Publications

2012

• Plasma Excitation using Tailored Voltage Waveforms for the Deposition of Thin Film Silicon for Photovoltaics: From Plasma Physics to Devices
  
  • Johnson E.V.
  • Delattre Pierre-Alexandre
  • Lafleur Trevor
  • Booth Jean-Paul
  , 2012.
• Electron temperature and plasma density distribution measurement along magnetic barrier in the PEGASES thruster
  
  • Bredin Jérôme
  • Aanesland Ane
  • Chabert Pascal
  • Godyak Valery
  , 2012.
• Inductively-coupled plasmas in pure chlorine: comparison experiments/HPEM
  
  • Booth Jean-Paul
  • Sirse Nishant
  • Azamoum Yasmina
  • Chabert Pascal
  , 2012.
• Panorama de la physique - nouvelle édition
  
  • Auvray Loïc
  • Berroir Jean-Marc
  • Billy Nicolas
  • Daudet Laurent
  • Fabre Claude
  • Laval Katia
  • Madariaga Raoul
  • Mégie Gérard
  • Ollitrault Jean-Yves
  • Oudar Jean-Louis
  • Pietryk Gilbert
  • Ravetta François
  • Rezeau Laurence
  • Uzan Jean-Philippe
  • Vigny Christophe
  , 2012.
• Reactive adsorption of molecules and radicals on surfaces under plasma exposure
  
  • Marinov Daniil
  , 2012. Atomic sources, thermal protection for atmospheric re-entry and plasma-catalyst systems for air pollution control are just few examples of applications where interaction between N2/O2 containing plasmas and the surface plays a central role. Mechanisms of heterogeneous processes in plasmas are still barely understood. Unknown conditions on the surface limit the accuracy and predictive capability of the kinetic models. In the first part of this work we investigate adsorption and chemical reactions of O and N atoms on oxide surfaces (silica, Pyrex, TiO2) under plasma exposure. We use tuneable laser absorption spectroscopy, broad-band UV absorption spectroscopy, two-photon absorption laser-induced fluorescence (TALIF) and mass spectrometry to monitor interaction between gas phase species and the surface. Surface analysis is performed using x-ray photoelectron spectroscopy (XPS). It has been shown that stable Oads and Nads atoms are grafted to oxide surfaces under exposure to low pressure (~1 mbar) plasmas in O2 and N2. The coverage and reactivity of adsorbed atoms has been probed by exposing the pretreated surface to stable molecules (NO, C2H2) and radicals (O, N). Using isotopic exchange 15N↔14Nads and 18O↔16Oads under plasma exposure the role of chemisorbed species in surface catalysed recombination of atoms has been investigated. In the second part of this thesis, relaxation of vibrationally excited N2 molecules on catalytic surfaces is studied using infrared (IR) titration technique. Mixtures containing 0.05 - 1% of CO2 (CO, N2O) in N2 at p=1.3 mbar are excited by a single dc discharge pulse. The kinetics of vibrational relaxation of IR tracers during the post-discharge is followed using quantum cascade laser absorption spectroscopy. Due to a very efficient vibrational energy transfer between N2 and CO2 (CO, N2O), excitation of IR tracers is an image of the vibrational excitation of N2. Relaxation measurements have been interpreted in terms of a numerical model of non-equilibrium vibrational kinetics. Probability of N2 vibrational quantum loss has been determined from the best agreement between the experiment and the model.
• Analyse et interprétation de la variation régulière du champ magnétique terrestre au Vietnam et modélisation de l'ionosphère
  
