Publications

2017

• THOR Ion Mass Spectrometer (IMS)
  
  • Retinò Alessandro
  , 2017, 19, pp.13992. Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The Ion Mass Spectrometer (IMS) onboard THOR will provide the first high-time resolution measurements of mass-resolved ions in near-Earth space, focusing on hot ions in the foreshock, shock and magnetosheath turbulent regions. These measurements are required to study how kinetic-scale turbulent fluctuations heat and accelerate different ion species. IMS will measure the full three-dimensional distribution functions of main ion species (H , He , O ) in the energy range 10 eV/q to 30 keV/q with energy resolution DE/E down to 10% and angular resolution down to 11.25˚ . The time resolution will be 150 ms for O , 300 ms for He and 1s for O , which correspond to ion scales in the the foreshock, shock and magnetosheath regions. Such high time resolution is achieved by mounting four identical IMS units phased by 90˚ in the spacecraft spin plane. Each IMS unit combines a top-hat electrostatic analyzer with deflectors at the entrance together with a time-of-flight section to perform mass selection. Adequate mass-per-charge resolution (M/q)/(DeltaM/q) (>= 8 for He and >= 3 for O ) is obtained through a 6 cm long Time-of-Flight (TOF) section. IMS electronics includes a fast sweeping high voltage board that is required to make measurements at high cadence. Ion detection includes Micro Channel Plates (MCPs) combined with Application-Specific Integrated Circuits (ASICs) for charge amplification and discrimination and a discrete Time-to-Amplitude Converter (TAC) to determine the ion time of flight. A processor board will be used to for ion events formatting and will interface with the Particle Processing Unit (PPU), which will perform data processing for THOR particle detectors. The IMS instrument is being designed and will be built and calibrated by an international consortium of scientific institutes from France, USA, Germany and Japan and Switzerland.
• Exact laws in compressible MHD turbulence
  
  • Andrés Nahuel
  • Hadid Lina Z.
  • Sahraoui Fouad
  • Galtier Sébastien
  • Banerjee Supratik
  • Dmitruk P.
  • Mininni P. D.
  , 2017, 19, pp.17638. The role of compressible fluctuations in the MHD turbulence is investigated using direct numerical simulations. A focus is put on verifying the exact third-order law derived for compressible isothermal turbulence by Banerjee and Galtier (2013). The numerical simulations use a 3D compressible MHD code in the isothermal limit for different low sonic Mach numbers (i.e., Ms<1). The main goal is to evaluate the relative importance of the new flux and source terms involved in the derived law. A discussion regarding the recent in-situ observations from the Themis spacecraft in the fast and slow solar wind are made.
• Optimized Reciprocal Vectors for Estimating Gradients of Physical Fields from Multi-Spacecraft Missions
  
  • Chanteur Gérard
  • Le Contel Olivier
  • Retinò Alessandro
  • Sahraoui Fouad
  • Mirioni Laurent
  , 2017, 19, pp.11728. Reciprocal Vectors of the tetrahedron have been used since the beginning of the CLUSTER mission for estimating gradients of physical fiels, either scalar (density) or vector (magnetic field). An introduction to the method was given in chapter 14 of the ISSI book SR001 published in 1998 ''Analysis Methods for Multi-Spacecraft Data'', and an updated review of the method has been presented in the second ISSI book SR008 ''Multi-Spacecraft Analysis Methods Revisited'' in 2008. This method encompasses the curlometer tool based on Ampère's theorem, moreover it allows a detailed analysis of errors affecting the estimated gradients and it handles symmetrically the four spacecraft. The quality of the estimated gradient depends upon the proximity of the real tetrahedron to the regular tetrahedron : geometrical errors due to uncertainties in spacecraft positions grow rapidly when the tetrahedron is flat or elongated. A new approach has been designed to remedy this caveat to some extent. By contrast to the original method Generalized Reciprocal Vectors (GRV's)result from the search of an optimal weighting of the data provided by the four spacecraft. We will present applications to MMS cases during crossings of current sheets.
• Equatorial noise emissions with a quasi-periodic modulation observed by DEMETER at harmonics of the O+ ion gyrofrequency
  
