A5041373194- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Laser-Matter Interactions and Applications
- Radiation Detection and Scintillator Technologies
- Laser Design and Applications
- Atomic and Molecular Physics
- Magnetic confinement fusion research
- Atomic and Subatomic Physics Research
- Fusion materials and technologies
- Cold Fusion and Nuclear Reactions
- Particle Accelerators and Free-Electron Lasers
- Luminescence Properties of Advanced Materials
- Ion-surface interactions and analysis
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray Imaging Techniques
- Terahertz technology and applications
- Nuclear Materials and Properties
- Planetary Science and Exploration
- Particle Detector Development and Performance
- Plasma Diagnostics and Applications
- Laser Material Processing Techniques
- Pulsed Power Technology Applications
- X-ray Spectroscopy and Fluorescence Analysis
Osaka University
2015-2024
National Institute for Fusion Science
2023
Hiroshima University
2023
National Institutes for Quantum Science and Technology
2023
Utsunomiya University
2023
Institute for Laser Technology
2010-2022
Tohoku University
2016
Lawrence Livermore National Laboratory
2016
University of California, San Diego
2016
University of Rochester
2016
Abstract Fast ignition (FI) is a promising approach for high-energy-gain inertial confinement fusion in the laboratory. To achieve ignition, energy of short-pulse laser required to be delivered efficiently pre-compressed fuel core via high-energy electron beam. Therefore, understanding transport and deposition this beam inside key FI. Here we report on direct observation compressed through stimulated Cu Kα emission super-penetration scheme. Simulations reproducing experimental measurements...
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 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...
Nuclear reactions between protons and boron-11 nuclei (p–B fusion) that were used to yield energetic α-particles initiated in a plasma was generated by the interaction PW-class laser operating at relativistic intensities (~3 × 1019 W/cm2) 0.2-mm thick boron nitride (BN) target. A high p–B fusion reaction rate hence, large α-particle flux measured, thanks proton stream accelerated target’s front surface. This first proof of principle experiment demonstrate efficient generation (~1010/sr)...
Abstract In special relativity, four-vectors, such as space–time, energy–momentum and electromagnetic potential vectors, follow the Lorentz transformation. The transformations of space–time vectors have been tested by time dilation rest mass energy experiments, respectively. However, transformation potentials has never directly demonstrated in experiments due to limitations diagnostics. Here we show spatiotemporal electric-field profiles around a highly energetic electron beam with...
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.
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...
In an experiment performed with a high-intensity and high-energy laser system, $\ensuremath{\alpha}$-particle production in proton-boron reaction by using laser-driven proton beam was measured. $\ensuremath{\alpha}$ particles were observed from the front also rear side, even after 2-mm-thick boron target. The data obtained this have been analyzed sequence of numerical simulations. simulations clarify mechanisms transport through targets. energies simulation reach 10--20 MeV energy transfer...
Abstract The temperature measurement of material inside an object is one the key technologies for control dynamical processes. For this purpose, various techniques such as laser-based thermography and phase-contrast imaging have been studied. However, it is, in principle, impossible to measure element using these techniques. One possible solutions measurements Doppler brooding effect neutron resonance absorption (NRA). Here we present a method or isotope NRA with single pulse approximately...
Solid-state nuclear track detectors (SSNTDs) are often used as ion in laser-driven acceleration experiments and considered to be the most reliable diagnostics since they sensitive only ions measure one by one. However, pit analyses require tremendous time effort chemical etching, microscope scanning, identification eyes. From a experiment, there typically millions of microscopic images, it is practically impossible analyze all them hand. This research aims improve efficiency automation SSNTD...
Based on the successful result of fast heating a shell target with cone for beam injection at Osaka University in 2002 using PW laser (Kodama et al Nature 418 933), FIREX-1 project was started 2004. Its goal is to demonstrate fuel up 5 keV an upgraded beam. For this purpose, LFEX laser, which can deliver energy to10 kJ 0.5–20 ps pulse its full spec, has been constructed addition Gekko-XII system Institute Laser Engineering, University. It activated and became operational since 2009....
