Publications

2013

• Capacitively coupled plasmas excited by tailored voltage waveforms
  
  • Lafleur Trevor
  • Delattre Pierre-Alexandre
  • Johnson E.V.
  • Booth Jean-Paul
  , 2013.
• New insights on the physics of radiative shocks
  
  • Chaulagain Uddhab
  • Stehlé Chantal
  • Larour Jean
  • Koszlova Michaela
  • Suzuki-Vidal Francisco
  • Acef Ouali
  • Dostál Jan
  • Krus Miroslav
  • Barroso Patrice
  • Reix Florent
  • Jagourel Pascal
  • Ciardi Andrea
  , 2013. Shock waves play a significant role in several astrophysical phenomena. Among them, Radiative shocks are strong shocks, in which the shock front is heated to very high temperature and thus emit an important radiation flux. The interesting feature of the radiative shocks is that their structure is strongly influenced by the coupling between hydrodynamics and radiation. They occur in astrophysical system in the different stages of the stellar evolution, for instance during the accretion processes in the stellar infancy, and are studied in high-energy density laboratory experiments using kJ class lasers. Such laser facilities enable to drive shocks in which the radiative flux may prevail hydrodynamic mechanism of energy transfer. Typical irradiances of 10**14 W.cm-2, allows to produce radiative shocks in high atomic gas medium at low pressure, where the important radiation generated by the shocked plasma leads to the formation of an ionizing wave, also call radiative precursor, in the cold upstream xenon. I will present new experimental results realized on the PALS laser installation aiming at improving the present knowledge of these complex flows. The greatest attention is paid to the application of to new diagnostics, namely, the instantaneous imaging of the whole shock structure using an auxiliary laser at 21.2 nm and a time-and-space resolved plasma self-emission using fast diodes. This work is supported by french ANR STARSHOCK (grant 08-BLAN-0263-07) and by Laserlab-Europe II programme.
• Investigation of turbulence and zonal flows for different shapes and scenarios in TCV using correlation ECE
  
  • Vuille V.
  • Porte L.
  • Brunner Stephan
  • Coda S.
  • Fasoli A.
  • Huang Z.
  • de Meijere C. A.
  • Merlo G.
  • Vermare Laure
  , 2013 (P2.176).
• On the nature, the scaling and the anisotropy of electron dissipation range in solar wind turbulence
  
  • Sahraoui Fouad
  • Huang S. Y.
  • Belmont Gérard
  • Goldstein M. L.
  • Retinò Alessandro
  , 2013.
• Micro fluctuation control and Hall thruster operation
  
  • Honoré Cyrille
  • Grésillon D.
  • Tsikata Sedina
  • Cavalier J.
  • Coulette D.
  • Lemoine N.
  • Largeau G.
  • Daniel G.
  , 2013.
• Geometrical aspects of the turbulence at the edge of tokamak plasmas and consequences on L-H transition threshold
  
  • Fedorczak N.
  • Diamond P.H.
  • Tynan G.R.
  • Manz P.
  • Hennequin Pascale
  • Xu G.S.
  • Bucalossi J.
  • Vermare Laure
  , 2013 (I4.111).
• Lanceur électromagnétique de chocs forts pour l'astrophysique de laboratoire : principe et premiers résultats
  
  • Larour Jean
  • Stehlé Chantal
  • Chaulagain Uddhab
  • Champion Norbert
  • Ciardi Andrea
  , 2013. Parmi les chocs forts présents en astrophysique, comme les chocs daccrétion lors de la formation des étoiles jeunes, les chocs radiatifs sont caractérisés par un pic de température localisé et une forte émission de rayonnement capable de structurer le choc. Par exemple, lionisation par ce rayonnement chauffe la matière en amont et modifie la propagation du choc (phénomène précurseur). Lastrophysique de laboratoire étudie ces chocs depuis une décennie en générant des chocs quasi plans par impact laser à haut flux. Récemment les auteurs ont ainsi pu mesurer des vitesses de 50 km/s dans le xénon dense. Il est apparu utile de créer des chocs forts par un moyen plus commode à mettre en uvre au laboratoire, permettant détudier une large gamme de chocs, de multiplier les expériences et de développer des diagnostics avec des contraintes dencombrement réduites. Or, des chocs daccrétion en gaz peu denses ont été documentés dans les années 70 dans les canons à plasma coaxiaux. Dans ces dispositifs, la pression magnétique générée par un courant fort (100 kA et plus) accélère une lame de plasma, ce qui constitue le lanceur du dispositif dit plasma focus. La puissance instantanée dun tel générateur ultra compact dépasse alors couramment les 500MWe. Après avoir obtenu dempêcher létape de focalisation du plasma, il a été possible de montrer quun choc quasi plan est créé et se déplace à une vitesse élevée dans un tube dont les dimensions sont dun ordre de grandeur supérieures à celles dun tube pour choc induit par laser. On présentera le mécanisme de formation et daccélération du plasma puis un modèle paramétrique régissant la vitesse terminale. Des exemples de mesures de la vitesse (de 5 à 20 km/s) et du profil du choc seront également présentés. Ce travail est soutenu par le DIM ACAV 2012 et par lOBSPM.
• Multi-diagnostic characterization of geodesic acoustic modes in the TCV tokamak
  