  • Parrot M.
  • Nemec F.
  • Santolík O.
  • Cornilleau-Wehrlin Nicole
  , 2017, 19, pp.2357. The analysis of ionospheric equatorial noise (EN) with a quasi-periodic (QP) modulation observed by the DEMETER spacecraft is presented. These EN emissions also called whistler mode or fast magnetosonic waves play an important role in acceleration of radiation belt electrons. A statistical analysis with 103 events shows that they occur just after intense magnetic storms. Usually, they are generated by unstable proton ring distribution close to the magnetic equator at harmonics of the proton gyrofrequency in the inner magnetosphere (2 < L < 8). But at lower L values down in the ionosphere three events have been analyzed and it appears that the EN waves are at harmonics of - or very close to - a O ion gyrofrequency which can be found close or slightly above the satellite. The wave propagation analysis indicates that these emissions are coming from an area above the satellite. Concerning one event, the EN emissions are observed on several consecutive orbits and there is a temporal coincidence with observations performed by the CLUSTER satellites at higher altitudes in the magnetosphere. EN emissions at lower frequencies have been also observed by the CLUSTER satellites in the same longitudinal sector as DEMETER but at 5 RE. The analysis of the STAFF data onboard C1 reveals that the magnetic field spectrogram has peaks close to harmonics of the local proton gyrofrequency as usually reported. It is shown that the DEMETER and CLUSTER EN waves have a similar QP modulation but with slightly different period and frequency.
• New insights into sub-ion scale turbulence in Earth's magnetosheath using MMS data
  
  • Breuillard Hugo
  • Andriopoulou M.
  • Graham Daniel
  • Le Contel Olivier
  • Huang S. Y.
  • Hadid Lina
  • Sahraoui Fouad
  • Alexandrova O.
  • Berthomier Matthieu
  • Retinò Alessandro
  • Nakamura R.
  • Baumjohann W.
  , 2017, 19, pp.16664. On January 22nd 2016, MMS was located in Earth's magnetosheath and detected intense lion roars showing a secondary bandwidth. Detailed polarization analysis, using burst data from SCM and EDP instruments, and numerical simulation, using WHAMP, are performed in this study. They show that these mainly perpendicular fluctuations are highly nonlinear whistler wave packets, and that a high sampling rate is needed to pick up the peaks of the signal. As a result, their amplitude might have been underestimated in previous missions such as Cluster, which can have a significant impact on electron dynamics. Using FPI burst data, we show that electron velocity distribution functions exhibit a gyrophase-bunched signature in the presence of these lion roars. The analysis of magnetic and density fluctuations, inferred from spacecraft potential, also show the highly-compressible nature of turbulence up to electron scales.
• Double Layers Throughout the Magnetosphere and Their Relation to Magnetic Reconnection
  
  • Goodrich Katherine
  • Ergun Robert
  • Wilder Frederick
  • Ahmadi Narges
  • Khotyaintsev Y. V.
  • Lindqvist Per-Arne
  • Torbert Roy
  • Argall Matthew
  • Le Contel Olivier
  • Russell C. T.
  • Strangeway R. J.
  • Giles B. L.
  • Burch J. L.
  , 2017, 19, pp.11806. Observations throughout the terrestrial magnetosphere have shown large-amplitude parallel electric field signatures in regions of strong magnetic turbulence. Debye-length, unipolar parallel electric fields identified as double layers have consistently been observed in regions such as the auroral acceleration region, near-Earth plasmasheet, and in the terrestrial bow shock. Double layers have been theorized to be a dissipation mechanism for magnetic turbulence. Recent observations from MMS have suggested that double layers can act as a signature of secondary magnetic reconnection, particularly in the Earth's magnetopause. We present a comparative study of double layer signatures in various regions of the Earth's magnetosphere to determine the relationship between secondary magnetic reconnection and turbulent dissipation.
• The Alfvén Mission for the ESA M5 Call
  
