A5042027542- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Energetic Materials and Combustion
- Diamond and Carbon-based Materials Research
- High-Velocity Impact and Material Behavior
- Combustion and Detonation Processes
- Surface Treatment and Residual Stress
- Laser Material Processing Techniques
- Laser-Ablation Synthesis of Nanoparticles
- Advanced X-ray Imaging Techniques
- Ion-surface interactions and analysis
- Intermetallics and Advanced Alloy Properties
- Thermal and Kinetic Analysis
- Metal and Thin Film Mechanics
- X-ray Spectroscopy and Fluorescence Analysis
- Fluid Dynamics and Heat Transfer
- Electromagnetic Launch and Propulsion Technology
- Atomic and Molecular Physics
- Inorganic Fluorides and Related Compounds
- Plasma and Flow Control in Aerodynamics
- Fluid Dynamics and Turbulent Flows
- Particle Dynamics in Fluid Flows
- Rare-earth and actinide compounds
- High-Temperature Coating Behaviors
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2025
Université Paris-Saclay
2020-2025
CEA DAM Île-de-France
2015-2025
CEA Paris-Saclay
2020-2025
University of Edinburgh
2024
Centre National de la Recherche Scientifique
2000-2014
École nationale supérieure d'arts et métiers
2009-2014
Laboratoire Procédés et Ingénierie en Mécanique et Matériaux
2014
École Nationale Supérieure de Mécanique et d'Aérotechnique
2007-2009
ParisTech
2009
Benefits from laser Peening have been demonstrated several times in fields like fatigue, wear or stress corrosion cracking. However, spite of recent work on the calculation residual stresses, very few authors considered a finite element method (FEM) approach to predict laser-induced mechanical effect. This comes mainly high strain rates involved during LP (106 s-1), that necessitate precise determination dynamic properties, and also possible combination thermal loadings case without...
Abstract Understanding Warm Dense Matter (WDM), the state of planetary interiors, is a new frontier in scientific research. There exists very little experimental data probing WDM states at atomic level to test current models and those performed up now are limited quality. Here, we report proof-of-principle experiment that makes microscopic investigations materials under dynamic compression easily accessible users with quality close achievable ambient. Using single 100 ps synchrotron x-ray...
When a shock wave propagating in solid sample reflects from free surface, geometrical effects predominantly governed by the roughness and defects of that surface may lead to ejection tiny jets breakup into high velocity, approximately micrometer-size fragments. This process referred as microjetting is major safety issue for engineering applications such pyrotechnics or armour design. Thus, it has been widely studied both experimentally, under explosive impact loading, theoretically. In this...
X-ray free electron laser (XFEL) sources coupled to high-power systems offer an avenue study the structural dynamics of materials at extreme pressures and temperatures. The recent commissioning DiPOLE 100-X on high energy density (HED) instrument European XFEL represents state-of-the-art in combining x-ray diffraction with compression, allowing for compressed be probed unprecedented detail. Here, we report quantitative measurements molten Sn 85(5) GPa ∼3500 K. capabilities HED enable liquid...
The transmission of breakdown plasma generated in water during laser shock processing experiments was investigated theoretically. A numerical model based on a rate equation formalism has been developed to calculate the characteristics (peak irradiance and duration) pulses transmitted through plasmas water. Results are good agreement with previous experimental data for 25 ns−1064 nm pulses. Above 10 GW/cm2, peak saturates starts decrease. results have extended shorter wavelengths (532 355...
With the objective to envisage short pulses for laser-shock hardening of materials, this paper reports experiments where amplitudes Pgenerated with 0.6-3 ns laser at = 1.06 µm in a confined regime water have been compared those achieved usual 10-30 configuration. First, experimental characterization shock waves polyvinylidene fluoride (PVDF) and electromagnetic (EMV) gauges shows that durations allow generation higher than longer duration (10 GPa versus 5 GPa) because an increase pressure...
Material ejection upon the breakout of a shock wave at rough surface is key safety issue for various applications, including pyrotechnics and inertial confinement fusion. For few years, we have used laser driven compression to investigate microjetting from calibrated grooves in free shock-loaded specimens. Fast transverse optical shadowgraphy, time-resolved measurements planar jet tip velocities, post-shock analysis some recovered material provided data over ranges small spatial temporal...
Abstract Laser ablation in liquid (LAL) is a reference technique for the synthesis of multicomponent non‐equilibrium nanomaterials which have potentially disruptive properties photonics, nanomedicine, and catalysis. Yet, dynamics poorly understood regarding multielement matter and, therefore, remarkable potential LAL controlling local atomic structure metastable nanophases remains largely unexploited. Here, are investigated with gold‐iron nanoalloys generated presence gas‐evolving additives,...
