Publications

2013

• IN-SITU OBSERVATION OF MICROCRYSTALLINE SILICON THIN FILM GROWTH USING TAILORED VOLTAGE WAVEFORMS
  
  • Johnson E.V.
  • Bruneau Bastien
  • Delattre Pierre-Alexandre
  • Lafleur Trevor
  • Booth Jean-Paul
  , 2013.
• Electrostatic and Magnetic Energy Analyzers for Bipolar Particle Beams
  
  • Rafalskyi D.V.
  • Dudin S.V.
  • Aanesland Ane
  , 2013, Book of Abstracts, pp.271.
• Extracted H<SUP>-</SUP> ion current enhancement due to caesium seeding at different plasma grid bias
  
  • Bacal M.
  • Mcadams R.
  • Surrey E.
  , 2014, 85 (2), pp.02B103. This paper discusses the possibility that there is an enhancement of volume production due to gettering of atomic hydrogen by the caesium deposited on the walls, which reduces the negative ion destruction by associative and non-associative detachment. Such an enhancement would take place for all plasma grid bias voltages. Furthermore at plasma grid bias voltages higher than the plasma potential there is flow of the negative ions from the bulk plasma. (10.1063/1.4825387)
  DOI : 10.1063/1.4825387
• Experimentally obtained values of electric field of an atmospheric pressure plasma jet impinging on a dielectric surface
  
  • Sobota Ana
  • Guaitella Olivier
  • Garcia-Caurel Enric
  Journal of Physics D: Applied Physics, IOP Publishing, 2013, 46, pp.372001. We report on experimentally obtained values of the electric field magnitude on a dielectric surface induced by an impinging atmospheric pressure plasma jet. The plasma plume was striking the dielectric surface at an angle of 45◦, at 5mm from the surface measured at the axis of the jet. The results were obtained using Pockels technique on a BSO (Bi12SiO20) crystal. A coaxial configuration of the plasma jet was used, operating in a stable mode with one bullet per voltage period, at 30 kHz and amplitude of 2 kV. The electric field was shown to be a function of the gas flow (He, at 300, 500 and 700 SCCM) and the manner in which the discharge spreads over the dielectric surface. The maximum value of 11.6 × 105Vm−1 was obtained at the negative half-period of the discharge current measured at the grounded electrode, at the flow of 300 SCCM. The largest electric field averaged over the area of the spreading of the discharge (3.6 × 105Vm−1) was found in the same conditions. (10.1088/0022-3727/46/37/372001)
  DOI : 10.1088/0022-3727/46/37/372001
• Plasmas for Energy and Fusion
  
  • Morel Pierre
  , 2013.
• Nuclear background effects on plasma diagnostics for megajoule class laser facility
  
  • Rousseau A.
  • Darbon S.
  • Paillet P.
  • Girard Sylvain
  • Bourgade J.L.
  • Raine Melanie
  • Duhamel O.
  • Goiffon Vincent
  • Magnan P.
  • Chabane A.
  • Cervantes Paola
  • Hamel Matthieu
  • Larour Jean
  , 2013, 8850, pp.885004. Estimating the vulnerability is a key challenge for plasma diagnostics designed to operate in radiative background associated with megajoule class laser facilities. Since DT shots at OMEGA laser facility reproduce the perturbing source expected during the first 100 nanoseconds of a typical DT shot realized at National Ignition Facility (NIF) and Laser MegaJoule facility (LMJ), vulnerability of diagnostic elements such as optical relays or optical analyzers were experimentally studied and, if necessary, hardening approaches have been initiated to authorize their use at higher radiative constraints. Other facilities such as nuclear reactor or accelerator have been also used to estimate vulnerability issues as radiation induced emission of glasses or damage in multilayer coatings. (10.1117/12.2024005)
  DOI : 10.1117/12.2024005
• On-board hybrid magnetometer of NASA CHARM-II rocket: principle, design and performances
  
