Publications

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Sont listées ci-dessous, par année, les publications figurant dans l'archive ouverte HAL.

2010

Simulations 2D PIC d'un choc courbe supercritique: dynamique du précurseur électromagnétique
- Stienlet J.
- Savoini Philippe
- Lembège Bertrand
, 2010, pp.5 p..
Météorologie de l'Espace en Afrique : les programmes Année 2010 Egypte France et ISWI
- Damé Luc
- Marhous Ayman
- Amory-Mazaudier Christine
- Petitdidier Monique
- Hady Ahmed
, 2010, pp.8 p..
Modelling of chlorine inductive discharges
- Chabert Pascal
- Despiau-Pujo Emilie
, 2010.
Effect of low-frequency power on electron density and ion flux in dual-frequency capacitive radiofrequency discharges
- Booth Jean-Paul
- Curley G.
- Chabert Pascal
, 2010.
Nonstationarity of two / three - dimensional supercritical perpendicular shocks: nonlinear whistler emission versus shock front self-reformation
- Lembège Bertrand
- Savoini Philippe
- Hellinger P.
- Travnicek P. M.
, 2010.
Measurements and Modeling of Turbulent Transport in the Tore Supra Tokamak
- Garbet X.
- Abiteboul J.
- Benkadda S.
- Bourdelle C.
- Casati A.
- Clairet F.
- Dubuit N.
- Falchetto G.
- Fenzi C.
- Futatani S.
- Grandgirard V.
- Guirlet R.
- Gürcan Özgür D.
- Hennequin Pascale
- Heuraux S.
- Hoang G.T.
- Honoré Cyrille
- Sabot R.
- Sarazin Y.
- Ségui J.-L.
- Smolyakov A.
- Trier Elisée
- Vermare Laure
- Villegas D.
, 2010, 1308, pp.75-84. This paper presents an overview of recent advances in modeling and measurements of turbulence in Tore Supra plasmas. Spatio‐temporal properties of turbulence are discussed in relation with transport models. An explanation is proposed for the k−3 decay of wave number spectra, which are observed by using both coherent laser scattering and Doppler reflectometry. Also the interplay between turbulence and flows has been investigated. It is shown that toroidal rotation results from a competition between neoclassical and turbulence flow generation. Finally a new method has been proposed to determine the transport coefficients of impurities. These coefficients are usually well above the neoclassical prediction. (10.1063/1.3526165)
DOI : 10.1063/1.3526165
Surface discharges: possible applications for plasma-assisted ignition and electric field measurements (AIAA 2010-1587)
- Starikovskaia Svetlana
- Allegraud Katia
- Guaitella Olivier
- Kosarev I.N.
- Mintoussov E.I.
- Pendleton S.J.
- Popov N.A.
- Sagulenko P.N.
- Rousseau Antoine
, 2010.
A model for the self-pulsing regime of microhollow cathode discharges
- Chabert Pascal
- Lazzaroni Claudia
- Rousseau Antoine
Journal of Applied Physics, American Institute of Physics, 2010, 108, pp.113307. Microhollow cathode discharges may operate in different regimes depending of the discharge current. They are subject to relaxation oscillations in the so-called self-pulsing regime in which the discharge oscillates between two quasiequilibria: at low current it remains confined in the microhole whereas it expands on the cathode backside during short high-current pulses. A model based on a nonlinear discharge resistance is proposed to describe the phenomenon. The analysis of the dynamics reveals that the current pulse rises in an extremely short time while the characteristic (longer) decay time is imposed by the resistance when the discharge is expanded outside the hole. It is shown how the nonlinear discharge resistance may be inferred from the experimental current-voltage signals. (10.1063/1.3518533)
DOI : 10.1063/1.3518533
Plasmas froids radiofréquence
- Chabert Pascal
- Raimbault Jean-Luc
Images de la physique 2009, 2010, pp.p27. L'interaction d'un plasma froid faiblement ionisé et d'une surface semiconductrice est à l'origine des technologies de nanostructuration de la matière en microélectronique. Ces plasmas sont générés et entretenus par des champs électromagnétiques radiofréquence. La compréhension des mécanismes fondamentaux du couplage de l'énergie électromagnétique au plasma et de son transport vers les surfaces du réacteur est un enjeu majeur pour la maîtrise des procédés industriels utilisant les plasmas froids radiofréquence.
Electric Current Systems in the Earths Environment
- Amory-Mazaudier Christine
Nigerian Journal of Space Research, National space research and development agency, 2010, 8, pp.178-255. ...
