A5004426449- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Earthquake Detection and Analysis
- Planetary Science and Exploration
- Laser-induced spectroscopy and plasma
- GNSS positioning and interference
- Spacecraft Design and Technology
- Space Satellite Systems and Control
- Atmospheric Ozone and Climate
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Mass Spectrometry Techniques and Applications
- Photocathodes and Microchannel Plates
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Inertial Sensor and Navigation
- Atomic and Molecular Physics
- Geophysics and Gravity Measurements
- Atomic and Subatomic Physics Research
- Electron and X-Ray Spectroscopy Techniques
- Radiation Therapy and Dosimetry
- Space Exploration and Technology
Nagoya University
2015-2025
Tokai National Higher Education and Research System
2023-2025
Earth and Space Research
2016-2021
Institute of Solar-Terrestrial Physics
2014-2015
The University of Tokyo
1993-2011
Marshall Space Flight Center
1998-2011
Tokyo University of Science
1993-2010
Rikkyo University
1998-2009
Bunkyo University
2008
Japan Aerospace Exploration Agency
2005
The low energy particle (LEP) instrument onboard GEOTAIL is designed to make comprehensive observations of plasma and energetic electrons ions with fine temporal resolution in the terrestrial magnetosphere (mainly magnetotail) interplanetary medium. It consists three units sensors (LEP-EA, LEP-SW LEP-MS) a common electronics (LEP-E). Energy-per-charge Analyzers (EA) measure three-dimensional velocity distributions (with EA-e) EA-i), simultaneously separately, over the. energy-per-charge...
We propose a model for the energy dispersion of electron precipitation associated with pulsating auroras, considering wave‐particle interactions propagating whistler mode waves from equator. Since resonant depends on magnetic latitude, pitch angle scattering different electrons can occur continuously along field line. Considering energy‐dependent path length and start time precipitating electrons, transit waves, frequency drift, we calculated observed at topside ionosphere. Note that higher...
The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well their interactions with the solar wind, radiation, interplanetary dust. Many scientific instruments onboard spacecraft be completely, or partially devoted study near-space environment of complex processes that govern it. issues remain unsolved even after MESSENGER ended in 2015. specific...
Abstract We investigate the origin of fine structure energy spectrum precipitating electrons for pulsating aurora (PsA) observed by low‐altitude Reimei satellite. The satellite achieved simultaneous observations optical images and PsA from altitude (~620 km) with resolution 40 ms. main modulation precipitation, a few seconds, internal modulations, hertz, that are embedded inside modulations identified above ~3 keV. Moreover, stable precipitations at ~1 keV found PsA. A “precipitation gap” is...
The medium-energy particle experiments—electron analyzer onboard the exploration of energization and radiation in geospace spacecraft measures energy direction each incoming electron range 7–87 keV. sensor covers a 2π-radian disklike field view with 16 detectors, full solid angle coverage is achieved through spacecraft’s spin motion. independently measured by both an electrostatic avalanche photodiodes, enabling significant background reduction. We describe technical approach, data output,...
We present small and meso‐scale properties of a substorm onset arc observed simultaneously by the Reimei THEMIS satellites together with ground‐based observations GBO system. The optical revealed slow equatorward motion growth‐phase development much brighter poleward it. Both arcs showed typical particle signature electrostatic acceleration in an inverted‐V structure strong Alfvén wave at edge arc. Two spacecraft encountered earthward flow bursts around times expanding aurora reached their...
In February 1996, the POLAR spacecraft was placed in an elliptical orbit with a 9 RE geocentric distance apogee northern hemisphere and 1.8 R E perigee southern hemisphere. The Thermal Ion Dynamics Experiment (TIDE) on has allowed sampling of three‐dimensional ion distribution functions excellent energy, angular, mass resolution. Plasma Source Instrument (PSI), when operated, allows sufficient diminution electric potential to observe polar wind at very high altitudes. this paper, we describe...
We have identified slow‐mode shocks between the plasma sheet and lobe in midtail to distant‐tail regions by using three‐dimensional magnetic field data including density, velocity, temperature, heat flux of both ions electrons observed GEOTAIL satellite. Analyzing obtained September 14, 1993, February 16, 1994, we found 303 sheet‐lobe boundary crossings at distances ‐ X GSE ∼ −30 R E −210 . Thirty‐two out these boundaries are as shocks. back streaming on upstream side shocks, which may be...
