A5035588100- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Laser Design and Applications
- Advanced X-ray Imaging Techniques
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
- Diamond and Carbon-based Materials Research
- X-ray Spectroscopy and Fluorescence Analysis
- Helicobacter pylori-related gastroenterology studies
- Laser Material Processing Techniques
- Advanced Electron Microscopy Techniques and Applications
- Solid State Laser Technologies
- High-Temperature Coating Behaviors
- Astro and Planetary Science
- Chemical Synthesis and Characterization
- Radiation Detection and Scintillator Technologies
- Radioactive element chemistry and processing
- Radiation Therapy and Dosimetry
- Transgenic Plants and Applications
- Magnetic confinement fusion research
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
National Institutes for Quantum Science and Technology
2016-2024
Kansai Photon Science Institute
2013-2024
The University of Tokyo
1995-2024
Kōchi University
2015-2021
Kyoto University
2021
KRI
2009-2020
Centre National de la Recherche Scientifique
2018
Queen's University Belfast
2018
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2018
École Polytechnique
2018
An approach for accelerating ions, with the use of a cluster-gas target and an ultrashort pulse laser 150-mJ energy 40-fs duration, is presented. Ions 10--20 MeV per nucleon having small divergence (full angle) 3.4\ifmmode^\circ\else\textdegree\fi{} are generated in forward direction, corresponding to approximately tenfold increase ion energies compared previous experiments using solid targets. It inferred from particle-in-cell simulation that high ions at rear side due formation strong...
We report the generation of 63 J broadband pulse energies at 0.1 Hz from J-KAREN-P laser, which is based on an OPCPA/Ti:sapphire hybrid architecture. Pulse compression down to 30 fs indicates a peak power over 1 PW. High temporal contrast 1012 prior main has been demonstrated with 10 output energy. intensities 1022 W/cm2 target by focusing 0.3 PW laser f/1.3 off-axis parabolic mirror have achieved. Fundamental processes matter interaction belong new branch science that will be principal...
J-KAREN-P is a high-power laser facility aiming at the highest beam quality and irradiance for performing state-of-the art experiments frontier of modern science. Here we approached physical limits quality: diffraction limit focal spot bandwidth pulse shape, removing chromatic aberration, angular chirp, wavefront spectral phase distortions. We performed accurate measurements peak fluence after an f/1.3 off-axis parabolic mirror under full amplification power 0.3 PW attenuated with ten...
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)...
Using a high-contrast (10(10):1) and high-intensity (10(21) W/cm(2)) laser pulse with the duration of 40 fs from an optical parametric chirped-pulse amplification/Ti:sapphire laser, MeV proton bunch is obtained, which record for energy less than 10 J. The efficiency generation protons kinetic above 15 0.1%.
Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating micron-thick Al foil impurity on the surface. An energetic low-emittance high-density beam of heavy large charge-to-mass ratio can be obtained, which is useful for many applications, such as compact radio isotope source in combination conventional technology.
A high-contrast high-intensity petawatt-class Ti:sapphire chirped-pulse amplification laser has been developed for research on high field science. saturable absorber and a low-gain optical parametric preamplifier in the front-end have improved temporal contrast system to ∼ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>$2 \times 10^{12}$</tex-math></inline-formula> subnanosecond time scale at ∼70 TW power level. In addition...
Crystalline cerium(IV) oxide nanoparticles with a cubic fluorite structure could be synthesized from ammonium nitrate solutions relatively high concentration of (such as 0.5 mol/dm 3 ) via thermal hydrolysis at 150°–240°C. The effects the treatment temperature, salt concentration, and addition sulfate ions on crystallite size morphology particles were investigated. crystalline had tendency to agglomerate form spherical secondary either or sulfuric acid. existence in acidified solution was...
We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred orders are resolved, giving μJ/sr pulses. Harmonics collectively emitted by an oscillating electron spike formed at joint of boundaries cavity and bow wave created relativistically self-focusing laser underdense plasma. The sharpness stability explained catastrophe theory. is corroborated...
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...
We described the output performance and temporal quality enhancement of J-KAREN-P petawatt laser facility. After wavefront correction using a deformable mirror, focusing with an f/1.3 off-axis parabolic mirror delivered peak intensity 1022 W/cm2 at 0.3 PW power levels. Technologies to improve contrast were investigated tested. The origins pre-pulses generated by post-pulses identified elimination most removal wedged optics was achieved. A cascaded femtosecond optical parametric amplifier...
