A5008305570- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Laser Design and Applications
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
- Laser Material Processing Techniques
- Superconducting Materials and Applications
- Solar and Space Plasma Dynamics
- Energetic Materials and Combustion
- Photonic Crystal and Fiber Optics
- Particle Dynamics in Fluid Flows
- Solid State Laser Technologies
- Dust and Plasma Wave Phenomena
- Multi-Criteria Decision Making
- Glass properties and applications
- Combustion and Detonation Processes
- Planetary Science and Exploration
Osaka University
2015-2024
Extreme Light Infrastructure - Nuclear Physics
2019
Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering
2019
University of California, San Diego
2019
National Institutes for Quantum Science and Technology
2019
The University of Tokyo
1988-2019
Oak Ridge National Laboratory
1990-2017
Shanghai Jiao Tong University
2017
University of Strathclyde
2017
Institute for Laser Technology
1998-2014
The interaction of relativistic electrons produced by ultrafast lasers focusing them on strongly precompressed thermonuclear fuel is analytically modeled. Energy loss to target treated through binary collisions and Langmuir wave excitation. overall penetration depth determined quasielastic multiple scattering ions. It thus appears possible ignite efficient hot spots in a with density larger than 300 g/c${\mathrm{m}}^{3}$.
An international stellarator database on global energy confinement is presented. It comprises a total of 859 discharges from the ATF, CHS and Heliotron-E heliotron/torsatrons W7-A W7-AS shearless stellarators. Some design aspects operation techniques different devices are discussed. The data in represent electron cyclotron heated (ECH) neutral beam injection (NBI) L mode regime. Results enhanced regimes such as H will be reported elsewhere. Regression expressions for time given individual...
Extreme ultraviolet (EUV) radiation from laser-produced plasma (LPP) has been thoroughly studied for application in mass production of next-generation semiconductor devices. One critical issue the realization an LPP-EUV light source lithography is conversion efficiency (CE) incident laser power to EUV 13.5-nm wavelength (within 2% bandwidth). Another solving problem damage caused when debris reaches collecting mirror. Here, we present improved balance model, which can be used optimization...
Human cancer cells are irradiated by laser-driven quasimonoenergetic protons. Laser pulse intensities at the 5×1019 W/cm2 level provide source and acceleration field for protons that subsequently transported four energy-selective dipole magnets. The transport line delivers 2.25 MeV with an energy spread of 0.66 a bunch duration 20 ns. survival fraction in vitro from human salivary gland tumor is measured colony formation assay following proton irradiation dose levels up to 8 Gy, which single...
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...
We report the demonstrated irradiation effect of laser-accelerated protons on human cancer cells. In vitro (living) A549 cells are irradiated with quasimonoenergetic proton bunches 0.8–2.4 MeV a single bunch duration 15 ns. Irradiation dose 20 Gy results in distinct formation γ-H2AX foci as an indicator DNA double-strand breaks generated This is pioneering result that points to future investigations radiobiological effects laser-driven ion beams. Unique high-current and short-bunch features...
Type I IFN receptor type 2 (IFNAR2) expression correlates significantly with clinical response to interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). However, some IFNAR2-positive patients show no the therapy. This result suggests possibility of other factors, which would be responsible resistance IFN-α/5-FU The aim this study was examine mechanism anti-proliferative effects and search a biological marker chemoresistance such Gene profiling...
A new self-similar solution is presented which describes nonrelativistic expansion of a finite plasma mass into vacuum with full account charge separation effects. The exists only when the ratio Λ=R∕λD scale length R to Debye λD invariant, i.e., under condition Te(t)∝[ne(t)]1−2∕ν, where ν=1, 2, and 3 corresponds, respectively, planar, cylindrical, spherical geometries. For Λ⪢1 position ion front maximum energy Ei,max accelerated ions are calculated analytically: in particular, for ν=3 one...
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.
The physics of indirectly driven targets for inertial confinement fusion — so-called hohlraum is investigated. Scaling relations radiation heat waves in high-Z and low-Z materials are derived from one-dimensional multigroup simulation. A two-temperature model developed cavities including capsules. efficiency X-ray transfer to the capsule by multiple absorption re-emission inside cavity obtained as a function areas materials. Using gold wall carbon ablator, efficiencies between 50% 33% area...
The propagation of a radiation heat wave through thin foil solid gold was investigated experimentally. is driven by the intense thermal in 1--3-mm-diam cavities heated an laser pulse (duration 0.8--0.9 ns, wavelength 0.35 \ensuremath{\mu}m) to temperatures more than 200 eV. Evidence propagating obtained from delayed onset emission outer side foil. results agree with theoretical predictions for self-similar ablative and numerical simulations.
