A5045376013- 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
- Magnetic confinement fusion research
- Laser Material Processing Techniques
- Advanced Fiber Laser Technologies
- Geophysics and Sensor Technology
- Graphene research and applications
- Fullerene Chemistry and Applications
- Quantum Electrodynamics and Casimir Effect
- Advanced Chemical Physics Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Semiconductor Quantum Structures and Devices
- Molecular Junctions and Nanostructures
- Thermoelastic and Magnetoelastic Phenomena
- Augmented Reality Applications
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Ion-surface interactions and analysis
- Pulsed Power Technology Applications
- Advanced X-ray Imaging Techniques
Osaka University
2016-2024
National Institutes for Quantum Science and Technology
2023
Graduate School for the Creation of New Photonics Industries
2017
Kyoto University
2010-2016
Nihon University
2006-2009
NEC (Japan)
1989-1990
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...
Abstract Using one of the world most powerful laser facility, we demonstrate for first time that high-contrast multi-picosecond pulses are advantageous proton acceleration. By extending pulse duration from 1.5 to 6 ps with fixed intensity 10 18 W cm −2 , maximum energy is improved more than twice (from 13 33 MeV). At same time, laser-energy conversion efficiency into MeV protons enhanced an order magnitude, achieving 5% above duration. The energies observed discussed using a plasma expansion...
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
Experiments identify the mechanism that accelerates ions in a laser-driven neutron source (LDNS) as well scaling law for yield, key insights move LDNS closer to practical generation.
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...
New short-pulse kilojoule, Petawatt-class lasers, which have recently come online and are coupled to large-scale, many-beam long-pulse facilities, undoubtedly serve as very exciting tools capture transformational science opportunities in high energy density physics. These lasers also happen reside a unique laser regime: high-energy (kilojoule), relatively long (multi-picosecond) pulse-lengths, large (10s of micron) focal spots, where their use driving energetic particle beams is largely...
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...
We discovered a simple regime where near-critical plasma irradiated by laser of experimentally available intensity can self-organize to produce positrons and accelerate them ultrarelativistic energies. The pulse piles up electrons at its leading edge, producing strong longitudinal electric field. field creates moving gamma-ray collider that generates via the linear Breit-Wheeler process-annihilation two gamma rays into an electron-positron pair. At same time, field, rather than laser, serves...
We study the one-dimensional expansion of a thin foil plasma irradiated by high intensity laser with multi-picosecond (ps) pulse durations using particle-in-cell simulation. Electrons are found to recirculate around expanding for many times, which results in stochastic heating leading increase electron temperature multi-ps time scale beyond ponderomotive scaling. The conventional isothermal model cannot describe such an plasmas long scale. here developed non-isothermal theory that takes...
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...
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....
For high repetition ultrahigh-intensity laser system, automatic alignment of structured target is key to achieving consistent particle acceleration and plasma heating. In this work, we demonstrate efficient electron with two sequential steps processing using a rate, 30-fs laser. The first pulse does machining creates steep cylindrical crater on the surface flat stainless-steel target. formed by hydrodynamic expansion heated spallation inner, deeper material nonthermal relativistic electrons....
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...
Abstract Proton radiography using short-pulse laser drivers is an important tool in high-energy density (HED) science for dynamically diagnosing key characteristics plasma interactions. Here we detail the first demonstration of target-normal sheath acceleration (TNSA)-based proton NIF-ARC system aided by use compound parabolic concentrators (CPCs). The multi-kJ energies available at allows a high-brightness source and thus enabling wide range applications HED science. In this demonstration,...
Interaction between media composed of clusters and high intensity lasers in the radiation dominant regime, i.e., 1022−23 W/cm2, is studied based on particle-in-cell simulation that includes reaction. By introducing target materials have same total mass but different internal structures, uniform plasma cluster with radii, we investigate effect structure interaction dynamics, energy emission, its Intense emission found where electrons exhibit non-ballistic motions suffering from strong...
The hole-boring by intense laser is one of the key issues for fast ignition fusion, radiation pressure ion acceleration, generation high energy radiations, and so on. In hole-boring, pulse propagation relativistic electrons magnetic fields are critical phenomena. When intensity higher than 1020W/cm2 a0 larger 10, self-generated quasi-static reaches Giga Gauss to play important roles in electron dynamics propagation. We explore hole boring a linearly circularly polarized laser-pulses with 3...
The production of high-energy ions is a momentous goal ultraintense laser lights. So far number experiments and numerical simulations have been conducted to obtain the scaling ion energy find optimal experimental condition. Due complexity relativistic laser-plasma interactions, it not easy evaluate for different configurations. We propose statistical approach using Bayesian inference multivariate predict maximum proton via target normal sheath acceleration. derive parameters also hot...
Abstract High energy density physics is the field of dedicated to study matter and plasmas in extreme conditions temperature, densities pressures. It encompasses multiple disciplines such as material science, planetary laboratory astrophysical plasma science. For latter, high states can be accompanied by radiation environments super-strong magnetic fields. The creation consists concentrating/depositing large amounts a reduced mass, typically solid sample or dense plasma, over time shorter...
Laser lights with relativistic intensities and pulse lengths exceeding the picosecond (ps) have been recently made available. Laser–plasma interactions such a parameter regime belong to mesoscale between kinetic fluid regimes, thus theories developed for sub-ps laser–plasma are not straightforwardly applicable those multi-ps regime. We here study generation of high-energy electrons in ps laser–foil by using particle-in-cell (PIC) simulation. show that dynamics laser hole boring, which stops...
We have developed a new formula for relativistic ponderomotive force of transversely localized laser fields based on the noncanonical Lie perturbation method by finding proper coordinates and gauges in variational principle. The involves terms represented second third spatial derivatives field amplitude, so that depends not only local gradient, but also curvature its variation. is then applicable to regime which conventional hardly applied such nonlocal and/or global extent profile becomes...
High-power, short-pulse laser-driven fast electrons can rapidly heat and ionize a high-density target before it hydrodynamically expands. The transport of such within solid has been studied using two-dimensional (2D) imaging electron-induced Kα radiation. However, is currently limited to no or picosecond scale temporal resolutions. Here, we demonstrate femtosecond time-resolved 2D electron in copper foil the SACLA x-ray free laser (XFEL). An unfocused collimated beam produced transmission...
In intense laser-plasma interactions, maximizing the density of fast electrons in laser spot area is key to achieving plasma heating and particle acceleration. We find that when size large compared with target foil thickness, circulating show a "random walk" lateral direction due scattering by fluctuating fields at surface inside area. model motion as diffusion, resulting diffusion velocity much slower than speed ballistic transport. Hence, accumulate region, over time their becomes...