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...
Abstract Tight focusing with very small f -numbers is necessary to achieve the highest at-focus irradiances. However, tight imposes strong demands on precise target positioning in-focus on-target irradiance. We describe several near-infrared, visible, ultraviolet and soft hard X-ray diagnostics employed in a ∼10 22 W/cm 2 laser–plasma experiment. used nearly 10 J total energy femtosecond laser pulses focused into an approximately 1.3-μm focal spot 5–20 μm thick stainless-steel targets....
A novel mathematical model for the investigations of a cluster formation process in gas jet is presented, which enables us to obtain detailed description spatial and temporal distributions all target parameters. In this model, considered as two-phase medium, consisting continuous phase discrete condensed (clusters). The nozzle geometry also taken into account model. order confirm advantage present over conventional considerable amount numerical computations has been carried out results are...
A high stability electron bunch is generated by laser wakefield acceleration with the help of a colliding pulse. The pulse; second pulse collides first at 180° and 135° realizing optical injection an bunch. has reproducibility compared single generation. In case collision, special measures have been taken to prevent damage. since countercrossing, it cannot damage system.Received 31 October 2008DOI:https://doi.org/10.1103/PhysRevLett.103.194803©2009 American Physical Society
We show experimentally the possibility of nanostructuring (about 20 nm) gold surface by picosecond soft x-ray single pulse with low fluence ∼20 mJ/cm2. The nanometer-scale changes structure are due to splash molten under gradient laser beam. In addition, ablation process occurs at slightly higher ∼50 atomistic model is developed which reveals that threshold this build-up high electron pressure and comparatively electron-ion energy relaxation rate in gold. calculated depths as a function...
We demonstrate the temporal contrast enhancement in a petawatt-class Ti:sapphire chirped-pulse amplification (CPA) laser system. An extra saturable absorber, introduced downstream after low-gain optical parametric (OPCPA) preamplifier, has improved system to 1.4×10(12) on subnanosecond time scale at 70 TW power level. have achieved 28 J of uncompressed broadband output energy with this system, indicating potential for reaching peak powers near 600 TW.
The generation of a plasma with an ultrahigh energy density 1.2 GJ/cm3 (which corresponds to about 12 Gbar pressure) is investigated by irradiating thin stainless-steel foils high-contrast femtosecond laser pulses relativistic intensities up 1022 W/cm2. parameters are determined X-ray spectroscopy. results show that most the absorbed at solid density, indicating no pre-plasma generated in current experimental setup.
We report on detailed investigations of ionization dynamics a Xe atom exposed to intense 800-nm pulses 20-fs duration in the extensive intensity range from 10(13)-10(18) W/cm(2). Ion yields Xe+-Xe20+ were observed as function laser and compared with results single active electron based Ammosov-Delone-Krainov model. Unexpected probabilities for lower charge states no interplay between inner outer shells by screening are inferred. Suppression nonsequential towards higher few optical cycle...
To elucidate the mechanism of elicitor-inducible gene expression, we investigated induction accumulation mRNAs transcribed from defense genes that encode class I basic chitinase (BCHN) and II acidic (ACHN), rβ-1,3-glucanase (GLN) 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) in tobacco cells treated with a fungal elicitor. The elicitor treatment was shown to increase steady-state levels for BCHN GLN, ACHN DAHPS. Expression these pairs induced by different kinetics mRNA...
Ablation of LiF crystal by soft x-ray laser (XRL) pulses with wavelength λ=13.9 nm and duration TL=7 ps is studied experimentally theoretically. It found that a crater appears on surface for XRL fluence, exceeding the ablation threshold Fa∼10.2 mJ/cm2 in one shot, or 5 each three shots. This substantially below thresholds obtained other lasers having longer pulse and/or wavelength. A mechanism thermomechanical large bandgap dielectrics proposed. The theory explains low Fa via small...
We report, for the first time, that energy of femtosecond optical laser pulses, E, with relativistic intensities I > 10(21) W/cm(2) is efficiently converted to X-ray radiation, which emitted by "hot" electron component in collision-less processes and heats solid density plasma periphery. As shown direct high-resolution spectroscopic measurements radiation from periphery exhibits unusual non-linear growth ~E(4-5) its power. The power occurs far earlier than known regime when reaction...