two ways: first by a change of materials, and second by a change of coupling structure (coaxial, or circular waveguide). Waveguide coupling yields insufficient ion energies for space propulsion requirements but manufacturing the coaxial coupling structure with graphite appears to substantially mitigate erosion. These results enable to design and test a ~ 30 W and a ~ 200 W thruster consistently yielding state-of-the-art efficiencies as compared to other thruster types while having sufficient estimated lifetime. In order to shed light on the experimental outcomes, a new modelling approach is developed based on the study of electron trajectories and a Fokker-Planck heating model calculating the formation of the electron energy distribution function in the thruster
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Rashid, Riyaz. "Low temperature electron cyclotron resonance plasma deposition of silicon dioxide." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620439.
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Majeri, Nassim. "Production de rayons X par plasma ECR." Thesis, Orléans, 2009. http://www.theses.fr/2009ORLE2077/document.
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Durant cette thèse nous avons caractérisé et amélioré une nouvelle source de rayons X avec unplasma ECR (résonance cyclotronique électronique) permettant de générer des électronsénergétiques de 10 à 120 keV, qui vont ensuite produire le rayonnement X par freinage(bremsstrahlung). Les améliorations de l’installation ont permis d’obtenir une source stable, pouvantfonctionner une journée entière de travail (huit heures) sans arrêt. Dans la première partie de l’étudeexpérimentale on a étudié et déterminé les paramètres optimaux de la source : la pression, lapuissance micro-onde et la configuration magnétique sur le rayonnement X du plasma. Nous avonségalement confirmé la localisation des électrons énergétiques sur un anneau due à la configurationmagnétique. L’intensité trop faible et la zone d’émission non ponctuelle du rayonnement plasma, nepermettant pas l’utilisation de la source à plasma, une cible a été insérée sur la trajectoire desélectrons énergétique pour résoudre ces deux problèmes.Le principal avantage de notre source par rapport aux tubes X, est l’absence de haute tension (20 à400 kV). Pour chauffer les électrons, nous utilisons une onde de 2,45 GHz, qui est la fréquenceindustrielle autorisée dans les fours à micro-ondes, délivrée par un magnétron. Les éléments simplesqui composent notre source donne un coût plus faible qu’un système classique de tubes X, dûprincipalement au prix élevé du générateur HT pour les tubes X. De plus, nous n’avons pas besoind’un vide très poussé car, à la différence des tubes X, la source ECRX fonctionne avec une pressionrésiduelle de 0,1mPa. Et enfin notre source est compacte ce qui la rend facilement transportable. Lesapplications de cette source sont nombreuses comme la radiologie, la stérilisation et le contrôle nondestructif industrielDuring this thesis we have characterised and developed a new X-ray source with an ECR plasma(electron cyclotron resonance) generating energetic electrons from 10 to 120 keV, which will emit adeceleration radiation (the Bremsstrahlung). The improvements of the installation permit to obtain astable source, which can work during one day (eight hours) without stop. In first part of theexperimental study we have studied and determined the optimal parameters of the source: pressure,micro-wave power and the magnetic configuration on the X radiation of the plasma. We also confirmedthe localisation of the energetic electron on a ring due to the magnetic configuration. The low intensityand the non punctual emission size of the X radiation, don’t allow the use of the source, so a target isinserted in the trajectory of the energetic electron to solve these two weaknesses.The main advantage of our source compared with X-ray tubes, is the absence of high voltage (20 to400 kV). For heating the electron, we use a 2,45 GHz wave, that is the industrial frequency authorizedfor the micro-wave oven, delivered by the magnetron. The simple elements that compose our sourceare less expensive than the classical X-ray tubes, due to mainly the high cost of the X-ray generator.Moreover, we don’t need a high vacuum, mandatory for the X-ray tubes; an ECRX operates at aresidual pressure of 0,1 mPa. And finally, we have a compact source. Applications will be various frommedical, like radiological, sterilization, to non-destructive industrial control
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Kroely, Laurent. "Process and material challenges in the high rate deposition of microcrystalline silicon thin films and solar cells by Matrix Distributed Electron Cyclotron Resonance plasma." Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00550241.
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High deposition rates on large areas are industrial needs for mass production of microcrystalline silicon (μc-Si:H) solar cells. This doctoral work aims at exploring the usefulness of Matrix Distributed Electron Cyclotron Resonance (MDECR) plasmas to process the intrinsic layer of μc-Si:H p-i-n solar cells at high rates. With the high dissociation of silane achieved in MDECR plasmas, deposition rates as high as 6nm/s and 2.8nm/s have been demonstrated in our lab for amorphous and microcrystalline silicon respectively, without hydrogen dilution. This technique is also promising because it can be easily scaled up on large areas, just by extending the matrix of elementary microwave applicators. This subject was a unique opportunity to cover the whole chain of this field of research : A new MDECR reactor has been specially designed and assembled during this project. Its maintenance and its improvement have been important technical challenges : for example, the addition of a load-lock enabled us to lower the oxygen concentration in our films by a factor of 10. The impact of the deposition parameters (e.g. the ion energy, the substrate temperature, different gas mixtures, the microwave power) has been explored in extensive parametric studies in order to optimize the material quality. Great efforts have been invested in the characterization of the films. Our strategy has been to develop a wide range of diagnostics (ellipsometry, Raman spectroscopy, SIMS, FTIR, XRD, electrical characterizations etc.). Finally, p-i-n cells have been processed with the selected interesting materials. The successive successful improvements in the material quality (e.g. diffusion lengths of holes parallel to the substrate as high as 250 nm) did unfortunately not result in high efficiency solar cells. Their limited performance is in particular due to a very poor response in the red part of the spectrum resulting in low current densities. Consequently, the potential sources of limitation of the reactor, the material and the device have been studied : e.g. the presence of “cracks” prone to post-oxidation in the highly crystallized materials and the risk of deterioration of the ZnO substrate or of the p-doped layer by a too high process temperature or by hydrogen diffusing from the plasma.
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GAUDIN, CHRISTELLE. "Emission de rayons x dans un plasma ecr (electron cyclotron resonance) en vue d'applications medicales." Toulouse 3, 1999. http://www.theses.fr/1999TOU30089.
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Nous avons developpe et etudie une nouvelle source de rayons x (dans la gamme 10-100 kev) en utilisant un plasma a la resonance cyclotronique des electrons. Le dispositif experimental a ete concu et ameliore afin d'obtenir une source a la fois compacte, stable et plus intense. Pour etudier le transfert d'energie de l'onde incidente aux electrons, nous avons d'abord calcule numeriquement la trajectoire des particules dans un champ magnetique homogene et obtenu la dependance de l'energie maximale de l'electron en fonction du champ electrique de l'onde. De plus, nous avons considere un processus de conversion de mode de l'onde electromagnetique incidente en onde de bernstein. Plusieurs etudes experimentales ont ete realisees sur le plasma de la source. Un anneau d'electrons energetiques, dans le plan median du miroir magnetique, a ete mis en evidence avec une camera stenope. Les populations ionique et atomique ont ete etudiees par spectroscopie dans le visible ; la densite et la temperature des zones externes du plasma ont ete estimees par sonde de langmuir. Les electrons energetiques, qui nous interessent particulierement pour produire des rayons x medicaux, ont ete caracterises par un diagnostic fonde sur l'analyse des spectres de bremsstrahlung. Nous avons montre l'influence des parametres de fonctionnement de la source (pression, puissance micro-onde, configuration magnetique) sur l'energie et sur l'intensite du rayonnement x produit par le plasma. Ensuite, pour augmenter l'intensite du rayonnement x, une cible a ete interposee de maniere judicieuse dans l'anneau d'electrons energetiques. Les resultats (dosimetrie, analyse des spectres en energie, etude de la taille du foyer) ont ete discutes du point de vue des applications medicales en radiologie et mammographie. Nous avons realise plusieurs types de radiographie.
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Sakildien, Muneer. "Plasma characterisation of an electron cyclotron resonance ion source by means of x-ray spectroscopy." Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/5212.
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>Magister Scientiae - MScThe ultimate aim of any multiply-charged ion source, like the Electron Cyclotron Resonance Ion Source, ECRIS, is the production of multiply-charged ions, in sufficiently large quantities. These multiplycharged ions, in the case of the ECRIS, are created by a step-by-step ionisation process, whereby neutral atoms are ionised by energetic electrons. The goal of this thesis was to gain an understanding of the relative importance of various ECRIS parameters on the production of these energetic electrons. This was done by measuring the bremsstrahlung continuum emitted by the mirror confined plasma of an ECR ion source. The focus of our study was to investigate the influence of neutral pressure, incident microwave power and magnetic field configuration on spectral temperature and electron density of the warm electron population of the ECRIS plasma. The thesis begins by familiarising the reader with various aspects of plasma physics as it relates to the measurements. The measurements were done with a high-purity germanium detector and processed with the DGF Pixie-4 module. Analyses of the measured spectra were done with subroutines written in Root. From the measured result, it was concluded that by increasing the incident microwave power from 50 W to 300 W, the spectral temperature increases by 14.01% for helium plasma and 7.88% for argon plasma. Evidence of saturation of spectral temperature and electron density with increasing microwave power was also noticed, as reported by other groups investigating plasma bremsstrahlung. The increase of spectral temperature with neutral pressure was found to be considerable, increasing by 20.23% as the neutral pressure in the plasma chamber of the ECRIS was decreased. This increase in spectral temperature was accompanied by a 40.33% decrease in electron density, which led us to conclude that the increase in spectral temperature was most likely due to an increase in the mean free path of the electrons. The influence of the magnetic field configuration on both spectral temperature and electron density was also investigated. During this investigation, one of the solenoid coil currents was increased, whilst keeping the other constant. This amounts to moving the plasma volume around axially in the plasma chamber of the ECRIS. This was found to significantly enhance the spectral temperature and this effect was attributed to more efficient heating of the electrons near the resonance zone. The electron density on the other hand was found to remain relatively constant, if one excludes the electron density as a result of one particularly setting of the solenoid coils. The decrease of electron density as a result of this particular setting of the solenoid coils enhanced the electron losses through the magnetic bottle. This is evidenced by the increase in photon counts as measured by our detector. The influence of neutral pressure, incident microwave power and magnetic field configuration on the extracted ion beam intensities was also investigated. This investigation led us to conclude that the mean charge state extracted increases with spectral temperature. This result was in agreement with those measured by other groups.
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Jaju, Vishwas. "Device quality low temperature gate oxide growth using electron cyclotron resonance plasma oxidation of silicon." [Ames, Iowa : Iowa State University], 2008.
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Zaïm-Bilheux, Hassina. "Design and initial comparative evaluation studies of conventional "surface" and new concept "volume"-type, all permanent magnet electron cyclotron resonance (ECR) ion sources." Versailles-St Quentin en Yvelines, 2003. http://www.theses.fr/2003VERS0008.
