A5035777497- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Magnetic confinement fusion research
- Semiconductor Quantum Structures and Devices
- Dust and Plasma Wave Phenomena
- Photoreceptor and optogenetics research
- Laser Design and Applications
- Ionosphere and magnetosphere dynamics
- GaN-based semiconductor devices and materials
- nanoparticles nucleation surface interactions
- Atomic and Molecular Physics
- Diamond and Carbon-based Materials Research
- Quantum and electron transport phenomena
- Advanced Chemical Physics Studies
- Solar and Space Plasma Dynamics
- Photocathodes and Microchannel Plates
- Electron and X-Ray Spectroscopy Techniques
- Metal and Thin Film Mechanics
- Chemical Reactions and Isotopes
- Nuclear Physics and Applications
- Mass Spectrometry Techniques and Applications
National Institute for Fusion Science
2023
National Institutes for Quantum Science and Technology
2021-2023
Kansai Photon Science Institute
2023
Osaka University
1977-2021
Kyoto University Institute for Chemical Research
2016
Kyoto Bunkyo University
2016
Kyoto University
2016
Nagoya University
2010-2015
Chiba University
1992-2004
Sanyo (Japan)
1992-2003
The quest for the inertial confinement fusion (ICF) ignition is a grand challenge, as exemplified by extraordinary large laser facilities. Fast isochoric heating of pre-compressed plasma core with high-intensity short-pulse an attractive and alternative approach to create ultra-high-energy-density states like those found in ICF sparks. This avoids quench caused hot spark mixing surrounding cold fuel, which crucial problem currently pursued scheme. High-intensity lasers efficiently produce...
Microscopic distributions of growth rates on GaAs(001) layers next to (111)A and (111)B surfaces were measured in real time during molecular beam epitaxy by scanning microprobe reflection high-energy electron diffraction. The increase the rate surface near edge is observed decrease found out. exponential variation as a function distance from edge, reflects diffusion Ga atoms. lengths along [110] [1̄10] directions are estimated be about 1 8 μm at 560 °C, respectively.
In this paper, high temperature (~10 keV) solid density silver plasma is generated experimentally by exposing a thin foil to the extreme fields of tightly focused high-power laser. The authors demonstrate that such an efficient source highly charged, energy heavy ions, with generation ultra-strong electric
Acceleration of particles from the interaction ultraintense laser pulses up to 5×10^{21} W cm^{-2} with thin foils is investigated experimentally. The electron beam parameters varied decreasing spot size, not just intensity, resulting in reduced temperatures and divergence. In particular, temperature saturated due insufficient acceleration length tightly focused spot. These dependencies affected sheath-accelerated protons, which showed poorer spot-size scaling than widely used laws. It...
Microscopic distribution of growth rates on mesa-etched GaAs(001) wafers was measured in real time during molecular beam epitaxy by scanning microprobe reflection high-energy electron diffraction. It has been observed that the rate surface near edge (111)A surfaces becomes larger. The exponential variation as a function distance from reflects diffusion Ga atoms. length (001) is estimated to be about 1 μm at 560 °C. relatively larger suggests incorporation migrating atoms steps much smaller...
High-power lasers in the relativistic intensity regime with multi-picosecond pulse durations are available many laboratories around world. Laser pulses at these intensities reach giga-bar level radiation pressures, which can push plasma critical surface where laser light is reflected. This process referred to as hole boring (HB), for heating, hence essential laser-based applications. Here we derive limit density HB, maximum reach, a function of intensity. The time scale when reaches also...
Fast isochoric laser heating is a scheme to heat matter with relativistic intensity ($>{10}^{18}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$) pulse for producing an ultrahigh-energy-density (UHED) state. We have demonstrated efficient fast of compressed dense plasma core multipicosecond kilojoule-class petawatt and assistance externally applied kilotesla magnetic fields guiding electrons the plasma. A UHED state 2.2 PPa achieved experimentally 4.6 kJ total energy that one order magnitude...
Laser pulse contrast exceeding 1011 was demonstrated on a kilojoule-class petawatt laser for fast ignition experiments (LFEX) system [J. Phys. IV France133, 81 (2006)10.1051/jp4:2006133016] by implementing 2 in. plasma mirror. beams of up to 1.2 kJ striking the mirror with duration 1.5 ps were reflected and focused onto target without significant distortions in focal spot. Transmitted light from reveals that it has high reflectivity before main peak. The estimated at 1 ns No preformed...
Abstract Increasing the laser energy absorption into energetic particle beams represents a longstanding quest in intense laser-plasma physics. During interaction with matter, part of is converted relativistic electron beams, which are origin secondary sources ions, γ-rays and neutrons. Here we experimentally demonstrate that using multiple coherent beamlets spatially temporally overlapped, thus producing an interference pattern focus, significantly improves conversion efficiency hot...
