A5090327993- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Laser Design and Applications
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Advanced Fiber Laser Technologies
- Advanced X-ray Imaging Techniques
- Laser Material Processing Techniques
- Magnetic confinement fusion research
- Diamond and Carbon-based Materials Research
- Ocular and Laser Science Research
- Space Satellite Systems and Control
- Mass Spectrometry Techniques and Applications
- Laser-Ablation Synthesis of Nanoparticles
- Random lasers and scattering media
- Traumatic Ocular and Foreign Body Injuries
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Photocathodes and Microchannel Plates
- Optical Systems and Laser Technology
- Nonlinear Optical Materials Studies
- Gas Dynamics and Kinetic Theory
- Radiation Detection and Scintillator Technologies
CEA DAM Île-de-France
2000-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2006-2025
Université Paris-Saclay
2024-2025
CEA Paris-Saclay
2024-2025
GANIL
2021
Centre d'Études Scientifiques et Techniques d'Aquitaine
2021
Institut de Recherche sur les Lois Fondamentales de l'Univers
2021
École Polytechnique
1988-1998
Laboratoire pour l'utilisation des lasers intenses
1992-1998
Centre National de la Recherche Scientifique
1998
The interaction of short and intense laser pulses with plasmas is a very efficient source relativistic electrons tunable properties. In low-density plasmas, we observed bunches up to 200 MeV, accelerated in the wakefield pulse. Less energetic (tens megaelectronvolt) have been obtained, albeit higher efficiency, during pre-exploded foil or solid target. When these slow down thick tungsten target, they emit Bremsstrahlung photons which diagnosed directly photoconductors, indirectly through...
The high-energy petawatt PETAL laser system was commissioned at CEA’s Laser Mégajoule facility during the 2017–2018 period. This paper reports in detail on first experimental results obtained energetic particle and photon generation from solid foil targets, with special emphasis proton acceleration. Despite a moderately relativistic (<1019 W/cm2) intensity, energies as high 51 MeV have been measured significantly above those expected preliminary numerical simulations using idealized...
Transmission of a subpicosecond relativistic laser pulse is observed through solid foils and preformed overcritical plasmas. rates near 10% for densities above $10\ifmmode\times\else\texttimes\fi{}{n}_{c}$ are measured. A moderately strong threshold in intensity found order to observe this effect. The experimental results as well preliminary particle-in-cell simulations suggest that thin the transmission explicable by rapid heating expansion transmissive conditions during pulse. Self-induced...
We report on an experiment performed at the Laser Mégajoule facility to investigate cross-beam energy transfer (CBET) between two kilojoule-nanosecond laser beams propagating through a neo-pentane gas pipe. CBET is diagnosed using time-resolved transmission measurements and x-ray imagers. The obtained calibrated emission conversion gold foil located behind target. Different shots, with without frequency shift, allow control amount of power transferred beams. In particular, we observe that...
Laser beam smoothing is a key element to enhance laser plasma hydrodynamic coupling in the context of high energy density physics experiments carried out Inertial Confinement Fusion Facilities. Here, we experimentally study effects different polarization implementations on Stimulated Brillouin Backscattering (B-SBS) and transmission using LULI2000 facility. First, show that state (linear or circular) has no effect B-SBS transmission. We also under our experimental conditions, both...
Using space-time-resolved Thomson scattering, we investigate experimentally the development of electrostatic waves in a preformed undercritical helium plasma driven by 1.059 μm laser pulse ∼1.5 ps duration and ∼10^{15-16} W cm^{-2} mean intensity. We observe excitation intense ion (IAWs) over broad wave number range, distinct from what is expected stimulated Brillouin scattering or Langmuir decay instability. These IAWs are correlated with occurrence backward Raman (B-SRS) at earlier times...
Measurements of stimulated Raman scattering (SRS) reflectivity produced by the interaction between a short 450-fs, 1.06-\ensuremath{\mu}m laser pulse and large underdense preformed plasma are presented. Experimental results show that SRS sharply increases as intensity beam approaches 1${0}^{16}$ W/c${\mathrm{m}}^{2}$ from below saturates for intensities greater than 1${0}^{17}$ W/c${\mathrm{m}}^{2}$. These found to be in very good agreement with those initial transient stage theory starting...
Very energetic electrons produced in laser–plasma interactions at 0.26, 0.53, and 1.05 μm laser wavelength have been measured. The targets were 1.5 plastic foils the intensity was around 1015 W/cm2. Detailed measurements of electron distribution performed a 0.26 exhibit an angular strongly peaked along axis highest energies (above 200 keV). Electrons up to 1.3 MeV observed experiments. hot temperatures inferred from measured energy distributions are order 100 keV experiments, 50 0.53 μm/0.26...
This Letter investigates experimentally the backward stimulated Raman scattering (SRS) of two copropagating, 1-$\ensuremath{\mu}\mathrm{m}$ wavelength, 1.5-ps duration laser pulses focused side by side, but not simultaneously, in a preformed underdense plasma. When lasers do interact, one (so-called strong) yields large SRS reflectivity, while other weak pulse is essentially ineffective as regards SRS. By contrast, shows significant activity if it launched plasma slightly after strong one,...
