Publications

2002

• Large-amplitude plasma wave generation with a high-intensity short-pulse beat wave
  
  • Walton B.
  • Najmudin Z.
  • Wei M. S.
  • Marle C.
  • Kingham R.J.
  • Krushelnick K.
  • Dangor A.E.
  • Clarke R.J.
  • Poulter M.J.
  • Hernandez-Gomez C.
  • Hawkes S.
  • Neely D.
  • Collier J. L.
  • Danson C.N.
  • Fritzler S.
  • Malka Victor
  Optics Letters, Optical Society of America - OSA Publishing, 2002, 27 (24), pp.2203-2205. A short-pulse laser beat wave scheme for advanced particle accelerator applications is examined. A short, intense (3-ps, >10^18-W cm^-2) two-frequency laser pulse is produced by use of a modified chirped-pulse amplification scheme and is shown to produce relativistic plasma waves during interactions with low-density plasmas. The generation of plasma waves was observed by measurement of forward Raman scattering. Resonance was found to occur at an electron density many times that expected, owing to ponderomotive displacement of plasma within the focal region. (10.1364/OL.27.002203)
  DOI : 10.1364/OL.27.002203
• A laser experiment for studying radiative shocks in astrophysics
  
  • Fleury X.
  • Bouquet S.
  • Stehlé C.
  • Koenig M.
  • Batani D.
  • Benuzzi-Mounaix A.
  • Chièze J. -P.
  • Grandjouan N.
  • Grenier J.
  • Hall T.
  • Henry E.
  • Lafon J.-P.
  • Leygnac S.
  • Malka Victor
  • Marchetti B.
  • Merdji H.
  • Michaut C.
  • Thais F.
  Laser and Particle Beams, Cambridge University Press (CUP), 2002, 20 (2), pp.263-268. In this article, we present a laboratory astrophysics experiment on radiative shocks and its interpretation using simple modelization. The experiment is performed with a 100-J laser (pulse duration of about 0.5 ns) which irradiates a 1-mm^3 xenon gas-filled cell. Descriptions of both the experiment and the associated diagnostics are given. The apparition of a radiation precursor in the unshocked material is evidenced from interferometry diagrams. A model including self-similar solutions and numerical ones is derived and fairly good agreements are obtained between the theoretical and the experimental results. (10.1017/S0263034602202165)
  DOI : 10.1017/S0263034602202165
• Ion Heating and Thermonuclear Neutron Production from High-Intensity Subpicosecond Laser Pulses Interacting with Underdense Plasmas
  
  • Fritzler S.
  • Najmudin Z.
  • Malka Victor
  • Krushelnick K.
  • Marle C.
  • Walton B.
  • Wei M. S.
  • Clarke R.J.
  • Dangor A.E.
  Physical Review Letters, American Physical Society, 2002, 89 (16), pp.165004. Thermonuclear fusion neutrons produced by D(d,n)3He reactions have been measured from the interaction of a high-intensity laser with underdense deuterium plasmas. For an input laser energy of 62 J, more than (1.0±0.2)×10^6 neutrons with a mean kinetic energy of (2.5±0.2) MeV were detected. These neutrons were observed to have an isotropic angular emission profile. By comparing these measurements with those using a secondary solid CD2 target it was determined that neutrons are produced from direct ion heating during this interaction. (10.1103/PhysRevLett.89.165004)
  DOI : 10.1103/PhysRevLett.89.165004
• New sources of ultrashort pulse X-ray radiation and applications
  
  • Gauthier J.-C.
  • Rousse Antoine
  Journal de Physique IV Proceedings, EDP Sciences, 2002, 12 (5), pp.59 - 67. The world of x-ray sources is divided between large "third generation" synchrotron and the user-friendlier "table-top" sources using the emission from plasmas produced by lasers or electrical discharges. The use of x-ray sources has become more and more widespread in many disciplines of basic research and engineering because x-rays are invaluable tools for imagery, defect analysis, and material composition and structure determination. X-ray sources are now capable of producing ultra short pulses with duration ranging from tens of picoseconds to less than one picosecond, giving access to the time scale of elementary processes such as molecular vibrations, and gaining information about the transition state in reactive biological molecules. This paper describes these new x-ray sources and techniques and reviews the first experiments dedicated to the analysis of atomic motions on this time-scale. (10.1051/jp4:20020097)
  DOI : 10.1051/jp4:20020097
• Experimental study on the mixing induced by inertia-gravity wave breaking on the dynamical barrier of a vortex
  