Abstract The scientific and technical advances continue to support novel discoveries by allowing scientists acquire new insights into the structure properties of matter using tools sources. Notably, neutrons are among most valuable sources in providing such a capability. At Institute Laser Engineering, Osaka, first steps taken towards development table-top laser-driven neutron source, capable producing wide range energies with high brightness temporal resolution. By employing pure hydrogen...
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...
Abstract Thermal neutron (∼25 meV) beam is a powerful tool for investigating the structure and properties of materials used in science technology. A laser-driven source generating 10 neutrons within 1 ns duration utilized to single shot radiography with dual thermal X-rays. As proof principle, we show non-destructive inspection hazardous substances (Cadmium) contained typical battery, when cadmium anode thickness evaluated from transmittance neutrons. The fact that above performed laser...
Abstract Electro-optic (EO) sampling is employed to measure the electric field profiles generated by a relativistic electron bunch along propagation and in radial directions. The longitudinal (temporal) profile investigated changing time delay between pulsed probe laser, while transverse (radial) acquired laterally shifting path of bunch. Experimental results show good agreement with three-dimensional particle-in-cell calculations. We demonstrated promising method simultaneously obtain beam...
The world's largest peta watt (PW) laser LFEX, which delivers energy up to 2 kJ in a 1.5 ps pulse, has been constructed beside the GEKKO XII at Institute of Laser Engineering, Osaka University. GEKKO-LFEX facility enables creation materials having high-energy-density do not exist naturally on Earth and have an density comparable that stars. High-energy-density plasma is source safe, secure, environmentally sustainable fusion energy. Direct-drive fast-ignition intensively studied this under...
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...
We present preliminary results on generation of energetic -particles driven by lasers. The experiment was performed at the Institute Laser Engineering in Osaka using short-pulse, high-intensity, high-energy, PW-class laser. laser pulse focused onto a thin plastic foil (pitcher) to generate proton beam well-known TNSA mechanism which, turn, impinging boron-nitride (BN) target (catcher) generated alpha-particles as result proton-boron nuclear fusion events. Our demonstrate with energies range...
We have investigated space and astrophysical phenomena in nonrelativistic laboratory plasmas with long high-power lasers, such as collisionless shocks magnetic reconnections, been exploring relativistic regimes intense short pulse energetic ion acceleration using large-area suspended graphene. Increasing the intensity repetition rate of we to handle large amounts data from experiments well control parameters laser beamlines. Artificial intelligence (AI) machine learning neural networks may...
Experimental results are presented on the neutron scintillating properties of a custom-designed Pr3+ (praseodymium)-doped lithium (Li) glass. Luminescence was observed at 278 nm wavelength, originating from 5d-4f transition. Time-resolved measurements yielded about 20 ns decay times for ultraviolet and x-ray excitation while much faster 6 were alpha particle excitation. Actual time-of-flight data in laser fusion experiments GEKKO XII facility Institute Laser Engineering, Osaka University...
The Nike krypton fluoride laser [S. P. Obenschain, S. E. Bodner, D. Colombant, et al., Phys. Plasmas 3, 2098 (1996)] is used to accelerate planar plastic foils velocities that for the first time reach 1000 km/s. Collision of highly accelerated deuterated polystyrene foil with a stationary target produces ∼Gbar shock pressures and results in heating thermonuclear temperatures. impact conditions are diagnosed using DD fusion neutron yield, ∼106 neutrons produced during collision....
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...
A novel direct core heating fusion process is introduced, in which a preimploded predominantly heated by energetic ions driven LFEX, an extremely ultrashort pulse laser. Consequently, we have observed the D(d,n)^{3}He-reacted neutrons (DD beam-fusion neutrons) with yield of 5×10^{8} n/4π sr. Examination verified that directly collide plasma. While hot electrons heat whole volume, deposit their energies locally core, forming spots for fuel ignition. As evidenced spectrum, simultaneously...
Time-resolved compression of a laser-driven solid deuterated plastic sphere with cone was measured flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams used for while 4.51 keV Ti backlighter produced high-intensity, picosecond laser LFEX (Laser Fast ignition EXperiment) near peak Areal densities the compressed core were inferred from two-dimensional backlit images recorded narrow-band spherical crystal imager. The maximum areal density in...