A5038389961- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Laser-Matter Interactions and Applications
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Atomic and Molecular Physics
- Laser Design and Applications
- Advanced X-ray Imaging Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Electromagnetic Launch and Propulsion Technology
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Glycosylation and Glycoproteins Research
- Astronomical Observations and Instrumentation
- Cellular Mechanics and Interactions
- Cold Fusion and Nuclear Reactions
- Radiation Detection and Scintillator Technologies
- Diamond and Carbon-based Materials Research
- Carbohydrate Chemistry and Synthesis
- Neuroscience and Neuropharmacology Research
- Pulsed Power Technology Applications
- Metallurgy and Material Forming
- Combustion and Detonation Processes
- Geophysics and Sensor Technology
Osaka University
2013-2022
Waseda University
2020-2021
Institute for Laser Technology
2013-2019
Hiroshima City University
2010
Kyoto University
1998-1999
National Institute of Dental and Craniofacial Research
1999
National Institutes of Health
1999
National Institute of Environmental Health Sciences
1999
A kilo-tesla level, quasi-static magnetic field (B-field), which is generated with an intense laser-driven capacitor-coil target, was measured by proton deflectometry a proper plasma shielding. Proton direct and reliable method to diagnose strong, mm3-scale laser-produced B-field; however, this not successful in the previous experiment. target-normal-sheath-accelerated beam deflected Lorentz force resulting deflection pattern recorded on radiochromic film stack. 610 ± 30 T of B-field...
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 Intense lasers interacting with dense targets accelerate relativistic electron beams, which transport part of the laser energy into target depth. However, overall laser-to-target coupling efficiency is impaired by large divergence beam, intrinsic to laser–plasma interaction. Here we demonstrate that an efficient guiding MeV electrons about 30 MA current in solid matter obtained imposing a laser-driven longitudinal magnetostatic field 600 T. In magnetized conditions transported...
Using the yeast two-hybrid system and an in vitro binding assay, we have identified a novel protein termed vinexin as vinculin-binding protein. By Northern blotting, two types of mRNA that were 3 2 kb length. Screening for full-length cDNA clones sequencing indicated encode 82- 37-kD polypeptides α β, respectively. Both forms share common carboxyl-terminal sequence containing three SH3 domains. The larger contains additional amino-terminal sequence. interaction between vinculin was mediated...
Powerful laser-plasma processes are explored to generate discharge currents of a few $100\,$kA in coil targets, yielding magnetostatic fields (B-fields) excess $0.5\,$kT. The quasi-static provided from hot electron ejection the laser-irradiated surface. According our model, describing qualitatively evolution current, major control parameter is laser irradiance $I_{\mathrm{las}}\lambda_{\mathrm{las}}^2$. space-time B-fields experimentally characterized by high-frequency bandwidth B-dot probes...
A petawatt laser for fast ignition experiments (LFEX) system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 beams, has been constructed beside the GEKKO-XII facility demonstrating efficient heating dense plasma up to temperature under auspices Fast Ignition Realization EXperiment (FIREX) project [H. Azechi Nucl. Fusion 49, 104024 (2009)]. In FIREX experiment, cone attached spherical target containing fuel...
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...
Recent progress in the generation laboratory of a strong ($>100$-T) magnetic field enables us to investigate experimentally unexplored magnetohydrodynamics phenomena high-energy-density plasma, which an external 200--300 T notably affects due anisotropic thermal conduction, even when pressure is much lower than plasma pressure. The reduces electron conduction across lines because Larmor radius electrons shorter mean free path electrons. velocity thin polystyrene foil driven by intense...
Magnetic reconnection in a relativistic electron magnetization regime was observed laboratory plasma produced by high-intensity, large energy, picoseconds laser pulse. conditions realized with laser-driven several kilotesla magnetic field is comparable to that the accretion disk corona of black hole systems, i.e., Cygnus X-1. We particle energy distributions outflow jets, which possess power-law component high-energy range. The hardness spectra could explain hard-state x-ray emission from...
A series of experiments were carried out to evaluate the energy-coupling efficiency from heating laser a fuel core in fast-ignition scheme laser-driven inertial confinement fusion. Although is determined by wide variety complex physics, intense plasma interactions properties high-energy density plasmas and transport relativistic electron beams (REB), here we simplify physics breaking down into three measurable parameters: (i) energy conversion ratio REB, (ii) probability collision between...
The generation of high-peak-intensity neutrons through a photonuclear reaction was demonstrated using the Laser for Fast Ignition Experiments (LFEX) at Osaka University. Up to 109 neutrons/shot were generated from 1 mm sized gold target. Using Monte Carlo simulations, neutron spectrum keV MeV found be independent γ-ray spectrum. typical peak intensity 1021 /cm2/s target surface estimated, and it should useful tool nuclear synthesis experiments.
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....
Laser experiments are becoming established as tools for astronomical research that complement observations and theoretical modeling. Localized strong magnetic fields have been observed at a shock front of supernova explosions. Experimental confirmation identification the physical mechanism this observation great importance in understanding evolution interstellar medium. However, it has challenging to treat interaction between hydrodynamic instabilities an ambient field laboratory. Here, we...
This paper reports an experimental investigation of a scheme to produce intense, pulsed, point-like, and quasi-monoenergy neutron source. In this scheme, the inner wall deuterated plastic spherical cavity is mono-directionally irradiated by 2.4 kJ laser beam through open-tip gold cone inserted into cavity. The whole illuminated light owing multiple reflections, laser-ablated plasma stagnates near center cavity, at which several keV hot spot generated. Thermonuclear D-D fusion reactions occur...
Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard detectors, which the responses have different thresholds, as a conventional single-shot spectrometer for high-flux (>1013 photons/shot) X-rays. However, resolution (Δhv/hv < 0.1) not achievable with differential threshold (DET) because its limited differences between response...
A multichannel low-energy neutron spectrometer for down-scattered (DSN) measurements in inertial confinement fusion (ICF) experiments has been developed. Our compact-size 256-channel lithium-glass-scintillator-based implemented and tested ICF with the GEKKO XII laser. We have performed time calibration of analog-to-digital convertor system used DSN via X-ray pulse signals. clearly observed DD-primary signal successfully studied detector's impulse response. detector is soon to be future experiments.
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...
Neutron diagnostic in the fast-ignition experiment was successfully demonstrated by multichannel time-of-flight neutron spectrometer MANDALA at Institute of Laser Engineering (ILE) Osaka University. A large collimator dramatically suppressed serious background noise caused photo-neutrons, and a peak yield 2 × 106 deuterium-deuterium (DD) fusion neutrons clearly observed. The new system will provide measurements ion temperature areal density core plasma next experimental campaign 2013. In...
A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma intense laser light. In this spectrometer, x-rays are converted neutrons through photonuclear reactions, counted with a bubble detector that insensitive x-rays. The consists bundle detectors respond different photon-energy ranges. Proof-of-principle experiment was performed on linear accelerator facility. quasi-monoenergetic...
In this work we report the successful implementation of plasma mirror (PM) technology on an LFEX laser facility at Institute Laser Engineering, Osaka University. The pulse was successfully refocused target chamber center (TCC) by means a spherical mirror, resulting in 5 × 1018 W cm−2 intensity, with 45% reflectivity flux about 90 J PM. Experimental results show stable focusing and pointing after PM refocusing. contrast improvement demonstrated both cooler fast electron slope temperature...