Publications

2018

Direct Observations of Whistler-Mode Chorus Modulation of 500eV EDI Electrons by MMS
- Paulson K. W.
- Argall M. R.
- Ahmadi N.
- Matsui H.
- Farrugia C. J.
- Forbes T. G.
- Torbert R. B.
- Vaith H.
- Le Contel Olivier
- Breuillard Hugo
, 2018, pp.SM33C-3596. We present here direct observations of chorus-wave modulated quasi field-aligned electrons using the Electron Drift Instrument (EDI) on board the Magnetospheric Multiscale mission. These events demonstrated fluctuations in the count rates of 500 eV electrons exhibiting the same spectral characteristics as simultaneously observed whistler-mode chorus waves using the on-board search coil magnetometer. As these observations were made by all four spacecraft in a tetrahedral formation, we can use the wave telescope method to verify wave-particle resonance. Additionally, we use the multiple look directions of EDI close to the alignment direction in combination with the sweep of the instrument as the spacecraft spins to generate both pitch angle and gyrophase plots of the fluctuating counts in the wave perturbation frame of reference. We identify periods of gyrophase bunching suggesting active wave-particle interactions. These periods of wave activity were additionally observed to be modulated by Pc5-frequency magnetic perturbations, some of which have been identified as mirror-mode structures. The spacecraft encountered these mirror-mode structures just inside of the duskside magnetopause.
(invité) Bepi Colombo plasma investigations after MESSENGER
- Delcourt Dominique
, 2018.
Electron Phase-Space Holes in Three Dimensions: Multispacecraft Observations by Magnetospheric Multiscale
- Holmes J.
- Ergun R.
- Newman D.
- Ahmadi N.
- Andersson L.
- Le Contel O.
- Torbert R.
- Giles B.
- Strangeway R.
- Burch J.
Journal of Geophysical Research Space Physics, American Geophysical Union/Wiley, 2018, 123 (12), pp.9963-9978. (10.1029/2018JA025750)
DOI : 10.1029/2018JA025750
Measurements of the electric field, electron properties and other plasma parameters: the influence of targets
- Hofmans Marlous
- Guaitella Olivier
- Sobota Ana
, 2018.
Coexisting crystal and liquid-like properties in a 2D long-range self-consistent model
- Maciel J. M
- Amato M. A
- Firpo Marie-Christine
Scientific Reports, Nature Publishing Group, 2018, 8 (1). A two-dimensional class of mean-field models serving as a minimal frame to study long-range interaction in two space dimensions is considered. In the case of an anisotropic mixed attractive-repulsive interaction, an initially spatially homogeneous cold fluid is dynamically unstable and evolves towards a quasi-stationary state in which the less energetic particles get trapped into clusters forming a Bravais lattice, mimicking a crystalline state. Superimposed to this, one observes in symplectic numerical simulations a flux of slightly more energetic particles channeling through this crystalline background. The obtained system combines the rigidity features of a solid, as particles from a displaced core are shown to snap back into place after a transient, and the dynamical diffusive features of a liquid for the fraction of channeling and free particles. This combination of solid and liquid properties is reminiscent of supersolidity, but observed here within classical mechanics. The quantum transposition of the model may be experimentally reached using the latest ultracold atoms techniques to generate long-range interactions. (10.1038/s41598-018-33889-8)
DOI : 10.1038/s41598-018-33889-8
(invité) Nonadiabatic energization and transport of ions in the magnetospheric flanks of Mercury
- Aizawa Sae
- Delcourt Dominique
- Terada Naoki
- Kasaba Yasumasa
- Katoh Y.
, 2018.
Inverse cascade of magnetic helicity in MHD turbulence
- Menu Mélissa
- Galtier Sébastien
- Petitdemange Ludovic
, 2018.
