A5049268296- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- High-pressure geophysics and materials
- Thermoregulation and physiological responses
- Nonlinear Optical Materials Research
- Optical Imaging and Spectroscopy Techniques
- Industrial Vision Systems and Defect Detection
- Fiber-reinforced polymer composites
- Photonic and Optical Devices
- Graphene research and applications
- Crystallization and Solubility Studies
- Numerical methods in engineering
- Photoacoustic and Ultrasonic Imaging
- Thermal properties of materials
- Fatigue and fracture mechanics
- Ultrasonics and Acoustic Wave Propagation
- Rock Mechanics and Modeling
- Medical Imaging Techniques and Applications
- Inhalation and Respiratory Drug Delivery
- Organic and Inorganic Chemical Reactions
- Ocular and Laser Science Research
- Transportation Safety and Impact Analysis
- Material Properties and Failure Mechanisms
University of Illinois Urbana-Champaign
2021-2024
Osaka University
2002-2023
Kyushu University
2022
Keio University
2008-2009
Institute for Laser Technology
1999
We have developed a prepulse-free short-pulse Nd:glass laser system of 0.9-PW peak power to heat pre-imploded high-density plasma. An optical parametric chirped amplification is introduced reduce the prepulses an amplitude (1.5/spl times/10/sup -8/) that main pulse. The compressor double-path grating pair 94 cm in diameter compressing 50-cm-diameter beam 470 fs. off-axis parabolic mirror has focused 420-J energy intensity 2.5/spl 19/ W/spl middot/cm/sup -2/. Part front end pulse seeded into...
Laser plasma interactions in a relativistic parameter regime have been intensively investigated for studying the possibility of fast ignition inertial confinement fusion (ICF). Using ultra-intense laser systems and particle-in-cell (PIC) simulation codes, light self-focusing, super hot electrons, ions, neutron production, are studied. The experiments performed with 50 J energy, 0.5–1 ps pulse at 1053 nm wavelength intensity 1019 W/cm2. Most shots studied under preformed conditions 100 μm...
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...
100 TW light from the Petawatt Module (PWM) laser illuminated a preimploded spherical deuterated polystyrene(CD) shell target. The DD neutron yield increased 2.5×105–106. Analysis indicates that hundreds of keV deuterons, generated around critical density, collide with cold fuel deuterons and play leading role in enhancement yield. A two-dimensional particle-in-cell (2D PIC) simulation predicted well deuteron spectrum. 60 was used for MeV proton emissions megagauss magnetic fields generation...
The LFEX laser system is under construction to realize the principle of fast ignition in FIREX-I program. 3.1-kJ output power chirped pulse has been obtained with main disk amplifier. 3.3-nm (FWHM) spectral width, which enough wide for less than 2-ps rise time compression, was by controlling seed both temporally and spectrally a spatial light modulation. beam aberration amplification reduced 0.2[03bb] rms far field pattern using two deformable mirrors
Herein, a theory for modeling the problem of scattering pulse-induced temporal contrast degradation in chirped-pulse amplification (CPA) lasers is introduced. Using this model, evolutions and signal pulses were simulated, contrasts different cases compared, finally theoretical prediction was verified by an experimental demonstration. The result shows that picosecond nanosecond mainly determined generated stretcher compressor, respectively. In addition, B-integral accumulation will further...
Although the electrical properties of carbon fibers and fiber composites are critical to design composite materials, a direct measurement transverse resistivity single has not yet been reported. Significant challenges arise in fabricating specimens making resistance measurements due geometry small diameter (about 4–7 μm). In this study, we report specimen fabrication technique for measuring an individual by van der Pauw method. IM7 fabricated combination photolithography focused ion beam....
Foot and pedestal pulses that precede the main pulse from a high-intensity laser greatly affect laser–plasma interactions. Especially in fast ignition schemes, preceding generate plasma prior to irradiation by pulse. This results too energetic divergent electron beam being generated preformed plasma, which reduces energy coupling efficiency heating dense fuel core. A with density scale length of 40–60 μm was observed time- space-resolved x-ray backlight technique using LFEX system at...
Magnetic reconnection in laser-produced magnetized plasma is investigated by using optical diagnostics. The magnetic field generated via Biermann battery effect, and the inversely directed lines interact with each other. It shown self-emission measurement that two colliding plasmas stagnate on a mid-plane forming planar dense regions, they later time. Laser Thomson scattering spectra are distorted direction of self-generated field, indicating asymmetric ion velocity distribution...
Laser plasma instabilities, such as stimulated Raman scattering (SRS) and two-plasmon decay (TPD), are basic phenomena in intense laser science applications. In direct-drive inertial confinement fusion (ICF) where a fuel capsule is imploded by high-power lasers, SRS TPD generally problematic because hot electrons (HEs) generated cause preheating, whereas HEs with acceptable energy expected to contribute ablation pressure enhancement. all cases, it necessary clarify the occurrence of SRS,...
The FIREX-1 project, the goal of which is to demonstrate fuel heating up 5 keV by fast ignition scheme, has been carried out since 2003 including construction and tuning LFEX laser integrated experiments. Implosion experiment Fast Ignition targets have performed 2009 with Gekko-XII lasers. A deuterated polystyrene shell target was imploded 0.53- μm Gekko-XII, 1.053- beam injected through a gold cone attached generate hot electrons heat plasma. Pulse contrast ratio significantly improved....
Thin films of amorphous silicon (a-Si) coated on metals such as nickel (Ni) are one the most promising anode architectures for high-energy-density lithium-ion (Li-ion) batteries. The performance and longevity batteries with this type electrode depend integrity Ni/a–Si interface. a-Si /Ni bonded interface during cycling is critical, but experimental characterization interfacial failure material system highly challenging there a sparsity strength data in literature. Here, we describe laser...
The change in the cortical blood flow of guinea pigs during auditory stimulation is measured by laser speckle flowgraphy (LSFG). Accuracy LSFG depends on number frames for calculation. blood-flow maps rotating disks and tissues are calculated from various numbers pattern, influence statistical error averaging effect results evaluated to optimise system. map obtained successive 24-30 can appropriately identify caused stimulation.
LFEX is a high-energy PW laser aiming for an output of 10 kJ/l-10 ps. In this paper the architecture multi-pass chirped pulse amplifier with 2x2 arrayed structure, newly designed diamond-shape compressor, shaping technique and other technological developments are reported.
The distribution coefficient of deuterium in the crystal depends on that growth solution. It was not affected, even if saturated temperature and supersaturation solution were changed. Thirteen percent-deuterated KDP 9 by 11 cm size grown which deuterated rate constant within measurement error plus or minus 1%. excess energy due to an over heating and/or acoustic pH control realized a higher level supersaturation. crystals up 50 mm/day.
In order to simulate three-dimensional dynamic crack propagation, a moving finite-element method was developed. A new expression also derived for the J integral (J') in terms of equivalent domain (EDI) method. The procedure together with evaluation made it possible evaluate distribution energy release rate along propagating front at each time step. Furthermore, formula converting stress intensity factor by introducing three-dimensionality parameter. Numerical simulation carried out several...