Publications

2013

• RF measurements in the ferrite-enhanced PEGASES II space thruster prototype : power efficiency and range of operation
  
  • Rafalskyi D.V.
  • Aanesland Ane
  • Bredin Jérôme
  • Chabert Pascal
  , 2013.
• Inductively-coupled plasmas in pure chlorine: comparison of atom density, electron density and gas temperature measurements with the HPEM hybrid model.
  
  • Booth Jean-Paul
  • Sirse Nishant
  • Chabert Pascal
  • Pruvost B.
  • Kushner M.J.
  , 2013.
• Status on the Project of Laser Based Production, Acceleration and Neutralization of High Power Neutral (H or D) Beam for Demo Application
  
  • Moustaizis Stavros
  • Auvray Philippe
  • Larour Jean
  • Perrakis C.
  • Ducret J.-E.
  , 2013. communication orale
• Origin of extracted H- ions at different plasma grid bias in caesiated ion sources
  
  • Bacal M.
  • Mcadams R.
  • Surrey E.
  , 2013.
• Generation of High Pulsed magnetic field using low inductance switches
  
  • Auvray Philippe
  • Larour Jean
  • Moustaizis Stavros
  , 2013. On présente plusieurs dispositifs de production de courants intenses (jusqu'à 900 kA sous 30 kV) pour magnétiser des volumes d'interaction laser-matière de quelques cm3 pendant environ 1 µs. L'accent est mis sur la réalisation de deux types d'éclateur à très faible inductance et sur la connexion à une chambre à vide.
• Numerical Evaluation of the Role of Reflectors to Maximize the Power Efficiency of an Axial Vircator (keynote)
  
  • Champeaux Stéphanie
  • Gouard Philippe
  • Cousin Richard
  • Larour Jean
  , 2013, pp.4A-High Power Microwaves I. Keynote speech on HPM. The effects of introducing one or more reflectors inside an axial Vircator are analyzed using CST-Particle Studio (TM) PIC simulation. The power conversion efficiency is shown to be enhanced from 1% to 13% at 3 GHz. The optimum output power is obtained with three reflectors. Abstract disponible sur http://www.ivec2013.org/ Texte de 2 pages sur clé USB distribué aux participants mais non public.
• Propagation of Plasmas in Liquids
  
  • Rousseau Antoine
  , 2013.
• Guiding of meter scale AC discharges by laser filamentation in air
  
  • Houard Aurélien
  • Brelet Yohann
  • Point G.
  • Carbonnel Jérôme
  • André Y-B.
  • Prade Bernard S.
  • Arantchouk Léonid
  • Mysyrowicz André
  , 2013. We report experiments of laser-guided discharges obtained in air with high voltage bursts delivered by a compact Tesla coil. Characteristics of the guided discharges are studied for electrode gaps ranging from 30 to 170 cm.
• Plasma column from laser filamentation in air as a virtual radio-frequency antenna
  
  • Point G.
  • Brelet Yohann
  • Houard Aurélien
  • Carbonnel Jérôme
  • Arantchouk Léonid
  • Prade Bernard S.
  • André Y-B.
  • Mysyrowicz André
  , 2013. We demonstrate the use of a plasma column created by femtosecond filamentation and heated by means of a high-voltage discharge communication orale CD-10.1
• Dynamics of Cl<SUB>2</SUB> inductively-coupled plasmas: Role of electronic and vibrational excitation
  
  • Booth Jean-Paul
  • Sirse Nishant
  • Chabert Pascal
  • Indelicato P.
  • Surzhykov A.
  • Kushner M.J.
  , 2013.
• Development of plasma and beam diagnostics for the PEGASES thruster experiment
  
  • Rafalskyi D.V.
  • Aanesland Ane
  , 2013.
• A simple high-voltage high current spark gap with subnanosecond jitter triggered by femtosecond laser filamentation
  
  • Arantchouk Léonid
  • Houard Aurélien
  • Brelet Yohann
  • Carbonnel Jérôme
  • Larour Jean
  • André Yves-Bernard
  • Mysyrowicz André
  Applied Physics Letters, American Institute of Physics, 2013, 102 (16), pp.162502. We describe a simple, sturdy, and reliable spark gap operating with air at atmospheric pressure and able to switch currents in excess of 10 kA with sub-nanosecond jitter. The spark gap is remotely triggered by a femtosecond laser filament. (10.1063/1.4802927)
  DOI : 10.1063/1.4802927
• Doppler backscattering measurements on TCV
  