Solar wind turbulent spectrum from MHD to electron scales
- Alexandrova O.
- Saur J.
- Lacombe C.
- Mangeney A.
- Schwartz S. J.
- Mitchell J.
- Grappin Roland
- Robert Patrick
, 2010, 1216, pp.144-147. Turbulent spectra of magnetic fluctuations in the free solar wind are studied from MHD to electron scales using Cluster observations. We discuss the problem of the instrumental noise and its influence on the measurements at the electron scales. We confirm the presence of a curvature of the spectrum ~expkrhoe over the broad frequency range ~ [10,100] Hz, indicating the presence of a dissipation. Analysis of seven spectra under different plasma conditions show clearly the presence of a quasi-universal power-law spectrum at MHD and ion scales. However, the transition from the inertial range ~k-1.7 to the spectrum at ion scales ~k-2.7 is not universal. Finally, we discuss the role of different kinetic plasma scales on the spectral shape, considering normalized dimensionless spectra. (10.1063/1.3395821)
DOI : 10.1063/1.3395821
Poloidal rotation and its relation to the potential vorticity flux
- Mcdevitt C.J.
- Diamond P.H.
- Gürcan Özgür D.
- Hahm T.S.
Physics of Plasmas, American Institute of Physics, 2010, 17, pp.112509. A kinetic generalization of a Taylor identity appropriate to a strongly magnetized plasma is derived. This relation provides an explicit link between the radial mixing of a fourdimensional (4D) gyrocenter fluid and the poloidal Reynolds stress. This kinetic analog of a Taylor identity is subsequently utilized to link the turbulent transport of poloidal momentum to the mixing of potential vorticity. A quasilinear calculation of the flux of potential vorticity is carried out, yielding diffusive, turbulent equipartition, and thermoelectric convective components. Self-consistency is enforced via the quasineutrality relation, revealing that for the case of a stationary small amplitude wave population, deviations from neoclassical predictions of poloidal rotation can be closely linked to the growth/damping profiles of the underlying drift wave microturbulence. (10.1063/1.3490253)
DOI : 10.1063/1.3490253
Cluster observations of outflowing electron distributions and broadband electrostatic emissions above the polar cap
- Teste A.
- Fontaine Dominique
- Canu Patrick
- Belmont Gérard
Geophysical Research Letters, American Geophysical Union, 2010, 37, pp.3103. We investigate the excellent correlation between ionospheric upgoing electron beams and broadband electrostatic emissions (0-6 kHz) observed by Cluster, at 5 to 9 Earth's radii above the polar cap. In the absence of detailed, high time resolution waveform data in that region, we precisely analyzed several electron beams to obtain information concerning wave-particle interactions. Our results indicate that these beams are extremely variable and occasionally show multiple components. The processes involved might then occur on very short time scales, of the order of or shorter than sampling rates, typically 100 ms. We suggest that non linearities are at the origin of the spread of the frequency range of the waves simultaneously observed, as well as of the beam variability. We conclude that these electron beams are likely to destabilize Langmuir waves and, by the non-linear evolution of the electron bump-on-tail instability, could be responsible for the appearance of electrostatic solitary waves above the polar cap. (10.1029/2009GL041593)
DOI : 10.1029/2009GL041593
Residual parallel Reynolds stress due to turbulence intensity gradient in tokamak plasmas
- Gürcan Özgür D.
- Diamond P.H.
- Hennequin Pascale
- Mcdevitt C.J.
- Garbet X.
- Bourdelle C.
Physics of Plasmas, American Institute of Physics, 2010, 17, pp.112309. A novel mechanism for driving residual stress in tokamak plasmas based on k∥ symmetry breaking by the turbulence intensity gradient is proposed. The physics of this mechanism is explained and its connection to the wave kinetic equation and the wave-momentum flux is described. Applications to the H-mode pedestal in particular to internal transport barriers, are discussed. Also, the effect of heat transport on the momentum flux is discussed. (10.1063/1.3503624)
DOI : 10.1063/1.3503624
Une recherche ITER...ative
- Hennequin Pascale
Pour la science, Pour la Science, 2010 (392).
ECRH for JET: A feasibility study
- Lennholm M.
- Giruzzi G.
- Parkin A.
- Bouquey F.
- Braune H.
- Bruschi A.
- Luna Elena de La
- Denisov G.
- Edlington T.
- Farina D.
- Farthing J.
- Figini Lorenzo
- Garavaglia S.
- Garcia J.
