Publications (350)548.52 Total impact
 Review of Scientific Instruments 02/2016; 87(2):02B134. DOI:10.1063/1.4935234 · 1.61 Impact Factor
 Plasma Physics and Controlled Fusion 01/2016; 58(1):014018. DOI:10.1088/07413335/58/1/014018 · 2.19 Impact Factor

Dataset: ChoCoLaT
 Physical Review E 11/2015; 92(5). DOI:10.1103/PhysRevE.92.059902 · 2.29 Impact Factor

Dataset: input 0000

Dataset: ChoCoLaT
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ABSTRACT: A model providing an accurate estimate of the charge accumulation on the surface of a metallic target irradiated by a highintensity laser pulse of fsps duration is proposed. The model is confirmed by detailed comparisons with specially designed experiments. Such a model is useful for understanding the electromagnetic pulse emission and the quasistatic magnetic field generation in laserplasma interaction experiments.Physical Review E 11/2015; 92(41):043107. DOI:10.1103/PhysRevE.92.043107 · 2.29 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We investigate the interaction of trains of femtosecond microjoule laser pulses with dielectric materials by means of a multiscale model. Our theoretical predictions are directly confronted with experimental observations in sodalime glass. We show that due to the low heat conductivity, a significant fraction of the laser energy can be accumulated in the absorption region. Depending on the pulse repetition rate, the material can be heated to high temperatures even though the single pulse energy is too low to induce a significant material modification. Regions heated above the glass transition temperature in our simulations correspond very well to zones of permanent material modifications observed in the experiments.Applied Physics Letters 11/2015; 107:181110. DOI:10.1063/1.4935119 · 3.30 Impact Factor 
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ABSTRACT: We present a formulation of the model of laserplasma interaction (LPI) at hydrodynamical scales that couples the plasma dynamics with linear and nonlinear LPI processes, including the creation and propagation of highenergy electrons excited by parametric instabilities and collective effects. This formulation accounts for laser beam refraction and diffraction, energy absorption due to collisional and resonant processes, and hot electron generation due to the stimulated Raman scattering, twoplasmon decay, and resonant absorption processes. Hot electron (HE) transport and absorption are described within the multigroup angular scattering approximation, adapted for transversally Gaussian electron beams. This multiscale inline LPIHE model is used to interpret several shock ignition experiments, highlighting the importance of target preheating by HEs and the shortcomings of standard geometrical optics when modeling the propagation and absorption of intense laser pulses. It is found that HEs from parametric instabilities significantly increase the shock pressure and velocity in the target, while decreasing its strength and the overall ablation pressure.Physical Review E 10/2015; 92(4):411012015. DOI:10.1103/PhysRevE.92.041101 · 2.29 Impact Factor 
Dataset: Laserdriven platform for generation and characterization of strong quasistatic magnetic fields