  • Fazakerley A.
  • Berthomier Matthieu
  • Pottelette Raymond
  • Forsyth C.
  , 2017, 19, pp.16809. The Alfvén mission will explore particle acceleration processes and their consequences for electromagnetic radiation and energy transport in strongly magnetised plasmas. In particular it will address the following three key questions. Alfvén will discover where and how particle acceleration occurs in strongly magnetized plasmas. Charged particle acceleration in strongly magnetized plasmas requires the conversion of electromagnetic energy into magnetic-field-aligned particle kinetic energy. Several pathways of energy conversion have been proposed; to understand which are important, Alfvén will measure for the first time in a strongly magnetized plasma the occurrence and distribution of small scale parallel electric fields in space and time. In order to determine the relative efficiency of the different conversion mechanisms, Alfvén will also measure the corresponding particle energy fluxes locally and into the aurora. Alfvén discoveries will inform efforts to understand similar processes in other strongly magnetized plasmas, such as recent work to resolve paradoxes in models of solar flares. Alfvén will discover how electromagnetic radiation is generated in the acceleration region and how it escapes. One of the most important consequences of particle acceleration in strong magnetic fields is the generation of non-thermal electromagnetic radiation. Some of the brightest astrophysical radio signals are from coherent generation in plasmas, which also occurs on every magnetized planet. Alfvén will make key measurements of Earth's powerful Auroral Kilometric Radiation (AKR) needed to test competing models of wave generation, mode conversion and escape from their source region. These will reveal the mode conversion processes and which information is ultimately carried by the polarization of radio waves reaching free space. The resulting discoveries will make a strong contribution to a better understanding of astrophysical radio sources. Alfvén will discover the global impact of particle acceleration on the dynamic coupling between a magnetized object and its plasma environment. Energy can be transported over vast distances in several forms regulated by the magnetic field, including Poynting flux of plasma waves, accelerated particle fluxes, and bulk plasma flows. A key to understanding the coupling between a magnetized object and the surrounding plasma is how the energy converts from one type to another. Dual spacecraft measurements offer the unique opportunity to unambiguously determine which part of the energy flowing into the ionosphere is eventually dissipated in this collisional plasma and which part is transmitted to outflowing ions of ionospheric origin. Alfvén will discover what combination of plasma and magnetic conditions controls the conversion of Poynting flux into particle energy at Earth. These conditions will be compared to those at the outer planets, illuminating the theoretical descriptions of energy deposition in these remote environments. The Alfvén mission design involves use of two simple identical spacecraft, a comprehensive suite of inter-calibrated particles and fields instruments, cutting edge auroral imaging, easily accessible orbits that frequently visit the region of scientific interest and straightforward operations. This has not previously been possible, but is now compelling and timely. It is a low risk mission that is compatible with the M5 cost cap.
• Probing mechanisms in low-temperature reactive gas plasmas: towards improved models of industrial plasma etch processes
  
  • Booth Jean-Paul
  , 2017. Inductively-coupled radiofrequency plasmas in molecular, electronegative gases are widely used for plasma processing of surfaces, and in particular for the etching of thin films. Such plasma processes have allowed the information revolution since they are essential for the manufacture of CMOS integrated circuits. The complexity of these systems is such that they can only be described by multi-physics models which simultaneously describe a) the dynamics of charged particles and electric fields, b) the elastic and inelastic collisional pro- cesses between charged and neutral (molecular) species, and c) plasma-surface interactions. However, these models have not previously been rigorously tested against comprehensive quantitative measurements of transient particle densities over a wide range of parameter space. We have studed the Cl2/O2 system because of its industrial process relevance but also because methods exist to measure the density of most of the transient species present. A microwave hairpin resonator is used to measure the electron density, and (combined with laser photo-detachment) the negative ion density. Absolute Cl and O atom densities are determined by Two-photon Absorption Laser-Induced Fluorescence, combined with novel calibration schemes. A new ultra-low noise broadband UV-visible absorption bench allows measurement of the densities of ground state Cl2 molecules, ClxOy reaction products and vibrationally excited states of Cl2 and O2. These measurements were compared to a state of the art 2-dimensional hybrid fluid model, showing considerable discrepancies in both the absolute values and trends with gas pressure.The models can be improved significantly by paying attention to gas heating mechanisms, surface processes (atom recombination and ther- mal accommodation) and by improved cross-sections for processes including electron-impact dissociation of molecules and vibrational excitation.
• Relaxation of electronic excitation in nitrogen discharge plasma at high specific deposited energy
  
  • Lepikhin N D
  • Popov N A
  • Starikovskaia Svetlana
  , 2017, pp.35-36.
• Proton and heavy ion acceleration by electromagnetic fluctuations in the Earth’s magnetotail
  
  • Catapano Filomena
  • Zimbardo Gaetano
  • Perri Silvia
  • Greco Antonella
  • Delcourt Dominique
  • Retino Alessandro
  , 2017.
• Statistical analysis of solar events associated with SSC over one year of solar maximum during cycle 23: propagation and effects from the Sun to the Earth
  