- Gerbaud Thomas
- Granucci G.
- Henderson M.
- Horton L.
- Kasparek W.
- Khilar P.
- Jennison M.
- Kirneva N.
- Kislov D.
- Kuyanov A.
- Litaudon X.
- Litvak A.
- Moro A.
- Nowak S.
- Parail V.
- Plaum B.
- Rimini F.
- Saibene G.
- Sips A. C. C.
- Sozzi C.
- Spaeh P.
- Trukhina E.
- Vaccaro A.
- Vdovin V.
Fusion Engineering and Design, Elsevier, 2010, 6-8, pp.805 - 809. For JET to fulfil its mission in preparing ITER operation, the installation of an electron cyclotron resonance heating system on JET would be desirable. The study described in this paper has investigated the feasibility of installing such a system on JET. The principal goals of such a system are: current drive over a range of radii for NTM stabilization, sawtooth control and current profile tailoring and central electron heating to equilibrate electron and ion temperatures in high performance discharges. The study concluded that a 12 gyrotron, 10 MW, system at the ITER frequency (170 GHz) adapted for fields of 2.7-3.3 T would be appropriate for the operation planned in JET. An antenna allowing toroidal and poloidal steering over a wide range is being designed, using the ITER upper launcher steering mechanism. The use of ITER diamond windows and transmission line technology is suggested while power supply solutions partially reusing existing JET power supplies are proposed. Detailed planning shows that such a system can be operational in about 5 years from the time that the decision to proceed is taken. The cost and required manpower associated with implementing such a system on JET has also been estimated. (C) 2011 EURATOM. Published by Elsevier B.V. All rights reserved.Commiss European Communities, B-1049 Brussels, Belgium.IRFM, CEA, F-13108 St Paul Les Durance, France.Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.EURATOM, Max Planck IPP, D-17491 Greifswald, Germany.EURATOM, CNR, Ist Fis Plasma, I-20125 Milan, Italy.Asociac EURATOM CIEMAT, Lab Nacl Fus, Madrid 28040, Spain.Inst Appl Phys, Nizhnii Novgorod 603155, Russia.Ecole Polytech, LPTP, F-91128 Palaiseau, France.ITER Org, F-13108 St Paul Les Durance, France.Univ Stuttgart, IPF, Stuttgart, Germany.RRC Kurchatov Inst, Moscow, Russia.Fus Energy, Barcelona 08019, Spain.Karlsruhe Inst Technol, Karlsruhe, Germany. (10.1016/j.fusengdes.2011.01.136)
DOI : 10.1016/j.fusengdes.2011.01.136
Evidence of atomic adsorption on TiO2 under plasma exposure and related C2H2 surface reactivity
- Guaitella Olivier
- Lazzaroni Claudia
- Marinov Daniil
- Rousseau Antoine
Applied Physics Letters, American Institute of Physics, 2010, 97, pp.011502. Adsorption/reaction kinetics of C2H2 on the surface of plasma-treated SiO2 and TiO2 catalysts is studied. The catalysts are pretreated with a dc discharge in Ar, O2, N2, or air. Then 950 ppm of C2H2 in air is introduced in the closed-volume reactor. It is found that TiO2 pretreated with O2 or air plasma catalyzes C2H2 removal from the gas phase without any UV activation. During 10 min after introduction the loss of C2H2 in the whole reactor is about 5×1015 molecules. Comparison between different pretreatment procedures shows that weakly bonded oxygen atoms may remain on TiO2 long after plasma exposure (10.1063/1.3462295)
DOI : 10.1063/1.3462295
On the Boltzmann relation in a cold magnetized plasma
- Nasi L.
- Raimbault Jean-Luc
Physics of Plasmas, American Institute of Physics, 2010, 17, pp.113513. A systematic and exact comparison between the forces acting on magnetized electrons in a current-free plasma is considered within a fluid model. We show that the Boltzmann relation is fulfilled in the drift-diffusion approximation when (hi/he)(1 he2)/(1 hi2)⪡1 where he (or hi) is the ratio of the electron (or ion) cyclotron to the collision frequency. When the nonlinear inertia terms are taken into account, the previous criterion is too rough and must be modified. In particular it is proved that the Boltzmann relation is not uniformly valid in the plasma. The case of bounded plasmas where the electron temperature must be determined self-consistently is discussed in detail. (10.1063/1.3517174)
DOI : 10.1063/1.3517174
Evidence for surface oxidation on Pyrex of NO into NO2 by adsorbed O atoms
- Guaitella Olivier
- Hübner M.
