Publications

2011

• Capillary nanosecond discharge as a tool for study of energy relaxation
  
  • Klochko A.V.
  • Starikovskaia Svetlana
  , 2011.
• C<SUB>2</SUB>H<SUB>2</SUB> oxidation by oxygen atoms adsorbed on plasma pretreated TiO<SUB>2</SUB>
  
  • Marinov Daniil
  • Lopatik D.
  • Guaitella Olivier
  • Roepcke J.
  • Rousseau Antoine
  , 2011.
• Evaluation of the PEGASES thruster performances
  
  • Popelier Lara
  • Bredin Jérôme
  • Aanesland Ane
  • Chabert Pascal
  , 2011.
• Global model of atmospheric pressure radio-frequency capacitive discharges
  
  • Lazzaroni Claudia
  • Chabert Pascal
  • Lieberman M.A.
  • Lichtenberg A.J.
  , 2011.
• Surface vibrational relaxation of N<SUB>2</SUB> studied by CO<SUB>2</SUB> titration with time resolved Quantum Cascade Laser diagnostics
  
  • Marinov Daniil
  • Lopatik D.
  • Hübner M.
  • Guaitella Olivier
  • Roepcke J.
  • Rousseau Antoine
  , 2011.
• Turbulence measurements by collective Thomson scattering in cross-field discharges
  
  • Tsikata Sedina
  • Honoré Cyrille
  • Grésillon D.
  • Lemoine N.
  , 2011.
• Absolute atomic chlorine densities in a Cl<SUB>2</SUB> ICP determined by TALIF with a new calibration method
  
  • Booth Jean-Paul
  • Sirse Nishant
  • Azamoum Yasmina
  • Chabert Pascal
  , 2011.
• Negative nanosecond discharge in water
  
  • Marinov Ilya
  • Guaitella Olivier
  • Rousseau Antoine
  • Starikovskaia Svetlana
  , 2011.
• Study of an ion-ion plasma by biasing a large planar probe with square waveforms
  
  • Bredin Jérôme
  • Aanesland Ane
  • Chabert Pascal
  , 2011.
• Adsorption and reactivity of nitrogen atoms on quartz surface under plasma exposure
  
  • Marinov Daniil
  • Guaitella Olivier
  • Arcos T. de Los
  • von Keudell A.
  • Rousseau Antoine
  , 2011.
• Global models of microdischarges
  
  • Chabert Pascal
  • Lazzaroni Claudia
  • Lieberman M.A.
  • Lichtenberg A.J.
  , 2011.
• Study of the EEDF and electronic temperature through a magnetic field measured in the PEGASES thruster
  
  • Bredin Jérôme
  • Aanesland Ane
  • Chabert Pascal
  • Godyak Valery
  , 2011.
• Plasma biasing and potential across the magnetic field in the PEGASES thruster
  
  • Popelier Lara
  • Aanesland Ane
  • Chabert Pascal
  , 2011.
• Electron Energy Distribution Function Measurements Across Magnetic Field Barriers
  
  • Aanesland Ane
  , 2011.
• Electric currents in the Earth's environment and impacts on new technologies
  
  • Amory-Mazaudier Christine
  , 2011.
• Tailored Voltage Waveforms for the Deposition of Microcrystalline Silicon
  
  • Johnson E.V.
  • Delattre Pierre-Alexandre
  • Booth Jean-Paul
  , 2011.
• In situ observations of magnetic reconnection in solar system plasmas
  
  • Retinò Alessandro
  • Sahraoui Fouad
  • Vaivads A.
  • Sundkvist D.
  • Mozer F. S.
  • Nakamura R.
  • Zieger B.
  • Fujimoto M.
  • Tanaka K.
  , 2011.
• Lessons learned from WHISPER relaxation sounder in ten years of CLUSTER mission
  