The medium-energy particle experiments–ion mass analyzer (MEP-i) was developed for the exploration of energization and radiation in geospace (ERG) mission (Arase), order to measure three-dimensional distribution functions inner-magnetospheric ions medium energy range between 10 180 keV/q. energy, mass, charge state each ion are determined by a combination an electrostatic energy/charge analyzer, time-of-flight mass/charge energy-sensitive solid-state detectors. This paper describes...
In Earth's environment, the observed polar outflow rate for O + ions, main source of oxygen above gravitational escape energy, corresponds to loss ∼18% present-day atmospheric over 3 billion years. However, part this apparent can actually be returned atmosphere. Examining rates four routes with high-altitude spacecraft observations, we show that total inferred from current knowledge is about one order magnitude smaller than rate. This disagreement suggests there may a substantial return flux...
The Japanese Akebono (EXOS-D) satellite was successfully put into a semipolar, elliptical orbit in order to study particle acceleration processes the auroral magnetosphere. onboard LEP (low energy particle) instrument makes three distinct types of charged observations: 1) and pitch-angle distributions electrons ions, 2) mass per charge analysis positive 3) detection flux modulations HF VLF ranges. In this report we describe instrumentation, present some preliminary results from item 1 above....
This paper reports the design, calibration, and operation of high-energy electron experiments (HEP) aboard exploration energization radiation in geospace (ERG) satellite. HEP detects 70 keV–2 MeV electrons generates a three-dimensional velocity distribution for these every period satellite's rotation. Electrons are detected by two instruments, namely HEP-L HEP-H, which differ their geometric factor (G-factor) range energies they detect. keV–1 its G-factor is 9.3 × 10−4 cm2 sr at maximum,...
Abstract MAP-PACE (MAgnetic field and Plasma experiment-Plasma energy Angle Composition Experiment) is one of the scientific instruments onboard SELENE (SELenological ENgineering Explorer) satellite. PACE consists four sensors: ESA (Electron Spectrum Analyzer)-S1, ESA-S2, IMA (Ion Mass Analyzer), IEA Energy Analyzer). ESA-S1 S2 measure distribution function low-energy electrons below 15 keV, while low ions 28 keV/q. Each sensor has a hemispherical view. Since three-axis stabilized...
[1] Using image and particle data sets obtained from observations by the Reimei satellite, we carried out time-of-flight (TOF) analysis for 29 pulsating aurora events to understand precise properties of auroras possible generation process. While sources identified using a standard TOF model were distributed almost continuously magnetic latitudes 50° −20°, different that takes into account whistler mode wave propagation confined equatorial region up about 15°. The latter source distribution...
In some types of mass spectrometers, such as time-of-flight spectrometers (TOF-MSs), it is necessary to control pulsed beams ions. This can be easily accomplished by applying a voltage the pusher electrode while ionizer continuously flowing method preferred for its simplicity, although ion utilization efficiency not optimized. Here we employed another pulse-control with higher rate, which bunch ions and kick them out instead letting stream. The benefit this that sensitivity achieved; since...
Abstract Previous studies have verified that upward geomagnetic field‐aligned electric fields (FAEFs) produce inverted‐V signatures of precipitating electrons generate discrete auroras in currents (FACs). However, clear ion rarely been reported the polar magnetosphere. Plasma measurements with high time resolution at altitude 630–670 km nightside auroral oval often detected ions adjoining active electron inverted‐Vs, suggesting downward acceleration by FAEFs associated intense FAC. The...
AbstractAnomalous reconnection layer (ARL) usually appears near the magnetopause when solar wind is in low Alfvén Mach number. The structure of an ARL similar to magnetic outflow region, i.e., a decrease total field and increase high-energy ion flux. seldom observed Earth’s magnetospheric environment because at Earth mostly high number regime. According previous observations, Mercury Therefore, we assume that such can be frequently Mercury’s magnetopause. To test...
Data from the GEOTAIL Low Energy Particle (LEP) instrument and magnetometer (MGF) for a plasmoid event on October 8, 1993 when spacecraft was located at X GMS ∼−142 R E were analyzed. The started 16 minutes after substorm onset with tailward flow of electrons whose characteristic energy several keV an apparent dispersion. This followed by arrival beam high ions, which also had similar dispersion, enhancement magnetic field intensity. There appreciably flux cold ions in lobe region, it...