  • Pham Thi Thu Hong
  , 2012. La circulation de courants électriques dans la région dynamo (90-150km) de l'ionosphère engendrent des variations journalières régulières du champ magnétique terrestre observées au sol, en basses et moyennes latitudes, appelées Sq (solar quiet) par Chapman et Bartels (1940) ou SR (Solar regular) par Mayaud (1967). Dans ce travail de thèse, nous étudions la variation régulière du champ magnétique terrestre au Vietnam et l'ionosphère, dans le cadre global des relations Terre Soleil. Le premier chapitre présente toutes les notions nécessaires pour comprendre cette étude, concernant le soleil et le champ magnétique solaire, le champ magnétique terrestre, et les interactions entre le soleil et la terre. Le deuxième chapitre présente les données- indices solaires, indices magnétiques, paramètres du vent solaire, observations magnétiques, données ionosphériques- et les modèles- MSIS90 et TIEGCM. Au chapitre trois, nous présentons pour la station de Phu Thuy (Vietnam) les résultats obtenus à partir des observations magnétiques concernant la variation régulière Sq du champ magnétique terrestre durant le cycle solaire 23, les résultats concernant l'analyse des paramètres ionosphériques sur plusieurs cycles solaires à Phu Thuy et le modèle de conductivités ionosphériques au Vietnam. Enfin le dernier chapitre présente les simulations des variations à long terme de la fréquence critique de la région F2, foF2, observée à Phu Thuy au Vietnam, à l'aide du modèle TIEGCM du NCAR. Ce modèle nous a permis d'étudier les influences des marées migrantes, des marées non-migrantes de la basse atmosphère, et des changements d'activités géomagnétiques sur la variation à long terme de foF2.
• Mesure de densité électronique dans les plasmas froids par techniques micro-ondes
  
  • Booth Jean-Paul
  , 2012.
• Design and Characterization of a High Dynamic Range and Ultra Low Power 16-Channel ASIC for an Innovative 3D Imaging Space Plasma Analyzer
  
  • Rhouni Amine
  • Techer Jean-Denis
  • Sou Gérard
  • Berthomier Matthieu
  IEEE Transactions on Nuclear Science, Institute of Electrical and Electronics Engineers, 2012, 59 (5), pp.2580 - 2586. A very low power 16-channel ASIC has been designed and fabricated in a standard 0.35 $mu{hbox{m}}$ CMOS technology. It is to be used as the front-end electronics of the micro-channel plates (MCPs) based detector of a 3D space plasma analyzer. Each channel includes a charge sensitive amplifier (CSA) and a discriminator. With a CSA conversion gain of 0.5 mV/fC, the ASIC is able to detect charges emitted by the MCPs over a wide dynamic range of 10 fC to 3.5 pC. The CSA pulse-pair-resolution (PPR) is 170 ns, and the maximum counting rate frequency is 7.5 MHz for input charges limited to 100 fC and 4.6 MHz for full scale inputs. The CSA input devices are optimized for a detector capacitance varying in the range of 2-12 pF. The measured input equivalent noise charge $({hbox{ENC}}_{rm in})$ is 1.3 fC $+$ 0.1 fC/pF rms. These features have been obtained with an unprecedented low power consumption of only 0.64 mW per channel. Experimental tests under the extended temperature range of $-{hbox{40}}~^{circ}{hbox{C}}$ to 85$~^{circ}{hbox{C}}$ have shown no significant performance variations. (10.1109/TNS.2012.2211933)
  DOI : 10.1109/TNS.2012.2211933
• Transport des électrons et des ions négatifs au travers d'une barrière de champ magnétique
  
  • Aanesland Ane
  • Bredin Jérôme
  • Chabert Pascal
  , 2012.
• Achievements IHY and ISWU
  
  • Amory-Mazaudier Christine
  , 2012.
• Indications of Nonlocality of Plasma Turbulence
  
  • Gürcan Özgür D.
  • Vermare Laure
  • Hennequin Pascale
  • Berionni Vincent
  • Diamond P.H.
  • Dif-Pradelier G.
  • Garbet X.
  • Ghendrih Ph.
  • Grandgirard V.
  • Mcdevitt C.J.
  • Morel Pierre
  • Sarazin Y.
  • Storelli A.
  • Bourdelle C.
  • Tore Supra Team
  , 2012 (TH-P2-12).
• A radio-frequency plasma antenna produced by filamentation in air
  
  • Brelet Yohann
  • Houard Aurélien
  • Arantchouk Léonid
  • Point G.
  • Prade Bernard S.
  • Carbonnel Jérôme
  • André Y-B.
  • Mysyrowicz André
  , 2012.
• CLUSTER observations of electron scale turbulence in the solar wind
  