  • Huang Z.
  • de Meijere C. A.
  • Coda S.
  • Vermare Laure
  • Vernay T.
  • Vuille V.
  • Brunner Stephan
  • Hennequin Pascale
  • Kraemmer-Flecken A.
  • Porte L.
  , 2013 (P2.175).
• Effects of the surface conductivity and IMF strength on dynamics of planetary ions in Mercurys magnetosphere
  
  • Seki K.
  • Terada N.
  • Yagi M.
  • Delcourt Dominique
  • Leblanc François
  • Ogino T.
  , 2013. A previous study of ion dynamics in the Mercury's magnetosphere, which uses a rescaled analytical model of the geomagnetic and electric fields for Mercury, shows that non-adiabatic motion of ions inthe magnetotail can cause a narrow band of energetic (several keV) Na+ precipitation in each hemisphere [Delcourt et al., 2003]. On the other hand, it is not evident that the magnetospheric configuration and global convection pattern in the Mercury's magnetosphere can be described with the rescaled geomagnetospheric model. In order to investigate whether the ion dynamics in the self-consistent field configuration differs from that in the rescaled model, we conducted systematic trajectory tracings of Na+ ions in the electric and magnetic fields obtained from MHD simulations of the Mercury-solar wind interaction. Comparison with a previous study, which used an analytical model by rescaling Earth's magnetosphere and assumed the existence of the distant neutral line (DNL) in Mercury's magnetotail, shows the drastic change in Na+ precipitation pattern onto due to formation of the near-Mercury neutral line (NMNL) in MHD simulations. Na+ precipitation band around 30 degrees of latitude (LAT) obtained in the previous study disappeared in the equivalent low-conductivity MHD case due to the NMNL formation, while the NMNL formation causes high-energy Na+ precipitation into equatorial region. The change in the strength of the southward IMF (sBz) alters the location ofNMNL and Na+ precipitation pattern. In the low-conductivity sBz=5 case, both the equatorial precipitation and Na+ band around LAT=30 are formed. In the high-conductivity sBz=5 case, on one hand, magnetospheric convection through polar regions is suppressed and it results in a region of dense Na+ near the planet. These results suggest that the dynamics of planetary ions in the magnetosphere of Mercury and related precipitation onto the planet surface change significantly with the activity level of Mercury'smagnetosphere. It is also suggested that we can gather information about the surface conductivity from observations of either the magnetospheric convection, distribution of Na+ ions around the planet, or precipitation pattern of Na+ ions onto the planetary surface
• Plasma assisted ignition inside a Rapid Compression Machine
  
  • Boumehdi M.A.
  • Stepanyan S.A.
  • Starikovskaia Svetlana
  • Desgroux Pascale
  • Vanhove G.
  , 2013.
• Sun Earth System : Connection through Dynamo process
  
  • Amory-Mazaudier Christine
  , 2013.
• Compact Marx Generator in Air Triggered by Femtosecond Filaments
  
  • Arantchouk Léonid
  • Houard Aurélien
  • Point G.
  • Brelet Yohann
  • Carbonnel Jérôme
  • André Y-B.
  • Larour Jean
  • Mysyrowicz André
  , 2013. oral 3C-1
• Study of Implosion Dynamics and Radiative Mechanisms of Planar Foil Liners in Comparison with Planar Wire Arrays at 1.7 MA UNR Zebra Generator
  
  • Kantsyrev Viktor L.
  • Safronova Alla S.
  • Esaulov A. A.
  • Shrestha Ishor
  • Zunino H. A.
  • Shlyaptseva V. V.
  • Weller Michael E.
  • Osborne Glenn C.
  • Stafford A.
  • Keim S. F.
  • Chuvatin Alexandre S.
  • Rudakov Leonid I.
  • Velikovich A. L.
  , 2013. oral 1A-7
• Laser induced plasma column heated by Tesla coil discharges as a radio-frequency antenna
  
  • Point Guillaume
  • Houard Aurélien
  • Brelet Yohann
  • Carbonnel Jérôme
  • Arantchouk Léonid
  • Prade Bernard S.
  • André Y-B.
  • Mysyrowicz André
  , 2013. oral 8D-6
• Analysis of Al Precursor wire array experiments on the 1 MA ZEBRA generator at UNR
  