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Les sources d'ions à "Résonance cyclotronique d'électrons"(RCE)constituent, à l'heure actuelle, le meilleur choix parmi les sources existantes en ce qui concerne la production des faisceaux continus d'ions positifs hautement chargés. Ces sources produisent des rapports charge-sur-masse très élevés (jusqu'à 0,35 pour l'uranium) et des intensités par charge du [microampère] au mA, ce qui fait leur succès auprès des accélérateurs d'ions lourds à haute énergie. Depuis la naissance du concept dans les années 1970, leurs performances ont régulièrement progressé (amélioration du confinement du plasma, utilisation d'ondes électromagnétiques à fréquence élevée, amélioration de la qualité du vide, addition d'électrons "froids", disque polarisé, effet Malter et utilisation d'un gaz plus léger). Récemment, il a été suggéré que les performances des sources RCE pouvaient être notablement améliorées en augmentant le volume de résonance soit en étendant la zone d'induction résonante soit en élargissant la bande HF de l'onde. Une source RCE à aimants permanents fonctionnant à la fréquence 6 GHz, avec la possibilité de créer un large volume de plasma résonant, a été dessinée, construite et testée au Laboratoire National d'Oak Ridge (ORNL), en avant-première. Le champ magnétique est flexible, de sorte qu'il peut être configuré en champ plat("volume") ou en champ conventionnel à B minimum ("surface") afin de pouvoir comparer directement les performances des deux types de sources dans des conditions expérimentales équivalentes. Les résultats expérimentaux préliminaires montrent que la source à champ plat surpasse celle en champ conventionnel, en terme de distribution de charge et d'intensitéECR ion sources are clearly the best choice of existing sources for the generation of CW beams of highly charged ions, and therefore, they are at a premium for high-energy accelerator-based applications. The technology of the source has slowly but steadily advanced over the past several years (improvement in plasma confinement; use of very high frequency microwave radiation; improvement in vacuum quality; supplementing their plasma discharges with cold electrons; biased disks; and gas mixing effect). Recently, it has been suggested that their performances can be significantly further enhanced by incresing the physical sizes of their ECR zones in relation to the sizes of their plasma volumes (spatial and frequency domain methods). A 6 GHz, all-permanent magnet ECR ion source with à large resonant plasma volume has been designed, constructed and initially tested at the Oak Ridge National Laboratory. The conventional minimum-B("surface") resonance conditions so that direct comparaisons of the performances of the two source types can be made under identical operating conditions. According to initial test results, the flat-B source performs better than its conventionnal-B conterpart, in terms of charge-state distribution and intensity within a particular charge-state. This is attributable to the very large ECR zones present in the source and their locations with respect to the launch direction of the RF power
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パスクワ, ロメーロ カミール フェイス, and Camille Faith Pascua Romero. "Development of an electron cyclotron resonance plasma source with an internal antenna for carbon film deposition." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13071665/?lang=0, 2018. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13071665/?lang=0.
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An electron cyclotron resonance (ECR) plasma source which couples microwave to the plasma using an internal antenna was developed. The use of internal antenna provides a "windowless" power coupling method that can eliminate the issues of contamination which require frequent source maintenance. Antenna structure, magnetic configuration and plasma parameters were modified for carbon film deposition by chemical sputtering. The ECR source generated low-plasma-potential (10 V), high-plasma-density (10^16 m^-3) discharges at low gas pressures (10^-1 Pa) and low input power (100 W). The antenna realized stable operation for more than 5 h and can be utilized for carbon film deposition.博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
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Vialis, Théo. "Développement d’un propulseur plasma à résonance cyclotron électronique pour les satellites." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS344.
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Ce travail de thèse porte sur le propulseur électrique de type ECR (résonance cyclotron électronique) développé à l’ONERA. Ce propulseur quasi-neutre, qui utilise une tuyère magnétique pour accélérer le plasma, produit une poussée d’environ 1 mN pour des puissances inférieures à 50 W. Dans cette thèse, on se propose de développer et d’optimiser les diagnostics de mesure des performances du propulseur ECR, d’identifier les paramètres expérimentaux pouvant influencer les performances et d’améliorer la compréhension des phénomènes physiques ayant lieu dans le propulseur. Ces objectifs ont pour finalité l’amélioration des performances. Pour répondre à ces objectifs, plusieurs prototypes à aimant permanent ont été développés, et une balance permettant de mesurer directement la poussée a été modifiée pour caractériser le propulseur. Différentes études paramétriques ont été conduites, qui ont montré que les performances dépendaient directement du rapport entre le débit de xénon et la puissance micro-onde injectée. Il a également été observé que la longueur du conducteur externe de la source plasma et la pression ambiante ont une influence significative sur le niveau de performance. Après optimisation de la géométrie, un rendement total supérieur à 12 % a été obtenu. Des mesures séparées de la poussée thermique et magnétique ont permis de montrer que la composante magnétique était la contribution principale de la poussée dans tous les cas testés. Un code PIC 1D-3V a été utilisé pour simuler le comportement du propulseur, et a permis de reproduire le chauffage des électrons par résonance et l’accélération des espèces chargées dans la tuyère. L’ensemble des travaux ont mis en avant le rôle des composantes parallèle et perpendiculaire de la pression électroniqueElectric propulsion is an alternative technology to the chemical propulsion that enables reducing propellant consumption for satellites. ONERA is developing an electric ECR thruster with a thrust around 1 mN and an electric power less than 50 W. The thruster creates a plasma by electron cyclotron resonance and accelerates it through a magnetic nozzle. In this thesis work, an optimization of the measurement diagnostics is done. The work also aims at identifying the important parameters for the performances of the thruster and at improving the understanding of underlying physics, in order to increase the thruster efficiency. Several prototypes have been developed and a thrust stand that can directly measure the thrust has been modified. Some parametric studies have been led and have shown that the thruster performance strongly depends on xenon mass-flow rate to microwave power ratio. It has also shown that the external conductor of the plasma source and the ambient pressure have a significant influence on the performances. Following a geometric optimization, a maximum total efficiency of more than 12% has been obtained. Separate measurements of the magnetic and thermal thrust have shown that the magnetic thrust is the main component of the total thrust. A 1D-3V PIC code has been used to simulate the behavior of the thruster. The analysis of the results has shown that the ECR heating and particle acceleration in the magnetic nozzle could be properly computed. The role of the parallel and perpendicular component of electron pressure has been evidenced by this work
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Summers, Scott. "Production of polycrystalline silicon thin films on foreign substrates using electron cyclotron resonance plasma enhanced chemical vapour deposition." Thesis, London South Bank University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288177.
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The wide spread adoption of solar photovoltaic cells is impeded by a number of factors, the primary one of which is the cost. The technology behind the most used cells today is based on bulk single crystalline silicon wafers. These wafers subsequently undergo numerous processesto produce a finished module capableo f delivering usable direct current electricity. Even with all these processes, the single biggest contributor to production costs is the starting wafer - estimated to account for some 50% of manufacturing costs. Removing these costs by replacing the wafer is the leading topic in solar cell research today. Glass is the most convenient starting point for replacing silicon wafers - it is benign, both from an environmental and manufacturing viewpoint, and is considerably less expensive than silicon wafers for a given quantity. As an amorphous material, glass is well suited to acting as a substrate for amorphous silicon layers used in low cost cells. Amorphous silicon cells suffer from stability issues and can degrade in performance substantially over the operational lifetime of the solar cell. To overcomethese problems the amorphous silicon can be replaced with crystalline silicon material. Generally, the deposition of suitable crystalline material occurs at a temperature in excess of the softening point of glass. So however useful glass is as a substrate it is incompatible with simple, low temperature formation of crystalline silicon using most techniques. There are two outstanding issues relating to the manufacture of thin film silicon solar cells that have been researched for this thesis. One is the deposition of silicon layers at a growth rate high enough to allow for a reasonable throughput of material. The second is the production of material suited to the task i.e. structurally and electrically. In this thesis the direct deposition of high quality polycrystalline silicon( near-single orientation with suitable electrical characteristics) using electron cyclotron resonance plasma enhanced chemical vapour deposition(E CR PECVD) onto glass is demonstrated. A new visualisation of the magnetic field used in E R PECVD has given an insight into the optimisation of the deposition process using this technique. By adjusting the magnetic field appropriately, an increase in growth rate for deposition of polycrystalline silicon of 2- 25 times that reported in the literature was found. In addition to the characterisation of the deposited material, the process parameters have been fully investigated by analysing the process plasma characteristics using a Langmuir probe. An amorphous incubation layer 1 micron thick is seen when the polycrystalline material is deposited directly on glass, however this layer can be substantially reduced by depositing on a thin layer of silicon (on the glass) which has been crystallised by excimer laser irradiation. This indicatesa possible direction in combining these two approaches in future manufacturing processes for the growth of low-temperature polycrystalline silicon layers on glass to form photovoltaic devices.
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Miyata, Koji, Hiroyoshi Arai, Masaru Hori, and Toshio Goto. "Absolute density measurement of cyanogen fluoride in CHF_3/N_2 electron cyclotron resonance plasma using infrared diode laser absorption spectroscopy." American Institute of Physics, 1997. http://hdl.handle.net/2237/7027.
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Gaudart, Georges. "Etude de la population électronique énergétique d'une source d'ions à résonance cyclotron des électrons." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10197.
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Le but de cette these est d'etudier la population electronique energetique d'une source d'ions a resonance cyclotron des electrons. Le diagnostic choisi pour l'etude de ces electrons energetiques est la detection du rayonnement de freinage. L'experience a tout d'abord ete realisee et montee sur la source quadrumafios qui a ete concue pour des etudes de physique et qui permet l'implantation de nombreux diagnostics. Les distributions trouvees pour ces electrons energetiques sont non maxwelliennes et l'energie moyenne des particules peut atteindre plusieurs centaines de kev. Par ailleurs la mesure du rayonnement de freinage en plusieurs points du plasma a permis de montrer que la fonction de distribution etait essentiellement dependante de la dynamique perpendiculaire des electrons par rapport au champ magnetique. Il est vrai que l'onde haute frequence (10 ghz et 18 ghz dans le cadre de cette etude) communique aux electrons une energie essentiellement perpendiculaire par rapport au champ magnetique. En parallele a ce travail experimental, un code de calcul de la fonction de distribution electronique a ete developpe. Dans un cadre unidimensionnel (vitesse perpendiculaire uniquement), non relativiste, ce code integre un certain nombre d'ingredients physiques pour modeliser la fonction de distribution electronique (chauffage des electrons par l'onde hf, pertes des electrons dans le cone de pertes, source d'electrons par ionisation, terme de relaxation entre electrons)
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Shahedipour, Fatemeh. "Diamond synthesis on steel substrates using magneto-active plasma chemical vapor deposition with novel in situ FTIR spectroscopy characterization /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901278.
