A5077607730- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Silicon Carbide Semiconductor Technologies
- Nuclear physics research studies
- Atomic and Molecular Physics
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Nuclear Physics and Applications
- Meteorological Phenomena and Simulations
- ZnO doping and properties
- Muon and positron interactions and applications
- Semiconductor Quantum Structures and Devices
- Magnetic confinement fusion research
- Advanced X-ray Imaging Techniques
- Magneto-Optical Properties and Applications
- Magnetic Properties and Applications
- Climate variability and models
- Magnetic Field Sensors Techniques
- Silicon and Solar Cell Technologies
- Plasma Diagnostics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
Osaka University
2022-2025
RIKEN Nishina Center
2012-2023
The University of Tokyo
1975-2023
Kyoto University
2019-2023
RIKEN
1979-2018
Ohnishi Neurological Center
2017
Rikkyo University
2017
Tohoku University
2017
Astronomy and Space
2017
Shandong University
2017
The first elastic electron scattering has been successfully performed at the self-confining radioactive-isotope ion target (SCRIT) facility, world's facility for SCRIT technique achieved high luminosity (over ${10}^{27}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$, sufficient determining nuclear shape) with only ${10}^{8}$ ions. While $^{132}\mathrm{Xe}$ used in this time as a is stable isotope, charge density distribution was extracted from momentum...
We successfully performed electron scattering off unstable nuclei which were produced online from the photofission of uranium. The target Cs137 ions trapped with a new target-forming technique that makes high-density stationary small number by confining them in an storage ring. After developments generation and transportation systems beam stacking method to increase ion intensity up approximately 2×107 per pulse beam, average luminosity 0.9×1026 cm−2 s−1 was achieved for Cs137. obtained...
We investigated the effect of post-deposition annealing on electrical characteristics SiO2/β-Ga2O3(001) MOS structures. While oxygen effectively improves interface properties, it induces acceptor defects in Ga2O3, leading to a decrease net donor density. With combination and nitrogen annealing, carrier compensation was suppressed, low state density about 1 × 1011 cm−2 eV−1 obtained near conduction band edge Ga2O3. High immunity against positive gate bias stress also confirmed.
In this study, we investigated the impact of SiO2 deposition temperature during plasma-enhanced chemical vapor on generation fast hole traps, which cause surface potential pinning, in p-type GaN MOS structures. The thickness a gallium oxide (GaOx) layer at SiO2/GaN interface was estimated and correlated with trap generation. 200 °C-deposited structures exhibited smaller amount traps thinner GaOx interlayer than 400 samples. samples, annealing below 600 °C did not lead to an increase...
Numerical calculation of trap-assisted tunneling (TAT) current was performed and trap levels that dominantly contribute to the TAT at non-alloyed contacts formed on phosphorus ion-implanted n-type SiC were speculated. Based a careful discussion focusing impact energy level traps probability current, it found contributing sensitively varied depending applied voltage. It turned out located half Schottky barrier height from conduction band edge mainly contributed enhanced under reverse bias,...
This paper presents a formulation and some calculations for the three dimensional analysis of RF electromagnetic fields by using finite element method. We adopted penalty method to obtain an approximate solution stationary Maxwell equations. The discussion is focused on waves as linear eigenvalue problem, which primitive variable approach based electric field, E, given. confirmed validity this two developed calculation code MAX3D. Satisfactory results are obtained rectangular cavities,...
Abstract Mg contacts are formed on P + -implanted SiC (1 × 10 17 –8 19 cm −3 ) and their current–voltage characteristics contact resistivity ( ρ c analyzed. The current density through the ion-implanted is several orders of magnitude larger than that epitaxial layers with same doping density. For 8 , a very low 2 −6 Ωcm which comparable to typical Ni-based sintered at high temperature, achieved without any thermal treatment after electrode deposition.
Article: Comparison of initial perturbation methods for the mesoscale ensemble prediction system Meteorological Research Institute WWRP Beijing 2008 Olympics and Development Project (B08RDP)
Abstract The current–voltage ( I – V ) characteristics and contact resistivity <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>ρ</mml:mi> </mml:mrow> <mml:mtext>c</mml:mtext> </mml:msub> </mml:math> of Ni electrodes formed on heavily Al + -implanted p-type SiC without an alloying process were investigated. A nearly ohmic curve with a 9.3 × 10 −2 Ωcm 2 was demonstrated for non-alloyed by very high-dose implantation (3.1 20 cm −3 )....
Abstract In this study, impacts of post-deposition annealing (PDA) on hole trap generation at SiO 2 /p-GaN MOS interfaces are investigated. While the surface potential is strongly pinned due to severe trapping after 800 °C PDA, successful accumulation observed when PDA performed 200 °C. The density interface traps causing pinning, extracted from hump in capacitance–voltage curves, about 10 12 cm –2 with while over 13 temperature exceeds 600 °C, regardless ambient. Consequently, origin these...
