| Project/Area Number |
05452084
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Space and upper atmospheric physics
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUMOTO Hiroshi Kyoto Univ.Radio Atmospheric Science Center, Professor, 超高層電波研究センター, 教授 (00026139)
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| Co-Investigator(Kenkyū-buntansha) |
USUI Hideyuki Kyoto Univ.Radio Atmospheric Science Center.Research Associate, 超高層電波研究センター, 助手 (10243081)
KOJIMA Hirotsugu Kyoto Univ.Radio Atmospheric Science Center.Research Associate, 超高層電波研究センター, 助手 (10215254)
OMURA Yoshiharu Kyoto Univ.Radio Atmospheric Science Center, Assistant Professor, 超高層電波研究センター, 助教授 (50177002)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | Magnetosphere / plasma wave / Boundary Layr / Magnetotail / Computer Experiment / particle simulation / Broadband Electrostatic Noise / Wave-Particle interaction / 磁気圏境界層 / GEO-TAIL / 波動粒子相互作用 / 磁気リコネクション / 広帯域静電ノイズ(BEN) / GEOTAIL / 広帯域静電ノイズ / 静電孤立波 |
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| Research Abstract |
We have studied nonlinear wave-plasma interaction by performing computer experiments with particle model. Since the GEOTAIL launch, various kinds of plasma wave have been observed in the boundary layrs and tail region of the magnetosphere. In those regions, plasma environment is rather turbulent due to high speed flow such as electron/ion beam, and spatial and temporal variation of the magentic field and plasma density. In such a situation, it is revealed that plasma wave activity is so high that is interaction with the charged particles becomes evident. These phenomena are described with nonlinear differential equations and, in general, they are hard to be solved exacely. In order to study such nonlinear Phenomena, we have performed computer experiments by solving the basic equations in space and time. The following is the major results obtained in the present research.
(1) We have examined the generation mechanism of Broadband Electrostatic Noize (BEN) which is frequenctly observed at the boundary layrs by GEOTAIL.Our computer experiments reveal that BEN is due to electrostatic solitary wave generated with electron beam in the boundary layr.
(2) According to the wave data obtained with the GEOTAIL spacecraft, we have examined the dependence of beam-plasma instabilities on plasma parameters such as flow velocity and plasma density.
(3) We have analyzed the magnetic reconnection with a hybrid simulation in which ions are treated as particles while electrons are fluid.
In addition to BEN and reconnection, we studied the generation of electron cyclotron harmonic wave and the amplitude modulation of Langmuir wave. We also examined the wave propagation in a case of a plasmoid encounter at the neutral sheet region.
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