1987 Fiscal Year Final Research Report Summary
Laboratory Experiments on Electrostatic Potential Structure concerned with Aurora Phenomenon
| Project/Area Number |
61460226
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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 |
プラズマ理工学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SATO Noriyoshi Faculty of Engineering, Tohoku University, 工学部, 教授 (40005252)
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| Co-Investigator(Kenkyū-buntansha) |
TSUSHIMA Akira Faculty of Engineering, Tohoku University, 工学部, 助手 (90171991)
MIENO Tetsu Tohoku University, Faculty of Engineering, 助手 (50173993)
HATAKEYAMA Rikizo Faculty of Engineering, Tohoku University, 工学部, 助教授 (00108474)
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| Project Period (FY) |
1986 – 1987
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| Keywords | AURORA / MAGNETIC MIRROR / 電位構造 |
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| Research Abstract |
It is quite important to understand aurora phenomena in order to clarify a dynamic feature of the Earth's madnetosphere. Electron acceleration inducing auroral discharge has been supposed to be due to a plasma potential slope along the magnetic field lines above the auroral oval
In this work, measurements were performed on porenrial formation along the mahnetic field lines in a loboratory plasma. A collisionless plasma, produced by surface ionization of k atoms on a hot tungsten plate heated up to about 2300k, was confined by a strong axial magnetic field with mirror configuration. The plasma flow speed V was varied in the wide range of V_o/C_s(C_s: ion acoustic speed)
The plasma potential is found to increase in the region where the magnetic field lines are converged, being consistent with theoretical prediction based on different pitch angles of electrons and ions. When the plasma front reaches the endplate, howevwe, a big effect of the end- plate is recognized, i.e., for a positive bias potential of the endplate, the plasma potential increase is drastically enhanced. Three-dimensional structure of the potential profile shows a large electric field across the magnetic field, being similar to that above the auroral oval.
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