  • Sahraoui Fouad
  • Huang S. Y.
  • Goldstein M. L.
  • Belmont Gérard
  , 2012.
• Cluster observations of band-limited Pc 1 waves associated with streaming H + and O + ions in the high-altitude plasma mantle
  
  • Engebretson M J
  • Kahlstorf C.R.G.
  • Murr D.L.
  • Posch J L
  • Keiling A.
  • Lavraud B.
  • Rème H.
  • Lessard M. R.
  • Kim E.-H.
  • Johnson J.R.
  • Dombeck J.
  • Grison B.
  • Robert Patrick
  • Glassmeier K.-H.
  • Décréau Pierrette
  Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2012, 117 (A10), pp.n/a-n/a. have been observed by the Cluster spacecraft during many passes through the high-latitude plasma mantle. These transverse, left-hand polarized waves are associated with regions of H + and O + ions streaming away from Earth along magnetic field lines at the same velocity ($140 km/s). Waves were observed only when H + fluxes increased by factors of 10-1000 and energies of both ion species increased by factors of up to 10. We present two satellite-ground conjunctions to demonstrate the high latitude localization of these waves and their ability to reach the polar ionosphere and two extended examples of waves and associated ion distribution functions near the southern dusk flank magnetopause. We also present the results of a search for all such events during Cluster's 2002 and 2003 passages through the magnetotail, with orbital precession covering dawn to dusk on Earth's night side (June through December). A total of 46 events (band-limited Pc 1-2 waves accompanied by a sustained population of streaming H + and O + ions, separated by at least 12 min) were observed on 29 days. The waves were generally associated with intervals of southward IMF Bz and/or large IMF By (times of active cusp reconnection), and often but not always occurred during the main phase or early recovery phase of magnetic storms. Analysis of selected events shows that the waves are associated with large H + temperature anisotropy, and that the waves propagate opposite to the direction of the streaming ions. A wave instability analysis using the WHAMP code confirms that the generation of these waves, via the ion cyclotron instability, is basically consistent with known physics. Their extended region of wave growth is likely, however, to reach tailward significantly beyond the Cluster orbit. (10.1029/2012JA017982)
  DOI : 10.1029/2012JA017982
• Anomalous heating of magnetically compressed plasmas : the role of reconnection
  
  • Chuvatin Alexandre S.
  , 2012.
• Conception d'une optique électrostatique à champ de vue hémisphérique pour l'étude des plasmas magnétosphériques, terrestre et planétaires
  
  • Morel Xavier
  , 2012. Nous présentons le développement d'une optique électrostatique à champ de vue hémisphérique fonctionnant dans la gamme d'énergie allant de quelques eV à 30 keV et dont nous avons étudié le principe de fabrication en mettant en place un procédé de lithographie innovant. Après avoir exposé nos motivations scientifiques et l'état de l'art des optiques électrostatiques dédiées à l'étude des plasmas spatiaux, nous présentons le concept optique à la base de cet instrument. Avec deux têtes de mesure, il est possible de s'affranchir de la période de rotation des satellites pour avoir une couverture complète des directions d'arrivée des particules. La résolution temporelle des mesures n'est plus déterminée que par la rapidité du balayage en énergie de l'instrument et par sa sensibilité qui s'avère équivalente à un ensemble de 8 détecteurs classiques à champ de vue 2D. Ce concept repose sur une polarisation indépendante des faces internes et externes des électrodes. Ceci est rendu possible par l'utilisation de plastique haute performance pour la réalisation des électrodes de l'optique. Deux procédés ont été mis en place ab initio pour permettre la fabrication de l'optique au laboratoire. Le premier est un procédé de métallisation chimique, le second un procédé de lithographie laser. Leur combinaison permet de réaliser une métallisation sélective des électrodes pour assurer une décroissance linéaire du potentiel en certaines zones de l'optique afin d'éviter les phénomènes de claquage. La question de la polarisation à haute tension de l'optique est également abordé, nous montrons comment l'ablation en profondeur du polymère permet de polariser l'optique à champ de vue 3D sans affecter ses performances.
• Hybrid simulation of the Solar wind interaction with the Martian ionosphere and magnetic field
  