To enhance the core heating efficiency in fast ignition laser fusion, concept of relativistic electron beam guiding by external magnetic fields was evaluated integrated simulations for FIREX class targets. For cone-attached shell target case, performance is deteriorated applying since considerably deformed and most electrons are reflected due to mirror formed through implosion. On other hand, case solid ball target, implosion more stable under kilo-tesla-class field. In addition, feasible...
Abstract The dependence of the mean kinetic energy laser-accelerated relativistic electrons (REs) on laser intensity, so-called ponderomotive scaling, explains well experimental results to date; however, this scaling is no longer applicable multi-picosecond (multi-ps) experiments. Here, production REs was experimentally investigated via multi-ps laser–plasma-interaction (LPI). lower slope temperature shows little pulse duration and close value, while higher appears be affected by duration....
We report the first direct measurement of emission duration laser-accelerated fast electrons from surface a solid target irradiated by high-intensity femtosecond laser pulse. The is determined autocorrelation using Coulomb repulsive forces that act on two equivalent electron pulses. depends pulse for pulses 200--690 fs. Numerical modeling three-dimensional charged particle dynamics indicates almost equal to
The interaction of dense plasmas with an intense laser under a strong external magnetic field has been investigated. When the cyclotron frequency for ambient is higher than frequency, laser's electromagnetic converted to whistler mode that propagates along line. Because nature wave, light penetrates into no cutoff density, and produces superthermal electrons through resonance. It found resonance absorption occurs effectively broadened conditions, or wider range field, which caused by...
Photocurrent (PC) spectroscopy was used to study exciton oscillator strengths in a (001)- and (111)-oriented GaAs/${\mathrm{Al}}_{0.33}$${\mathrm{Ga}}_{0.67}$As quantum-well structure (QWS) as function of the electric field. In (111) quantum well, an extremely large strength ${\mathit{e}}_{1}$-${\mathrm{hh}}_{2}$ forbidden-transition observed that larger than ${\mathit{e}}_{1}$-${\mathrm{lh}}_{1}$ exciton, even at low fields. [The notation ${\mathit{e}}_{\mathit{n}}$-hh(lh${)}_{\mathit{m}}$...
For the fast ignition of laser fusion, a reliable target design is required for an scale target. This paper shows first optimized implosion phase ignition, which scalable to larger targets. The requirements from heating process are taken account. In conclusion, can be highly compressed using multi-step pulse irradiation solid spherical with inserted gold cone. 8 kJ implosion, maximum areal density deuterium–tritium fuel reaches 0.39 g cm−2 according 2D simulation results, 62% case without...
Efficient energy transfer from electromagnetic waves to ions has been demanded control laboratory plasmas for various applications and could be useful understand the nature of space astrophysical plasmas. However, there exists severe unsolved problem that most wave is converted quickly electrons but not ions. Here, an energy-to-ion conversion process in overdense associated with whistler investigated by numerical simulations a theoretical model. Whistler propagating along magnetic field...
A mechanism of the diamond synthesis in hydrocarbon plasmas were investigated case where carbon atoms are reactive species for epitaxial growth taking place on (001) surfaces lowest singlet state. The results obtained as follows: i) Two types step generated growth; i.e, type I and II ; ii) is dimer row growth. surface grows independently. This situation explains ragged line step; iii) a complex process. It initiated by nucleation at edge followed propagation; iv) nucleus which has reactivity...
We studied the compression and heating of cone-inserted spherical, solid CD shell DT ice layer targets in strong external magnetic fields using fast ignition integrated interconnecting simulation system (FI3). The results show that these spherical is stable it has potential to produce a high-areal-density core plasma. In compressed plasma an field, mirror ratio less than four, which does not reflect hot electrons needed for heating. Magnetic beam guiding also significantly enhances...
The dependence of high-energy electron generation on the pulse duration a high intensity LFEX laser was experimentally investigated. (λ = 1.054 and 2.5 – 3 x 1018 W/cm2) pulses were focused 1 mm3 gold cubic block after reducing intensities foot pedestal by using plasma mirror. full width at half maximum (FWHM) intense could be set to either 1.2 ps or 4 temporally stacking four beams laser, for which slope temperature distribution 0.7 MeV 1.4 MeV, respectively. increment cannot explained...
MD simulation of sensory rhodopsin II was executed for three intermediates (ground-state, K-state, M-state) appearing in its photocycle. We observed a large displacement the cytoplasmic side helixF only M-state among intermediates. This transmitted to TM2, and TM2 rotated clockwise. These transient movements are agreement with results an EPR experiment. That is, early stage signal transduction sRII-HtrII complex successfully reproduced by silico simulation. By analyzing structure complex,...