  • Vermare Laure
  • Coda S.
  • Hennequin Pascale
  • de Meijere K.
  • Honoré Cyrille
  • Giacalone J-C.
  • Tcv Team
  , 2013 (oral).
• The optimized steerable W-band Doppler reflectometer on ASDEX Upgrade: possibilities and issues
  
  • Happel T.
  • Conway G. D.
  • Hennequin Pascale
  • Honoré Cyrille
  • Giacalone J-C.
  • Simon P.
  • Stroth U.
  • Vermare Laure
  • Asdex Upgrade Team The
  , 2013 (http://www.lptp.polytechnique.fr/News/11/Workshop/papers/Happel_IRW11-paper.pdf).
• Observation of a poloidal asymmetry of fluctuation perpendicular velocity measured by Doppler backscattering on Tore Supra plasmas
  
  • Storelli A.
  • Hennequin Pascale
  • Vermare Laure
  • Gürcan Özgür D.
  • Tore Supra Team
  , 2013 (oral).
• Damping of Geodesic Acoustic Modes.
  
  • Vermare Laure
  • Hennequin Pascale
  • Gürcan Özgür D.
  • Morel Pierre
  • Tore Supra Team
  , 2013 (oral).
• Geodesic acoustic modes:ffsimultaneous observation of density,ff magnetic-field, and flow componentsff in the TCV tokamak
  
  • Coda S.
  • de Meijere K.
  • Huang Z.
  • Vermare Laure
  • Vernay T.
  • Vuille V.
  • Brunner Stephan
  • Dominski J.
  • Hennequin Pascale
  • Krämer-Flecken A.
  • Merlo G.
  • Porte L.
  , 2013 (oral).
• Spatial propagation of turbulence and formation of mesoscopic structures in GK simulations
  
  • Dif-Pradalier Guilhem
  • Ghendrih Ph.
  • Diamond P.H.
  • Garbet X.
  • Grandgirard V.
  • Palermo F.
  • Sarazin Y.
  • Strugarek Antoine
  • Abitboul J.
  • Gürcan Özgür D.
  • Hennequin Pascale
  • Morel Pierre
  • Vermare Laure
  , 2013 (http://ttf2013.ucsd.edu/TTF_Meeting/Home.html).
• A 3D parallel model of Ganymede's exosphere
  
  • Leclercq Ludivine
  • Turc Lucile
  • Leblanc François
  • Modolo Ronan
  , 2013, pp.EGU2013-9679. Ganymede is a unique object : it is the biggest moon of our solar system, and the only satellite which has its own intrinsic magnetic field. Its surface is covered by water ice and by regolith. Some previous observations suggest that below its surface may exist an ocean of liquid water. The atmosphere of the planet is poorly known but should be composed essentially of water, hydrogen and oxygen (Marconi et al., Icarus, 2007). These atmospheric particles mainly originate from the surface thanks to sublimation of water-ice and sputtering, a process driven by the magnetospheric Jovian particles impacting Ganymede surface and leading to ejection of atoms and molecules into Ganymede atmosphere. We developed a model of Ganymede's atmosphere based on a 3D Monte Carlo description of the fate of the ejected particles from the surface. This model has been parallelized allowing a much better statistical, spatial and temporal description of Ganymede's environment. This model includes the main sources of the neutral atmosphere and is able to calculate all its characteristics. It was successfully compared to the few known observations as well as to previous modeling. In this presentation, we will present the main characteristics of this model and what it tells us on Ganymede's atmosphere, in terms of spatial structure, composition, temporal variability and relations with both magnetosphere and surface.
• Detection of thin current sheets and associated reconnection in the Earth's turbulent magnetosheath using cluster multi-point measurements
  
  • Chasapis A.
  • Retinò Alessandro
  • Sahraoui Fouad
  • Greco A.
  • Vaivads A.
  • Sundkvist D.
  • Canu Patrick
  , 2013, 15, pp.EGU2013-5796.
• Suprathermal electron acceleration at reconnection jet fronts and braking regions in the Earth's magnetotail
  
  • Retinò Alessandro
  • Vaivads A.
  • Zieger B.
  • Fujimoto M.
  • Kasahara S.
  • Nakamura R.
  • Chasapis A.
  • Fu H.S.
  , 2013, 15, pp.EGU2013-5627. Magnetic reconnection is an efficient mechanisms for accelerating charged particles to energies much higher than their thermal energy. Important examples are the solar corona and planetary magnetospheres. A number of recent numerical simulations as well as in situ observations in Earth's magnetotail indicate that strong acceleration occurs at reconnection jet fronts, the boundary separating jetting from ambient plasma, and in jet braking regions, where jets eventually stop/dissipate. Yet the details of the acceleration mechanisms are not fully understood. Here we present a few examples of jet fronts/braking regions and associated suprathermal electron acceleration in the Earth's magnetotail, by using Cluster spacecraft data. We discuss the properties of accelerated electrons and electromagnetic fields for both jet front and jet braking regions.
• Impact of the Earth bow shock crossing on magnetic clouds structure
  