  • Hess Sebastien
  • Modolo Ronan
  • Richer Emilie
  • Mancini Marco
  • Leblanc François
  • Chaufray Jean-Yves
  • Chanteur Gérard
  • Mazelle Christian
  • Grimald S.
  • Forget François
  • Gonzalez-Galindo F.
  , 2012, 7, pp.EPSC2012-299. In the frame of the HELIOSARES project (PI F.Leblanc) dedicated to the modeling of Mars environment (neutral and charged species) from the lower atmosphere to the solar wind, a modeling effort has been conducted to parallelize a multi-species hybrid simulation code. This code now provides a kinetic description of the ions with a rather improved spatial resolution (smaller than the ion inertial length). The latest progresses are reported and simulations results with a uniform spatial resolution of 80 km are presented. This fully parallelized code describes both the dynamics and physical and chemical processes involved in the interaction. Photoproduction, charge exchange and electron impact ionization are computed dynamically through the simulation domain. The Martian ionosphere can be described either by external profile - e.g. by coupling with the result of ionosphere-exosphere simulations - or internally computed profiles obtained by assuming an equilibrium between several chemical processes (in which case transport is neglected). Moreover, the Martian crustal field can be integrated in our model to study its influence on the interaction dynamic and the ionosphere escape rate. We hereby show the results of these simulations and discussed their impact on the understanding of the Martian environment.
• Modélisation et simulation de l'interaction du Vent Solaire avec Mercure et Mars
  
  • Richer Emilie
  , 2012. L'objectif de ce travail est d'étudier les interactions du Vent Solaire (VS) avec Mercure et Mars par le biais de la simulation numérique. Dans le contexte des observations effectuées lors des seules missions ayant exploré l'environnement de Mercure, Mariner 10 et MESSENGER, et de la préparation de la mission Bepi Colombo, nous avons développé un modèle hybride tridimensionnel parallèle de l'interaction du VS avec la magnétosphère de Mercure. Nous avons également étudié la réflexion de particules incidentes sur un choc planétaire courbe, celui de Mars, grâce à un modèle de particules-tests combiné aux résultats de simulations hybrides. Les observations, bien qu'indispensables à l'étude de l'interaction du VS avec un obstacle planétaire, ne sont pas suffisantes et la modélisation numérique est un outil nécessaire. Dans le second chapitre nous présentons les différents modèles de simulation utilisés pour analyser les interactions du VS avec Mercure et Mars. Nous décrivons en particulier la construction de notre modèle hybride de Mercure. Les résultats sur l'environnement Herméen, obtenus à l'aide de modèles antérieurs au notre sont décrits dans la première partie du Chapitre 3. Dans la suite de ce chapitre nous présentons nos résultats sur le champ intrinsèque et le plasma magnétosphérique de Mercure. Dans le Chapitre 4, nous décrivons le modèle hybride et le programme de particules-tests que nous avons utilisés pour étudier la réflexion des protons du VS et des protons planétaires sur l'onde de choc Martienne. Nous montrons par la suite les résultats obtenus. Bien que cette analyse ait été menée sur l'onde de choc de Mars, elle peut être adaptée au cas de Mercure.
• Dynamos in the Sun Earth's system
  
  • Amory-Mazaudier Christine
  , 2012.
• Mars-Solar wind interaction: coupling between hybrid and exospheric models
  