  • Cornilleau-Wehrlin Nicole
  • Bocchialini Karine
  • Menvielle Michel
  • Chambodut Aude
  • Fontaine Dominique
  • Grison Benjamin
  • Marchaudon Aurélie
  • Pick Monique
  • Pitout Frederic
  • Schmieder Brigitte
  • Régnier Stéphane
  • Zouganelis Yannis
  , 2017. Taking the 32 sudden storm commencements (SSC) listed by the observatory de l'Ebre / ISGI over the year 2002 (maximal solar activity) as a starting point, we performed a statistical analysis of the related solar sources, solar wind signatures, and terrestrial responses. For each event, we characterized and identified, as far as possible, (i) the sources on the Sun (Coronal Mass Ejections -CME-), with the help of a series of criteria (velocities, drag coefficient, radio waves, helicity), as well as (ii) the structure and properties in the interplanetary medium, at L1, of the event associated to the SSC: magnetic clouds -MC-, non-MC interplanetary coronal mass ejections -ICME-, co-rotating/stream interaction regions -SIR/CIR-, shocks only and unclear events that we call "miscellaneous" events. The observed Sun-to-Earth travel times are compared to those estimated using existing simple models of propagation in the interplanetary medium. This comparison is used to statistically assess performances of various models. The geoeffectiveness of the events, classified by category at L1, is analysed by their signatures in the Earth ionized (magnetosphere and ionosphere) and neutral (thermosphere) environments, using a broad set of in situ, remote and ground based instrumentation. The role of the presence of a unique or of a multiple source at the Sun, of its nature, halo or non halo CME, is also discussed. The set of observations is statistically analyzed so as to evaluate and compare the geoeffectiveness of the events. The results obtained for this set of geomagnetic storms started by SSCs is compared to the overall statistics of year 2002, relying on already published catalogues of events, allowing assessing the relevance of our approach (for instance the all 12 well identified Magnetic Clouds of 2002 give rise to SSCs).
• Comparison of detailed experimental wavenumber spectra with gyrokinetic simulation aided by two-dimensional full-wave simulations
  
  • Happel T.
  • Görler T.
  • Hennequin Pascale
  • Lechte C.
  • Bernert Matthias
  • Conway G. D.
  • Freethy Simon
  • Honoré Cyrille
  • Pinzón J R
  • Stroth Ulrich
  Plasma Physics and Controlled Fusion, IOP Publishing, 2017, 59 (5), pp.054009. The importance of using a comprehensive suite of tools for the validation of a gyrokinetic code is described. This is detailed by presenting experimental wavenumber spectra which show pronounced differences, although they are measured at the same toroidal, poloidal and radial location. They are obtained via Doppler reflectometry and the differences are due to the probing beam polarization. These differences are reproduced convincingly using turbulence from a gyrokinetic simulation as input for two-dimensional full-wave simulation. It is demonstrated that the application of synthetic diagnostics is indispensable if non-trivial diagnostics are used in the experiment. Furthermore, the measurement of wavenumber spectra via Doppler reflectometry with X-mode probing beam polarization might be problematic due to nonlinear wave?plasma interactions and should be regarded with care when used for quantitative statements or the validation of gyrokinetic codes. (10.1088/1361-6587/aa645b)
  DOI : 10.1088/1361-6587/aa645b
• Electric field measurement in the dielectric tube of helium atmospheric pressure plasma jet
  
  • Sretenović Goran
  • Guaitella Olivier
  • Sobota Ana
  • Krstić Ivan
  • Kovačević Vesna
  • Obradović Bratislav
  • Kuraica Milorad
  Journal of Applied Physics, American Institute of Physics, 2017, 121 (12). The results of the electric field measurements in the capillary of the helium plasma jet are presented in this article. Distributions of the electric field for the streamers are determined for different gas flow rates. It is found that electric field strength in front of the ionization wave decreases as it approaches to the exit of the tube. The values obtained under presented experimental conditions are in the range of 511 kV/cm. It was found that the increase in gas flow above 1500 SCCM could induce substantial changes in the discharge operation. This is reflected through the formation of the brighter discharge region and appearance of the electric field maxima. Furthermore, using the measured values of the electric field strength in the streamer head, it was possible to estimate electron densities in the streamer channel. Maximal density of 41011cm3 is obtained in the vicinity of the grounded ring electrode. Similar behaviors of the electron density distributions to the distributions of the electric field strength are found under the studied experimental conditions. (10.1063/1.4979310)
  DOI : 10.1063/1.4979310
• Introduction to Space Weather
  