In this Letter, we introduce an inline model for stimulated Raman scattering (SRS), which runs on our radiation hydrodynamics code troll. This accounts nonlinear kinetic effects and the SRS feedback plasma hydrodynamics. We dubbed it PIEM because is a fully ``PredIctivE Model,'' no free parameter to be adjusted posteriori in order match experimental results. predictions are compared against measurements performed at Ligne d'Int\'egration Laser. From these comparisons, discuss ability...
Laser ablation propulsion and orbit cleaning are developing areas of research. The general aim laser-based techniques applied to this field is maximize the momentum transfer produced by a laser shot. This work presents results from ballistic pendulum experiments under vacuum on aluminum, copper, tin, gold, porous graphite targets. has focused metrology ensure good stability over wide range parameters (laser intensity ranging 4 GW/cm2 8.7 TW/cm2, pulse duration 80 ps 15 ns, wavelengths 528 or...
We report one of the first measurements induced heating due to transport a fast electron beam generated by an ultrashort pulse laser interaction with solid targets. Rear-side optical reflectivity and emissivity have been used as diagnostics for size temperature heated zone. A narrow spot has observed order focus size. Values up approximately 10 eV at target back surface were inferred from experimental data compared predictions hybrid collisional-electromagnetic simulation.
The excitation and the relaxation of plasma waves ion acoustic (IAW), respectively, driven by stimulated Raman (SRS) Brillouin (SBS) backscatterings have been experimentally investigated with short-pulse lasers. spectra obtained a 0.3 ps time resolution. It is shown that SRS develops before SBS suddenly decays around peak pump, as IAW reaches saturation. On this short scale, electron kinetic effects play major role for saturation, contrary to dynamics. These results are supported...
The Laser Megajoule (LMJ) facility located at CEA/CESTA started to operate in the early 2014 with two quadruplets (20 kJ 351 nm) focused on target for first experimental campaign. We present here set of gated x-ray imaging (GXI) diagnostics implemented LMJ since mid-2014. This consists spatial, temporal, and broadband spectral resolution. These will give basic measurements, during entire life facility, such as position, structure, balance beams, but they also be used characterize gas filled...
We report experiments demonstrating enhanced coupling efficiencies of high-contrast laser irradiation to nanofabricated conical targets. Peak temperatures near 200 eV are observed with modest energy (10 J), revealing similar hot-electron localization and material heating reduced mass targets (RMTs), despite having a significantly larger mass. Collisional particle-in-cell simulations attribute the enhancement self-generated resistive (∼10 MG) magnetic fields forming within curvature cone...
We present the results of experiments performed at LULI laboratory, using 100 TW laser facility, on study propagation fast electrons in gas targets. The implemented diagnostics included chirped shadowgraphy and proton imaging. Proton images showed presence very large fields (produced by charge separation). In turn, these imply a strong inhibition propagation, slowing down electron cloud as it penetrates gas. Indeed show reduction time velocity from initial value, order fraction c, over scale...
Experimental investigation of stimulated Raman (SRS) and Brillouin (SBS) scattering have been obtained at the Ligne-d'Intégration-Laser facility (LIL, CEA-Cesta, France). The parametric instabilities (LPI) are driven by firing four laser beamlets (one quad) into millimeter size, gas-filled hohlraum targets. A quad delivers energy on target 15 kJ 3ω in a 6-ns shaped pulse. is focused means gratings optically smoothed with kinoform phase plate smoothing spectral dispersion-like 2 GHz and/or 14...
This article reports the first measurements of high-energy photons produced with high-intensity PETawatt Aquitaine Laser (PETAL) laser. The experiments were performed during commissioning laser had an energy about 400 J, intensity 8 × 1018 W·cm−2, and a pulse duration 660 fs (FWHM). It was shot at 2 mm-thick solid tungsten target. mainly from bremsstrahlung process for relativistic electrons accelerated inside plasma generated on front side paper electrons, protons photons. Hot up to ≈35 MeV...
The dependence of the stimulated Brillouin scattering (SBS) reflectivity on both focusing aperture and incident laser intensity has been experimentally studied in case a spatially smoothed beam. experiment was performed millimeter size, homogeneous, stationary plasmas created by irradiating helium gas jet. SBS excited 1.053-\ensuremath{\mu}m wavelength, 600-ps interaction beam at intensities up to $4\ifmmode\times\else\texttimes\fi{}{10}^{14} {\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.$...
We report on the optimization of a BremsStrahlung Cannon (BSC) design for investigation laser-driven fast electron populations in shock ignition relevant experimental campaign at Laser Megajoule-PETawatt Aquitaine facility. In this regime with laser intensities 1015 W/cm2–1016 W/cm2, electrons energies ≤100 keV are expected to be generated through Stimulated Raman Scattering (SRS) and Two Plasmon Decay (TPD) instabilities. The main purpose BSC our experiment is identify contribution x-ray...
Propagation of electron beams generated in laser-plasma interactions is strongly influenced by self-induced electrostatic fields at target-vacuum interfaces, resulting the refluxing electrons. We confirmed and propagation electrons with three different kinds target configurations; thin-wide foil, thin-narrow long-wire geometry. Enhancement heating, effective guiding collimation high density MeV were observed.