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Kim, Danny. "Dry passivation studies of GaAs(110) surfaces by Gallium Oxide thin films deposited by electron cyclotron resonance plasma reactive molecular beam epitaxy for optoelectronic device applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63140.pdf.
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Adrouche, Nacer. "Diagnostic du plasma de la source d'ions ECR SIMPA par spectroscopie X : collisions d'ions néon hydrogenoïdes avec des agrégats d'argon." Paris 6, 2006. https://tel.archives-ouvertes.fr/tel-00105774.
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La première partie est consacrée à la caractérisation de la source d’ions ECR SIMPA. En analysant les spectres Bremsstrahlung du plasma, nous avons déterminé la température et la densité électronique et la densité ionique. Nous avons également enregistré des spectres haute résolution des plasmas d’argon et de krypton pour déterminer la densité ionique des états de charges. La seconde partie est consacrée à la collision des ions de Ne9+ avec des agrégats d’argon. Nous avons effectué une application théorique pour une collision d’un ion Ne9+ avec un agrégat d’argon, pour connaître les niveaux énergétiques peuplés lors de la capture électronique et suivre l’évolution du nombre d’électrons dans les couches du projectile. Enfin, nous avons présenté les résultats de collisions entre un faisceau d’ion Ne9+ et des agrégats d’argon, mettant en évidence une forte agrégation des cibles et une multi-capture faite par les ions.
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Regnard, Guillaume. "Développement d'une nouvelle génération de plasmas micro-onde à conditions opératoires étendues." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENY060/document.
Full textAbstract:
Ce travail de thèse a été réalisé au Laboratoire de Physique Subatomique et de Cosmologie (IN2P3) deGrenoble en collaboration avec le groupe Thalès avec pour objectif le développement d’une nouvellegénération de plasmas micro-onde fonctionnant sur une gamme de pression étendue allant de 0,5 mtorrà 10 torr en argon. La travail présenté porte donc en : i) la conception des applicateurs basés sur destronçons de longueur λ/4 faisant office de transformateurs d’impédance entre le générateur et leplasma d’impédance supposée donnée (adaptation d’impédance approchée); ii) la déterminationexpérimentale de l’impédance réelle du plasma (partie réelle et partie imaginaire) par mesure dumodule et de la phase du coefficient de réflexion dans des conditions opératoires définies; iii) leredimensionnement des différents tronçons de l’applicateur par simulation numérique en tenantcompte de l’impédance réelle du plasma; iv) la validation expérimentale de l’adaptation d’impédanceentre générateur et plasma. Les résultats obtenus démontrent clairement qu’il est possible, à fréquencedonnée (2.45 GHz dans le cas présent), de concevoir et de dimensionner une source plasma avec uneefficacité énergétique supérieure à 80% pour des fenêtres en pression (d’au moins une décade)équivalentes à des fenêtres opératoires en termes de paramètres plasma. Ces sources individuelles àabsorption localisée de micro-ondes peuvent être utilisées en nombre pour la réalisation des plasmasuniformes de grandes dimensions par leur distribution selon des réseaux à deux dimensions (sourcesplanes) ou à trois dimensions (volumes de plasma), et donc pour des applications industrielles auxtraitements de surfaceThis work was done in the « Laboratoire de Physique Subatomique et de Cosmologie (IN2P3,Grenoble) » during a collaboration with Thales. The aim of the project was the development of a newgeneration of microwave plasma with extended operating conditions in the pressure range 0.5 mtorr to10 torr in argon. The presented work consists of: i) designing applicators based on sections of λ/4length serving as impedance transformers between the generator and the plasma with impedance ofgiven assumed value (approximate impedance adaptation); ii) experimentally determine the realplasma impedance (the real part and the imaginary part) for given operating conditions from themeasurement of modulus and phase of the reflection coefficient S11; iii) resize the different sections ofthe applicator by digital simulation taking the real plasma impedance into account; iv) finally, verifyexperimentally that the impedance adaptation between the generator and the plasma is correct. Theobtained results clearly demonstrate that it is possible, at a given frequency (here 2.45 GHz), to designand size a plasma source with an efficiency greater than 80 % for a window in pressure (at least onedecade) equivalent to an operating window in terms of plasma parameters. These individual sourceswith localized absorption of microwaves can be used in numbers to achieve uniform plasmas via theirdistribution over two-dimensional (planar sources) or tri-dimensional (volume plasma) networks, andthus for industrial surface treatments
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Mitrou, Maria. "Etude des mécanismes de production d'ions négatifs d'hydrogène (H-) et de deutérium (D-) en plasmas micro-ondes continu et pulsé par des diagnostics complémentaires." Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALI035.
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Les sources d'ions négatifs d'hydrogène font partie intégrante des accélérateurs modernes et des systèmes d'injection de neutres (NBI) dans les futurs réacteurs de fusion. Cette dernière application nécessite le développement de sources très puissantes et l'extension de leur fonctionnement au deutérium. De nombreuses activités de recherche sur des expériences à l'échelle du laboratoire ont été dédiées à ce sujet dans le but de comprendre les processus fondamentaux qui régissent la production d'ions négatifs. Les connaissances acquises ont essentiellement contribué au développement des sources prototypes qui seront employées dans le système NBI d’ITER, le plus grand réacteur Tokamak en construction destiné à démontrer le potentiel d’exploitation de la fusion en tant que source d’énergie alternative. Toutefois, d’importantes contraintes technologiques liées à la physique fondamentale gouvernant le fonctionnement de ces sources doivent être surmontées pour qu’elles puissent délivrer des faisceaux de neutres dont les caractéristiques satisfassent les exigences initiales.Dans cette thèse, la production d’ions négatifs d’hydrogène (H-) et de deutérium (D-) est étudiée dans des plasmas entretenus à la résonance cyclotron électronique. En particulier, des études expérimentales ont été réalisées dans deux réacteurs présentant des caractéristiques similaires, “Prometheus I” et “SCHEME-II+”, en utilisant des diagnostics conventionnels et avancés adaptés à l’étude des propriétés macroscopiques et atomiques des plasmas de ces deux isotopes. Dans ces réacteurs, la production d’ions négatifs est basée sur le mécanisme dit de production en volume. Dans ce cas, la réaction d’attachement dissociative des électrons (ADE) est identifiée comme la réaction prédominante. La compréhension des facteurs influençant cette réaction peut donc conduire à un meilleur contrôle de la production d’ions négatifs.Dans le réacteur “Prometheus I”, des études paramétriques dans des plasmas d’hydrogène et de deutérium, en fonction de la puissance micro-onde et de la pression du gaz, révèlent des optima pour la production d’ions négatifs et permettent de mettre en évidence des particularités isotopiques. Le rendement en ions négatifs atteint 0.57×10^16 m^(-3 ) dans les deux plasmas, mais le rapport entre les ions négatifs et la densité du plasma est systématiquement plus élevée pour H2 que pour D2. Par exemple, un rapport de 0.225 pour H2 contre 0.125 pour D2 est obtenu dans des conditions représentatives de fonctionnement. En outre, la mesure de l’énergie des ions négatifs révèle l’existence de deux populations ioniques d’énergies différentes. Ceci a été attribué principalement à deux mécanismes responsables de l’excitation des molécules à des niveaux vibrationnels/rotationnels élevés participant à la formation d’ions négatifs via la réaction ADE.En revanche, le réacteur "SCHEME-II+" est destiné à l'étude de l'influence de divers matériaux exposés au plasma pour la production de molécules ro-vibrationnellement excitées. Un diagnostic spectroscopique complexe, la spectroscopie d'absorption dans l'ultraviolet du vide à transformée de Fourier (VUV-FT) utilisant le rayonnement synchrotron, est utilisée pour les sonder directement différentes conditions de fonctionnement du plasma. L’effet significatif des surfaces métalliques sur la création de ces espèces ro-vibrationnellement excitées a pu être démontré. Une augmentation de près d’un facteur quatre pour les molécules D2 dans les états vibrationnels élevés (v"= 4-8) est observée lorsqu’une surface de tantale remplace une surface de quartz face au plasma.Enfin, des plasmas de deutérium fonctionnant en mode pulsé sont examinés. Des mesures résolues en temps des paramètres plasma, effectuées dans des impulsions de plasma de l'ordre du kHz, révèlent d'importants effets post-plasma. Notamment, un rendement en ions négatifs plus élevé que celui mesuré dans un plasma fonctionnant en mode continu a été observéHydrogen negative ion sources are integral components in modern accelerator facilities and in the Neutral Beam Injection (NBI) systems of future fusion reactors. The latter application necessitates the development of such very powerful sources and the extension of their operation to deuterium. Numerous research activities on laboratory-scale experiments have been devoted to this subject aiming at understanding the fundamental processes that govern negative ion production. The gained knowledge has contributed essentially to the development of the prototype sources that will be employed in the NBI system of ITER, the largest Tokamak reactor under construction which is foreseen to demonstrate the potential of exploitation of thermonuclear fusion as an alternative source of energy. Nonetheless, there are important technological issues arising from the fundamental physics underlying these sources which need to be overcome in order for them to be able to deliver neutral beams with characteristics satisfying the baseline requirements.In the present thesis, the production of hydrogen (H-) and deuterium (D-) negative ions is studied in Electron Cyclotron Resonance (ECR) driven plasmas. In particular, experimental studies have been carried out in two reactors of similar characteristics, namely “Prometheus I” and “SCHEME-II+”, by means of conventional and state-of-the-art diagnostic techniques tailored to investigate the macroscopic and atomic properties of the plasmas of the two isotopes. In these reactors, negative ion production is based on the so-called volume production mechanism. In this case, the Dissociative Electron Attachment (DEA) reaction is identified as the predominant one. Understanding those factors which influence this reaction may lead to its control and thus an even better control of the negative ion production.In the “Prometheus I” reactor, parametric studies in hydrogen and deuterium plasmas as a function of the supplied microwave power and working gas pressure reveal the existence of optima for negative ion production and allow the identification of isotopic differences. The negative ion yield reaches a value of 0.57×10^16 m^(-3 ) in both plasmas, although in the hydrogen case the ratio of the negative ions to the plasma density is consistently higher than in the case of deuterium. Indicatively, a ratio of 0.225 in H2 versus 0.125 in D2 is observed in representative operating conditions. Measurements, moreover, of the negative ion energies disclose the existence of two ionic populations of different energies. This has been attributed to the two main mechanisms leading to the excitation of molecules in high vibrational/rotational states, which in turn participate in the formation of negative ions via the DEA reaction.On the other hand, the “SCHEME-II+” reactor is intended for studies of the influence of various materials exposed to the produced plasma on the production of the highly ro-vibrationally excited molecules. An advanced spectroscopic diagnostic technique, Vacuum Ultraviolet Fourier Transform (VUV-FT) absorption spectroscopy using synchrotron radiation, is utilized in order to directly probe these species under different plasma operating conditions. The significant positive effect of metallic surfaces on the creation of these species is demonstrated, since a nearly fourfold increase of deuterium molecules in high vibrational states (v"= 4-8) is observed when the plasma faces a tantalum surface as opposed to a Quartz surface.Finally, deuterium plasmas sustained in the pulsed mode of operation are investigated. Time-resolved measurements of the basic plasma parameters, performed in plasma pulses lying in the kHz range, reveal important post-plasma effects. In particular, a higher negative ion yield with respect to that measured in a plasma sustained in the continuous mode of operation has been observed
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Leduc, Alexandre. "Etude par la simulation et l'expérimentation de la production d'ions métalliques Calcium à l'aide d'une source d'ions du type Résonance Cyclotronique Electronique." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC239.
