| Project/Area Number |
03680004
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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 | University of Tokyo, |
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Principal Investigator |
YOSHIDA Zensho University of Tokyo, Department of Nuclear Engineering, Associate Professor, 工学部, 助教授 (80182765)
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| Co-Investigator(Kenkyū-buntansha) |
MORIKAWA Junji University of Tokyo, Department of Nuclear Engineering, Techincal Staff, 工学部, 教務職員 (70192375)
NIHEI Hitoshi University of Tokyo, Departmwnt of Nuclear Engineering, Research Associate, 工学部, 助手 (70010973)
OGAWA Yuichi University of Tokyo, Department of Nuclear Engineering, Associate Professor, 工学部, 助教授 (90144170)
INOUE Nobuyuki University of Tokyo, Department of Nuclear Engineering, Professor, 工学部, 教授 (60023719)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Plasma / Turbulence / Chaos / Anomalous Transports / Helicity / MHD relaxation / ヘリシティ- / 異常加熱 |
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| Research Abstract |
Heat and particle transports which are associated with the helicity transport are obtained in a current-carrying plasma. The helicity flux represents the transport of parallel current density and is produced by an electric field with a circularly polarized component. Fluctuations with circularly polarized components induce finite average in cross-field nonlinear parallel current, which leads to generation of frictional electron heat flux as well as ion nonlinear polarization current which produces particle flux. The circular polarization of the perturbed electric field thus relates the helicity flux, electron heat flux and the particle flux in such a manner that the heat and the particle transports in the direction opposite to the helicity flux. This result applies whether the helicity is injected externally by oscillating fields or it is generated internally in the plasma.
In the magnetohydrodynamic relaxation accompanying fast reconnections, magnetic fluctuations originating from kink-type instabilities yield a finite magnetic compression, and the corresponding transverse electric field is dissipated through the transit-time damping. This dissipation mechanism does not change the helicity, while it dissipates the fluctuation energy to result in direct heating of ions. This is in contrast to a slow relaxation process based on the tearing mode turbulence, where the parallel electric field is predominantly dissipated, which accompanies preferential heating of electrons and dissipation of the helicity.
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