Investigation of Plasma Surface Interactions using Mueller Polarimetry
- Slikboer Elmar
, 2018. In this thesis, a new diagnostic method called Mueller Polarimetry is examined for the investigation of plasma-surface interactions. This imaging technique allows the time-resolved optical characterization of targets under plasma exposure. The measured Mueller matrices are analyzed by using the logarithmic decomposition providing polarimetric data on diattenuation, depolarization, and birefringence. The latter is used by examining materials that possess optically active behavior to identify specific aspects of the plasma interaction, e.g. electric fields or temperature.This work focusses on electro-optic targets, which primarily enables the detection of electric fields induced by surface charge deposited during the interaction. The birefringence is coupled to the externally induced electric field by analytically relating the phase retardance for the probing polarized light beam to the perturbed index ellipsoid, according to the Pockels effect. Through this analytical approach, materials with specific electro-optic properties can be chosen in such a way – together with the orientation of the Mueller polarimeter itself – that all the individual electric field components (axial and radial) induced inside the sample are imaged separately. This has never been done before and allows to better understand the plasma dynamics in the vicinity of a dielectric surface.It is used to investigate the surface impact by guided ionization waves generated by a kHz-driven atmospheric pressure plasma jet. These non-thermal filamentary discharges are generally applied to various samples for e.g. surface functionalization of polymers or biomedical treatment of organic tissues. However, available diagnostic tools are limited to study these interactions. Imaging Mueller polarimetry applied to electro-optic targets examines the axial and radial field patterns in terms of amplitude (3-6 kV/cm), spatial scales (< 1mm axial and <1cm radial), and timescales (<1μs pulsed and <10μs AC) for various operating parameters of the jet, for example voltage amplitude and surrounding gas.Simultaneous with the transient birefringence induced by the electric field, a constant background pattern is also observed. This results from strain induced by temperature gradients inside the targeted material. An analytical relation is obtained following the photo-elastic effect, which allowed a fitting procedure to be designed to retrieve the temperature pattern. This procedure is used after calibration to show that the temperature of the sample can vary up to 25 degrees relative to room conditions – while changes in the electric field are seen as well – depending on the operating frequency of the AC driven plasma jet. The accurate determination of the temperature is important since most applications involve temperature sensitive samples.Lastly, this work shows how complex samples (in terms of surface geometry and/or chemical composition) can be examined during a plasma-surface interaction. This is done by combining them with the electro-optic targets. Due to the addition of a (thin) complex sample, depolarization is added to the system through scattering of the polarized light beam. In-situ observed changes of depolarization relate to the evolution of the complex sample during the plasma treatment. This, coupled with the simultaneously monitored electric field patterns, provides a unique diagnostic tool to examine the plasma-surface interactions. This has been applied for a test case where a single layer of onion cells is exposed to the ionization waves generated by the non-thermal plasma jet.
Rippled Electron‐Scale Structure of a Dipolarization Front
- Pan Dong‐xiao
- Khotyaintsev Yuri
- Graham Daniel
- Vaivads Andris
- Zhou Xu‐zhi
- André Mats
- Lindqvist Per‐arne
- Ergun Robert
- Le Contel Olivier
- Russell Christopher
- Torbert Roy
- Giles Barbara
- Burch James
Geophysical Research Letters, American Geophysical Union, 2018, 45 (22), pp.12,116-12,124. (10.1029/2018GL080826)
DOI : 10.1029/2018GL080826
A cryogenic 0.35 μm CMOS technology BSIM3.3 model for space instrumentation: Application to a bandgap design
- Varizat Laurent
- Sou Gérard
- Mansour Malik
- Alison Dominique
IEEE Aerospace and Electronic Systems Magazine, Institute of Electrical and Electronics Engineers, 2018, 33 (8), pp.24-29. (10.1109/MAES.2018.170149)
DOI : 10.1109/MAES.2018.170149
In situ observations of energy dissipation and particle energization in near-Earth space
- Retino A.
, 2018.
Plasma turbulence structure in the ASDEX Upgrade tokamak, Overview
- Hennequin Pascale
- Happel T.
- Pinzón J R
- Freethy Simon
- Görler T.
- Conway G. D.
- Angioni C.
- Trier Elisée
- Schneider P.
- Stroth U.
- Asdex Upgrade Team The
- Eurofusion Mst1 Team The
, 2018.
Erratum: “3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?” (2018, ApJ, 853, 85)
- Verdini Andrea
- Grappin Roland
- Alexandrova Olga
- Lion Sonny
The Astrophysical Journal, American Astronomical Society, 2018, 867 (2), pp.168. (10.3847/1538-4357/aae821)
DOI : 10.3847/1538-4357/aae821
Plasma sheath in presence of secondary electron emission in Hall Effect Thrusters
- Tavant Antoine
- Croes Vivien
- Lucken Romain
- Bourdon Anne
- Chabert Pascal
, 2018.
Anomalous transport in a magnetized plasma column under laboratory conditions
- Lucken Romain
- Tavant Antoine
- Bourdon Anne
- Lieberman M.A.
- Chabert Pascal
, 2018.
Effects of electron-drift instability in 1D fluid simulations of Hall Effect Thrusters
- Martorelli Roberto
- Lafleur Trevor
- Bourdon Anne
- Chabert Pascal
, 2018.
Electric field characterization of a plasma-target interaction at atmospheric pressure:modeling and experiments
- Bourdon Anne
- Viegas Pedro
- Slikboer Elmar
- Hofmans Marlous
- Sobota Ana
- Obrusník A.
- Bonaventura Z.
- Guaitella Olivier
, 2018.
Asymptotic-preserving finite volume scheme for the multi-fluid equations towards electric propulsion applications
- Alvarez-Laguna Alejandro
- Magin T.
- Chabert Pascal
- Massot M.
- Bourdon Anne
, 2018.
Density of metastable O2(b 1 Sigma g+) molecules in an O2 DC discharge measured by vacuum ultraviolet absorption and optical emission spectroscopy
- Booth Jean-Paul
- Guaitella Olivier
- Chatterjee Abhyuday
- Lopaev Dmitry
- Zyryanov Sergey
- Rakhimova Tatyana
- Voloshin Dmitry
- Mankelevich Y.
