1990 Fiscal Year Final Research Report Summary
Investigation of the Characteristics of String-Plasma
| Project/Area Number |
01460251
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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 | Tokai University |
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Principal Investigator |
TANIKAWA Takao R&D Institute, Tokai Univ. Assoc. Prof., 開発技術研究所, 助教授 (70207174)
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| Co-Investigator(Kenkyū-buntansha) |
SUNAKO Katsuhiko School of Science, Tokai Univ. Prof., 理学部, 教授 (50056016)
YABE Eiji R&D Institute, Tokai Univ. Prof., 開発技術研究所, 教授 (70056018)
NANRI Kenzou R&D Institute, Tokai Univ. Prof., 開発技術研究所, 教授 (20056211)
SHINOHARA Motoo R&D Instutute, Tokai Univ. Prof., 開発技術研究所, 教授 (60162616)
TAKAYAMA Kazuo R&D Institute, Tokai Univ. Prof., 開発技術研究所, 教授 (20023690)
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| Project Period (FY) |
1989 – 1990
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| Keywords | String-Plasma / TP-D Type Discharge / Mass Separation / Plasma Sheaths / Ion Cyclotron Resonance / Low-Energy Ion Beams / Diamagnetic Effect of Plasmas / Steady-State High-beta Plasmas |
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| Research Abstract |
Achievements of our two-year research project on string-plasma are summarized below.
1. A technique to produce a new type of filamentary plasma (or "string-plasma") in steady-state has been established by utilizing a TP-D type discharge apparatus. In this plasma, the majority of ion guiding centers are placed in the vicinity of the axis of the plasma column. In order to attain this situation, the following two methods were employed utilizing :
(1) Radial dc-electric fields generated inside cylindrical floating electrodes with an extremely small inner diameter
and
(2) A point-cusp magnetic-field configuration.
2. Detailed measurements of string-plasma revealed several characteristics of this plasma :
(1) The column radius is equal to or less than the ion Larmor radius.
(2) The majority of iow guiding centers lie in the vicinity of the axis of the plasma column ; then, the plasma as a whole appears to rotate diamagnetically.
(3) The profile of the plasma space potential has a steep gradient in the radial direction ; as a result, strong radial dc-electric fields exist across plasma.
(4) In spite of the above peculiar characteristics, string-plasma as a whole is electrically neutral.
3. Applications that utilize the above special characteristics of string-plasma such as the following have been proposed :
(1) Production of impurity-free, low-energy ion-beam or stream applying ion-cyclotron resonance technique to this plasma to separate different mass ion species
and
(2) Production of high-beta steady-state plasma using the efficient diamagnetic effect of string-plasma
Some experiments and computer simulations have been carried out in order to verify the usefulness of these applications.
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