A5090700555- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Astro and Planetary Science
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Planetary Science and Exploration
- Geological and Geochemical Analysis
- Laser Material Processing Techniques
- Advanced X-ray Imaging Techniques
- Energetic Materials and Combustion
- Ion-surface interactions and analysis
- Crystal Structures and Properties
- Surface Treatment and Residual Stress
- Nuclear Physics and Applications
- Geotechnical and Geomechanical Engineering
- Metal and Thin Film Mechanics
- High-Velocity Impact and Material Behavior
- Advanced Chemical Physics Studies
- Force Microscopy Techniques and Applications
- Laser-Ablation Synthesis of Nanoparticles
- Earthquake Detection and Analysis
- Microstructure and Mechanical Properties of Steels
- Atomic and Subatomic Physics Research
- Advanced Electron Microscopy Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
SPring-8
2020-2025
Osaka University
2014-2024
RIKEN
2020-2023
Institute for Laser Technology
2017-2022
École Polytechnique
2009-2020
Okayama University
2020
Center for High Pressure Science and Technology Advanced Research
2020
Pioneer (Japan)
2016
Graduate School USA
2012
Shandong University
2009
We report an experimental study of the phase diagrams periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. investigated with laser driven decaying shocks pressure/temperature curves MgO, MgSiO3 Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa 0.2-0.85 respectively. A melting signature has been observed in MgO 0.47 9860 K, while no changes were neither nor Mg2SiO4. An increasing reflectivity liquids have detected 0.55 -12 760 0.15 - 7540 0.2 5800 In contrast to SiO2,...
Extreme conditions inside ice giants such as Uranus and Neptune can result in peculiar chemistry structural transitions, e.g., the precipitation of diamonds or superionic water, so far experimentally observed only for pure C─H H 2 O systems, respectively. Here, we investigate a stoichiometric mixture C by shock-compressing polyethylene terephthalate (PET) plastics performing situ x-ray probing. We observe diamond formation at pressures between 72 ± 7 125 13 GPa temperatures ranging from...
The motion of line defects (dislocations) has been studied for more than 60 years, but the maximum speed at which they can move is unresolved. Recent models and atomistic simulations predict existence a limiting velocity dislocation between transonic subsonic ranges self-energy diverges, though do not deny possibility dislocations. We used femtosecond x-ray radiography to track ultrafast in shock-compressed single-crystal diamond. By visualizing stacking faults extending faster slowest sound...
Taking advantage of the new opportunities provided by x-ray free electron laser (FEL) sources when coupled to a long pulse as available at Linear Coherent Light Source (LCLS), we have performed absorption near-edge spectroscopy (XANES) shock compressed iron up 420 GPa ($\ifmmode\pm\else\textpm\fi{}50$) and 10 800 K ($\ifmmode\pm\else\textpm\fi{}1390$). Visible diagnostics with hydrodynamic simulations were used infer thermodynamical conditions along Hugoniot release adiabat. A modification...
Magnesium oxide has been experimentally and computationally investigated in the warm-dense solid liquid ranges from 200 GPa to 1 TPa along principal Hugoniot. The linear approximation between shock velocity particle is validated up a of 15 km/s experimental data, this suggesting that MgO B1 structure stable corresponding pressure $\ensuremath{\sim}350$ GPa. Moreover, our Hugoniot combined with ab initio simulations, show two crossovers extrapolation line, occurring at pressures approximately...
We present measurements on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>Fe</a:mi><a:mn>2</a:mn></a:msub><a:msub><a:mi mathvariant="normal">O</a:mi><a:mn>3</a:mn></a:msub></a:mrow></a:math> amorphization and melt under laser-driven shock compression up to 209(10) GPa via time-resolved x-ray diffraction. At 122(3) GPa, a diffuse signal is observed indicating the presence of noncrystalline phase. Structure factors have been extracted 182(6) showing two well-defined...
Femtosecond laser-driven shock waves exhibit characteristic features that form distinctive microstructures not formed by plate impacts or nanosecond waves. A key to understanding this phenomenon is the lattice behavior inside front, which boundary between ambient and compression states. However, direct measurements of spacing a femtosecond front have yet been performed. Here, we report in situ using x-ray free electron laser diffraction with pulse width &lt;10 fs during rise...
Nanowire arrays—vertically aligned metal wires with a few hundred nanometers in diameter—are promising nano-structured targets for high-energy-density physics and related applications. We have been developing ultrafast, time-resolved measurements on laser-irradiated using the x-ray free electron laser at SACLA facility. Here, we present fabrication of various kinds nanowire array order to explore absorption mechanism ultrahigh intensity irradiation, their application laser-irradiation...
We propose that most of the collisionless shocks in Universe, for example, supernova remnant shocks, are produced because magnetic field generated by Weibel instability and its nonlinear process. In order to verify validate computational result confirming this theory, we carrying out model experiments with intense lasers. going make a counter-streaming plasma laser ablation based on scaling law particle-in-cell simulation resulting Weibel-mediated shock formation. Preliminary experimental...
In this article, we investigate the kinetics of iron $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\varepsilon}$ transition under laser-driven ramp compression for deformation rates ranging from 3 to $9\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.28em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$. As in previous work, observe a plateau rear surface velocity profile at transition. With increasing rate onset pressure raises 11 25 GPa, while duration decreases. These kinetic effects are...