- de Oliveira N.
- Nahon L.
- Western Colin
, 2018. The number density O2 (b1g ) molecules in the positive column of a dc discharge in pure O2 was determined by tow methods : high-resolution vacuum ultraviolet (VUV) absorption of the (4pπ1Σu b1g ).band at 131.3nm (using the Fourier Transform Spectrometer (FTS) at the DESIRS beamline at Synchrotron Soleil) and absolute intensity measurements of the integrated A-band (b1g ,v=0 X3g-,v=0) emission around 760nm. The 131.3nm absorption band was chosen because it is the only one that is well separated from O2 X and O2 a absorption bands. An analysis of the rotational structure of this heavily-perturbed band is presented as well as an ab initio calculation of the (previously-unknown) transition strength. The densities obtained by the two methods agree within 20%, confirming the accuracy of the transition strength calculation. The O2 b density increases with O2 pressure up 2 Torr (to about 1 % of the total gas density), then decreases at higher pressure. At low pressure the b density increases with discharge current, whereas opposite trend is observed at high pressure. These observations can be explained by O2 b quenching by O 3P atoms with a rate that increases with gas temperature.
Spectroscopic study of an iodine plasma in a low pressure RF-ICP ion source
- Marmuse Florian
- Courtois Theo
- Booth Jean-Paul
- Drag Cyril
- Aanesland Ane
- Chabert Pascal
, 2018. Iodine is being considered as an alternative to Xenon for plasma propulsion, mainly because of its lower cost and possibility for solid storage. However, iodine plasmas are less well understood than Xenon plasmas, making a need for reliable diagnostic measurements to validate the models of iodine plasmas. We present initial measurements on two iodine plasma systems: an RF-CCP plasma in a closed cell (around 50 Pa), and an RF-ICP plasma (PEGASES plasma source) with flowing I2 gas in the pressure range 0.2-20 Pa. Several diagnostics are presented: emission spectroscopy, laser absorption spectroscopy, cavity ring-down spectroscopy, and a RF compensated Langmuir probe. Absorption from excited states of atomic iodine (at 804, 906 and 911nm) were measured using a cw Ti:Sa laser. Ground state I atoms were measured by the magnetic-dipole allowed spin-orbit transition at 1315nm using a diode laser, either by multi-pass absorption or by cavity ring-down spectroscopy (for greater sensitivity). The absolute atom density was deduced using the transition strengths found in the literature, and the gas temperature was deduced from the Doppler width. The electron density and temperature was deduced from the RF-compensated Langmuir probe. An early comparison with a global model is presented.
Benchmarks for Two Dimensional Particle in Cell Simulations with Monte Carlo Collisions
- Turner M.M.
- Chabert Pascal
- Donkó Z.
- Derszi Aranka
- Eremin D.
- Hartmann P.
- Lucken Romain
- Mussenbrock T.
- Stoltz P.
, 2018. Code correctness is a matter of concern in any computational investigation. The strongest assurances of correctness are obtained by comparison of code calculations with exact solutions, but this approach is not yet feasible for all categories of code. An alternative in this case is benchmarking, in the sense of comparison of a number of codes solving the same problem. In this presentation, we will describe a suite of benchmarks aimed at two dimensional particle-in-cell simulations of low-temperature plasmas, in which collisional phenomena are necessarily included. The initial benchmarks address Cartesian geometries with a variety of different combinations of boundary conditions. We will describe the benchmark cases, and report on progress towards consistent solutions obtained with several independent codes.
Oxygen metastable molecule densities in inductively-coupled plasmas in pure O2 measured by VUV absorption
- Booth Jean-Paul
- Chatterjee Abhyuday
- Guaitella Olivier
- de Oliveira N.
- Nahon L.
- Western Colin
, 2018.
2D (axial-azimuthal) Particle-In-Cell simulations of Hall Effect Thrusters
- Charoy Thomas
- Tavant Antoine
- Bourdon Anne
- Chabert Pascal
, 2018.
In LANDMARK : The 2D axial-azimuthal Particle-In-Cell benchmark on ExB discharges
- Charoy Thomas
- Boeuf Jean-Pierre
- Villafana Willca
- Tavant Antoine
- Bourdon Anne
- Chabert Pascal
, 2018.
Plasma shape and fueling dependence on the small ELMs regime in TCV and AUG IAEA Fusion Energy Conference 2018 (IAEA FEC 2018)
- Labit B.
- Eich T.
- Harrer G.
- Bernert M.
- de Oliveira H.
- Dunne M.
- Frassinetti L.
- Hennequin Pascale
- Maurizio R.
- Merle A.
- Meyer H.
- Molina P.
- Stober J.
- Wolfrum E.
- Tcv Team The
- Asdex Upgrade Team The
- Eurofusion Mst1 Team The
, 2018, pp.EX 2-5.

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