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Dans le cadre du projet SPIRAL2, la source d'ions à la résonance cyclotronique électronique (RCE) PHOENIX V3 (amélioration par rapport à la précédente version PHOENIX V2) a été développée afin d'augmenter la production d'ions avec un A/Q=3. La source vise principalement la production d'ions métalliques. Pour cela, des atomes métalliques sont sublimés dans un four avant d'être injectés dans la source d'ions. Lors de la production de tels faisceaux d'ions, la grande majorité des atomes se fixe au niveau de la paroi de la chambre à plasma et y reste. Ces pertes mènent à une faible efficacité globale d'ionisation (de l'ordre de la dizaine de pour cent).Un code hybride PIC (Particle In Cells) a été développé pour étudier la dynamique des particules chargées et reproduire les spectres d'ions en A/Q expérimentaux produits par la source d'ions PHOENIX V3. La simulation se concentre sur la propagation des ions en trois dimensions. A l'aide de plusieurs paramètres ajustables, la simulation reproduit la distribution des états de charges à la sortie de la source d'ions. Ce code a fourni des résultats encourageants.En parallèle de l'étude par simulation de la dynamique des particules dans le plasma, un ensemble de simulations reproduisant le fonctionnement du four pour atomes métalliques a été conçu. Les simulations permettent également l'analyse de la distribution angulaire des impulsions des particules quittant le creuset du four. Les distributions angulaires fournies par les simulations sont comparées à celles obtenues grâce à des mesures expérimentales.Une étude expérimentale a également été initiée afin de réduire le temps de collage des atomes métalliques injectés sur la chambre à plasma. Pour cela, un cylindre thermorégulé a été réalisé afin de favoriser la réévaporation des particules fixées. Il est ainsi possible d'augmenter l'efficacité globale d'ionisation d'au moins un facteur 2 et de mesurer l'augmentation de l'efficacité en fonction de la température de la paroiIn the framwork of the SPIRAL2 project, the Electron Cyclotron Resonance Ion Source PHOENIX V3 (upgrade of the previous source PHOENIX V2) has been developed to improve the production of highly charged ions with A/Q=3. The ion source mainly aims at the production of metal ion beams. For this, condensable atoms are sublimated into oven before being injected into the ion source. During the production of such ion beams, the major part of atoms travel towards the plasma chamber wall and remains there. Those losses lead to low global ionization efficiency (of the order of ten percent).An hybrid code PIC (Particle In Cells) was developed to study the dynamic of charged particles and to reproduce the experimental A/Q spectrum produced by the PHOENIX V3 ion source. The simulation focuses on the propagation of ions in 3D. Using several adjustable parameters, the simulation outcomes fit the charge state distribution at the exit of the ion source. This code has provided encouraging results.In parallel with the simulation study of particle dynamic in the plasma, a series of simulations have been run to reproduce the operation of an oven leading to the emission of metallic atoms. The outcomes of the simulations allow analysis of the angular distribution of the particles leaving the hot crucible. The angular distributions provided by the simulations are compared with those obtained through experimental measurements.An experimental study was also initiated to reduce the sticking time of the metal atoms on the plasma chamber. For this, a thermoregulated cylinder has been designed and realised to promote the re-evaporation of fixed paricles. It is thus possible to increase the global ionization efficiency by a factor 2 at least and to study the variation of the efficiency as a fonction of the cylinder temperature
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Hedin, Johan. "Ion cyclotron resonance heating in toroidal plasmas." Doctoral thesis, KTH, Alfvén Laboratory, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3073.
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Hedin, Johan. "Ion cyclotron resonance heating in toroidal plasmas /." Stockholm, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3073.
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Vargheese, K. Deenamma. "ECR Assisted Deposition of Tin And Si3N4 Thin Films For Microelectronic Applications." Thesis, Indian Institute of Science, 2000. https://etd.iisc.ac.in/handle/2005/202.
Full textAbstract:
The broad theme of the present research investigation is Ion Assisted Deposition of thin films and its effect on the properties of thin films. Though this activity has been of interest to researchers for more than a decade, the development of different types of ion sources with control over the ion flux and energy, makes it a current topic of interest. Ion assisted deposition was successful in depositing thin films of many material with desired qualities, however, there are certain class of materials whose deposition has been rather difficult. This has mainly been attributed to higher energies and low ion flux of conventional ion sources. The advent of ECR ion sources for thin film deposition has given impetus to the deposition of such materials. This is due to the low energy high-density plasma generated in this type of sources. Hitherto, these sources were widely used in PECVD techniques and only recently the importance of ECR sources in PVD techniques has been realized. This thesis is on the development of ECR plasma source for ion assisted deposition of thin films using PVD techniques. This thesis is organized into six chapters.
The first chapter gives an introduction on the ion assisted growth of thin films and the importance of ECR plasma. A detailed discussion on various aspects of ECR sources has been included.
The design details on the development of ECR source have been discussed in the second chapter. The performance of ECR source as analyzed by the Langmuir probe are also discussed. Variation of plasma parameters like ion density, electron temperature, plasma potential and floating potential as a function of pressure and microwave power have been studied using Langmuir probe analysis. An ion density of the order of 1011/cm3 was measured at a distance of 8 cm from the plasma source with a microwave power of 400 watts. This was comparable to the ion density reported in downstream plasma of ECR sources. The behavior of plasma parameters with variation in microwave power and pressure was explained on the basis of microwave transmission above critical ion density and the microwave power absorption. The uniformity of the plasma parameters at the substrate position (29 cm from the ECR source) was found to be ± 2% over a diameter of 12 cm, which makes the ion source suitable for ion assisted deposition.
The third chapter deals with the simulation and experimental study of the ECR sputtering process. ECR sputter type sources are equipped with cylindrical targets. The sputtered flux distribution on the substrate depends on target geometry, sputtering pressure and target-substrate distance. The effect of cylindrical geometry on the distribution of sputtered flux has been simulated by Monte Carlo methods. It is found that the sputtered flux distribution at different pressures and target-substrate distances in ECR sputter type source differs from the conventional glow discharge sputtering system equipped with planar targets. The simulated results are compared with the experimental results. The simulated data agree very well with the experimental data.
The deposition and characterization of the TiN thin films for diffusion barrier applications in copper metallization have been discussed in the fourth chapter. Titanium nitride films are prepared by ECR sputtering. The effect of high density ion bombardment on the morphology, orientation and resistivity of the films was studied. It was observed that films with atomic smoothness could be prepared by ECR sputtering. Also the high density ion bombardment has been found to be effective for the film growth in (100) orientation. The behavior of TiN films deposited by this method as a diffusion barrier in copper metallization has been investigated. The resistivity measurements and RBS depth profile studies showed that up to 700°C there is no diffusion of copper into silicon. This shows that ECR sputtered TiN can be used as an effective diffusion barrier in copper metallization.
The fifth chapter contains investigations on the ECR assisted growth of silicon nitride films. The films are characterized for composition, morphology and chemical bonding using AES, RBS, AFM, XPS and FTIR. AFM studies revealed that ion bombardment results in the reduction of surface roughness, which indicates dense film growth. The effect of ion assistance on the optical and electrical properties is studied in detail. Films prepared with microwave power ranging from 100 to 200 watts are having bandgap and refractive index of 4.9 eV and 1.92 respectively. Interface state density of silicon nitride films prepared in the above mentioned range was found to be 5x10 10 eVcm2. These films exhibited a resistivity of 10 13 Ω, cm and critical field of 4 MV/cm. The electrical conductivity in these films has been explained on the basis of Poole and Frenkel conduction. The low value of interface state density, higher resistivity, and critical field show that good quality SiN4 films can be deposited with low energy high density ECR plasma.
A detailed summary of this research investigation has been discussed in the last chapter. The thesis is concluded with a discussion on the need of focused ECR source to establish ECR assisted deposition as a versatile technique for the growth of thin films.
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Vargheese, K. Deenamma. "ECR Assisted Deposition of Tin And Si3N4 Thin Films For Microelectronic Applications." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/202.
Full textAbstract:
The broad theme of the present research investigation is Ion Assisted Deposition of thin films and its effect on the properties of thin films. Though this activity has been of interest to researchers for more than a decade, the development of different types of ion sources with control over the ion flux and energy, makes it a current topic of interest. Ion assisted deposition was successful in depositing thin films of many material with desired qualities, however, there are certain class of materials whose deposition has been rather difficult. This has mainly been attributed to higher energies and low ion flux of conventional ion sources. The advent of ECR ion sources for thin film deposition has given impetus to the deposition of such materials. This is due to the low energy high-density plasma generated in this type of sources. Hitherto, these sources were widely used in PECVD techniques and only recently the importance of ECR sources in PVD techniques has been realized. This thesis is on the development of ECR plasma source for ion assisted deposition of thin films using PVD techniques. This thesis is organized into six chapters.
The first chapter gives an introduction on the ion assisted growth of thin films and the importance of ECR plasma. A detailed discussion on various aspects of ECR sources has been included.
The design details on the development of ECR source have been discussed in the second chapter. The performance of ECR source as analyzed by the Langmuir probe are also discussed. Variation of plasma parameters like ion density, electron temperature, plasma potential and floating potential as a function of pressure and microwave power have been studied using Langmuir probe analysis. An ion density of the order of 1011/cm3 was measured at a distance of 8 cm from the plasma source with a microwave power of 400 watts. This was comparable to the ion density reported in downstream plasma of ECR sources. The behavior of plasma parameters with variation in microwave power and pressure was explained on the basis of microwave transmission above critical ion density and the microwave power absorption. The uniformity of the plasma parameters at the substrate position (29 cm from the ECR source) was found to be ± 2% over a diameter of 12 cm, which makes the ion source suitable for ion assisted deposition.
