1995 Fiscal Year Final Research Report Summary
Optimization of Radial Electric Field in Toroidal Plasmas
| Project/Area Number |
06680476
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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 |
Nuclear fusion studies
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
WAKATANI Masahiro Plasma Physics Laboratory, KYOTO UNIV.PROFESSOR, ヘリオトロン核融合研究センター, 教授 (00109357)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Yuji Plasma Physics Laboratory, KYOTO UNIV.Associate Professor, ヘイオトロン核融合研究センター, 助教授 (20198245)
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| Project Period (FY) |
1994 – 1995
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| Keywords | radial electric field / poloidal shea flow / L-H transition / ELM (Edge Localized Mode) / Neoclassical Visoosity / K-H (Kelvin-Helmboltz instobility) / 径電場 |
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| Research Abstract |
For improving the efficiency of high temperature plasma confinement in toroidal devices, it has been shown that the radial electric field or the poloidal shear flow generated by the E * B drift is effective. The L-H transition for confinement improvement may be triggered by the bifurcation of radial electric field in the edge region. We have obtained the following results for the improvement of confinement with the radial electric field.
(1) The interaction between the interchange mode and the poloidal shear flow is considered as the origin of the L-H transition. The modeling of ELM (Edge Localized Mode) observed during the H mode is also possible based on this interaction.
(2) Nonlinear viscosity to determine the poloidal velocity in tokamaks and stellarators is evaluated for studying whether the L-H transition is possible or not in some specific devices. A strategy to obtain the H mode in a stellarator is discussed.
(3) When the velocity shear of poloidal flow becomes large, one negative effect is the excitation of Kelvin-Helmholtz (K-H) instability. The condition for exciting the K-H instability and its nonlinear behavior have been shown for the heliotron device.
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