  • Modolo Ronan
  • Leblanc François
  • Hess Sebastien
  • Yagi M.
  • Chaufray Jean-Yves
  • Mancini Marco
  • Forget François
  • Gonzalez-Galindo F.
  • Grimald S.
  • Mazelle Christian
  • Chanteur Gérard
  , 2012, pp.EPSC2012-294. Solar wind interacts efficiently with Mars, it contributes to the erosion of the gazeous envelope and concurs to the atmospheric dynamic. The electromagnetic coupling with the neutral environment takes place with ionization processes which act as a catalyzer. A three-dimensional model has been developped to describe the solar wind and planetary plasma dynamic. Parallelization of the model has been accomplished and enable us to reach a grid resolution of 80 km or less, which are slightly more than plasma scale height in the ionophere. This model has been coupled to a three dimensional exospheric model giving the description of the neutral corona at different seasons. The seasonal effect of the thermosphere-exosphere on the Martian plasma environment is investigated and discussed in this presentation.
• Use of GPS for Ionospheric studies
  
  • Amory-Mazaudier Christine
  , 2012.
• Europlanet-RI IDIS - Information System and Virtual Observatory for Planetary Research
  
  • Schmidt Walter
  • Capria Maria Teresa
  • Chanteur Gérard
  , 2012, pp.EPSC2012-377. As the Europlanet-Research Infrastructure project draws to its close at the end of 2012, the various results of the different activities will be made publically available via the project's Integrated and Distributed Information System IDIS [1].
• New insight into short wavelength solar wind turbulence from linear Vlasov theory
  
  • Sahraoui Fouad
  • Belmont Gérard
  • Goldstein M. L.
  , 2012.
• Guiding 1-m scale discharge created by a Tesla generator triggered with femtosecond laser filament in air
  
  • Arantchouk Léonid
  • Brelet Yohann
  • Houard Aurélien
  • André Y-B.
  • Prade Bernard S.
  • Carbonnel Jérôme
  • Mysyrowicz André
  , 2012, pp.251. oral presentation We report experiments on laser guided discharges obtained in air by the high voltage delivered by a compact Tesla coil. The home-made Tesla generator provides bursts of voltage oscillations at 100 kHz with peak amplitude of about 350 kV. The voltage is applied between two spherical electrodes. The discharge is triggered by a laser pulse at 800 nm of 350 mJ energy and 700 fs duration. Before reaching the electrodes, the pulse undergoes filamentation, producing thereby a 2 m long continuous plasma column with a diameter of 5 mm and a nearly constant electron density of n ~ 1016 electrons/cm3. No electric discharge is produced by the Tesla generator in the absence of the laser when the interelectrode distance is larger than 32 cm because the electric field is less than the critical value for spontaneous breakdown. Guided discharges activated by filament plasma column are obtained up to an interelectrode distance of 150 cm. The triggering of the guided discharge depends sensitively on the laser arrival time with respect to the phase and amplitude of theTesla voltage cycles. Data on the discharge current, delay between the laser arrival and the initiation of the discharge will be presented. Images of the discharging path guided by the filament will be shown as well.
• Low jitter, high current spark gap operating with air at normal pressure
  
  • Arantchouk Léonid
  • Houard Aurélien
  • Brelet Yohann
  • Forestier Benjamin
  • Carbonnel Jérôme
  • Larour Jean
  • Mysyrowicz André
  , 2012, pp.250. oral presentation. We demonstrate a simple, reliable air spark gap operating at atmospheric pressure and able to switch currents in excess of 10 kA. The spark gap with an interelectrode spacing close to10 mm is remotely triggered by a femtosecond laser system. This laser delivers pulses at 800 nm of typically 350 fs duration and energy of 200-250 mJ, corresponding to a peak power of about 600 GW. After propagation in air, the weakly converging laser beam undergoes filamentation. This leads to the production of a 1-2 m long continuous plasma column of nearly uniform longitudinal electron density n ~ 1016 electrons/cm3. The plasma column of diameter ~ 5 mm connects quasi instantaneously to electrodes. We studied two switch configurations. In first one two cylindrical electrodes of diameter 36 mm pulse charged up to 0.6-1.2 of the self-break voltage (25-30 kV). The triggered laser beam passes through holes 3 and 5 mm diameter. A sub-nanosecond jitter is demonstrated. The second configuration consists of spherical metal electrodes of 10 and 20-mm diameter DC-charged. They are connected to the laser produced plasma channel by grazing contact with vertical electrode shift of 2-3 mm. Jitter of 1-3 ns have been measured here.