  • Coillot Christophe
  • Moutoussamy Joël
  • Chanteur Gérard
  • Robert Patrick
  • Alves F.
  Journal of Sensors and Sensor Systems, Copernicus Publ, 2013, 2, pp.137 - 145. We present a hybrid tri-axes magnetometer designed to measure weak magnetic fields in space from DC (direct current) up to a few kHz with a better sensitivity than fluxgate magnetometers at frequencies above a few Hz. This magnetometer combines a wire-wound ferromagnetic ribbon and a classical induction sensor. The nature of the wire-wound ferromagnetic ribbon sensor, giant magneto-impedance or magneto-inductance, is discussed. New configurations of wire-wound ferromagnetic ribbon sensors based on closed magnetic circuits are suggested and the hybrid sensor is described. The electronic conditioning of the wire-wound ribbon makes use of an alternating bias field to cancel the offset and linearize the output. Finally we summarize the main performances of the hybrid magnetometer and we discuss its advantages and drawbacks. A prototype has been built and was part of the scientific payload of the NASA rocket experiment CHARM-II (Correlation of High Frequency and Auroral Roar Measurements) launched in the auroral ionosphere. Unfortunately the launch campaign ended without any noticeable magnetic event and the rocket was eventually launched on 16 February 2010, through a very quiescent arc in the magnetic cusp and no wave activity was detected at frequencies observable by the hybrid magnetometer. (10.5194/jsss-2-137-2013)
  DOI : 10.5194/jsss-2-137-2013
• Tailoring plasma properties using pulse-shaping technology,
  
  • Booth Jean-Paul
  • Johnson E.V.
  • Lafleur Trevor
  • Delattre Pierre-Alexandre
  • Boswell R.W.
  , 2013.
• Time variations of the total electron content in the Southeast Asian equatorial ionization anomaly for the period 2006-2011
  
  • Le Huy Minh
  • Amory-Mazaudier Christine
  • Fleury Rolland
  • Bourdillon Alain
  • Lassudrie Duchesne Patrick
  • Nguyen Chien Thang
  • Nguyen Ha T
  • Vila Paul
  Advances in Space Research, Elsevier, 2013, 53 (3), pp.355 - 368. This study presents the time variations of the total electron content in the South East Asian equatorial ionization anomaly. The time variation of the TEC is analyzed through the period 2006-2011 by using a latitudinal chain of GPS stations extending in the northern and southern hemisphere. The data shows that the shape of the diurnal variation of the TEC depends on the latitude: a plateau is observed at the stations near the equator and a Gaussian at the station distant from the equator. We observe a semiannual pattern in all the stations with maxima at equinox. In both hemispheres, the amplitude of the crest is larger in spring than autumn from 2006 to 2008 and smaller in spring than in autumn from 2009 to 2011. We also observe an asymmetry between the amplitude and the position of the two crests of ionization. There is a very high level of correlation between the amplitude of the TEC at the two crests and the sunspot number: ~0.88. During the deep solar minimum 2008-2009, the amplitude of crests of ionization becomes small during several months in summer and winter. The results show that both crests move significantly equatorward in winter than other seasons and there is a tendency for both crests to appear earlier in winter and later in summer. (10.1016/j.asr.2013.08.003)
  DOI : 10.1016/j.asr.2013.08.003
• Hall thruster plasma fluctuations identified as the E x B electron drift instability: Modeling and fitting on experimental data
  
  • Tsikata S.
  • Honoré Cyrille
  • Grésillon D.
  • Cavalier Jordan
  • Lemoine Nicolas
  • Bonhomme Gérard
  Physics of Plasmas, American Institute of Physics, 2013, 20 (8), pp.082107. Microturbulence has been implicated in anomalous transport at the exit of the Hall thruster, and recent simulations have shown the presence of an azimuthal wave which is believed to contribute to the electron axial mobility. In this paper, the 3D dispersion relation of this E x B electron drift instability is numerically solved. The mode is found to resemble an ion acoustic mode for low values of the magnetic field, as long as a non-vanishing component of the wave vector along the magnetic field is considered, and as long as the drift velocity is small compared to the electron thermal velocity. In these conditions, an analytical model of the dispersion relation for the instability is obtained and is shown to adequately describe the mode obtained numerically. This model is then fitted on the experimental dispersion relation obtained from the plasma of a Hall thruster by the collective light scattering diagnostic. The observed frequency-wave vector dependences are found to be similar to the dispersion relation of linear theory, and the fit provides a non-invasive measurement of the electron temperature and density. (10.1063/1.4817743)
  DOI : 10.1063/1.4817743
• Hybrid simulations of small planets and planetary moons
  