The third chapter deals with the simulation and experimental study of the ECR sputtering process. ECR sputter type sources are equipped with cylindrical targets. The sputtered flux distribution on the substrate depends on target geometry, sputtering pressure and target-substrate distance. The effect of cylindrical geometry on the distribution of sputtered flux has been simulated by Monte Carlo methods. It is found that the sputtered flux distribution at different pressures and target-substrate distances in ECR sputter type source differs from the conventional glow discharge sputtering system equipped with planar targets. The simulated results are compared with the experimental results. The simulated data agree very well with the experimental data.
The deposition and characterization of the TiN thin films for diffusion barrier applications in copper metallization have been discussed in the fourth chapter. Titanium nitride films are prepared by ECR sputtering. The effect of high density ion bombardment on the morphology, orientation and resistivity of the films was studied. It was observed that films with atomic smoothness could be prepared by ECR sputtering. Also the high density ion bombardment has been found to be effective for the film growth in (100) orientation. The behavior of TiN films deposited by this method as a diffusion barrier in copper metallization has been investigated. The resistivity measurements and RBS depth profile studies showed that up to 700°C there is no diffusion of copper into silicon. This shows that ECR sputtered TiN can be used as an effective diffusion barrier in copper metallization.
The fifth chapter contains investigations on the ECR assisted growth of silicon nitride films. The films are characterized for composition, morphology and chemical bonding using AES, RBS, AFM, XPS and FTIR. AFM studies revealed that ion bombardment results in the reduction of surface roughness, which indicates dense film growth. The effect of ion assistance on the optical and electrical properties is studied in detail. Films prepared with microwave power ranging from 100 to 200 watts are having bandgap and refractive index of 4.9 eV and 1.92 respectively. Interface state density of silicon nitride films prepared in the above mentioned range was found to be 5x10 10 eVcm2. These films exhibited a resistivity of 10 13 Ω, cm and critical field of 4 MV/cm. The electrical conductivity in these films has been explained on the basis of Poole and Frenkel conduction. The low value of interface state density, higher resistivity, and critical field show that good quality SiN4 films can be deposited with low energy high density ECR plasma.
A detailed summary of this research investigation has been discussed in the last chapter. The thesis is concluded with a discussion on the need of focused ECR source to establish ECR assisted deposition as a versatile technique for the growth of thin films.
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Touchais, Emmanuelle. "Étude et développement d'une source de plasma micro-onde pour déposer des revetements par pulvérisation sur des grandes surfaces." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0106.
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Les caracteristiques d'une nouvelle source de plasma pour le depot de revetements par pulverisation sur des grandes surfaces ont ete etudiees. Cette source utilise une onde electromagnetique de frequence 2. 45 ghz pour accelerer les electrons qui ionisent les atomes d'argon par impact electronique. Un champ magnetique permet de confiner les electrons pour d'une part optimiser le couplage avec l'onde en tout lieu ou il est egal a 875 gauss et d'autre part transporter le plasma vers une cible de pulverisation polarisee negativement. Une source produisant une nappe de plasma de section rectangulaire de 75 cm2 a ete realisee. La caracterisation du plasma a ete effectuee en termes de densite electronique par interforemetrie, de temperature electronique par mesure de sonde et de courant d'ions recueillis sur la cible en fonction des parametres puissance micro-onde, pression d'argon, champ magnetique. Les valeurs obtenues ont montre que ce plasma est dense, avec une independance entre les parametres de creation du plasma et ceux de la pulverisation. L'usure des cibles de pulverisation est uniforme et correspond a l'intersection entre les lignes de champ magnetique et la surface de la cible. L'etude des couches de chrome deposees par ce procede a montre que la diminution de la pression permet d'obtenir des couches de densite proche de celle du chrome massique, avec des vitesses de depot elevees, et des contraintes residuelles faibles. Sous pression reduite constante, l'incorporation de carbone dans les couches de chrome par pulverisation reactive a permis d'augmenter la durete de ces couches. La morphologie devient plus dense, avec des contraintes residuelles faibles et une resistivite electrique faible. D'autres revetements (fer, oxyde de chrome, oxyde d'aluminium) ont ete realises pour demontrer la potentialite de ce nouveau dispositif a deposer en tension de polarisation negative continue de la cible des materiaux magnetiques et des oxydes
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Chatain, Franck. "Caractérisation de réacteurs à plasma basse pression-haute densité : étude de la cinétique des ions par fluorescence induite par laser." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10121.
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Les traitements de materiaux par plasma sont actuellement largement utilises dans la plupart des industries bien que les processus physiques qui regissent ces decharges ne soient pas totalement maitrises. Avec l'essor de nouvelles sources optiques, le diagnostic de fluorescence laser, non perturbatif vis a vis du milieu, associe aux diagnostics electriques, permet la caracterisation de sources a plasma basse pression. Grace a cet outil, on peut ainsi comprendre la cinetique des ions (production, excitation, diffusion) et mesurer les parametres critiques influant sur la qualite du traitement (flux, directionalite, fonction de distribution en energie des particules bombardant la surface, temperature du substrat)
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Shadman, K. (Khashayar) 1972. "Copper metallization with an electron cyclotron resonance." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47685.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998.Includes bibliographical references.
An "electron cyclotron resonance" plasma source, used for physical vapor deposition of copper into sub-micron features, was studied to determine whether parameters, such as gas atom density, electron density and temperature, surface bias, and copper ionization fraction at the deposition surface, influenced fill quality of the features. The results indicated that the fill quality was insensitive to all parameters except for the surface biasing conditions; however, with the use of an argon plasma, the bias was limited to less than ~- 40V due to the sputtering of the dielectric features by the argon ions (a phenomenon know as faceting). Switching to a copper evaporative system allowed for a pure copper plasma, enabling the use of greater (in magnitude) surface bias, ; I- 200V , before faceting by copper ions was observed. The fill quality of the features degraded with moderate bias ( 150V . These results suggest that one formula for successful metallization is the use of an etch-resistant dielectric material in conjunction with large negative surface bias.
by Khashayar Shadman.
S.M.
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Biodedet, Lambert. "Intéraction d'une onde produite par un laser à électrons libres avec le plasma du tokamak alcator C : Étude numérique par la méthode des éléments finis." Nancy 1, 1988. http://www.theses.fr/1988NAN10021.
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Étude de l'intéraction d'une onde laser à électrons libres, polarisée sur le mode ordinaire, avec le plasma du tokamak alcator C. On considère le modèle "slab" pour la description spatiale du plasma toroïdal. Les résultats obtenus par un code à éléments finis confirment que la fonction de distribution des vitesses des particules se déforme au cours du temps et en chaque point de l'espace sous l'effet de l'onde. On note l'apparition d'effets quasi linéaires, qui réduisent localement l'absorption de l'énergie de l'onde. L'effet prédominant de l'absorption résonnante est l'augmentation de la température perpendiculaire des électrons dont la vitesse parallèle est de l'ordre de 3 fois la vitesse thermique
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Miller, Andrew Gilbert. "Microinstabilities in high power electron cyclotron heating of plasmas." Thesis, University of St Andrews, 1991. http://hdl.handle.net/10023/13977.
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Electron cyclotron resonance heating has been successfully used in a number of experiments, firstly to raise the plasma temperature and secondly to drive currents noninductively. Recently the microwaves in tokamak experiment (MTX) has been proposed at the Lawrence Livermore Laboratory, which will involve pulsed heating at powers much higher than have previously been possible, using a Free Electron Laser (PEL). The physics of such an experiment differs greatly from the physics of experiments using less powerful but continuous operation gyrotron sources. An analytical model of the interaction between a wave and an electron is presented on the assumption that the wave amplitude experienced along the electron guiding centre changes slowly with time as it passes through the beam. This model is tested numerically by integrating the equations of motion governing the electron's motion as it interacts with the wave. Finally this model is used to predict the possible growth of instabilities in a plasma heated by a FEL. The growth rates of these waves may be large enough to act on the plasma in time scales much shorter than typical electron collision times.
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Al-Arab, A. M. H. "Cyclotron resonance lineshape of free electrons." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381924.
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Wang, Junkang. "Novel Concepts in the PECVD Deposition of Silicon Thin Films : from Plasma Chemistry to Photovoltaic Device Applications." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX079/document.
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Ce manuscrit présente l'étude de la fabrication de couches minces de silicium basée sur des différents types de dépôt chimique en phase vapeur assisté par plasma (PECVD) pour des applications dans le photovoltaïque. Tout d'abord, nous avons combiné une chimie du plasma halogéné en utilisant un mélange de SiF4/H2 et la technique plasmas distributés matriciellement à résonance cyclotronique électronique (MDECR) PECVD pour le dépôt de μc-Si:H à grande vitesse. Nous trouvons que les conditions d'énergie ionique modérée sont bénéfiques pour obtenir une diminution significative de la densité des nano-vides, et ainis nous pouvons obtenir un matériaux de meilleure qualité avec une meilleure stabilité. Une méthode de dépôt en deux étapes a été introduite comme moyen alternatif d'éliminer la formation d'une couche d'incubation amorphe pendant la croissance du film. Ensuite, nous avons exploré la technique d'excitation Tailored Voltage Waveform (TVW) pour les processus plasma radiofréquence capacitivement couplé (RF-CCP). Grâce à l'utilisation de TVW, il est possible d'étudier indépendamment l'influence de l'énergie ionique sur le dépôt de matériaux à une pression de processus relativement élevée. Basé sur ce point, nous avons étudié le dépôt de μc-Si:H et a-Si:H à partir des plasma de SiF4/H2/Ar et de SiH4/H2, respectivement. A partir d'une analyse des propriétés structurelles et électroniques, nous constatons que la variation de l'énergie ionique peut directement traduite dans la qualité du matériaux. Les résultats se sont appliqués aux dispositifs photovoltaïques et ont établi des liens complets entre les paramètres de plasma contrôlables par TVW et les propriétés de matériaux déposé, et finalement, les performances du dispositif photovoltaïque correspondant. Enfin, nous avons trouvé que dans le cas du dépôt de couches minces de silicium à partir du plasma de SiF4/H2/Ar à l'aide de sawtooth TVW, on peut réaliser un processus de dépôt sur une électrode, sans aucun dépôt ou gravure. contre-électrode. Ceci est dû à deux effets: la nature multi-précurseur du processus de surface résultant et la réponse de plasma spatiale asymétrique par l'effet d'asymétrie de pente de la sawtooth TVW. La découverte de tels procédés “electrode-selective” encourage la perspective que l'on puisse choisir un ensemble de conditions de traitement pour obtenir une grande variété de dépôts désirés sur une électrode, tout en laissant l'autre viergeThis thesis describes the study of silicon thin film materials deposition and the resulting photovoltaic devices fabrication using different types of plasma-enhanced chemical vapour deposition (PECVD) techniques.In the first part, we combine a SiF4/H2 plasma chemistry with the matrix-distributed electron cyclotron resonance (MDECR) PECVD to obtain high growth rate microcrystalline silicon (µc-Si:H). Due to the special design of MDECR system, careful investigation of the impact energy of impinging ions to material deposition can be accessible. We find that moderate ion energy conditions is beneficial to achieve a significant drop in the density of nano-voids, thus a higher quality material with better stability can be obtained. A two-step deposition method is introduced as an alternative way to eliminate the existence of amorphous incubation layer during film growth.The second part of work is dedicate to the exploration of the Tailored Voltage Waveforms (TVWs) excitation technique for capacitively coupled plasmas (CCP) processes. As an advantage over the conventional sinusoidal excitations, TVWs technique provide an elegant solution for the ion flux-energy decoupling in CCP discharges through the electrical asymmetry effect, which makes the independent study of the impact of ion energy for material deposition at relatively high process pressure possible. Based on this insight, we have studied the deposition of µc-Si:H and amorphous silicon (a-Si:H) from the SiF4/H2/Ar and SiH4/H2 plasma chemistry, respectively. From the structural and electronic properties analysis, we find that the variation of ion energy can be directly translated into the material quality. We have further applied these results to photovoltaic applications and established bottom-up links from the controllable plasma parameters via TVWs to the deposited material properties, and eventually to the resulting device quality.In the last part, as a further application of TVWs, an “electrode-selective” effect has been discovered in the CCP processes. In the case of silicon thin film deposition from the SiF4/H2/Ar plasma chemistry, one can achieve a deposition process on one electrode, while at the same time either no deposition or an etching process on the counter electrode. This is due to two effects: the multi-precursor nature of the resulting surface process and the asymmetric plasma response through the utilization of TVWs. Moreover, such deposition/etching balance can be directly controlled through H2 flow rate. From a temporal asymmetry point of view, we have further studied the impact of process pressure and reactor geometry to the asymmetric plasma response for both the single-gas and multi-gas plasmas using the sawtooth waveforms. The product of pressure and inter-electrode distance P·di is deduced to be a crucial parameter in determine the plasma heating mode, so that a more flexible control over the discharge asymmetry as well as the relating “electrode-selective” surface process can be expected
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Khallaayoune, Jamal. "Dépot d'oxyde de silicium aplanissant par plasma multipolaire micro-onde à résonance cyclotronique électronique répartie." Université Joseph Fourier (Grenoble ; 1971-2015), 1992. http://www.theses.fr/1992GRE10153.
