- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Demonstration of Scale-Invariant Rayleigh-Taylor Instability Growth in Laser-Driven Cylindrical Implosion Experiments
摘要： Rayleigh-Taylor instability growth is shown to be hydrodynamically scale invariant in convergent cylindrical implosions for targets that varied in radial dimension and implosion timescale by a factor of 3. The targets were driven directly by laser irradiation providing a short impulse, and instability growth at an embedded aluminum interface occurs as it converges radially inward by a factor of 2.25 and decelerates on a central foam core. Late-time growth factors of 14 are observed for a single-mode m ? 20 azimuthal perturbation at both scales, despite the differences in laser drive conditions between the experimental facilities, consistent with predictions from radiation-hydrodynamics simulations. This platform enables detailed investigations into the limits of hydrodynamic scaling in high-energy-density systems.
关键词： high-energy-density physics,hydrodynamic scaling,laser-driven implosions,Rayleigh-Taylor instability
更新于2025-09-23 15:21:01
-
Maximizing magnetic field generation in high power laser–solid interactions
摘要： In order to understand the transport of fast electrons within solid density targets driven by an optical high power laser, we have numerically investigated the dynamics and structure of strong self-generated magnetic fields in such experiments. Here we present a systematic study of the bulk magnetic field generation due to the ponderomotive current, Weibel-like instability and resistivity gradient between two solid layers. Using particle-in-cell simulations, we observe the effect of varying the laser and target parameters, including laser intensity, focal size, incident angle, preplasma scale length, target thickness and material and experimental geometry. The simulation results suggest that the strongest magnetic field is generated with laser incident angles and preplasma scale lengths that maximize laser absorption efficiency. The recent commissioning of experimental platforms equipped with both optical high power laser and X-ray free electron laser (XFEL), such as European XFEL-HED, LCLS-MEC and SACLA beamlines, provides unprecedented opportunities to probe the self-generated bulk magnetic field by X-ray polarimetry via Faraday rotation with simultaneous high spatial and temporal resolution. We expect that this systematic numerical investigation will pave the way to design and optimize near future experimental setups to probe the magnetic fields in such experimental platforms.
关键词： laser–plasmas interaction,X-ray free electron laser probing,high energy density physics
更新于2025-09-19 17:13:59
-
High-Energy-Density Physics and Laser Technologies
摘要： This paper is devoted to the jubilee of I.M. Khalatnikov, the founder and the first director of the Landau Institute for Theoretical Physics of the Russian Academy of Sciences. I.M. Khalatnikov organized a first-class institute the studies at which cover a broad spectrum of research directions. The plasma and lasers department of the Institute conducts research on plasma physics problems, laser–matter interaction, questions pertaining to laser applications, and hydrodynamics problems. Much attention is given to solid-state physics with an emphasis on the behavior of matter in extreme conditions under intense laser irradiation. A number of new results are presented: the behavior of metals in two-temperature states (when the temperature of the electron subsystem of a metal is much greater than the temperature of the ion subsystem due to ultrafast laser heating); determining the boundaries of existence of a single-wave propagation mode of elastoplastic shock waves in ductile metal crystals; the formation of a laser torch from target materials and liquids under metal laser ablation of a metal into the surrounding liquid; the physical–mechanical consequences (melting, capillarity, recrystallization) of nonuniform (along the irradiated surface) energy dissipation caused by the interference of plasmon–polariton and laser electromagnetic fields.
关键词： laser–matter interaction,plasma physics,laser ablation,hydrodynamics,two-temperature states,plasmon–polariton,solid-state physics,high-energy-density physics,laser technologies,elastoplastic shock waves
更新于2025-09-12 10:27:22
-
Coarse Grained Simulation and Turbulent Mixing || Laser Driven Turbulence in High Energy Density Physics and Inertial Confinement Fusion Experiments
摘要： The mixing of initially separate materials in a turbulent ?ow by the small scales of turbulent motion is a critical and often poorly understood element of many research programs, such as inertial con?nement fusion (ICF), supernova implosions and explosions, and combustion, as well as many other applications in engineering, geophysics, and astrophysics. In typical contexts of interest, we are interested in achieving detailed understanding of interpenetration, hydrodynamical instabilities, and mixing arising from perturbations at the material interfaces, that is, driven by Rayleigh–Taylor (RT), Richtmyer–Meshkov (RM), and Kelvin–Helmholtz (KH) instabilities (buoyancy, shock, and shear induced instabilities, respectively). Laboratory observations typically provide only limited integrated measures of complex nonlinear three-dimensional physical processes, leaving many details and mechanisms unresolved. Carefully controlled computational experiments based on the numerical simulations play a crucial complementary role, providing insight into the underlying dynamics. Collaborative laboratory/computational studies are used to establish predictability of the models in conjunction with the development of frameworks for analysis, metrics for veri?cation and validation, and uncertainty quanti?cation.
关键词： Richtmyer–Meshkov instability,Rayleigh–Taylor instability,inertial con?nement fusion,turbulent mixing,high energy density physics,Kelvin–Helmholtz instability
更新于2025-09-12 10:27:22
-
Optimization and Characterization of High-Harmonic Generation for Probing Solid Density Plasmas
摘要： The creation of high energy density plasma states produced during laser–solid interaction on a sub-picosecond timescale opens a way to create astrophysical plasmas in the lab to investigate their properties, such as the frequency-dependent refractive index. Available probes to measure absorption and phase-changes given by the complex refractive index of the plasma state are extreme-UV (EUV) and soft X-ray (XUV) ultra-short pulses from high harmonic generation (HHG). For demanding imaging applications such as single-shot measurements of solid density plasmas, the HHG probe has to be optimized in photon number and characterized in intensity and wavefront stability from shot-to-shot. In an experiment, a coherent EUV source based on HHG driven by a compact diode-pumped laser is optimized in photons per pulse for argon and xenon, and the shot-to-shot intensity stability and wavefront changes are characterized. The experimental results are compared to an analytical model estimating the HHG yield, showing good agreement. The obtained values are compared to available data for solid density plasmas to con?rm the feasibility of HHG as a probe.
关键词： pump-probe,XUV,diode-pumped lasers,high energy density physics,high-harmonic generation
更新于2025-09-04 15:30:14