- Welzel S.
- Marinov Daniil
- Röpcke J.
- Rousseau Antoine
Plasma Sources Science and Technology, IOP Publishing, 2010, 19, pp.045026. The surface of a Pyrex discharge tube was treated by a capacitively coupled RF plasma at low pressure. In cases where the plasma contained oxygen, O atoms deposition on the tube surface could be confirmed via the time-dependent conversion of NO to NO2 in a post-plasma experiment. Inside the discharge tube, the evolution of the concentrations of NO and of NO2 was measured using quantum cascade laser absorption spectroscopy in the mid-infrared spectral range. The surface density of atomic oxygen was estimated to be about 2 × 1014 cm−2 based on NO oxidation in the closed reactor. The production rate of NO2 is in the range of 2 × 1011 molecules cm−3 s−1. (10.1088/0963-0252/19/4/045026)
DOI : 10.1088/0963-0252/19/4/045026
Comparison of the use of SQUID an Hall effect sensors in NDE
- Bettaieb L.
- Kokabi H.
- Poloujadoff M.
- Sentz A.
- Krause H. J
- Coillot Christophe
Materials Evaluation, American Society for Nondestructive Testing, 2010, 68 (5), pp.535-554. ...
THEMIS analysis of observed equatorial electron distributions responsible for the chorus excitation
- Li W.
- Thorne R. M.
- Nishimura Y.
- Bortnik J.
- Angelopoulos V.
- Mcfadden J. P.
- Larson D. E.
- Bonnell J. W.
- Le Contel Olivier
- Roux A.
- Auster U.
Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2010, 115 (A6). A statistical survey of plasma densities and electron distributions (0.5-100 keV) is performed using data obtained from the Time History of Events and Macroscale Interactions During Substorms spacecraft in near-equatorial orbits from 1 July 2007 to 1 May 2009 in order to investigate optimum conditions for whistler mode chorus excitation. The plasma density calculated from the spacecraft potential, together with in situ magnetic field, is used to construct global maps of cyclotron and Landau resonant energies under quiet, moderate, and active geomagnetic conditions. Statistical results show that chorus intensity increases at higher AE index, with the strongest waves confined to regions where the ratio between the plasma frequency and gyrofrequency, fpe/fce, is less than 5. On the nightside, large electron anisotropies and intense chorus emissions indicate remarkable consistency with the confinement to 8 RE. Furthermore, as injected plasma sheet electrons drift from midnight through dawn toward the noon sector, their anisotropy increases and peaks on the dayside at 7 < L < 9, which is well correlated with intense chorus emissions observed in the prenoon sector. These statistical results are generally consistent with the generation of both lower-band and upper-band chorus through cyclotron resonant interactions with suprathermal electrons (1-100 keV). Two typical events on the nightside and dayside are studied in greater detail and additional interesting features are identified. Pancake distributions of electrons with energy below 2 keV, which could be responsible for the excitation of upper-band chorus, are observed at lower L shells (<7) on the nightside and at larger L shells (>6) on the dayside. In addition, very isotropic distributions at a few keV, which may be produced by Landau resonance and contribute to the formation of the typical gap in the chorus spectrum near 0.5 fce, are commonly observed on the dayside. (10.1029/2009JA014845)
DOI : 10.1029/2009JA014845
Measurements of stray antenna capacitance in the STEREO/WAVES instrument: Comparison of the measured voltage spectrum with an antenna electron shot noise model
- Zouganelis I.
- Maksimovic M.
- Meyer-Vernet N.
- Bale S. D.
- Eastwood Jonathan P.
- Zaslavsky A.
- Dekkali M.
- Goetz K.
- Kaiser M. L.
Radio Science, American Geophysical Union, 2010, 45, pp.1005. One of the most accurate techniques for in situ measuring the electron density and temperature in space plasmas is the quasi-thermal noise spectroscopy, which uses the voltage fluctuation spectrum on an electric antenna. This technique has been used successfully on the WIND and ULYSSES spacecraft; however, on STEREO this technique may only work in high-density filamentary structures, where the Debye length is small, because the STEREO/WAVES antennas have a large surface area, so that the resulting shot noise spectrum in the solar wind dominates the power at lower frequencies. In the unperturbed solar wind, we can use instead the electron shot noise to infer the plasma density. For doing so, we use well calibrated WIND particle data to deduce the stray capacitance of the STEREO/WAVES antenna system in a special configuration when the STEREO-B spacecraft was just downstream of WIND. This stray capacitance is also compared to ground experiments done on the flight spare equipment and independent calibrations performed using the galactic radio background. (10.1029/2009RS004194)
DOI : 10.1029/2009RS004194
Determination of the averaged charge-to-mass ratio of the heavy charged constituents of a magnetoplasma using whistler wave measurements
- Krafft C.