Forsterite (Mg2SiO4) is one of the major planetary materials, and its behavior under extreme conditions important to understand interior structure large planets, such as super-Earths, large-scale impact events. Previous shock compression measurements forsterite indicate that it may melt below 200 GPa, but these did not go beyond GPa. We report response above ~250 obtained using laser wave technique. simultaneously measured Hugoniot temperature shocked interpreted results suggest following:...
Equation-of-state data, not only pressure and density but also temperature, for polystyrene (CH) are obtained up to 510 GPa. The region investigated in this work corresponds an intermediate region, bridging a large gap between available gas-gun data below 60 GPa laser shock above 500 Hugoniot parameters temperature were simultaneously determined by using optical velocimeters pyrometers as the diagnostic tools α-quartz new standard material. CH tends become stiffer than semiempirical chemical...
Abstract Turbulence is ubiquitous in the universe and fluid dynamics. It influences a wide range of high energy density systems, from inertial confinement fusion to astrophysical-object evolution. Understanding this phenomenon crucial, however, due limitations experimental numerical methods plasma complete description turbulent spectrum still lacking. Here, we present measurement down micron scale laser-plasma experiment. We use an platform, which couples power optical laser, x-ray...
Theory and experiments show that, with increasing pressure, the chemical bonds of methane rearrange, leading to formation complex polymers then dissociation. However, there is disagreement on exact conditions where these changes take place. In this study, samples were precompressed in diamond-anvil cells shock compressed pressures reaching 400 GPa, highest yet explored methane. The results reveal a qualitative change Hugoniot curve at 80–150 which interpreted as signature dissociation based...
The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under laser-driven shock loading. pressure and density of compressed were determined by impedance matching a quartz standard. temperature independently measured from the brightness front. data provide good benchmark modern theories condensed matter. initial number is lower than that deuterium, this results in shock-compressed having higher compression deuterium at same pressure.
Plastic materials (CH) doped with mid-$Z$ elements are used as ablators in inertial confinement fusion (ICF) capsules and their surrogates. Hugoniot equation of state (EOS) electronic properties CH germanium (at 2.5% 13% dopant fractions) investigated experimentally up to 7 Mbar using velocity reflectivity measurements shock fronts on the GEKKO laser at Osaka University. Reflectivity temperature were updated a quartz standard. Shocked was measured 532 1064 nm. Theoretical investigation...
We developed an experimental platform for combinative use of X-ray free electron laser (XFEL) and a high-power nanosecond laser. The main target the is investigation matter under high-pressure states produced by laser-shock compression. In this paper, we show details platform, including XFEL parameters focusing optics, irradiation system diagnostics. As demonstration laser-pump XFEL-probe experiment, performed diffraction measurement. An in-situ single-shot pattern expands to large angle...
$I\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$ x-ray diffraction of shock-compressed plastics suggests the formation liquid metallic hydrogen via carbon-hydrogen phase separation.
In this work, we demonstrate simultaneous phase-contrast imaging (PCI) and X-ray diffraction from shock compressed matter at the Matter in Extreme Conditions endstation, Linac Coherent Light Source (LCLS). We utilize chromaticity compound refractive lenses to focus 24.6 keV 3rd order undulator harmonic of LCLS a spot size 5 μm on target perform diffraction. Simultaneous PCI 8.2 fundamental beam is used visualize measure transient properties wave over 500 field view. Furthermore, ability...
Hugoniot of full-dense nanopolycrystalline diamond (NPD) was investigated up to 1600 GPa. The elastic limit NPD is 208 ($\ifmmode\pm\else\textpm\fi{}14$) GPa, which more than twice as high that single-crystal diamond. stiffer 500 while no significant difference observed at higher pressures where the precursor overdriven by a following plastic wave. These findings confirm grain boundary strengthening effect recognized in static compression experiments also effective against strain-rate...
Abstract Laser-driven dynamic compression experiments of plastic materials have found surprisingly fast formation nanodiamonds (ND) via X-ray probing. This mechanism is relevant for planetary models, but could also open efficient synthesis routes tailored NDs. We investigate the release mechanics compressed NDs by molecular dynamics simulation isotropic expansion finite size diamond from different P - T states. Analysing structural integrity along paths simulations, we substantial...
High resolution X-ray imaging is crucial for many high energy density physics (HEDP) experiments. Recently developed techniques to improve have, however, come at the cost of a decreased field view. In this paper, an innovative experimental detector in context HEDP experiments with spatial resolution, as well large view, presented. The platform based on coupling backligther source Lithium Fluoride detector, characterized by its dynamic range. A 2 µm over view greater than mm2 reported. was...
Water, ethanol, and ammonia are the key components of mantles Uranus Neptune. To improve structure evolution models give an explanation magnetic fields luminosities icy giants, those need to be characterised at planetary conditions (some Mbar a few $10^3$ K). Those typical Warm Dense Matter regime, which exhibits rich phase diagram, with coexistence many states matter large variety chemical processes. H$_2$O, C:H:O, C:H:N:O mixtures have been compressed up 2.8 along principal Hugoniot using...
Understanding the behavior of matter at extreme pressures order a megabar (Mbar) is essential to gain insight into various physical phenomena macroscales—the formation planets, young stars, and cores super-Earths, microscales—damage ceramic materials high-pressure plastic transformation phase transitions in solids. Under dynamic compression solids up Mbar pressures, even solid with high strength exhibits properties, causing induced shock wave split two: an elastic precursor wave. This...