Full textAbstract:
Dans cette etude, nous avons utilise un plasma multipolaire microonde pour deposer l'oxyde de silicium a partir du melange sih#4/o#2 a basse temperature (< 400c) ; le plasma est genere par resonance cyclotronique electronique repartie (rcer) a basse pression (< 10 mtorr). Nous avons etudie l'influence des parametres du procede, tels que les debits des gaz, la puissance microonde, l'energie des ions, la temperature,. . . , sur les proprietes physico-chimiques et electriques de ces oxydes. Il a ete ainsi possible de determiner les conditions d'obtention de couches presentant des caracteristiques proches de celles de la silice thermique. Le plasma rcer permet de dissocier la polarisation du substrat de la creation du plasma, et donc de controler independamment l'energie des ions. La planarisation des oxydes deposes par rcer resulte d'une competition entre le depot et la gravure par pulverisation. Dans un premier temps, nous avons etudie l'evolution topologique d'une surface lors de la gravure par pulverisation. Dans le cas du depot aplanissant, les effets topologiques observes indiquent une tres forte influence de la gravure par pulverisation. La reduction de dimensions des dispositifs entraine une augmentation du rapport de forme (hauteur/largeur) des tranchees que les procedes cvd ne peuvent remplir sans formation de cavite. Ici encore, en maitrisant la competition entre le depot et la gravure par pulverisation, nous avons considerablement deplace la limite de formation de cavite (rapport de forme > 2). Les resultats developpes dans ce memoire confirment le potentiel technologique de ce procede pour les nouvelles generations de composants de tres faible dimension.
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Taylor, A. W. "Theory of high power electron cyclotron resonance heating." Thesis, University of St Andrews, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384587.
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KLEIN, JEAN-PIERRE. "Etude des particules diffusees par un plasma de source d'ions a resonance cyclotron des electrons." Paris 6, 1995. http://www.theses.fr/1995PA066127.
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Un double analyseur electrostatique a cylindre a ete mis au point pour etudier principalement la population electronique du cone de perte ; l'etude de la population ionique a egalement permis de determiner le potentiel plasma. La possibilite d'appliquer deux potentiels d'analyse le long de la decroissance de champ magnetique a l'extraction a permis de determiner l'anisotropie de la fonction de distribution electronique, de temperatures parallele tpar et perpendiculaire tper, a la sortie de la source. La temperature tpar reste dans tous les cas voisine de 10 ev alors que tper passe de 30 ev a 150 ev lorsque l'on ameliore les conditions de confinement. Le chauffage cyclotronique electronique communique aux electrons une vitesse essentiellement perpendiculaire au champ magnetique v#p#e#r. Celle-ci est progressivement convertie en vitesse parallele principalement suite a des collisions avec les ions. Ces electrons sortent de la source avec une frequence de collision en v#-#3#p#e#r. En prenant une maxwellienne de temperature t#c#e#n#t#p#e#r pour decrire la fonction de distribution electronique f#c#e#n#t (v#p#e#r) au centre de la source un bon accord est obtenu avec la caracteristique experimentale effectuee a l'aide d'un seul potentiel d'analyse. Les temperatures obtenues peuvent atteindre 2 kev a 10 ghz et 6 kev a 18 ghz. Des mesures de densite et de diamagnetisme ont permis de preciser la place qu'occupent ces electrons tiedes: ils dominent en nombre mais quittent le plasma beaucoup plus rapidement que les electrons chauds (que l'on etudie a l'aide des x). Pour cette raison leur densite d'energie est nettement inferieure a celle de la population chaude mais ils consomment une grande partie de la puissance hf injectee
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Booth, Ian. "Optical detection of paramagnetic and cyclotron resonance in semiconductors." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25566.
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Optical Detection of Magnetic Resonance (ODMR) has been used to observe both paramagnetic and diamagnetic resonance of photo-excited electrons and holes in GaP, ZnTe and AgBr. Paramagnetic resonance of conduction electrons in GaP has been studied and the microwave frequency and power dependence of the effect analysed. The maximum signal strength was observed to produce approximately 1% change in luminescence at 1.6 K. The g value deduced from the resonance was 2.000 ± 0.005. The resonance was homogeneously broadened giving the electron lifetime as approximately 4 nanoseconds.
Paramagnetic resonance of electrons and holes has also been detected in AgBr.
The background signals present in ODMR experiments have been investigated and are shown to be caused by diamagnetic or cyclotron resonance heating of photoexcited carriers. Measurements at microwave frequencies of 9.2 and 36.3 GHz have been made on GaP,ZnTe and AgBr, and cyclotron resonance of electrons and holes observed. The effective masses of light and heavy holes in GaP were found to be 0.154 ± 0.01 and 0.626 ± 0.06 respectively while the electron effective mass was 0.36 ± 0.10. The electron scattering time was shorter than that for holes by a factor of approximately three, most likely due to scattering by isoelectronic nitrogen impurities. Resonances were observed in ZnTe at effective mass values of 0.30 ± 0.20 and 0.76 ± 0.20 corresponding to electrons and heavy holes. In both GaP and ZnTe resonances due to electrons and holes appeared in different luminescence bands indicating the sensitivity of different recombination centres to heating of either carrier type. Cyclotron resonance of electrons and holes was also observed in AgBr and showed the effects of conduction and valence band non-parabolicity. A feature in the electron resonance indicated enhanced trapping of electrons with certain energies by emission of one or more LO phonons.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Mariani, A. "WAVE ENERGY FLUX AND ABSORPTION OF ELECTRON CYCLOTRON GAUSSIAN BEAMS IN TOKAMAK PLASMAS." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/231161.
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In this thesis some theoretical problems related to the propagation and absorption of Electron Cyclotron Gaussian beams in tokamak plasmas of interest for nuclear fusion applications are investigated. To account for diffraction effects, beam propagation is analyzed in the framework of the complex eikonal method, a generalization of geometrical optics in which the phase function is assumed to be complex valued, with the non-negative imaginary part accounting for the
finite width of the beam cross section. Within this framework, the solution at the dominant order in the expansion parameter is well-known, and the wave beam is modeled as a bundle of “extended rays”. The derivation of the transport equation for the
field amplitude is much more complicated with respect to the standard geometrical optics one, hampering the derivation of the wave energy flux. In this work, an argument is proposed that greatly simplifies the analysis of the transport equation allowing us to derive the wave energy flux. This result, not available in the literature in the case of beam propagation in anisotropic media like magnetized plasmas, has been obtained in collaboration with O. Maj (IPP, Garching, Germany), and published on Physics of Plasmas. The effects of the
finite beam width on the Electron Cyclotron resonant interaction have been described with a model that takes into account the transverse wave vector spectrum width and the non-uniformity of the equilibrium magnetic
field. The model has been implemented in a modified version of the GRAY code [D. Farina, Fusion Sci. Technol. 52, 154 (2007)]. The differences between the power absorption profi
les obtained using this model and the “plane wave” one are illustrated numerically in ITER conditions and are found to be small for realistic cases, thus justifying the use of the usual model for practical purposes.
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Weichsel, Tim. "Entwicklung und Charakterisierung einer Elektron-Zyklotron-Resonanz-Ionenquelle mit integriertem Sputtermagnetron für die Erzeugung intensiver Ströme einfach geladener Aluminiumionen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-206003.