  • Moulin F.Y.
  • Flór Jan-Bert
  , 2002. We present the results of an experimental investigation on the material transport across the shear zone of a cyclonic vortex induced by the breaking of inertia-gravity waves. As has been suggested by McIntyre (1995) this could be a possible mechamism of ozone transport across the dynamical barrier of the polar vortex. The experiments were conducted in a 1 meter size tank containing a rotating stratified fluid. Barotropic vortices were generated by siphoning off fluid with a long perforated tube and per- turbed by planar internal waves generated by the vertical oscillation of a horizontal circular cylinder. As predicted by theorical results based on the WKB approximation, the waves opposing the vortex velocity field were trapped in the outer edge of the vor- tex. In some cases, the increase of wave energy in this region was strong enough to lead to 3-dimensional breaking of the wave pattern. Experimental visualization tech- niques were used to determine the class of instability responsible for this breaking and to measure the induced mixing. A simple model to predict the efficiency of the mixing process will be presented.
• X-ray emission of a xenon gas jet plasma diagnosed with Thomson scattering
  
  • Chenais-Popovics Claude
  • Malka Victor
  • Gauthier J.-C.
  • Gary S.
  • Peyrusse O.
  • Rabec-Le Gloahec M.
  • Matsushima I.
  • Bauche-Arnoult C.
  • Bachelier A.
  • Bauche J.
  Physical Review E : Statistical, Nonlinear, and Soft Matter Physics [2001-2015], American Physical Society, 2002, 65 (4), pp.046418. We present the results of a benchmark experiment aimed at validating recent calculation techniques for the emission properties of medium and high-Z multicharged ions in hot plasmas. We use space- and time-resolved M-shell x-ray spectroscopy of a laser-produced gas jet xenon plasma as a primary diagnostic of the ionization balance dynamics. We perform measurements of the electron temperature, electron density, and average charge state by recording simultaneous spectra of ion acoustic and electron plasma wave Thomson scattering. A comparison of the experimental x-ray spectra with calculations performed ab initio with a non-local-thermodynamic-equilibrium collisional-radiative model based on the superconfiguration formalism, using the measured plasma parameters, is presented and discussed. (10.1103/PhysRevE.65.046418)
  DOI : 10.1103/PhysRevE.65.046418
• Lack of conscious recognition of one's own actions in a haptically deafferented patient.
  
  • Fourneret Pierre
  • Paillard Jacques
  • Lamarre Yves
  • Cole Jonathan
  • Jeannerod Marc
  NeuroReport, Lippincott, Williams & Wilkins, 2002, 13 (4), pp.541-7. How do we become aware of our own actions? This classical question is still a matter of debate: does consciousness depend on central efferent signals or derive from peripheral information? In this paper, we had the opportunity to study a haptically deafferented patient using a well-tested experimental paradigm where a cognitive conflict is produced between motor intention, proprioception and visual feedback. Our results show that the patient was able to solve the conflict and to generate accurate movements to a target in the absence of proprioceptive feedback and with very limited visual feedback from her movements. Yet, she could not report any conscious perception of the conflict and showed no conscious knowledge of her actual performance. We suggest that information derived from efferent processes cannot in themselves be a source for conscious experience about our own actions.
• Ultra-High-Intensity Laser Propagation Through Underdense Plasma
  
  • Najmudin Z.
  • Tatarakis M.
  • Krushelnick K.
  • Clark E. L.
  • Malka Victor
  • Faure Jérôme
  • Dangor A.E.
  IEEE Transactions on Plasma Science, Institute of Electrical and Electronics Engineers, 2002, 30 (1), pp.44. Picosecond resolution shadowgraphy is a powerful tool for measurement of high-intensity laser propagation instabilities through underdense plasma. It is shown that as the plasma density increases, the laser beam is subject to severe filamentation instabilities—likely due to the effect of stimulated Raman side-scattering. At higher plasma densities, scattering and absorption are so severe that the propagation distance of the high intensity laser pulse is reduced.
• Production of ultracollimated bunches of multi-MeV electrons by 35 fs laser pulses propagating in exploding-foil plasmas
  