  • Amory-Mazaudier Christine
  , 2017. Sun and Earth two magnetic bodies in motion Emission from the Sun Sunspot cycle Solar Dynamo: the true solar cycle / solar indices Regular Radiation channel Ionosphere / Ionospheric dynamo Disturbed Radiation channel Solar flare Regular ParticlesParticles channel Regular solar wind Disturbed Particles channel : Magnetic storm CME, Coronal Hole Coupling between high and low latitudes Auroral zone Thermal expansion of the atmosphere, PPEF, DDEF The Equatorial Ionosphere Case study : showing the importance of systemic analysis
• Simulation numérique de décharges nanosecondes pulsées à pression atmosphérique : application à la combustion assistée par plasma
  
  • Bourdon Anne
  , 2017.
• High pressure nanosecond surface dielectric barrier discharges: physics and application for plasma-assisted combustion
  
  • Starikovskaia Svetlana
  , 2017.
• Study of nanosecond discharges in different H2/air mixtures at atmospheric pressure for plasma-assisted applications
  
  • Bourdon Anne
  , 2017.
• Improvements in global modeling of gridded ion thrusters
  
  • Lucken Romain
  • Lafleur Trevor
  • Grondein Pascaline
  • Bourdon Anne
  • Chabert Pascal
  • Aanesland Ane
  , 2017. PEGASES is an ion-ion thruster concept developed at LPP for over ten years. The neutralization of the plume by alternate negative and positive ion extraction leads to a thruster design where no external neutralizer is required anymore. First 0D fluid models - or global models - of plasma thrusters were developed for DC ion thrusters operated with Xenon. The model was extended to RF gridded thrusters including more complex molecular iodine chemistry. Recently, neutral gas heating by ion acceleration in the sheath was added to the model, which has a very large influence on the neutral power balance. Following the description of collisionless heating in inductively coupled RF plasma provided in, stochastic heating was also taken into account both through an effective collision frequency, and a heating term in the electron power balance. defining the global model leads to a better predictability of the thruster efficiency. Both numerical PIC simulations and experiments are in progress to validate the analyses that were conducted here.
• Electron drift instability and secondary electron emission in Hall effect thrusters: Insights from 2D PIC simulations
  
  • Croes Vivien
  • Tavant Antoine
  • Lucken Romain
  • Lafleur Trevor
  • Bourdon Anne
  • Chabert Pascal
  , 2017.
• Wall interactions in Hall Effect Thruster, investigation with bidimensional Particle-in-cell model and simulation
  
  • Tavant Antoine
  • Croes Vivien
  • Bourdon Anne
  • Chabert Pascal
  , 2017.
• Strong radiative shocks relevant for stellar environments : experimental study and numerical approach
  
  • Singh Raj Laxmi
  , 2017. Strong shocks are present in various astrophysical phenomena. Such shocks are strongly influenced by the radiation through its coupling with hydrodynamics. Thus their topology and dynamics are quite complex. Generating such hypersonic shocks in the laboratory, with controlled conditions, is thus an adequate tool to study the influence of radiation and to compare them with numerical simulations. Such shocks can be generated by intense lasers and electromagnetic devices.The first part of this dissertation concerns the numerical and experimental study of the interaction of two counter propagating laser-driven shocks. The experiments, performed at the kJ PALS laser facility allowed to generate shocks with different speeds (~ 30-55 km/s and 10-25 km/s), in noble gases and low pressure (less than 1 bar). Several diagnostics were implemented: visible interferometry, time- and space-resolved visible spectroscopy, and time integrated XUV spectroscopy. Our experiment shows a strong interaction of one radiative precursor onto the second one. The physical parameters of the plasma were deduced from the diagnostics and compared with 1-D simulation results. The second part is devoted to the design of an experiment where the shock is generated electromagnetically. The optimization of this generator is presented and also the full experimental set up which allows studying shock ~ 30 km/s in noble gas at ~ 1 mbar.
• 2D particle-in-cell simulations of the electron drift instability and associated anomalous electron transport in Hall-effect thrusters
  