  • Décréau Pierrette
  • Trotignon Jean-Gabriel
  • Canu Patrick
  • Kougblénou S.
  • Lointier G.
  • Rauch Jean-Louis
  • Vallières Xavier
  , 2011. The four WHISPER instruments, part of the Wave Experiment Consortium on board the multi satellite CLUSTER mission, include each a relaxation sounder aimed to measure with a good precision and reliability the frequency positions of F p , electron plasma frequency, and of F ce , electron gyro-frequency. Those quantities give access to electron density and intensity of magnetic field, key parameters defining local plasma regime. WHISPER sounder's design and realization, based on the expertise provided by successful missions operated in late seventies and eighties (GEOS, ISEE, Viking), is characterized by use of a processor devoted to on board frequency analysis via FFT. This choice makes those relaxation sounders unique of their kind, allowing in particular a complete plasma diagnostic to be made in only 1.5 s, almost one order of magnitude faster than in the past. The CLUSTER mission itself is unique, by its multi-point capability, and by its orbit, which along the mission allowed exploring a large variety of key regions of the magnetosphere. We present in this paper a few examples of WHISPER instrument behaviour and results, exploring in particular magnetosheath, polar cap, outer and inner plasmasphere. In the latter region, F p and F ce frequency values are far above the working frequency range of the instrument. This range, however, includes the lower hybrid frequency, F lh , which shows up as a clear resonance triggered by the sounder, and allows measurement of Ne whenever F p /F ce <; 1. (10.1109/URSIGASS.2011.6051119)
  DOI : 10.1109/URSIGASS.2011.6051119
• Evidence of ion foreshock in 2-D PIC simulations of a curved collisionless shock: Statistical and individual trajectory approach
  
  • Stienlet J.
  • Savoini Philippe
  • Lembège Bertrand
  , 2011, pp.1 p.. 2-D Full particle simulations are used to investigate the so-called foreshock region which is filled with energized backstreaming particles. Two populations are observed for 90° ≥ ΘBn ≥ 45°: (i) field-aligned ion beams collimated along the IMF and having a gyrotropic distribution and (ii) gyro-phase bunch ions having a global gyration around the magnetic field. Our analysis evidences that these two populations are reflected by the shock itself and can have different origins both in term of interaction time, drift along the shock front and distance of penetration ("leaked" ions are observed). (10.1109/URSIGASS.2011.6051139)
  DOI : 10.1109/URSIGASS.2011.6051139
• CLUSTER observations of electrostatic acceleration structures above the polar cap and implications for their origin in the magnetopause boundary layer
  
  • Fontaine Dominique
  • Teste A.
  , 2011 (ISBN 978-1-4244-5117-3). During quiet periods of Northward IMF, CLUSTER observed electron acceleration structures at high altitudes along magnetic field lines connected to the polar and extended along the magnetopause boundary layers. The electrons are observed to be successively earthward and outward accelerated, forming current sheets of opposite polarities. The precipitating electrons are accelerated to keV-energies in relatively stable and broad structures. The outflowing electron beams, accelerated to weaker energies (tens of eV), form structures at much smaller scales. These acceleration structures are suggested to result from electrostatic structures generated at the interface between the magnetopause boundary layers and the lobes. (10.1109/URSIGASS.2011.6051059)
  DOI : 10.1109/URSIGASS.2011.6051059
• Response of an ionion plasma to dc biased electrodes
  