Relativistic laser pulse propagation into homogeneous plasmas has been investigated as a function of plasma density. At first, the features are compared systematically between relativistic transparency (RT) and hole-boring (HB). Paramountly, considerably broad intermediate regime, namely incomplete HB found RT regime for an extremely intense circularly polarized (CP) pulse. In this proceeds in collaboration with RT, resulting much faster speed higher cut-off energy fast ions than classic...
Properties of ion debris emitted from laser-produced mass-limited tin plasmas have been experimentally investigated for an application to extreme ultraviolet (EUV) lithography. Simple scaling laws design the target, which is a key technique minimize contamination first EUV collection mirror, discussed. The measured energy spectrum ions consistent with prediction by isothermal expansion model. average charge state evaluated be +5 at 180mm away plasma, and higher-energy higher state. It was...
A scheme to suppress the Rayleigh-Taylor instability has been investigated for a direct-drive inertial fusion target. In high-Z doped-plastic target, two ablation surfaces are formed separately-one driven by thermal radiation and other electron conduction. The growth of is significantly suppressed on radiation-driven surface inside target due large velocity long density scale length. significant reduction rate was observed in simulations experiments using brominated plastic new pellet...
A simple analytical model is presented for hydrodynamic expansion of laser-produced plasma with a limited mass, which expands quasi-isothermally during laser irradiation and quasiadiabatically after turning off the laser. During isothermal expansion, masses undergo entire disintegration under relatively long pulse, while ions are being kept accelerated. This physical picture significantly contrasts that described by orthodox self-similar solution semi-infinite planar rarefaction wave. The...
Pre-ionization experiments have been performed on a tokamak by injecting about 80 kW of microwave power at 35 GHz for up to 15 ms. Microwave absorption occurs the electron cyclotron and upper hybrid resonance frequencies as predicted theory. causes substantial (40%) reductions in loop voltage during initial phase shot. Flux (volt-second) savings with pre-ionization are 30% first 2 ms or 2% total flux expenditure The plasma current begins 200 μs earlier rises 1.4 times more rapidly...
Conversion efficiencies (CEs) from incident laser energy to 13.5nm light within a 2% bandwidth were measured with changing pulse durations for laser-produced tin plasmas. Experimental results indicate that the optimum duration is determined by two parameters: one optical depth of plasma and other absorption rate in emission-dominant region. The maximum CE 2.2% obtained 2.3ns.
By combination of the benefits magnetic and inertial confinements, a new fusion scheme is introduced with plasma density \ensuremath{\gtrsim}${10}^{21}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ whose pressure confined by inertia metallic container cannonball type while its heat insulated self-generated field \ensuremath{\gtrsim}100 T.
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....
The Faraday effect, caused by a magnetic-field-induced change in the optical properties, takes place vast variety of systems from single atomic layer graphenes to huge galaxies.Currently, it plays pivot role many applications such as manipulation light and probing magnetic fields material's properties.Basically, this effect causes polarization rotation during its propagation along field medium.Here, we report an extreme case where linearly polarized ultrashort laser pulse splits time into...
Abstract A microtube implosion driven by ultraintense laser pulses is used to produce ultrahigh magnetic fields. Due the laser-produced hot electrons with energies of mega-electron volts, cold ions in inner wall surface implode towards central axis. By pre-seeding uniform fields on kilotesla order, Lorenz force induces Larmor gyromotion imploding and electrons. resultant collective motion relativistic charged particles around axis, strong spin current densities $$\sim$$ <mml:math...
Symmetrization of the radiation field by multiple absorption and re-emission in hohlraum targets for indirectly driven inertial confinement fusion (ICF) is investigated. The on confining wall capsule calculated self-consistently, taking into account angular distribution X-rays received emitted each surface element. Wall physics are described approximate ablative heat wave relations, giving absorbed flux, temperature thermally re-emitted flux Hydrodynamic motion not taken account. Concerning...
Access to the MHD second stability regime has been achieved in ATF torsatron. Experimental \ensuremath{\beta} values (${\ensuremath{\beta}}_{0}$\ensuremath{\le}3%, with fast ions contributing \ensuremath{\approxeq}(1/3 of pressure at high \ensuremath{\beta}) are well above theoretical transition value (${\ensuremath{\beta}}_{c}$\ensuremath{\approxeq}1.3% for ideal modes) required reach this regime. The relatively low ${\ensuremath{\beta}}_{c}$ results from operation peaked profiles. measured...
Since the approval of first phase Fast-Ignition Realization Experiment (FIREX-I), we have devoted our efforts to designing advanced targets and constructing a petawatt laser, which will be most energetic laser in world. Scientific technological improvements are required efficiently heat core plasma. There two methods that can used enhance coupling efficiency heating thermal energy compressed plasma: adding low- Z foam layer inner surface cone employing double cone. The implosion performance...