  • Giulietti Danilo
  • Galimberti M.
  • Giulietti Antonio
  • Gizzi L. A.
  • Numico R.
  • Tomassini Pascale
  • Borghesi M.
  • Malka Victor
  • Fritzler S.
  • Pittman M.
  • Ta Phuoc Kim
  • Pukhov A.
  Physics of Plasmas, American Institute of Physics, 2002, 9 (9), pp.3655. Very collimated bunches of high energy electrons have been produced by focusing super-intense femtosecond laser pulses in submillimeter under-dense plasmas. The density of the plasma, preformed with the laser exploding-foil technique, was mapped using Nomarski interferometry. The electron beam was fully characterized: up to 10^9 electrons per shot were accelerated, most of which in a beam of aperture below 10^−3 sterad, with energies up to 40 MeV. These measurements, which are well modeled by three-dimensional numerical simulations, validate a reliable method to generate ultrashort and ultracollimated electron bunches. (10.1063/1.1498116)
  DOI : 10.1063/1.1498116
• Hot-electron influence on L-shell spectra of multicharged Kr ions generated in clusters irradiated by femtosecond laser pulses
  
  • Hansen S. B.
  • Shlyaptseva A. S.
  • Faenov A. Y.
  • Skobelev I. Y.
  • Magunov A. I.
  • Pikuz T. A.
  • Blasco F.
  • Dorchies F.
  • Stenz C.
  • Salin F.
  • Auguste T.
  • Dobosz S.
  • Monot P.
  • d'Oliveira P.
  • Hulin S.
  • Safronova U. I.
  • Fournier K. B.
  Physical Review E, American Physical Society (APS), 2002, 66 (4). no abstract
• Evidence of supercritical density in 45-fs-laser-irradiated Ar-cluster plasmas
  
  • Junkel-Vives G. C.
  • Abdallah J.
  • Blasco F.
  • Dorchies F.
  • Caillaud T.
  • Bonte C.
  • Stenz C.
  • Salin F.
  • Faenov A. Y.
  • Magunov A. I.
  • Pikuz T. A.
  • Skobelev I. Y.
  Physical Review A : Atomic, molecular, and optical physics [1990-2015], American Physical Society, 2002, 66 (3). no abstract
• Experimental observations of wave-vortex interactions in a stratified rotating fluid
  
  • Moulin F.Y.
  • Flór Jan-Bert
  , 2002.
• Dynamique sub-picoseconde de l'interaction laser de puissance – agrégats de gaz rare : émission intense de rayons X et production d'ions multichargés.
  
  • Prigent Christophe
  • Adoui Lamri
  • Dreuil S.
  • Gauthier J.-C.
  • Gobert Olivier
  • Lamour Emily
  • Meynadier Pierre
  • Normand Didier
  • Perdrix Michel
  • Rozet Jean-Pierre
  • Vernhet Dominique
  , 2002, 108, pp.191-194. Lors de campagnes d'expériences réalisées sur le Laser Ultra Court Accordable du CEA/Saclay, nous avons étudié le rayonnement X, tant qualitativement (spectroscopie et énergie moyenne des photons) que quantitativement (taux absolus et lois d'évolution), émis lors de l'interaction d'un jet effusif d'agrégats de gaz rare (Ar, Kr, Xe comprenant entre 10^4 et 10^6 atomes/agrégat) avec un laser femtoseconde de puissance (éclairement jusqu'à quelques 10^17 W/cm2). Les résultats présentés dans ce manuscrit sont uniquement dédiés aux agrégats d'Ar pour lesquels nous avons observé un rayonnement X issu d'ions fortement multichargés (jusqu'à l'Ar16+) présentant des lacunes en couches K. La technique de spectroscopie X utilisée a permis de déterminer pour la première fois des taux absolus ainsi que les lois d'évolution de l'émission X en fonction de l'ensemble des paramètres gouvernant l'interaction (intensité, polarisation, longueur d'onde et durée du pulse laser aussi bien que taille, densité et numéro atomique des agrégats). (10.1051/jp4:20030625)
  DOI : 10.1051/jp4:20030625
• Beam-focus shaping by use of programmable phase-only filters: application to an ultralong focal line
  
  • Wattellier B.
  • Sauteret C.
  • Chanteloup Jean-Christophe
  • Migus A.
  Optics Letters, Optical Society of America - OSA Publishing, 2002, 27 (4), pp.213. (10.1364/OL.27.000213)
  DOI : 10.1364/OL.27.000213
• X-ray spectroscopy diagnostic of a plasma produced by femtosecond laser pulses irradiating a cluster target
  