  • Popelier Lara
  • Aanesland Ane
  • Chabert Pascal
  Journal of Physics D: Applied Physics, IOP Publishing, 2011, 44 (31), pp.315203. Electronegative plasmas are plasmas containing a significant fraction of negative ions, when magnetized they are very often segregated: the core is electropositive or weakly electronegative whereas a highly electronegative plasma forms at the periphery. At strong magnetic fields this segregation can lead to the formation of ion-ion plasmas almost free of electrons close to the walls or extraction surfaces and allows access to both positive and negative ions. The PEGASES thruster aims at alternately extract and accelerate positive and negative ions from the ion-ion plasma region to provide thrust by both types of ions. The acceleration schemes depends on the possible control of the potential in an ion-ion plasma relative to the acceleration grids. In this paper continuous extraction and acceleration of positive ions from the PEGASES thruster is investigated by a Retarding Field Energy Analyzer (RFEA). It is shown from the measured Ion Energy Distribution Functions (IEDF) that the continuous acceleration potential can be controlled by biasing bare electrodes in contact with the region of the plasma with high electron density (i.e. the weakly electronegative plasma core). A grounded grid placed in the ion-ion regions allowed consequently the acceleration of positive ions, where the ion velocity is controlled by the bias applied to the electrodes in the plasma core. On the contrary, when the grid in the ion-ion region is biased, positive ion beams were not detected downstream of the grid. The results indicate that biasing a grid positively in the ion-ion region results in an electronegative space charge sheath in front of the grid, which traps the positive ions inside the thruster. (10.1088/0022-3727/44/31/315203)
  DOI : 10.1088/0022-3727/44/31/315203
• Self-consistent 2-D Full-particle Simulations of the ion Foreshock: Statistical and Individual Trajectory Approach
  
  • Savoini Philippe
  • Stienlet J.
  • Lembège Bertrand
  , 2011.
• Ion acoustic waves and double-layers in electronegative expanding plasmas
  
  • Plihon Nicolas
  • Chabert Pascal
  Physics of Plasmas, American Institute of Physics, 2011, 18, pp.082102. Ion acoustic waves and double-layers are observed in expanding plasmas in electronegative gases, i.e., plasmas containing an appreciable fraction of negative ions. The reported experiments are performed in argon gas with a variable amount of SF 6 . When varying the amount of SF 6 , the negative ion fraction increases and three main regimes were identified previously: (i) the plasma smoothly expands at low negative ion fraction, (ii) a static double-layer (associated with an abrupt potential drop and ion acceleration) forms at intermediate negative ion fraction, (iii) double-layers periodically form and propagate (in the plasma expansion direction) at high negative ion fraction. In this paper, we show that transition phases exist in between these regimes, where fluctuations are observed. These fluctuations are unstable slow ion acoustic waves, propagating in the direction opposite to the plasma expansion. These fluctuations are excited by the most unstable eigenmodes and display turbulent features. It is suggested that the static double layer forms when the ion acoustic fluctuations become non-linearly unstable: the double layer regime being a bifurcated state of the smoothly expanding regime. For the highest negative ion fraction, a coexistence of (upstream propagating) slow ion acoustic fluctuations and (downstream) propagating double layers was observed. (10.1063/1.3620405)
  DOI : 10.1063/1.3620405
• Assessment of massive gas injection as a disruption mitigation tool in Tore Supra
  
  • Bucalossi J.
  • Reux C.
  • Saint-Laurent F.
  • Becoulet M.
  • Corre Y.
  • Devynck P.
  • Gardarein J. L.
  • Gil C.
  • Gunn J.
  • Huysmans G.
  • Monier-Garbet P.
  • Segui J. L.
  • Tsitrone E.
  Journal of Nuclear Materials, Elsevier, 2011, 415 (1, S), pp.S832-S835. Massive gas injection was used on Tore Supra to study disruption mitigation. The cooling time between the injection and the thermal quench drops to 2 ms for larger gas flow rates (similar to 5e24 atoms/s) limiting the radiated energy to similar to 10% of the plasma thermal energy content. A significant reduction of the heat load on the limiter is nevertheless observed in the mitigated cases. The broadening factor of the power decay length in the scrape-off layer during the thermal quench estimated around 10 (+/-5) does not change significantly between mitigated and unmitigated. Reached densities with He injections are sufficient to suppress primary runaway electrons (dominant on Tore Supra) but still far too low to avoid avalanche process (dominant in ITER). The extension of the current quench time, which is observed in mitigated disruptions (typically by 50%), could be an attractive feature to reduce the requirements on the density. (C) 2011 Elsevier B.V. All rights reserved. (10.1016/j.jnucmat.2011.01.045)
  DOI : 10.1016/j.jnucmat.2011.01.045
• All you ever wanted to know about Fluorocarbon Plasmas but never dared to ask
  
  • Booth Jean-Paul
  , 2011.