We investigated the doping concentration dependence of barrier height and forward carrier transport mechanism in Ni/SiC Schottky diodes (SBDs) wide range 6.8 × 1015–. Forward current–voltage characteristics heavily-doped SiC SBDs () can be well reproduced by a thermionic field emission model. The decreased with increasing drop most SBD was about 0.2 eV, which quantitatively agreed image force lowering 0.18 eV caused high electric field.
Abstract We investigated the Hall electron mobility in 4H-SiC along and perpendicular to c -axis ( μ H,// H,⊥ ) using bar structures fabricated on n-type SiC( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>11</mml:mn> <mml:mover accent="true"> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:mo stretchy="true">̅</mml:mo> </mml:mover> <mml:mo>0</mml:mo> </mml:math> epitaxial layers over a wide range of donor concentration (2.1 × 10 15 –3.2 18 cm −3...
In this study, n-type SiC Schottky barrier diodes (SBDs) with various doping concentrations (Nd=4×1015–1×1019cm−3) were fabricated, and their forward reverse current–voltage (I–V) characteristics analyzed focusing on tunneling current. Numerical calculation the fundamental formula of current gives good agreement experimental I–V curves in heavily doped SBDs (Nd&gt;2×1017cm−3). The analysis energy where electron most frequently occurs revealed that field emission (FE) dominates conduction...
Abstract Ni/p-type SiC Schottky barrier diodes with various acceptor densities ( N A = 5 × 10 15 to 3 19 cm −3 ) are fabricated and the measured current–voltage characteristics analyzed by numerical calculation of tunneling current. The current is calculated taking account multiple valence bands. It revealed that holes in split-off band, which has a light effective mass (0.21 m 0 ), dominant conduction mechanism at metal/heavily-doped p-type interfaces.
We have investigated distinctive transport phenomena in two-dimensional electron gas (2DEG) narrow channel subjected to a large magnetic field gradient, unique situation created ferromagnet/2DEG hybrid structure. The so-called snake orbits which propagate the direction determined by sign of give rise conductivity enhancement and rectification effect with respect DC bias current.
We have developed a method of measuring magnetization process in ferromagnetic ring by analyzing characteristic response semiconductor two-dimensional electron gas (2DEG) lying beneath the ring. A 2DEG microcross structure is formed underneath to detect position paired domain walls onion state. The variation bend resistance due rotation quantitatively reproduced semiclassical billiard model.
The authors fabricated Co nanorings incorporated in the vertical pseudo-spin-valve nanopillar structures with deep submicron lateral sizes. It is shown that current-perpendicular-to-plane giant magnetoresistance can be used to characterize a very small magnetic nanoring effectively. Both onion state and flux-closure vortex are observed. switched between states as well not only by external field but also perpendicularly injected dc current.
The Beijing 2008 Olympics Research and Development Project (B08RDP), initiated in 2004 under the World Meteorological Organization (WMO) Weather Programme (WWRP), undertook research development of mesoscale ensemble prediction systems (MEPSs) their application to weather forecast support during Olympic Games. Six MEPSs from six countries, representing state-of-the-art regional EPSs with near-real-time capabilities emphasizing on 6–36-h lead times, participated project. background,...
Hofstadter butterfly spectra of tight-binding electron systems under spacially modulated magnetic fields are calculated. The dependence the spectrum on symmetry and strength spatially varying field is elucidated. Little-Parks oscillation superconducting network a produced by decoration with mesoscopic structure exhibits behavior reproducing edge corresponding spectra.
Abstract The barrier heights in Ti/ and Ni/n-SiC Schottky diodes (SBDs) a wide range of the donor density ( N d = 2 × 10 17 –1 19 cm −3 ) were investigated. forward current–voltage characteristics heavily-doped SBDs > are described by thermionic field emission (TFE) model, which includes an electron tunneling induced high electric (> MV −1 at interface. also causes significant image force lowering (Δ ϕ ∼ 0.2 eV) 1 ). Through analysis carefully considering such strong lowering, same...
The SCRIT electron scattering facility is under construction at the RIKEN RI Beam Factory. This worlds first dedicated to study of structure short-lived nuclei by scattering, which has been a long-standing dream for nuclear physics. A novel Self-Confining Target (SCRIT) technique makes this challenging research possible. series test experiments using stable performed partially completed show that collision luminosity between beam and target nucleus reaches 10^27cm^-'2s^-'1, required an...
The self-confining RI target (SCRIT) electron scattering facility has been constructed at RIKEN Beam Factory. commissioning experiment was performed, and the luminosity achieved to around 1027 cm−2 s−1 with stable ions a 250 mA beam current. For short-lived unstable nuclei, radioactive isotope production started electron-beam-driven separator for SCRIT. Furthermore, new devices, spectrometer window frame cooler buncher system were constructed. After setup of first nuclei will be performed soon.