The generation of shock waves by laser-induced plasma in a water confinement regime has been investigated with 0.308 µm/50 ns and µm/150 excimer laser pulses. Shock-wave profiles have characterized numerical simulations rear surface velocity measurements behind Al foils the use interferometer system. results are compared those obtained third harmonic Nd:Yag. Above 1-2 GW cm-2, pressure levels saturate at 2-2.5 GPa duration is much shortened breakdown which occurs water. Therefore we suggest...
Synchrotron nanosecond time-resolved x-ray diffraction has been performed on dynamically compressed bismuth along various compression and release paths, hence exploring the Bi phase diagram up to 8 GPa 600 K. Marked departures from static is observed. The sequence of structural changes different upon release. Bi-III complex host-guest structure never obtained. Instead Bi-V observed over a large domain. Melting crystallization fluid into Bi-I are clearly identified stress Supercooling...
Dynamic fragmentation in the liquid state after shock-induced melting, usually referred to as micro-spallation, is an issue of great interest for both basic and applied sciences. Recent efforts have been devoted characterization resulting ejecta, which consist a cloud fine molten droplets. Major difficulties arise from loss free surface reflectivity at shock breakout wide distribution particle velocities within this cloud. We present laser experiments on tin aluminium, pressures ranging...
Time-resolved X-ray diffraction measurements have been carried out on dynamically compressed Sn up to a maximum pressure of ∼13 GPa at the European Synchrotron Radiation Facility. The phase transition from β-Sn body-centered tetragonal (b.c.t.) has observed using synchrotron for first time undergoing shock compression and release. Following compression, sample releases lower pressures several nanoseconds until reverse occurs. data are in good agreement with previous boundaries that indicate...
We present a combined molecular dynamics and kinetic study of carbon cluster aggregation process in thermodynamic conditions relevant for the detonation products oxygen deficient explosives. Molecular simulations with LCBOPII potential under gigapascal pressure high temperatures indicate that (i) motion gas is compatible Brownian diffusion (ii) coalescence probability 100% two clusters entering interaction cutoff distance. used these results subsequent Smoluchowski model, realistic models...
The propagation of laser-induced shock waves in a transparent epoxy sample is investigated by optical shadowgraphy. are generated focused laser (3 ns pulse duration—1.2 to 3.4 TW cm−2) producing pressure from 44 98.9 GPa. It observed that the wave and release created reverberation at rear face both followed dark zone pictures. This corresponds creation tensile resulting crossing on loading axis coming edge impact area (2D effects). After experiment, residual stresses targets identified...
In this work, original shock experiments are presented. Laser-induced and shear wave propagations have been observed in an epoxy resin, the case of femtosecond laser irradiation. A specific time-resolved shadowgraphy setup has developed using photoelasticimetry principle to enhance observation. Shear waves resin after Their propagation quantified comparison with main propagation. discussion, hinging on numerical results, is finally given improve understanding phenomenon.
Laser direct drive (LDD) inertial confinement fusion (ICF) involves irradiating a spherical target of thermonuclear fuel coated with an ablator, usually made polystyrene. energy absorption near the surface leads to matter ablation, hydrodynamic shocks, and ultimately capsule implosion. The conservation symmetry is crucial for implosion efficiency, yet spatial modulations in laser intensity can induce nonuniformities, causing imprint phenomenon. Understanding imprint, especially considering...
We present detonation wave profiles measured in T2 (97 wt. % TATB) and TX1 (52 TATB 45 HMX) high explosives. The experiments consisted initiating a 15 mm diameter cylinder of explosive using an wire detonator booster. Free surface velocity were at the explosive/air interface Photon Doppler Velocimetry system. demonstrate that comparison these free with those explosive/window interfaces similar conditions allows to bracket von Neumann spike narrow range. For T2, our measurements show pressure...
Results of the 2018 commissioning and experimental campaigns new High Power Laser Facility on Energy-dispersive X-ray Absorption Spectroscopy (ED-XAS) beamline ID24 at ESRF are presented. The front-end future laser, delivering 15 J in 10 ns, was interfaced to beamline. Laser-driven dynamic compression experiments were performed iron oxides, alloys bismuth probed by online time-resolved XAS.
Shock waves induced by laser-plasma in Water Confinement Regime (WCR) are used order to improve the metallurgical properties of metallic materials. In a first part this paper we discuss basic principles which limit pressure generation regime: effects laser intensity, target material, pulse duration and wavelength discussed. Depending on parameters, peak is saturated its reduced above intensity threshold, due laser-induced breakdown plasma confining water. The observation interaction zone...