1998 Fiscal Year Final Research Report Summary
Generation and propagation of electromagnetic waves resonantly excited by a heating wave near the electron cyclotron frequency.
| Project/Area Number |
09480089
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
プラズマ理工学
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| Research Institution | KYOTO UNIVERSITY (1998)
University of Tsukuba (1997) |
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Principal Investigator |
KIWAMOTO Yasuhito Kyoto University, Fac.of Integrated Human Stucies professor, 総合人間学部, 教授 (50018040)
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| Co-Investigator(Kenkyū-buntansha) |
YUYAMA Tetsumori Kyoto University, Fac.of Integrated Human Studies Research Associate, 総合人間学部, 助手 (90026815)
TATEMATSU Yoshinori University of Tsukuba, Institute of Physics Assistant Professor, 物理学系, 講師 (50261756)
SAITO Teruo University of Tsukuba, Institute of Physics Associate Professor, 物理学系, 助教授 (80143163)
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| Project Period (FY) |
1997 – 1998
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| Keywords | plasma / electron cyclotron heating / resonance / cyclotron emission / nonlinear wave / phase-bunching / orbit-modification / プラズマ |
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| Research Abstract |
In electron cyclotron heating (ECH) of tenuous plasmas in a magnetic beach configuration, two resonant processes complicates physical analyses, i.e. divergent increase of the parallel wave number and synchronized acceleration of increasing number of resonantly gyrating electrons. In this task, we have made a new trial to look into the process in terms of frequency-spectrum-analyses of electromagnetic waves excited in the cyclotron range under the stimulation of a strong monochromatic heating wave.
We have constructed a compact sensitive diagnostic system that fit in a narrow accessible pace for diagnoses of a hot plasma in a tandem mirror, We have observationally confirmed a broad-band spectrum that is attributable to cyclotron emissions by individual hot electrons.
New finding in this research is a strong narrow band spectrum at a few per-cent above the heating wave frequency. The peak frequency and the width decreases with increasing power of the heating wave, and the spectral structure depends on the magnetic field profile. We conclude that this narrow-band wave is generated by a resonant group of electrons which are phase-modulated in the velocity space under ECU and spatially bunched in the magnetic slope to generate coherent emissions at the local cyclotron frequency.
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