| Project/Area Number |
60580002
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | The University of Tokyo |
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Principal Investigator |
KANEKO Shobu Faculty of Engineering, The University of Tokyo; Associate Professor, 工学部, 助教授 (70010717)
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| Co-Investigator(Kenkyū-buntansha) |
TAGICHI Masayoshi Faculty of Engineering, The University of Tokyo; Assistant, 工学部, 助手 (30154959)
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| Project Period (FY) |
1985 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1985: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Spheromak / Compact Toroid / MHD Equilibrium / MHD Stability / Resistive Instability / 輸送現象 / プラズマ / 閉じ込め / 安定性 |
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| Research Abstract |
The stability analysis by the ideal magnetohydrodynamic (MHD) plays an important role to investigate the resistive instabilities of a plasma. Hence, we need investigate the ideal MHD stability of the spheromak by use of a realistic model. The following investigations were made for this purpose.
1. We investigated how the Mercier criterion is useful to analyze the stability of the spheromak and found that it gives a good criterion for internal modes other than kink modes.
2. The flux conserver (FC) has a hole and a duct to introduce the plasma into it, and also has an external coil to close all the magnetic surfaces in FC. THE MHD equilibrium configurations in such a complex region are determined by using the boundary fitted curvilinear coordinate system. The stabilities of them are investigated by use of the Mercier criterion. As results of computations, we obtained the plasma confinement is improved considerably by the external coil current, and the improvement is larger when a center conductor is installed in FC. Experimental results show all the magnetic surfaces are surely closed when the external coil current is applied. However, the life time of the plasma does not change appreciably whether the center conductor is installed or not. Measurements of the magnetic field distribution revealed there exists a region near the symmetric axis, where no toroidal magnetic field is found. We call this region ther flux hole (FH).
3. We investigated the effect of FH on the stability of the spheromak and found that it has a stabilizing effect. We made other investigations. For examples,
4. the resistive instabilities of the spheromak by using Glasser, Green and Johnson's results, and 5. the effects of trapped particles on the transport phenomena. About detailed points, see the report on the results obtained by this Grant-in-Aid.
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