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Es wurde eine Elektron-Zyklotron-Resonanz-Ionenquelle mit einer Mikrowellenfrequenz von2,45 GHz für die Produktion intensiver Ströme einfach geladener Metallionen entwickelt. Deren Beladung mit Metalldampf erfolgt über ein integriertes zylindrisches Sputtermagnetron, welches speziell für diese Aufgabe entworfen wurde. Die entstandene MECRIS, engl. Magnetron Electron Cyclotron Resonance Ion Source, vereinigt die ECR-Ionenquellentechnologie mit der Magnetron-Sputtertechnologie auf bisher einzigartige Weise und verkörpert so ein neues Metallionen-Quellenkonzept. Unter Verwendung eines Al-Sputtertargets konnte die Funktionsfähigkeit der MECRIS an dem Beispiel der Al+-Ionenerzeugung erfolgreich demonstriert werden. Der extrahierbare Al+-Ionenstrom wurde über einen neuartigen, im Rahmen der Arbeit entwickelten, Hochstrom-Faraday-Cup gemessen. Auf Basis numerischer Berechnungen wurde das Gesamtmagnetfeld so ausgelegt, dass die Permanentmagnete des Magnetrons und die Spulen der ECR-Quelle eine Minimum-B-Struktur erzeugen, welche einen effektiven Elektroneneinschluss nach dem magnetischen Spiegelprinzip ermöglicht. Gleichzeitig wird durch eine geschlossene ECR-Fläche, mit der magnetischen Resonanzflussdichte von 87,5 mT, eine optimale Heizung der Plasmaelektronen realisiert. Die mithilfe einer Doppel-Langmuir-Sonde gemessene Elektronentemperatur steigt in Richtung Quellenmitte an und beträgt maximal 11 eV. Geheizte Elektronen erlauben die effiziente Stoßionisation der Al-Atome, welche mit einer Rate von über 1E18 Al-Atome/s eingespeist werden und eine höchstmögliche Dichte von 2E10 1/cm³ aufweisen. Die MECRIS erzeugt hauptsächlich einfach geladene Ionen des gesputterten Materials (Al+) und des Prozessgases (Ar+). Der Al+-Ionenextraktionsstrom ist über die Erhöhung der Prozessparameter Sputterleistung, Mikrowellenleistung, Spulenstrom und Extraktionsspannung um eine Größenordnung bis auf maximal 135 μA steigerbar, was einer Stromdichte von 270 μA/cm² über die Extraktionsfläche von rund 0,5 cm² entspricht. Dies steht im Einklang mit der Prozessparameterabhängigkeit der anhand der Sonde bestimmten Plasmadichte, welche einen größtmöglichen Wert von etwa 6E11 1/cm³ annimmt. Das Verhältnis von extrahiertem Al+- zu Ar+-Ionenstrom kann durch Optimierung der Prozessparameter von 0,3 auf maximal 2 angehoben werden. Sondenmessungen des entsprechenden Ionendichteverhältnisses bestätigen diesen Sachverhalt. Um möglichst große Extraktionsströme und Al+/Ar+-Verhältnisse zu generieren, muss die ECR-Fläche demnach in dem Bereich der höchsten Al-Atomdichte in der Targetebene lokalisiert sein. Gegenüber dem alleinigen Magnetronplasma (ohne Mikrowelleneinspeisung) können mit dem MECRIS-Plasma um bis zu 140 % höhere Al+-Ionenströme produziert werden. Aus Sondenuntersuchungen geht hervor, dass dies eine Folge der um etwa eine Größenordnung gesteigerten Plasmadichte und der um rund 7 eV größeren Elektronentemperatur des MECRIS-Plasmas ist. Das MECRIS-Plasma wurde außerdem mittels optischer Emissionsspektroskopie charakterisiert und durch ein globales sowie ein zweidimensionales Modell simuliert. Die gewonnenen Prozessparameterabhängigkeiten der Plasmadichte, Elektronentemperatur sowie Al+- und Ar+-Ionendichte stimmen mit den Sondenergebnissen überein. Teilweise treten jedoch Absolutwertunterschiede von bis zu zwei Größenordnungen auf. Die Erhöhung der Sputterleistung und Extraktionsspannung über die derzeitigen Grenzen von 10 kW bzw. 30 kV sowie die Optimierung der Extraktionseinheit hinsichtlich minimaler Elektrodenblindströme bietet das Potential, den Al+-Ionenstrom bis in den mA-Bereich zu steigernAn electron cyclotron resonance ion source working at a microwave frequency of 2.45 GHz has been developed in order to generate an intense current of singly charged metal ions. It is loaded with metal vapor by an integrated cylindrical sputter magnetron, which was especially designed for this purpose. The MECRIS (Magnetron Electron Cyclotron Resonance Ion Source) merges ECR ion source technology with sputter magnetron technology in a unique manner representing a new metal ion source concept. By using an Al sputter target, the efficiency of the MECRIS was demonstrated successfully for the example of Al+ ion production. The extractable ion current was measured by a newly developed high-current Faraday cup. On the basis of numerical modeling, the total magnetic field was set in a way that the permanent magnets of the magnetron and the coils of the ECR source are forming a minimum-B-structure, providing an effective electron trap by the magnetic mirror principle. Simultaneously, optimal electron heating is achieved by a closed ECR-surface at resonant magnetic flux density of 87.5 mT. Electron temperature increases towards the center of the source to a maximum of about 11 eV and was measured by a double Langmuir probe. Due to the heated electron population, efficient electron impact ionization of the Al atoms is accomplished. Al atoms are injected with a rate of more than 1E18 Al-atoms/s resulting in a maximum Al atom density of 2E10 1/cm³. The MECRIS produces mainly singly charged ions of the sputtered material (Al+) and the process gas (Ar+). The Al+ ion extraction current is elevated by one order of magnitude to a maximum of 135 μA by increasing the process parameters sputter magnetron power, microwave power, coil current, and acceleration voltage. Related to the extraction area of about 0.5 cm², the highest possible Al+ ion current density is 270 μA/cm². A corresponding process parameter dependency was found for the plasma density showing a peak value of about 6E11 1/cm³, which was deduced from probe measurements. The ratio of the extracted Al+ ion current to the Ar+ ion current can be enhanced from 0.3 to a maximum of 2 by optimization of the process parameters. This was confirmed by probe investigations of the appropriate ion density ratio. In conclusion, the ECR-surface needs to be located in the area of the highest Al atom density in the target plane in order to improve the extraction current and Al+/Ar+ ratio. The MECRIS plasma produces an Al+ ion current, which is up to 140 % higher compared to that of the sole sputter magnetron plasma (without microwave injection). As revealed by probe measurements, this effect is due to the higher plasma density and electron temperature of the MECRIS plasma, leading to a difference of one order of magnitude and 7 eV, respectively. Additionally, the MECRIS plasma has been characterized by optical emission spectroscopy and simulated by a global and a two-dimensional model. Retrieved process parameter dependencies of plasma density, electron temperature, Al+ ion density, and Ar+ ion density coincide with probe findings. Although a discrepancy of the absolute values of partly up to two orders of magnitude is evident. Potentially, the Al+ ion current can be enhanced to the mA-region by optimizing the ion extraction system for minimal idle electrode currents and by rising sputter magnetron power as well as acceleration voltage above the actual limits of 10 kW and 30 kV, respectively
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Sheikh, Shaheen Anwar. "Development of an ECR ion source with a high ionization efficiency." Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/844445/.
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Separation of rare or expensive isotopes, whether radioactive or stable, requires a high efficiency of the separation process. Electromagnetic isotope separation is the most widely-used of all separation processes. Its separation efficiency depends mainly upon the ionization efficiency of its ion source. An Electron Cyclotron Resonance (ECR) ion source has been developed for the separation of both stable and radioactive isotopes on account of its high ionization efficiencies. The maximum ionization efficiencies achieved with the ECR ion source for singly charged ions for a range of materials were: radioiodine (8%), carbon (10%), nitrogen (26%), oxygen (53%), neon (31%) and xenon (83%). A computer code ECREFF, based on the atomic processes which occur in the plasma, is described for the calculation of the ionization efficiency of an ECR ion source. The experimental and calculated data are compared.
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PAILLOUX, AGNES. "Fluorescence induite par laser sur des plasmas fortement magnetises, chauffes par resonance cyclotron ionique." Université Louis Pasteur (Strasbourg) (1971-2008), 1997. http://www.theses.fr/1997STR13002.
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Ce travail est realise dans le cadre des etudes de separation isotopique par resonance cyclotron ionique (rci). Dans ce procede qui necessite un plasma d'ions d'une espece metallique fortement magnetise (2 a 3 tesla) et en limite collisionnelle (10#1#2 ions/cm#3), on cherche a chauffer le plus selectivement possible une espece donnee en injectant une onde a la frequence cyclotron ionique. Nous avons mis en uvre un diagnostic de fluorescence induite par laser (fil) sur les plasmas de baryum et de gadolinium. La rotation de larmor des ions modifie considerablement l'interaction. Afin de montrer que la fil mesure encore la fonction de distribution de vitesse des ions, nous avons resolu l'equation de schrodinger variable en temps. La probabilite d'exciter un ion ainsi obtenue est alors sommee sur l'ensemble des ions excites dans le volume de mesure. Nous avons egalement mis en evidence theoriquement et experimentalement l'influence de ce mouvement de larmor des ions sur la distribution spectrale du signal de fil. La fil est realisee avec un laser a colorant continu. L'ion baryum est excite sur la transition 614,2 nm (colorant rhodamine 6g) et l'ion gadolinium sur le pseudo-triplet zeeman 385,1 nm (colorant exalite). Les methodes d'analyse des donnees experimentales sont developpees en considerant l'effet zeeman, et le chauffage different de chaque isotope. Nous avons mesure la temperature ionique (de l'ev a quelques centaines d'ev) en fonction du chauffage radiofrequence. Les resultats experimentaux sont en bon accord avec la theorie. Nous avons egalement verifie localement le caractere maxwellien de la fonction de distribution de vitesse, et etudie le comportement du plasma en fonction des parametres reglables de la source de plasma
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Tsybin, Youri. "High Rate Electron Capture Dissociation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry." Doctoral thesis, Uppsala universitet, Jonfysik, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4136.
Full textAbstract:
Advances in science and technology during the past decade have greatly enhanced the level of the structural investigation of macromolecules – peptides and proteins. Biological mass spectrometry has become one of the most precise and sensitive techniques in peptide and protein analysis. However, increasing demands of biotechnological applications require further progress to be made. In the present thesis the development and improvement of peptide and protein characterization methods and techniques based on ion-electron and ion-photon reactions in electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry are described. The focus is on the development of the electron capture dissociation method, recently discovered by the group of professor McLafferty, into a high rate, efficient tandem mass spectrometrical technique. The rate and reliability of the electron capture dissociation technique were greatly increased by implementation of low-energy pencil electron beam injection systems based on indirectly heated dispenser cathodes. Further implementation of a hollow electron beam injection system combined, in a single experimental configuration, two rapid fragmentation techniques, high rate electron capture dissociation and infrared multiphoton dissociation. Simultaneous and consecutive irradiations of trapped ions with electrons and photons extended the possibilities for ion activation/dissociation reaction schemes and lead to improved peptide and protein characterization. Using these improvements, high rate electron capture dissociation was employed in time-limited experiments, such as liquid chromatography–tandem mass spectrometry and capillary electrophoresis-tandem mass spectrometry. The analytical applications of the developed techniques have been demonstrated in top-down sequencing of peptides and proteins up to 29 kDa, improved sequencing of peptides with multiple disulfide bridges and secondary fragmentation (w-ion formation), as well as extended characterization of peptide mixtures separated by liquid chromatography and capillary electrophoresis. For instance, the dissociation of peptides resulting from enzymatic digestion of proteins provided complementary structural information on peptides and proteins, as well as their post-translational modifications.