  • Skobelev I. Y.
  • Faenov A. Y.
  • Magunov A. I.
  • Pikuz T. A.
  • Boldarev A. S.
  • Gasilov V. A.
  • Abdallach J.
  • Junkel-Vives G. C.
  • Auguste T.
  • Dobosz S.
  • d'Oliveira P.
  • Hulin S.
  • Monot P.
  • Blasco F.
  • Dorchies F.
  • Caillaud T.
  • Bonte C.
  • Stenz C.
  • Salin F.
  • Loboda P. A.
  • Litvinenko I. A.
  • Popova V. V.
  • Baidin G. V.
  • Sharkov B. Y.
  Journal of Experimental and Theoretical Physics (JETP) / Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki, MAIK Nauka/Interperiodica, 2002, 94 (5), pp.966-976. no abstract
• Effects of pulse duration on self-focusing of ultra-short lasers in underdense plasmas
  
  • Faure Jérôme
  • Malka Victor
  • Marques J.R.
  • David P.-G.
  • Amiranoff François
  • Ta Phuoc Kim
  • Rousse Antoine
  Physics of Plasmas, American Institute of Physics, 2002, 9 (3), pp.756. An experiment investigating laser self-focusing in underdense plasmas is presented. It was shown experimentally that the critical power for relativistic self-focusing Pc is not the only relevant parameter, in particular when the laser pulse duration is comparable to plasma particle motion times: ωp−1 for electrons and ωpi−1 for ions. Using time resolved shadowgraphy, it was demonstrated that: (i) a pulse does not relativistically self-focus if its duration is too short compared to ωp−1, even in the case where the power is greater than Pc. This is due to defocusing by the longitudinal wake which is generated by the laser pulse itself. (ii) For pulses longer than ωpi−1, self-focusing can occur even for powers lower than Pc. This is due to the radial expansion of ions, creating a channel whose effect combines with relativistic focusing and helps the pulse to self-focus. (10.1063/1.1447556)
  DOI : 10.1063/1.1447556
• On the interaction of femtosecond laser pulses with cluster targets
  
  • Skobelev I. Y.
  • Faenov A. Y.
  • Magunov A. I.
  • Pikuz T. A.
  • Boldarev A. S.
  • Gasilov V. A.
  • Abdallach J.
  • Junkel-Vives G. C.
  • Auguste T.
  • d'Oliveira P.
  • Hulin S.
  • Monot P.
  • Blasco F.
  • Dorchies F.
  • Caillaud T.
  • Bonte C.
  • Stenz C.
  • Salin F.
  • Sharkov B. Y.
  Journal of Experimental and Theoretical Physics (JETP) / Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki, MAIK Nauka/Interperiodica, 2002, 94 (1), pp.73-83. no abstract
• Observation of dielectronic satellites in the K-spectrum of argon ions in plasma produced by femtosecond laser pulses
  
  • Magunov A. I.
  • Faenov A. Y.
  • Skobelev I. Y.
  • Pikuz T. A.
  • Biémont É.
  • Quinet P.
  • Blasco F.
  • Bonte C.
  • Dorchies F.
  • Caillaud T.
  • Salin F.
  • Stenz C.
  Journal of Experimental and Theoretical Physics (JETP) / Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki, MAIK Nauka/Interperiodica, 2002, 95 (6), pp.998-1005. no abstract
• Spectral studies of short pulse laser irradiated argon clusters
  
  • Junkel-Vives G. C.
  • Abdallah J.
  • Blasco F.
  • Dorchies F.
  • Stenz C.
  • Salin F.
  • Faenov A. Y.
  • Magunov A. I.
  • Pikuz T. A.
  • Skobelev I. Y.
  • Auguste T.
  • Dobosz S.
  • d'Oliveira P.
  • Hulin S.
  • Monot P.
  , 2002, 635, pp.82-91. no abstract
• L-band x-ray absorption of radiatively heated nickel
  
  • Chenais-Popovics C.
  • Fajardo M.
  • Gilleron F.
  • Teubner U.
  • Gauthier J. C.
  • Bauche-Arnoult C.
  • Bachelier A.
  • Bauche J.
  • Blenski T.
  • Thais F.
  • Perrot F.
  • Benuzzi A.
  • Turck-Chieze S.
  • Chièze J. P.
  • Dorchies F.
  • Andiel U.
  • Foelsner W.
  • Eidmann K.
  Physical Review E, American Physical Society (APS), 2002, 65 (1). no abstract (10.1103/PhysRevE.65.016413)
  DOI : 10.1103/PhysRevE.65.016413