- Lundin B. V.
Annales Geophysicae, European Geosciences Union, 2010, 28, pp.2237-2247. In a cold magnetized plasma with two light ions of comparable gyrofrequencies and any species of heavy ions and/or charged dust particulates, a technique is developed to recover the relative charge density of the heavy plasma population and to estimate its effective averaged charge-to-mass ratio. Such results can be obtained without using mass spectrometer data but only the measurements of the ion plasma frequency, the electron gyro- and plasma frequencies as well as the two highest ion cutoff frequencies. (10.5194/angeo-28-2237-2010)
DOI : 10.5194/angeo-28-2237-2010
Scientific objectives and instrumentation of Mercury Plasma Particle Experiment (MPPE) onboard MMO
- Saito Y.
- Sauvaud J.-A.
- Hirahara M.
- Barabash S.
- Delcourt Dominique C.
- Takashima T.
- Asamura K.
Planetary and Space Science, Elsevier, 2010, 58 (1-2), pp.182-200. Mercury is one of the least explored planets in our solar system. Until the recent flyby of Mercury by MESSENGER, no spacecraft had visited Mercury since Mariner 10 made three flybys: two in 1974 and one in 1975. In order to elucidate the detailed plasma structure and dynamics around Mercury, an orbiter BepiColombo MMO (Mercury Magnetospheric Orbiter) is planned to be launched in 2013 as a joint mission between ESA and ISAS/JAXA. Mercury Plasma Particle Experiment (MPPE) was proposed in order to investigate the plasma/particle environment around Mercury. MPPE is a comprehensive instrument package for plasma, high-energy particle and energetic neutral atom measurements. It consists of seven sensors: two Mercury electron analyzers (MEA1 and MEA2), Mercury ion analyzer (MIA), Mercury mass spectrum analyzer (MSA), high-energy particle instrument for electron (HEP-ele), high-energy particle instrument for ion (HEP-ion), and energetic neutrals analyzer (ENA). Since comprehensive full three-dimensional simultaneous measurements of low to high-energy ions and electrons around Mercury as well as measurements of energetic neutral atoms will not be realized before BepiColombo/MMO's arrival at Mercury, it is expected that many unresolved problems concerning the Mercury magnetosphere will be elucidated by the MPPE observation. (10.1016/j.pss.2008.06.003)
DOI : 10.1016/j.pss.2008.06.003
Non adiabatic electron behavior through a supercritical perpendicular collisionless shock: Impact of the shock front turbulence
- Savoini Philippe
- Lembège Bertrand
Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2010, 115 (A11), pp.A11103. Adiabatic and nonadiabatic electrons transmitted through a supercritical perpendicular shock wave are analyzed with the help of test particle simulations based on field components issued from 2 − D full-particle simulation. A previous analysis (Savoini et al., 2005) based on 1 − D shock profile, including mainly a ramp (no apparent foot) and defined at a fixed time, has identified three distinct electron populations: adiabatic, overadiabatic, and underadiabatic, respectively, identified by μds/μus ≈ 1, >1 and <1, where μus and μds are the magnetic momenta in the upstream and downstream regions. Presently, this study is extended by investigating the impact of the time evolution of 2 − D shock front dynamics on these three populations. Analysis of individual time particle trajectories is performed and completed by statistics based on the use of different upstream velocity distributions (spherical shell of radius vshell and a Maxwellian with thermal velocity vthe). In all statistics, the three electron populations are clearly recovered. Two types of shock front nonstationarity are analyzed. First, the impact of the nonstationarity along the shock normal (due to the front self-reformation only) strongly depends on the values of vshell or vthe. For low values, the percentages of adiabatic and overadiabatic electrons are almost comparable but become anticorrelated under the filtering impact of the self-reformation; the percentage of the underadiabatic population remains almost unchanged. In contrast, for large values, this impact becomes negligible and the adiabatic population alone becomes dominant. Second, when 2 − D nonstationarity effects along the shock front (moving rippling) are fully included, all three populations are strongly diffused, leading to a larger heating; the overadiabatic population becomes largely dominant (and even larger than the adiabatic one) and mainly contributes to the energy spectrum. (10.1029/2010JA015381)
DOI : 10.1029/2010JA015381

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