  • Stafford A.
  • Safronova Alla S.
  • Kantsyrev Viktor L.
  • Esaulov A. A.
  • Weller Michael E.
  • Osborne Glenn C.
  • Shrestha Ishor
  • Keim S. F.
  • Shlyaptseva V. V.
  • Petkov E. E.
  • Coverdale C. A.
  • Chuvatin Alexandre S.
  , 2013. affiche P1-18
• Radiation Signatures of Large Sized Multi-Planar Wire Arrays
  
  • Safronova Alla S.
  • Kantsyrev Viktor L.
  • Esaulov A. A.
  • Weller Michael E.
  • Shrestha Ishor
  • Shlyaptseva V. V.
  • Stafford A.
  • Osborne Glenn C.
  • Keim S. F.
  • Petkov E.E.
  • Chuvatin Alexandre S.
  • Coverdale C. A.
  • Jones B.
  , 2013. oral 6A-4
• Predator prey dynamics in numerical simulations of turbulence in tokamaks
  
  • Morel Pierre
  • Gürcan Özgür D.
  • Berionni Vincent
  , 2013.
• Role of the terrestrial bow shock on magnetic clouds structure: 1. CLUSTER observations downstream of the bow shock
  
  • Fontaine Dominique
  • Turc Lucile
  • Savoini Philippe
  , 2013. Magnetic clouds are known as very geoeffective structures, in the sense that they can be at the origin of large magnetic storms in the Earths environment, as measured by the Dst index. An important parameter considered in the geoeffectiveness studies is the North-South component of the Interplanetary Magnetic Field (IMF). But the correlation between geoeffectiveness and IMF is not straightforward and statistical studies revealed a much more complex situation. Indeed, before reaching the magnetosphere, the magnetic clouds encounter first the bow shock which decreases the solar wind velocity down to sub-sonic and sub-Alvénic values, modifies the magnetic field structure, and finally changes the conditions of the interaction with the magnetosphere. These modifications can be observed by the CLUSTER satellites along orbits that go out of the magnetosphere and cross the region downstream of the bow shock. We show cases where the magnetic field structure of the magnetic clouds is maintained. But we also observed cases where it is strongly modified, with large rotations of the magnetic field. We interpret these modifications as a function of the magnetic field direction relative to the local normal, leading to different shock conditions: quasi-parallel, quasi-perpendicular, The consequences are that the interaction of these magnetic clouds with the magnetosphere and thus their geoeffectiveness differ from what could be assumed from their initial configuration in the solar wind. This effect stresses the need of modeling to predict accurate interaction conditions with the magnetosphere.
• Cassini observations of whistler waves at high Mach number Saturn's shock wave
  
  • Retinò Alessandro
  • Masters Adam
  • Schimpf A.
  • Hadid L. Z.
  • Sundkvist David
  • Vaivads A.
  • Fujimoto Masaki
  • Canu Patrick
  • Modolo Ronan
  • Sahraoui Fouad
  • Le Contel Olivier
  • Chust Thomas
  • Dougherty Michele K.
  , 2013.
• Laboratory experiments of Radiative Shocks, in the context of stellar accretion
  
  • Chaulagain Uddhab
  • Stehlé Chantal
  • Larour Jean
  , 2013. Radiative shocks are high Mach number shocks with a strong coupling between radiation and hydrodynamics. These shocks occour in astrophysical system and in high-energy density laboratory experiments. High-energy lasers can be used to simulate astrophysical phenomena in the Laboratory. PALS Laser facility provides irradiance of 10¹4 W/cm², lasting less than 1 ns, and allows to produce radiative shocks in high atomic gas medium at low pressure. The radiative energy is converted into mechanical energy, generating the shock in the gas. The system is optimized for reaching conditions where the shock is radiative, i.e. it presents a radiative precursor. The experimental results of two new diagnostics: first a XUV instantaneous imaging at 21.2 mm, and second, a time and space resolved plasma self-emission using fast diodes will be highlighted. communication orale Atelier S08 Actes à paraître 2013 sur le site de la SF2A
• X-ray laser imaging of a radiative shock
  
  • Chaulagain Uddhab
  • Stehlé Chantal
  • Larour Jean
  • Kozlová Michaela
  , 2013, SF2A Proceedings. communication orale actes à paraître sur http://2013.sf2a.eu
• 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.
• Thin Film Deposition with Tailored Voltage Waveforms: Material Questions and Practical Answers
  
  • Johnson E.V.
  • Bruneau Bastien
  • Delattre Pierre-Alexandre
  • Lafleur Trevor
  • Booth Jean-Paul
  , 2013.
• Physics and design of wide-aperture bipolar particle sources
  
  • Stanislav Dudin
  • Aanesland Ane
  , 2013.