  • Croes Vivien
  • Lafleur Trevor
  • Bonaventura Zdeněk
  • Bourdon Anne
  • Chabert Pascal
  Plasma Sources Science and Technology, IOP Publishing, 2017, 26 (3), pp.034001. In this work we study the electron drift instability in Hall-effect thrusters (HETs) using a 2D electrostatic particle-in-cell (PIC) simulation. The simulation is configured with a Cartesian coordinate system modeling the radial-azimuthal (r − θ) plane for large radius thrusters. A magnetic field, B 0 , is aligned along the Oy axis (r direction), a constant applied electric field, E 0 , along the Oz axis (perpendicular to the simulation plane), and the E 0 × B 0 direction is along the Ox axis (θ direction). Although electron transport can be well described by electron-neutral collisions for low plasma densities, at high densities (similar to those in typical HETs), a strong instability is observed that enhances the electron cross-field mobility; even in the absence of electron-neutral collisions. The instability generates high frequency (of the order of MHz) and short wavelength (of the order of mm) fluctuations in both the azimuthal electric field and charged particle densities, and propagates in the E 0 × B 0 direction with a velocity close to the ion sound speed. The correlation between the electric field and density fluctuations (which leads to an enhanced electron-ion friction force) is investigated and shown to be directly responsible for the increased electron transport. Results are compared with a recent kinetic theory, showing good agreement with the instability properties and electron transport. (10.1088/1361-6595/aa550f)
  DOI : 10.1088/1361-6595/aa550f
• Space weather, from the sun to the earth, the key role of GNSS
  
  • Amory-Mazaudier Christine
  • Fleury Rolland
  • Gadimova Sharafat
  • Touzani Abderrahmane
  Coordinates, 2017, 13 (2), pp.6-14. The goal of this paper is to give a clear view of the Sun Earth relationships that are complex. The phenomena acting at large scales and essentially related to dynamic and electromagnetic physical processes have been addressed. Besides physics, the work done to develop the training in Space Weather by focusing on Global Navigation Satellite Systems has also been presented. We present this paper as a series in two parts. In this issue the focus is on physics of the relationships Sun, Earth and Meteorology of Space. In March issue, GNSS training and capacity building would be discussed
• Météorologie de l'Espace : du Soleil à la Terre
  
  • Amory-Mazaudier Christine
  , 2017. Emissions du Soleil Pourquoi la Météorologie de lEspace ? LE SOLEIL LA TERRE LIONOSPHERE Lionosphère aurorale et le phénomène des aurores Du Soleil vers la Terre / perturbations des systèmes GNSS et radar Extra radiations : Solar Flare (Radiation X), Solar bursts (Ondes radio) CME , chocs, Vents solaires rapides, Orages magnétiques Scintillations du signal GNSS Le réseau ISWI
• On the response of quasi-adiabatic particles to magnetotail reconfigurations
  
  • Delcourt Dominique C.
  • Malova Helmi V.
  • Zelenyi Lev M.
  Annales Geophysicae, European Geosciences Union, 2017, 35 (1), pp.11 - 23. We investigate the response of quasi-adiabatic particles to dynamical reconfigurations of the magnetotail field lines. Although they travel through a sharp field reversal with a characteristic length scale smaller than their Larmor radii, these quasi-adiabatic particles experience a negligible net change in magnetic moment. We examine the robust-ness of such a quasi-adiabatic behavior in the presence of a large surging electric field induced by magnetic field line reconfiguration as observed during the expansion phase of substorms. We demonstrate that, although such a short-lived electric field can lead to substantial nonadiabatic heating, quasi-adiabaticity is conserved for particles with velocities larger than the peak ExB drift speed. Because of the time-varying character of the magnetic field, it is not possible to use the adiabaticity parameter κ in a straightforward manner to characterize the particle behavior. We rather consider a κ parameter that is averaged over equatorial crossings. We demonstrate that particles intercepting the field reversal in the early stage of the magnetic transition may experience significant energization and enhanced oscillating motion in the direction normal to the midplane. In contrast, particles interacting with the field reversal in the late stage of the magnetic transition experience weaker energization and slower oscillations about the midplane. We show that quasi-adiabatic particles accelerated during such events can lead to energy–time dispersion signatures at low altitudes as is observed in the plasma sheet boundary layer. (10.5194/angeo-35-11-2017)
  DOI : 10.5194/angeo-35-11-2017