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Urano, Hajime; Kamiya, Kensaku; Koide, Yoshihiko; Takizuka, Tomonori; Oyama, Naoyuki; Kamada, Yutaka; JT-60 Team
Plasma Physics and Controlled Fusion, 48(5A), p.A193 - A199, 2006/05
Times Cited Count：10 Percentile：32.46(Physics, Fluids & Plasmas)The characteristics of the H-mode pedestal structure were investigated by conducting the power scans for a variation of the toroidal momentum sources at different toroidal field ripple in JT-60U. It was found that the pedestal pressure is increased by reduced loss power of fast ions, independently of toroidal rotation. However, the energy confinement is improved with the CO-directed toroidal momentum source at H-mode plasmas with small ripple loss.
Furukawa, Masaru; Tokuda, Shinji
Nuclear Fusion, 45(5), p.377 - 383, 2005/05
Times Cited Count：12 Percentile：37.36(Physics, Fluids & Plasmas)A ballooning perturbation in a toroidally rotating tokamak is expanded by square-integrable eigenfunctions of an eigenvalue problem associated with ballooning modes in a static plasma. Especially a weight function is chosen such that the eigenvalue problem has only the discrete spectrum. The eigenvalues evolve in time owing to toroidal rotation shear, resulting in countably infinite number of crossings among them. The crossings cause energy transfer from an unstable mode to the infinite number of stable modes; such transfer works as the stabilization mechanism of the ballooning mode. A simple analytic formula is derived for estimating the toroidal rotation shear required to stabilize the ballooning mode.
Furukawa, Masaru; Tokuda, Shinji
Physical Review Letters, 94(17), p.175001_1 - 175001_4, 2005/05
Times Cited Count：20 Percentile：67.40(Physics, Multidisciplinary)A ballooning perturbation in a toroidally rotating tokamaks is expanded by square-integrable eigenfunctions of an eigenvalue problem associated with ballooning modes in a static plasma. Especially a weight function is chosen such that the eigenvalue problem has only the discrete spectrum. The eigenvalues evolve in time owing to toroidal rotation shear, resulting in countably infinite number of crossings among them. The crossings cause energy transfer from an unstable mode to the infinite number of stable modes; such transfer works as the stabilization mechanism of the ballooning mode.
Furukawa, Masaru; Tokuda, Shinji; Wakatani, Masahiro*
Plasma Physics and Controlled Fusion, 46(2), p.409 - 421, 2004/02
Times Cited Count：7 Percentile：21.86(Physics, Fluids & Plasmas)In the H-mode (high-confinement mode) pedestal region of a static or a toroidally rotating D-shaped tokamak plasma, the separatrix or the X-point affects the high-n ballooning stability (n: toroidal mode number) only in a thin layer in the pedestal region. Therefore, D-shaping effectively stabilizes the ballooning modes even for a toroidally rotating plasma with a separatrix.
Furukawa, Masaru; Tokuda, Shinji
Journal of Plasma and Fusion Research SERIES, Vol.6, p.210 - 213, 2004/00
A model equation for ballooning modes in toroidally rotating tokamaks is derived. It is confirmed that the model equation is appropriate for analyzing the stabilization mechanism of the ballooning modes by comparing the numerical solutions of the model equation with those of the original ballooning equations.
Koide, Yoshihiko; Ishida, Shinichi; Sakasai, Akira; Shirai, Hiroshi; Hirayama, Toshio; Kubo, Hirotaka; Sugie, Tatsuo;
Nuclear Fusion, 33(2), p.251 - 261, 1993/00
Times Cited Count：14 Percentile：46.74(Physics, Fluids & Plasmas)no abstracts in English
Narita, Emi*; Honda, Mitsuru; Hayashi, Nobuhiko; Urano, Hajime; Ide, Shunsuke; Fukuda, Takeshi*
no journal, ,
no abstracts in English
