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Tanaka, Hirohiko*; Ono, Noriyasu*; Asakura, Nobuyuki; Tsuji, Yoshiyuki*; Kawashima, Hisato; Takamura, Shuichi*; Uesugi, Yoshihiko*; JT-60U Team
Nuclear Fusion, 49(6), p.065017_1 - 065017_7, 2009/06
Times Cited Count:38 Percentile:78.94(Physics, Fluids & Plasmas)Comparison between fluctuation characteristics at high-field-side (HFS) and low-field-side (LFS) scrape off layers (SOLs) has been made, for the first time, in the L mode plasma of the JT-60U tokamak using reciprocating Langumuir probes. Statistical analysis based on probability distribution function (PDF) was employed to describe intermittent (non-diffusion) transport in SOL plasma fluctuations. The positive bursty events appeared most frequently at LFS midplane associated with blobby plasma transport, then the PDF is strongly skewed positively, while the PDF in HFS SOL is close to Gaussian distribution. Conditional averaging analysis of the positive bursty events at LFS midplane indicates the intermittent feature with a rapid increase and a slow decay is similar to that of plasma blobs theoretically predicted. Statistical self-similarity was also investigated with Fourier power spectrum and statistics of waiting-time and duration-time of the fluctuation.
Asakura, Nobuyuki; Ono, Noriyasu*; Kawashima, Hisato; Miyoshi, Hideaki*; Matsunaga, Go; Oyama, Naoyuki; Takamura, Shuichi*; Uesugi, Yoshihiko*; Takechi, Manabu; Nakano, Tomohide; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
Radial transport of the SOL plasma was recently studied in order to understand heat and particle loading to the first wall and the SOL formation mechanism. Fast propagation of the ELM plasma and fluctuation properties in H- and L-modes were determined at low-field-side (LFS) SOL using reciprocating Mach probes in JT-60U. Large and short peaks were found in ELM plasma flux, which was regularly enhanced after each ELM event. Transport dynamics of the first large peak was determined, i.e. it propagated to near the first wall with the fast velocity of 1.3-2.5 km/s. Statistical analysis of a probability distribution function was applied to describe intermittent (non-diffusion) transport in SOL plasma fluctuations. It was found that the positive bursty events appeared in a wide SOL region, where the flow reversal of the SOL plasma was observed. Influences of the radial transport of the convective blobby plasma on the SOL formation and the flow reversal were investigated.
Watanabe, Kazuhiro; Kashiwagi, Mieko; Kawashima, Shuichi*; Ono, Yoichi*; Yamashita, Yasuo*; Yamazaki, Choji*; Hanada, Masaya; Inoue, Takashi; Taniguchi, Masaki; Okumura, Yoshikazu; et al.
Nuclear Fusion, 46(6), p.S332 - S339, 2006/06
Times Cited Count:33 Percentile:71.74(Physics, Fluids & Plasmas)no abstracts in English
Watanabe, Kazuhiro; Higa, Osamu*; Kawashima, Shuichi*; Okumura, Yoshikazu; Ono, Yoichi*; Tanaka, Masanobu*
JAERI-Tech 2000-033, p.72 - 0, 2000/03
no abstracts in English
Matsukawa, Makoto; Miura, Yushi; Terakado, Tsunehisa; Kimura, Toyoaki; Oshima, Iwao*; Kawashima, Shuichi*
Proceedings of International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV 2000), 2, p.415 - 418, 2000/00
no abstracts in English
Matsukawa, Makoto; Miura, Yushi; Kimura, Toyoaki; ; ; Kawashima, Shuichi*
Fusion Technology, 34(3), p.684 - 688, 1998/11
no abstracts in English
Omori, Kenichiro; Usui, Katsutomi; Oshima, Katsumi*; Oga, Tokumichi; Kawai, Mikito; Watanabe, Kazuhiro; Ito, Takao; Kuriyama, Masaaki; Ono, Yoichi*; Kawashima, Shuichi*
Fusion Technology 1998, 1, 4 Pages, 1998/00
no abstracts in English
Watanabe, Kazuhiro; Higa, Osamu*; Kawashima, Shuichi*; Ohara, Yoshihiro; Okumura, Yoshikazu; Ono, Yoichi*; Tanaka, Masanobu*;
JAERI-Tech 97-034, 106 Pages, 1997/07
no abstracts in English
Kato, Takashi; Hamada, Kazuya; Kawano, Katsumi; Matsui, Kunihiro; Hiyama, Tadao; Nishida, Kazuhiko*; Honda, Tadaaki*; Taneda, Masanobu*; Sekiguchi, Shuichi*; Otsu, Kiichi*; et al.
ICEC16/ICMC Proceedings, p.127 - 130, 1996/00
no abstracts in English
Asakura, Nobuyuki; Kawashima, Hisato; Ono, Noriyasu*; Nakano, Tomohide; Takamura, Shuichi*; Uesugi, Yoshihiko*
no journal, ,
no abstracts in English
Asakura, Nobuyuki; Ono, Noriyasu*; Kawashima, Hisato; Matsunaga, Go; Oyama, Naoyuki; Nakano, Tomohide; Takamura, Shuichi*; Uesugi, Yoshihiko*
no journal, ,
no abstracts in English
Asakura, Nobuyuki; Kawashima, Hisato; Ono, Noriyasu*; Nakano, Tomohide; Takamura, Shuichi*; Uesugi, Yoshihiko*
no journal, ,
Measurement of visible image emitted during its ablation started since 2006, using a fast TV camera located at tangential port in the JT-60U tokamak. Typical frame rate of the TV camera was between 2 kHz and 8 kHz. Trajectory and velocity of emission during dust ablation were measured in ELMy H-mode plasmas. Trajectory of the ablating dust corresponded to a few meter (near-poloidal case) to several meters (near-toroidal case), and toroidal or poloidal velocity was evaluated to be 0.2-0.5 km/s. In divertor, many dusts were observed in inner divertor just after ELM events, in particular, for the inner strike-point located above the normal operations. Toroidal movement of the dusts (ion drift side) was seen frequently and velocity was 0.2-0.4 km/s, which was similar to those at main chamber. Specific movement of dusts was sometimes seen in outer divertor when ELM occurred: dust moved towards separatrix (inboard), then the direction changed away from separatrix (outboard).
Asakura, Nobuyuki; Ono, Noriyasu*; Kawashima, Hisato; Matsunaga, Go; Oyama, Naoyuki; Takechi, Manabu; Nakano, Tomohide; Takamura, Shuichi*; Uesugi, Yoshihiko*
no journal, ,
no abstracts in English
Asakura, Nobuyuki; Kawashima, Hisato; Ono, Noriyasu*; Takechi, Manabu; Matsunaga, Go; Oyama, Naoyuki; Nakano, Tomohide; Takamura, Shuichi*; Uesugi, Yoshihiko*
no journal, ,
no abstracts in English