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Ido, Takeshi*; Miura, Yukitoshi; Kamiya, Kensaku; Hamada, Yasuji*; Hoshino, Katsumichi; Fujisawa, Akihide*; Ito, Kimitaka*; Ito, Sanae*; Nishizawa, Akimitsu*; Ogawa, Hiroaki; et al.
Plasma Physics and Controlled Fusion, 48(4), p.S41 - S50, 2006/04
Times Cited Count:127 Percentile:96.74(Physics, Fluids & Plasmas)The potential and density fluctuations of Geodesic-Acoustic-Mode (GAM) were investigated through the direct and simultaneous measurement of electrostatic and density fluctuations with a heavy ion beam probe(HIBP). It was found that the amplitude of the fluctuation has a maximum inside of the plasma boundary and that it has an almost constant frequency. It was also found that the mode propagates in the radial direction and that the GAM affects the background turbulence. The influence to the background turbulence was found to be in consistent with a theoretical prediction.
Kamiya, Kensaku; Oyama, Naoyuki; Ido, Takeshi*; Bakhtiari, M.*; JFT-2M Group
Physics of Plasmas, 13(3), p.032507_1 - 032507_9, 2006/03
Times Cited Count:13 Percentile:42.48(Physics, Fluids & Plasmas)Accompanying the HRS H-mode transition, the coherent magnetic fluctuations in the frequency range of the order of 10-100 kHz with significant variation are seen on the magnetic probes at the vessel wall. Above all, two types of edge MHD activities, which have associated toroidal mode number of n=1 and n7, respectively, seem to be more important for the HRS H-mode plasmas. To investigate their interaction, bi-spectral analysis is applied for the magnetic probe data. It is found to be a powerful tool, exhibiting the phase-coupled oscillations between two types of edge MHD activities having n=1 and n
7.
Hoshino, Katsumichi; Yamamoto, Takumi; Tamai, Hiroshi; Oasa, Kazumi; Kawashima, Hisato; Miura, Yukitoshi; Ogawa, Toshihide; Shoji, Teruaki*; Shibata, Takatoshi; Kikuchi, Kazuo; et al.
Fusion Science and Technology, 49(2), p.139 - 167, 2006/02
Times Cited Count:2 Percentile:17.58(Nuclear Science & Technology)The main results obtained by the various heating and current drive systems, external coil system and divertor bias system are reviewed from the viewpoint of the advanced active control of the tokamak plasma. Also, the features of each system are described. The contribution of the JFT-2M in these areas are summarized.
Kamiya, Kensaku; Kawashima, Hisato; Ido, Takeshi*; Oyama, Naoyuki; Bakhtiari, M.*; Kasai, Satoshi; Kusama, Yoshinori; Miura, Yukitoshi; Ogawa, Hiroaki; Tsuzuki, Kazuhiro; et al.
Nuclear Fusion, 46(2), p.272 - 276, 2006/02
Times Cited Count:3 Percentile:11.03(Physics, Fluids & Plasmas)An attractive operational regime without any large ELMs, namely High Recycling Steady (HRS) H-mode, was found on JFT-2M during Y2000 campaign after boronization. Recent experiments have concentrated on the studies of the access conditions for the HRS regime, in terms of the pedestal parameters. The HRS regime was more likely at higher edge density and lower edge temperature, which corresponds to the normalized electron collisionality of 1 in the plasma edge region.
Nagashima, Yoshihiko*; Hoshino, Katsumichi; Ejiri, Akira*; Shinohara, Koji; Takase, Yuichi*; Tsuzuki, Kazuhiro; Uehara, Kazuya; Kawashima, Hisato; Ogawa, Hiroaki; Ido, Takeshi*; et al.
Physical Review Letters, 95(9), p.095002_1 - 095002_4, 2005/08
Times Cited Count:100 Percentile:92.73(Physics, Multidisciplinary)By a reciprocating electrostatic probe, two types of low frequency coherent electrostatic modes (about1kHz and 10-15kHz) are found,for the first time, in the edge region of ohmically heated plasmas in the JFT-2M tokamak. These modes exists in the last closed surface. The higher frequency mode has features of the geodesic acoustic mode (GAM), though the low frequency mode is not identified yet. A bispectral analysis revealed that significant nonlinear couplings (parametric modulation) between these coherent fluctuations and broadband background turbulent potential fluctuations occur. In the other words, the GAM and the back ground turbulence are modulated by the newly found low frequency electrostatic mode (further, the GAM modulates the background turbulence, also) for the first time. The newly found low frequency mode (frequency about 1kHz) is supposed to contribute to the turbulent diffusion nonlinearly.
Kamiya, Kensaku; Oyama, Naoyuki; Miura, Yukitoshi; Hubbard, A. E.*
Plasma Physics and Controlled Fusion, 46(11), p.1745 - 1755, 2004/11
Times Cited Count:13 Percentile:40.92(Physics, Fluids & Plasmas)Recent experiments in the JFT-2M tokamak have concentrated on the studies of the access condition for the H-mode operation without any large ELMs, namely High Recycling Steady (HRS) H-mode regime in terms of the pedestal parameters. The HRS regime is more likely at the higher edge density and lower edge temperature, while the ELMy H-mode having large ELMs appears at the lower edge density and higher edge temperature. It is found that the ELMy/HRS operational boundary occurs at the normalized electron collisionality of *
1 in the plasma edge region, depending slightly on q
. A key feature of the HRS H-mode is the presence of the coherent magnetic fluctuations in the frequency range of the order of 10-100 kHz. It is suggested that the edge MHD activities may keep an edge pressure below a certain level needed to induce a large ELM.
