K. Yoshimura
A5101559642- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Muon and positron interactions and applications
- Quantum Chromodynamics and Particle Interactions
- Masonry and Concrete Structural Analysis
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Radiation Therapy and Dosimetry
- Structural Behavior of Reinforced Concrete
- High-Energy Particle Collisions Research
- Atmospheric Ozone and Climate
- Structural Load-Bearing Analysis
- Structural Engineering and Vibration Analysis
- Quantum, superfluid, helium dynamics
- Crystallography and Radiation Phenomena
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Electron and X-Ray Spectroscopy Techniques
- Structural Analysis of Composite Materials
Okayama University of Science
2018-2024
Hosei University
2024
Okayama University
1996-2023
Japan Aerospace Exploration Agency
2017-2021
Institute of Space and Astronautical Science
2017-2021
High Energy Accelerator Research Organization
2006-2019
Mazda Motor Corporation (Japan)
2019
Okayama Prefecture
2018
Kobe University
1996-2017
The University of Tokyo
1956-2017
Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons helium nuclei energy ranges, 1–540 GeV 1–250 GeV/n, respectively, flux muons range 0.6–400 GeV/c.
The energy spectra of cosmic-ray low-energy antiprotons ( $\overline{p}$'s) and protons $p$'s) have been measured by BESS in 1999 2000, during a period covering reversal at the solar magnetic field. Based on these measurements, sudden increase $\overline{p}/p$ flux ratio following field was observed, it generally agrees with drift model modulation.
The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two long-duration balloon flights over Antarctica in December 2004 2007, at substantially different levels solar modulation. Proton probe origin propagation history cosmic rays galaxy, are essential to calculations expected antiprotons, positrons, electrons from interactions primary nuclei with interstellar gas, atmospheric muons neutrinos. We report absolute top atmosphere for kinetic range...
We performed a search for cosmic-ray antideuterons using data collected during four BESS balloon flights from 1997 to 2000. No candidate was found. derived, the first time, an upper limit of 1.9 x 10(-4) (m2s sr GeV/nucleon)(-1) differential flux antideuterons, at 95% confidence level, between 0.17 and 1.15 GeV/nucleon top atmosphere.
The international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate principle of ionization cooling as a technique for reduction phase-space volume occupied by muon beam. channels are required Neutrino Factory and Collider. MICE evaluate in detail performance single lattice cell Feasibility Study 2 channel. Beam has been constructed ISIS synchrotron RAL, Step I, it characterized using beam-instrumentation...
The differential cross sections of the Σ^{-}p→Λn reaction were measured accurately for Σ^{-} momentum (p_{Σ}) ranging from 470 to 650 MeV/c at J-PARC Hadron Experimental Facility. Precise angular information about was obtained first time by detecting approximately 100 events each step Δcosθ=0.1. show a slightly forward-peaking structure in regions. integrated -0.7≤cosθ≤1.0 as 22.5±0.68 [statistical error(stat.)] ±0.65 [systematic error(syst.)] mb and 15.8±0.83(stat)±0.52(syst)...
The radioisotope thorium-229 (
We have studied the low-energy antiprotons in cosmic rays by utilizing data obtained Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) flown 1993 July from Lynn Lake, Manitoba, Canada. A detailed description of event selection criteria and background corrections is given. Seven are found that give an antiproton flux 6.4+ 5.5−3.5 × 10-3(m2 sr s GeV)-1 antiproton/proton ratio 5.2+ 4.4−2.8 10-6 200-600 MeV energy range. These results consistent secondary...
The absolute fluxes of the cosmic-ray antiprotons at solar minimum are measured in energy range 0.18 to 1.4 GeV, based on 43 events unambiguously detected BESS '95 data. resultant spectrum appears be flat below 1 compatible with a possible admixture primary antiproton component soft spectrum, while possibility secondary alone explaining data cannot excluded present accuracy. Further improvement statistical accuracy and extension planned future flights.
We propose and study a method of optical crosstalk suppression for silicon photomultipliers (SiPMs) using filters. demonstrate that attaching absorptive visible bandpass filters to the SiPM can substantially reduce crosstalk. Measurements suggest absorption near infrared light is important achieve this suppression. The proposed technique be easily applied suppress in SiPMs cases where filtering compatible with application.
The radioisotope Th-229 is renowned for its extraordinarily low-energy, long-lived nuclear first-excited state. This isomeric state can be excited by VUV lasers and the transition from ground has been proposed as a reference ultra-precise clocks. Such clocks will find multiple applications, ranging fundamental physics studies to practical implementations. Recent investigations extracted valuable constraints on energy lifetime, populating isomer in stochastic decay of U-233 or Ac-229....
An extremely thin superconducting solenoid magnet is being developed to investigate cosmic-ray antiparticles in the Universe. The uniform solenoidal field provided a particle detector system analyze momentum. coil wound with advanced aluminum stabilized superconductor recently by using micro-alloying Ni, followed cold-work mechanical hardening. It designed central magnetic of 1.2 T volume 0.9 m diameter and 1.4 length. radiation thickness be 0.056 X/sub 0/ physical 3.4 mm. This paper...
We have searched for antihelium in the galactic cosmic rays using data obtained on flight of Balloon-borne Experiment with a Superconducting Spectrometer (BESS) launched from Lynn Lake, Manitoba, northern Canada 1995 July 25. The balloon reached an altitude 36.5 km residual overburden 5 g cm-2. total observation time was 12.2 hr live-time fraction 0.61. No observed after selections based dE/dx and event quality cuts at rigidities between 1.6 16 GV/c; we infer that 536,420 helium nuclei...
The multipixel photon counter (MPPC) is a newly developed photodetector with an excellent counting capability. It also has many attractive features such as small size, high gain, low operation voltage and power consumption, capability of operating in magnetic fields room temperature. basic performance samples been measured. A gain ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> achieved noise rate less than 500 kHz 1 p.e. threshold,...