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Yamamoto, Yasuhiro. "Studies of Toroidal Flows Driven by Electron Cyclotron Heating in Three-Dimensional Torus Plasmas." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263655.
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Oi, Curran Y. M. "Studies of electron temperature fluctuations in the core of Alcator C-Mod plasmas via correlation electron cyclotron emission." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82446.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 55-56).
Transport in tokamak plasmas is higher than predicted by neoclassical theory; this anomalous transport is believed to be attributed to turbulent fluctuations. New Correlation Electron Cyclotron Emission (CECE) experiments on Alcator C-Mod show lower levels of electron temperature fluctuations in the saturated ohmic confinement (SOC) regime than in the linear ohmic confinement (LOC) regime, however the lineaveraged density fluctuation data collected from ohmic plasmas previously showed the opposite trends. The apparent contradiction is explained by a change in the dominant turbulence modes in each confinement regime. Linear stability analysis shows that the LOC regime is dominated by trapped electron mode (TEM) turbulence and the SOC regime is on the border between the ion temperature gradient (ITG) and TEM turbulence modes being dominant. It is reasonable to believe that the TEM turbulence mode drives electron temperature fluctuations, which explains the higher electron temperature fluctuation levels seen in the LOC regime compared to the SOC regime.
by Curran Y. M. Oi.
S.B.
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Pilipenko, Denis. "Influence of ion cyclotron resonance heating on tranport of seeded impurities in the tokamak plasmas." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210947.
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Experiments on several tokamaks convincingly demonstrated that a deliberate seeding of selected impurities can have a positive effect on the plasma performance. On the one hand, a significant reduction of the head load on divertor plates, one of the main concerns by constructing a thermonuclear reactor, has been achieved due to the increase of edge radiation. On the other hand, in some devices impurity seeding has led to an improvement of the energy confinement and the so called radiation improved (RI) mode has been established with the same or even better confinement than in the H-mode. However, in order to make use of these positive impacts, the behaviour of seeded impurity has to be strictly controlled and such negative developments as the accumulation of impurity ions in the plasma core accompanied by a strong increase of the central radiation losses should be avoided.Plasma heating by radio-frequency (RF) waves has been proven to be a useful tool to control the behaviour of puffed impurities. In order to asses the prospective of impurity control by RF waves in larger devices and under reactor conditions, proper modelling approaches have been developed. One of the important parameters, which should be evaluated, is the averaged energy or temperature of heated impurity ions. The latter determines, in particular, the power transported to the main species, and, thus, the heating efficiency. Besides, the temperature of impurity ions characterizes the intensity of particle losses for heated impurities. An approach to compute the impurity temperature under such conditions is elaborated. It is based on the construction of a hierarchy of approximate solutions to the impurity heat balance equation and takes into account that the density and, thus, the heat conductivity of heated ion species can change by many orders of magnitude with the position in the plasma. The developed method has been incorporated into 1D transport code RITM. Coupled with the full wave code TORIC, the particle and heat balances for impurity and main plasma species provide a self-consistent approach to model the ion cyclotron resonance heating (ICRH) scenario. The modelling of various heating scenarios for several tokamaks displays the impacts of impurity heating on the heat and particles transport and heating efficiency. To investigate the possibility of impurity control at the large tokamak the experiment on selective impurity heating in the mode conversion H/D plasma was prepared and carried out in the tokamak JET.
Doctorat en sciences, Spécialisation physique
info:eu-repo/semantics/nonPublished
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Skoug, Ruth Marie. "The origin of narrow band cyclotron wave emissions called chorus /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/9685.
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Hirata, Yosuke. "Shaping of Millimeter Waves and Its Applications to Gyrotrons For Electron Cyclotron Heating of Magnetized Plasmas." Kyoto University, 1998. http://hdl.handle.net/2433/182235.
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Woodling, Kellie Ann. "Using electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry to study modified polypeptides." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012801.
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Deliyanakis, Nicholas. "A study of tokamak energy and particle transport, based on modulated electron cyclotron resonance heating." Thesis, University of Oxford, 1989. http://ora.ox.ac.uk/objects/uuid:b5426c92-b6ee-43fb-ad46-6fcb9ae9b4fe.
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A dynamical technique for the study of tokamak energy and particle transport has been developed. The plasma in the medium-sized DITE tokamak was perturbed by the application of modulated electron cyclotron resonance heating, with wave-launching from the high-field side. These experiments were carried out with absorption at various distances from the plasma centre, over a range of densities. Energy transport through the electron channel was dominant, and the variations in electron temperature and density were measured using the soft X-ray, electron cyclotron emission and microwave interferometer diagnostics. Analysis in the frequency domain enabled the propagation of the thermal wave to be followed. The observed behaviour was generally indicative of diffusive propagation of the thermal perturbation. Further observations indicated a modulation of the horizontal plasma shifts, diffusive propagation to the edge and a low modulation level of line-averaged density. In some atypical cases, the observed behaviour was qualitatively different; this type of behaviour was accompanied by a pronounced sawtooth oscillation locked with the modulation. Two models have been employed for the interpretation of these results. The first model, based on the diffusive thermal transport of the perturbation, has led to results in good agreement with the experimental data. Values of the electron thermal diffusivity were deduced, in good agreement with those obtained from the alternative techniques of power balance analysis and sawtooth heat pulse propagation analysis; such agreement has not been universally obtained in similar experiments. The width of the absorption region has emerged as an important consideration in this analysis. A more complex model, including non-linear, coupled equations of particle and energy balance, has produced results in partial agreement with the experimental data, supporting, to some extent, the presence of coupled transport. It has been demonstrated how perturbation techniques can afford a useful means of testing transport models.
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Maimone, Fabio Antonio. "Investigation on the Microwave-based techniques to improve the performances of the Electron Cyclotron Resonance Ion Sources." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/1016.
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Le sorgenti di ioni di tipo ECR (Electron Cyclotron Resonance) si sono rivelate molto importanti per la produzione continua ed affidabile di fasci intensi di ioni ad alto stato di carica destinati alle facilities di acceleratori di particelle. Recentemente, nuove tecniche sono state sviluppate per migliorare le prestazioni delle sorgenti ioniche esistenti e di quelle in fase di sviluppo. La variazione della frequenza delle microonde e l iniezione di due onde elettromagnetiche a frequenza diversa nella sorgente di ioni sono due aspetti importanti per tale miglioramento. Queste tecniche, basate sulle diverse distribuzioni di campo elettromagnetico che possono essere eccitate dentro una sorgente ECR e sul miglioramento dell accoppiamento a microonde tra le onde elettromagnetiche e il plasma magneticamente confinato, sono state analizzate in questa tesi. Abbiamo condotto la maggior parte degli esperimenti con la sorgente ECR CAPRICE istallata al GSI Helmholtzzentrum fuer Schwerionenforschung GmbH e i risultati conseguiti si sono rivelati importanti sia dal punto di vista scientifico che per lo sviluppo di nuove sorgenti ECR. Le analisi teoriche e sperimentali presentate con questo lavoro di tesi hanno fornito infatti utili spiegazioni sull aumento delle prestazioni di tali sorgenti di ioni in termini di produzione di fasci più intensi di ioni a più alto stato di carica.
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Martinet, Christine. "Oxydation du silicium par plasma d'oxygène : Cinétiques de croissance et analyses physiques des couches." Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10162.
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Ce travail est consacre a l'etude de l'oxyde de silicium realise par oxydation plasma a basse temperature dans un reacteur a resonance cyclotronique electronique repartie. Nous nous sommes interesses aux cinetiques de croissance en anodisation plasma (tension appliquee au substrat superieure au potentiel plasma) a courant constant qui decrivent bien un modele de diffusion d'ions o#- assistee champ. Mais, nous avons mis en evidence l'existence d'un premier regime, ou la tension reste constante, qui correspondrait a la formation d'une couche conductrice d'epaisseur 10-15 nm due aux photons u. V. Energetiques du plasma d'oxygene. Nous avons caracteris e physiquement nos oxydes plasmas. La methode d'absorption infrarouge s'est revelee tres adaptee a l'etude des couches minces de silice, en tenant compte des effets geometriques, mis en evidence par calcul et experimentalement, provoquant un deplacement fictif du pic du mode principal optique transverse (to) avec l'epaisseur d'oxyde, tandis que la position du pic du mode optique longitudinal (lo) reste invariante. La position des pics des modes lo et to nous permet de determiner l'angle moyen si-o-si et la densite de la silice. Les oxydes plamas montrent une position de ces deux pics tres deplacee par rapport aux oxydes thermiques laissant presager des oxydes denses. La reflectometrie x s'est revelee tres sensible a la rugosite de surface de l'oxyde tandis qu'il est difficile d'obtenir des valeurs precises pour les autres parametres (rugosite d'interface sio#2/si, densite). Les resultats des mesures sur les oxydes anodiques en absorption infrarouge et en reflectometrie x montrent une inhomogeneite en epaisseur. Enfin, des mesures c(v) montrent une caracteristique convenable bien que ces oxydes soient contamines par les metaux constituant le reacteur
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Artz, Mark E. "Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/79029.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 78-82).
The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion source into a high magnetic field cyclotron. Axial injection from an ion source with high brightness is important to reduce particle losses in the first several turns of acceleration within the cyclotron. Beam brightness is a measure of the beam current and rate of spread of the beam. The ultimate goal in developing an ECR ion source is to enable reduced beam losses along the entire acceleration path from the ion source through the cyclotron, allowing for a high beam current accelerator. Cyclotrons with high beam current have the potential to improve the availability of proton radiation therapy. Proton radiation therapy is a precisely targeted treatment capable of providing an excellent non-invasive treatment option for tumors located deep within tissue. In order to model injection into high field it is necessary to measure the parameters of the beam extracted from the ion source. The two most important beam parameters are emittance and beam current. The emittance of the beam is a measurement of the rate of beam spread along the path of the beam and beam current is a measurement of the energy and quantity of particles within a charged particle beam. This thesis presents the design and analysis of an ECR Ion Source and the instruments used to measure the emittance and beam current. Based on the modeling of the ECR ion source beam and the data gathered during testing, the ECR ion source presented in this thesis has the potential to provide a high brightness beam capable of high field axial injection. Beam simulations provide insight into the performance of the ECR ion source in high magnetic field. Axial beam injection from an external ion source is promising with moderate refinements to the ECR ion source.
by Mark E. Artz.
S.M.
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Panitzsch, Lauri [Verfasser]. "Spatial Distribution of Charged Particles Along the Ion-Optical Axis in Electron Cyclotron Resonance Ion Sources - Experimental Results / Lauri Panitzsch." Kiel : Universitätsbibliothek Kiel, 2013. http://d-nb.info/1031421483/34.
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