Miura, Yukitoshi; Hoshino, Katsumichi; Kusama, Yoshinori
Purazuma, Kaku Yugo Gakkai-Shi, 80(8), p.653 - 661, 2004/08
A series of experimental program on the JAERI Fusion Torus-2M (JFT-2M) was completed in March, 2004. In the experimental operation for 21 years since the first plasma on April 27, 1983, many significant results leading the fusion energy research and plasma physics have been produced in researches on high confinement mode (H-mode), heating and current drive, advanced plasma control, compatibility of low activation ferritic steel with improved confinement mode, etc. Among these results, some important results are presented.
Hoshino, Katsumichi; Nagashima, Yoshihiko*; Ido, Takeshi*; Tsuzuki, Kazuhiro; Kawashima, Hisato; Ogawa, Hiroaki; Bakhtiari, M.; Shinohara, Koji; Uehara, Kazuya; Oasa, Kazumi; et al.
Journal of Plasma and Fusion Research SERIES, Vol.6, p.345 - 348, 2004/00
no abstracts in English
Kamiya, Kensaku; Kimura, Haruyuki; Ogawa, Hiroaki; Kawashima, Hisato; Tsuzuki, Kazuhiro; Sato, Masayasu; Miura, Yukitoshi; JFT-2M Group
Nuclear Fusion, 43(10), p.1214 - 1219, 2003/10
no abstracts in English
Kamiya, Kensaku; Kimura, Haruyuki; Ogawa, Hiroaki; Kawashima, Hisato; Tsuzuki, Kazuhiro; Sato, Masayasu; Miura, Yukitoshi; JFT-2M Group
Nuclear Fusion, 43(10), p.1214 - 1219, 2003/10
Times Cited Count:35 Percentile:71.63(Physics, Fluids & Plasmas)no abstracts in English
Kamiya, Kensaku; Miura, Yukitoshi; Ido, Takeshi*; Hamada, Yasuji*
Review of Scientific Instruments, 74(9), p.4206 - 4208, 2003/09
Times Cited Count:0 Percentile:0.01(Instruments & Instrumentation)no abstracts in English
Kamiya, Kensaku; Kimura, Haruyuki; Ogawa, Hiroaki; Kawashima, Hisato; Tsuzuki, Kazuhiro; Isei, Nobuaki; Sato, Masayasu; Shinohara, Koji
Purazuma, Kaku Yugo Gakkai-Shi, 78(12), p.1361 - 1367, 2002/12
no abstracts in English
Yamamoto, Kenzo*; Koizumi, Koichi
JAERI-Review 2002-023, 156 Pages, 2002/09
no abstracts in English
Kamiya, Kensaku; Kimura, Haruyuki; Hoshino, Katsumichi; Isei, Nobuaki; Kawashima, Hisato; Ogawa, Hiroaki; Ogawa, Toshihide; Tsuzuki, Kazuhiro; Uehara, Kazuya; JFT-2M Group
Review of Scientific Instruments, 72(7), p.2931 - 2935, 2001/07
Times Cited Count:6 Percentile:40.52(Instruments & Instrumentation)no abstracts in English
Kamiya, Kensaku; Miura, Yukitoshi
JAERI-Tech 2000-090, 17 Pages, 2001/02
no abstracts in English
Kamiya, Kensaku; Miura, Yukitoshi; Tsuzuki, Kazuhiro; Ido, Takeshi*; Hamada, Yasuji*; Nakayama, Takeshi*
Review of Scientific Instruments, 72(1), p.579 - 582, 2001/01
Times Cited Count:2 Percentile:20.39(Instruments & Instrumentation)no abstracts in English
W.Liu*; Miura, Yukitoshi; JFT-2M Group
Purazuma, Kaku Yugo Gakkai-Shi, 74(7), p.753 - 757, 1998/07
no abstracts in English
Shinohara, Koji; Miura, Yukitoshi; Hoshino, Katsumichi
Purazuma, Kaku Yugo Gakkai-Shi, 74(6), p.607 - 615, 1998/06
no abstracts in English
Miura, Yukitoshi; Nagashima, Keisuke; Ito, Kimitaka; Ito, Sanae*; Okano, Fuminori; Suzuki, Norio; Mori, Masahiro; Hoshino, Katsumichi; Maeda, Hikosuke; Takizuka, Tomonori; et al.
Plasma Physics and Controlled Fusion, 36(7A), p.A81 - A86, 1994/07
Times Cited Count:5 Percentile:24.48(Physics, Fluids & Plasmas)no abstracts in English
Miura, Yukitoshi; Okano, Fuminori; Suzuki, Norio; Mori, Masahiro; Hoshino, Katsumichi; Maeda, Hikosuke; Takizuka, Tomonori; JFT-2M Group; Ito, Sanae*; Ito, Kimitaka
NIFS-134, 20 Pages, 1992/02
no abstracts in English