Dataset: Laserdriven platform for generation and characterization of strong quasistatic magnetic fields
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ABSTRACT: Hot electrons created in laser plasma interaction at laser intensities 1  10 PW cm  2 in shock ignition scheme can deposit their energy in the shell of the target, augmenting the strength of the ignitor shock. Here, we present a model that describes the effect of the spatial profile of fast electron energy deposition on the dynamics of shock wave formation. A criterion of a strong shock formation is obtained for an arbitrary electron beam distribution function. It is shown that the time and the position of the shock formation are defined by the electron average stopping range, while the strength of the shock decreases as the width of electron energy distribution increases. The latter feature is explained by the fast electron target preheat. The conclusions of theoretical model are confirmed in numerical simulations. The pressure, the strength of the shock, and the efficiency of shock generation are calculated for different electron distributions with the same average stopping range.Physics of Plasmas 10/2015; 22(10):102704. DOI:10.1063/1.4933119 · 2.14 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: An exact analytic solution is found for the steadystate distribution function of fast electrons with an arbitrary initial spectrum irradiating a planar lowZ plasma with an arbitrary density distribution. The solution is applied to study the heating of a material by fast electrons of different spectra such as a monoenergetic spectrum, a steplike distribution in a given energy range, and a Maxwellian spectrum, which is inherent in laserproduced fast electrons. The heating of shock and fastignited precompressed inertial confinement fusion (ICF) targets as well as the heating of a target designed to generate a Gbar shock wave for equation of state (EOS) experiments by laserproduced fast electrons with a Maxwellian spectrum is investigated. A relation is established between the energies of two groups of Maxwellian fast electrons, which are responsible for generation of a shock wave and heating the upstream material (preheating). The minimum energy of the fast and shock igniting beams as well as of the beam for a Gbar shock wave generation increases with the spectral width of the electron distribution.Journal of Experimental and Theoretical Physics 09/2015; 121(3):529540. DOI:10.1134/S106377611509006X · 0.88 Impact Factor 
Conference Paper: Laser structuration of dielectric materials by a train of femtosecond pulses through cumulative effects
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ABSTRACT: Optical materials can be structured by laser pulses to get new material functionalities in various scientific area going from photonics to medicine. For instance, wave guides, nanogratings, emergence of nonlinear optical properties for data storage [1], cutting and welding of materials are applications of great interest. Structuration driven by a train of laser pulses is strongly emerging due to its advantages: table top laser facility, very well controlled structuration with energy deposition accuracy in the nJ range by adjusting the number of pulses, etc. The material structuration due to pulsetopulse cumulative effects should be deeply understood to design specific structures. This may be achieved by modelling the main physical processes and their possible coupling. Briefly, each laser pulse first induces photoionization and heats the conduction electrons which can then transfer their energy to the lattice. That leads to a local increase in the material temperature together with heat diffusion and thermallyactivated ions migration on longer timescales. Since the laser pulse is partially absorbed, the electron dynamics and the pulse propagation are closely coupled. Due to the low heat diffusion coefficient of dielectric materials, the laser energy may be accumulated in the absorption region, leading to high temperatures even if the single pulse energy is too low to induce itself any significant material modification. A general modelling including all the abovementioned processes will be presented, including the two following applications of interest.COLA 2015, Cairns, Australia; 08/2015 
Dataset: Laserdriven platform for generation and characterization of strong quasistatic magnetic fields
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ABSTRACT: The use of femtosecond (fs) trains of pulse is now well established as an efficient technique to modify dielectric materials. Through numerous experimental parameters, it is possible to adjust the amount of deposited energy into the material with a great accuracy. When an intense fs laser pulse is focused inside a dielectric material, here sodalime glass, electrons get promoted from the valence band (VB) to the conduction band (CB) by photoionization processes. After the fs pulse interaction, electrons in the CB transfer their energy to the lattice through collisional processes, and heat diffusion towards the surrounding cold matter of the focal point sets in. Due to the low heat diffusion coefficient (a few microseconds for micronsize volume), and by using a few hundreds kilohertz repetition rate (RR), one can achieve pulsetopulse accumulation of temperature. For sufficiently large number of pulses, it is possible to exceed the annealing temperature, and the dielectric material gets modified permanently. Our approach to simulate this phenomenon is based on the separation of the different timescales of the key physical processes. To this end, the laser pulse propagation is simulated by a paraxial Forward Maxwell code taking into account key nonlinear effects, in order to compute the single pulse energy deposition in the material. Thermal diffusion is taken into account by the heat equation, where we use the (repeated) single pulse energy deposition as heat source. Finally, reaching the annealing temperature is used as a threshold to get the dimensions of the permanent modification of the matter. Simulations and experiments were performed in sodalime glass for a train of 300 fs pulses with an incident energy of 1.3 µJ per pulse. The laser beam, with a wavelength centered around 1030 nm, was focused into the glass bulk by a 10× objective. The theoretically predicted dimensions of the glass transition temperature zone are confronted with the dimensions of the experimental modifications of the glass. We note a thresholdlike behavior for the onset of measurable modifications between 100 and 200 kHz, in the experiments as well as in the simulation results. The experimental dimensions are well reproduced by our model, despite a slight deviation in the predicted length for 200 and 300 kHz. We attribute this discrepancy to changes in the propagation dynamics due to successive material modification which is not (yet) taken account in this work.24th International Laser Physics Workshop, Shanghai, China; 08/2015  [Show abstract] [Hide abstract]
ABSTRACT: Angular moments closures are widely used in numerical solutions of kinetic equations. While in the strongly collisional limit they provide a good approximation of the full kinetic equation, their validity domain in the weakly collisional limit is unknown. This work is devoted to defining the validity domain of the M1 model and its extensions, the two populations M1 and the M2 angular moments models for the collisionless kinetic physics applications. Three typical kinetic plasma effects are considered, which are the charged particle beams interaction, the Landau damping and the electromagnetic wave absorption in an overdense semiinfinite plasma. For each case, a perturbative analysis is performed and the dispersion relation is established using the moments models. These relations are compared with those computed by considering the Vlasov equation. The validity limits of each model are demonstrated.Journal of Physics A Mathematical and Theoretical 08/2015; 48(33):335501. DOI:10.1088/17518113/48/33/335501 · 1.58 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Hydrodynamic simulations of highenergydensity plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified FokkerPlanck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman Htheorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ionacoustic waves, driven by the heat flux, are presented and compared with the classical formula.Physics of Plasmas 08/2015; 22(8):082706. DOI:10.1063/1.4926824 · 2.14 Impact Factor 
Conference Paper: The PETAPHYS diagnostics
LAPHIA international symposium  3rd edition; 07/2015
Publication Stats
4k  Citations  
548.52  Total Impact Points  
Top Journals
Institutions

20102015

University of Bordeaux
Burdeos, Aquitaine, France


20022014

Université Bordeaux 1
 UMR CELIA  Centre Lasers Intenses et Applications
Talence, Aquitaine, France


20072012

French National Centre for Scientific Research
Lutetia Parisorum, ÎledeFrance, France 
Institute of Geophysics, China Earthquake Administration
Peping, Beijing, China


19882007

Russian Academy of Sciences
 Keldysh Institute of Applied Mathematics
Moskva, Moscow, Russia


19942006

University of Alberta
 • Department of Physics
 • Theoretical Physics Institute
Edmonton, Alberta, Canada


1997

École Polytechnique
 Centre de Physique Théorique
Paliseau, ÎledeFrance, France