  • Chanteur Gérard
  , 2013. This tutorial is an introduction to the hybrid modeling of the interactions of small planetary objects (planets or moons) with their surrounding plasmas. This presentation will not discuss per se the various hybrid schemes used in plasma physics from a numerical analysis point of view but will rather be focused on the modeling and implementation of the main physical phenomena involved in these interactions. The plasma surrounding the planetary object is either the solar wind or a magnetospheric plasma and the corresponding flow is either super or subcritical leading or not to the formation of a bow shock upstream of the obstacle. The required external boundary conditions will be briefly discussed. The object itself may possess an intrinsic magnetic field driven by a dynamo or a fossile field: we will discuss how to handle this field. The object may possess a more or less dense atmosphere requiring to implement the ion photoproduction by taking into account the photoabsorption. If a dense atmosphere is present it is necessary to modelize its effects on the dynamics of energetic particles. If an ionosphere is present it may involve a complex chemistry requiring a simplified model to produce the main escaping species. At last the object may have an ordinary exosphere fed by its atmosphere or a surface bounded exosphere requiring specific models. The implementation of the main processes coupling the neutral species and the plasma - photoionization, electron impacts and charge exchange reactions will be discussed. The examples of Mercury, Mars and Titan will support and illustrate these discussions. Another aim of this presentation is to show what can be inferred about a planetary environment like the Martian one by means of global three-dimensional simulations combining a self-consistent hybrid simulation model with a variety of derived models involving test particles.
• Lifetime of quasistationary states in the Hamiltonian Mean Field model
  
  • Ettoumi Wahb
  • Firpo Marie-Christine
  , 2013, pp.PP2-3-8.
• Development of magnetohydrodynamic modes during sawteeth in tokamak plasmas
  
  • Firpo Marie-Christine
  • Ettoumi Wahb
  • Farengo Ricardo
  • Ferrari Hugo
  • Garcia-Martinez Pablo Luis
  • Lifschitz Agustin
  Physics of Plasmas, American Institute of Physics, 2013, 20 (7), pp.072305. A dynamical analysis applied to a reduced resistive magnetohydrodynamics model is shown to explain the chronology of the nonlinear destabilization of modes observed in tokamak sawteeth. A special emphasis is put on the nonlinear self-consistent perturbation of the axisymmetric m=n=0 mode that manifests through the q-profile evolution. For the very low fusion-relevant resistivity values, the q-profile is shown to remain almost unchanged on the early nonlinear timescale within the central tokamak region, which supports a partial reconnection scenario. Within the resistive region, indications for a local flattening or even a local reversed-shear of the q-profile are given. The impact of this ingredient in the occurrence of the sawtooth crash is discussed. (10.1063/1.4816025)
  DOI : 10.1063/1.4816025
• Application of nanosecond surface dielectric barrier discharge for ignition of combustible mixtures at elevated pressures
  
  • Stepanyan S.A.
  • Boumehdi M.A.
  • Vanhove G.
  • Desgroux Pascale
  • Starikovskaia Svetlana
  , 2013.
• Visualization of the nanosecond surface dielectric barrier discharge in air and argon
  
  • Stepanyan S.A.
  • Starikovskaia Svetlana
  , 2013.
• Detailed electrical description of a guided streamer source
  
  • Guaitella Olivier
  • Sobota Ana
  • Rousseau Antoine
  , 2013.
• Gas temperature variation in millisecond pulsed discharges in air
  
  • Pintassilgo C.D.
  • Marinov Daniil
  • Guaitella Olivier
  • Rousseau Antoine
  , 2013.
• Experimental study of a helium discharge propagating in a dielectric capillary - Influence of the charge deposition on inner surfaces
  
  • Dang van Sung Mussard Marguerite
  • Guaitella Olivier
  • Rousseau Antoine
  , 2013.
• Experimental measurements of atomic oxygen concentrations in a capillary nanosecond discharge
  
  • Klochko A.V.
  • Salmon A.
  • Popov N.A.
  • Starikovskaia Svetlana
  , 2013.
• Optical diagnostics of low-pressure plasmas in halogen gases
  
  • Booth Jean-Paul
  • Chabert Pascal
  • Sirse Nishant
  • Indelicato P.
  • Surzykov A.
  • Kushner M.J.
  , 2013.
• In situ observations of magnetic reconnection and associated particle energization in turbulent plasmas
  
