1992 Fiscal Year Final Research Report Summary
Study of Direct Excitation of Shear Alfven and its Development to Nonlinear Phenomena
| Project/Area Number |
03452283
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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 | Shizuoka University |
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Principal Investigator |
AMAGISHII Yoshimitsu Shizuoka University, Faculty of Liberal Arts, Professor, 教養部, 教授 (10042409)
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| Co-Investigator(Kenkyū-buntansha) |
MIENO Tetsu Shizuoka University, faculty of Science, Associate Professor, 理学部, 助教授 (50173993)
SAEKI Kohichi Shizuoka University, Faculty of Liberal Arts, Professor, 教養部, 教授 (90005546)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Alfven wave / magnetohydrodynamic wave / Alfven resonance / Heating and acceleration of particle / Kramers-Kronig relation |
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| Research Abstract |
From the basic point of view of the waves in magnetohydrodynamics, we had the first aim to solve whether the shear Alfven waves can be excited directly or not. The reason why we had such a question is that the most shear Alfven waves excited so far in laboratories including ours are generated "indirectly" from the mode conversion from compressional Alfven waves(MHD surface waves). Such conclusion has been unveiled from our long research concerned with the coupling of shear Alfven waves with compressional waves. Therefore, we study the direct excitation in connection with such mode conversion phenomena.
During the research in two years, we have succeeded to directly excite the shear Alfven waves by developing a small and special antenna, and moreover, we have found a new phenomenum as follows; the m = 0 shear Alfven wave excited directly suffers at frequency below omega i from strong absorption owing to the collision with neutral particles, connecting its dispersion relation to that of the compressional Alfven wave. Near the absorption region, we found the Kramers-Kronig relation between real part and imaginary part of the dielectric function. This is the first experiment to find such a relation in the field of plasma physics.
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