  • Turc Lucile
  • Fontaine Dominique
  • Savoini Philippe
  • Kilpua E. K. J.
  , 2013, 15, pp.4848. In the solar wind, magnetic clouds (MC) display a well-defined magnetic structure. When they reach the vicinity of the Earth, their structure is modified by their interaction with the Earth environment. In this study, we focus on the bow shock crossing of MCs, and more specifically on how it alters their magnetic structure. We compare observations from the Cluster spacecraft in the magnetosheath to ACE magnetic field measurements in the solar wind, in order to highlight the differences before and after the bow shock crossing. We find that the magnetic field amplitude is higher inside the magnetosheath, as expected from the compression behind the shock, but that the magnetic field direction can exhibit different features. It can be similar to the solar wind magnetic field direction, display a phase shift or the smooth rotation can even disappear in the magnetosheath. The correlation between the variation of the magnetic field direction from the solar wind to the magnetosheath and the shock obliquity angle is investigated. Finally, a simple 3D MHD model is developed to describe the interaction of a MC with the bow shock and calculate the magnetic field amplitude and direction inside the magnetosheath. We show several outputs of the model, corresponding to different orientations of the MC axis. We compare these modeled cases to observations. In some cases, the results show that the trends are in qualitative agreement, and other cases are further discussed.
• Case study of an atypical magnetopause crossing
  
  • Dorville Nicolas
  • Belmont Gérard
  • Rezeau Laurence
  • Grappin Roland
  • Retinò Alessandro
  , 2013, 15, pp.EGU2013-2279.
• Analysis of amplitudes of equatorial noise emissions and their variation with L, MLT and magnetic activity
  
  • Hrbackova Z.
  • Santolík O.
  • Cornilleau-Wehrlin Nicole
  , 2013, 15, pp.EGU2013-10281. Wave-particle interactions are an important mechanism of energy exchange in the outer Van Allen radiation belt. These interactions can cause an increase or decrease of relativistic electron flux. The equatorial noise (EN) emissions (also called fast magnetosonic waves) are electromagnetic waves which could be effective in producing MeV electrons. EN emissions propagate predominantly within 10° of the geomagnetic equator at L shells from 1 to 10. Their frequency range is between the local proton cyclotron frequency and the lower hybrid resonance. We use a data set measured by the STAFF-SA instruments onboard four Cluster spacecraft from January 2001 to December 2010. We have compiled the list of the time intervals of the observed EN emissions during the investigated time period. For each interval we have computed an intensity profile of the wave magnetic field as a function of frequency. The frequency band is then determined by an automatic procedure and the measured power spectral densities are reliably transformed into wave amplitudes. The results are shown as a function of the McIlwain's parameter, magnetic local time and magnetic activity - Kp and Dst indexes. This work has received EU support through the FP7-Space grant agreement n 284520 for the MAARBLE collaborative research project.
• Magnetic field and plasma fluctuations in CME-driven sheath regions
  
  • Kilpua E. K. J.
  • Hietala H.
  • Koskinen H.
  • Fontaine Dominique
  • Turc Lucile
  , 2013, 15, pp.2855. Coronal mass ejection (CME)-driven sheath regions exhibit large-amplitude interplanetary magnetic field and dynamic pressure fluctuations, which may enhance the solar wind-magnetosphere coupling and lead to larger geomagnetic activity. The internal structure of CME sheath region is extremely complex as it gradually forms when the CME propagates from the Sun to the orbit of the Earth. In this study we perform a statistical superposed epoch analysis of the magnetic field and dynamic pressure fluctuations in sheath regions observed by the ACE spacecraft near Lagrangian point L1 using the wavelet analysis. In particular, we investigate where in the sheath the fluctuation power is strongest and how its level and distribution within the sheath depends on the CME properties (speed, strength and the closest approach distance from the CME center). We found that there is a sharp decrease in the magnetic field Ultra Low Frequency (2-15 minutes) power between the sheath and the CME leading edge. We suggest that this decrease can be used as a proxy for the CME front boundary.