  • Retinò Alessandro
  • Vaivads A.
  • Sundkvist D.
  • Chasapis A.
  • Greco A.
  • Sahraoui Fouad
  • Rossi C.
  , 2013.
• Modelling of mesoscales and nonlocal transport in plasma turbulence
  
  • Gürcan Özgür D.
  , 2013. http://www.festival-theorie.fr
• Interaction of magnetic clouds with the Earth's magnetosphere
  
  • Turc Lucile
  • Fontaine Dominique
  • Kilpua E. K. J.
  • Savoini Philippe
  , 2013. Magnetic clouds (MC) are well-defined solar wind structures, known to trigger intense geomagnetic storms. When studying their impact on the Earth's environment, it is generally assumed that the structures observed in the upstream solar wind are unchanged when they interact with the magnetosphere. However, before encountering the magnetopause, the MCs cross the terrestrial bow shock which alters their structure. Therefore their expected geoeffectivity may be modified by the shock. In this study, we focus on the magnetic structure of MCs. A simple 3D MHD model is used to describe the interaction of a MC with the bow shock and its propagation in the magnetosheath. Several cases are presented, corresponding to different orientations of the MC axis and different impact parameters. The results show that the shock obliquity plays a major role in determining the variation of the magnetic field direction. Asymmetries can be observed inside the magnetosheath. Moreover, the Bz component can even reverse in some parts of the magnetosheath. The outputs of the model are compared to spacecraft observations, and the implications on a MC's geoeffectivity are discussed.
• Ramp compression of a metallic liner driven by a shaped 5 MA current on the SPHINX machine
  
  • d'Almeida Thierry
  • Lassalle Francis
  • Morell Alain
  • Grunenwald Julien
  • Zucchini Frédéric
  • Loyen Arnaud
  • Maysonnave Thomas
  • Chuvatin Alexandre S.
  , 2013. SPHINX is a 6MA, 1-&#956;s Linear Transformer Driver operated by the CEA Gramat (France) and primarily used for imploding Z-pinch loads for radiation effects studies. Among the options that are currently being considered for improving the generator performances, there is a compact Dynamic Load Current Amplifier (DLCM). A method for performing magnetic ramp compression experiments, without modifying the generator operation scheme, was developed using the DLCM to shape the initial current pulse. We present the overall experimental configuration chosen for these experiments, based on electrical and hydrodynamic simulations. Initial results obtained over a set of experiments on an aluminum cylindrical liner, ramp-compressed to a peak pressure of 23 GPa, are presented. Details of the electrical and Photonic Doppler Velocimetry (PDV) setups used to monitor and diagnose the ramp compression experiments are provided. Current profiles measured at various locations across the system, particularly the load current, agree with simulated current profile and demonstrate adequate pulse shaping by the DLCM. The liner inner free surface velocity measurements agree with the hydrocode results obtained using the measured load current as the input. Higher ramp pressure levels are foreseen in future experiments with an improved DLCM system. oral communication, abstract in Bulletin of the American Physical Society, vol 58, num 7, V5.00003
• Optical Diagnostics For High Power Pulsed Underwater Electrical Discharge Characterization
  
  • Deroy Julien
  • Claverie Alain
  • Avrillaud Gilles
  • Boustié Michel
  • Mazanchenko Ekaterina
  • Assous David
  • Chuvatin Alexandre S.
  , 2014, 500, pp.142010. In order to evaluate the behavior of a high power pulsed underwater electrical discharge, and especially characterize the pressure generated by such a discharge, we implemented several optical diagnostics. We first observed directly the expansion of the plasma produced by the dielectric breakdown of the water between the electrodes and the resulting gaseous pulsating bubble. This observation led to an estimate of the pressure inside the bubble with respect to time. We then visualized the propagation of the pressure wave generated by the discharge with shadowgraphy and Schlieren set-up. The obtained velocity was then used to evaluate the theoretical maximum pressure at the pressure front. Finally, we measured the velocity induced by the pressure wave on a thin aluminum disk with a heterodyne velocimeter and used numerical simulation to obtain a temporal form of pressure. These methods and results can be used to develop and assess performances of processes using underwater electrical discharges to generate pressure waves such as electrohydraulic forming. commincation orale abstract dans Bulletin of the American Physical Society, vol 58, num 7, Y3.00002 (10.1088/1742-6596/500/14/142010)
  DOI : 10.1088/1742-6596/500/14/142010