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Ichimura, Makoto*; Higaki, Hiroyuki*; Kakimoto, Shingo*; Yamaguchi, Yusuke*; Nemoto, Kenju*; Katano, Makoto*; Kozawa, Isao*; Muro, Taishi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
Fusion Science and Technology, 51(2T), p.150 - 153, 2007/02
Times Cited Count：1 Percentile：11.32(Nuclear Science & Technology)In magnetically confined plasmas, fluctuations in the ion cyclotron range of frequency (ICRF) will be driven by the presence of non-thermal ion energy distribution. In strong ICRF heating experiments on the GAMMA 10 tandem mirror, plasmas with a strong temperature anisotropy have been formed. Alfven-ion-cyclotron (AIC) modes are spontaneously excited due to strong temperature anisotropy. High-energy ions are trapped in the local mirror and will form the velocity distribution with the strong anisotropy. To study the relation among the AIC modes, ICEs and beam-driven electrostatic instabilities with non-thermal energy distribution is the main purpose of this work. When the NBs are injected, the magnetic fluctuations due to injected beams and FP ions are detected by ICRF antennas used as pickup loops on JT-60U. The wave excitation near ion cyclotron and its higer harmonic frequencies are studied experimentally and theoretically in plasmas with non-thermal ion energy distribution.
Ichimura, Makoto*; Higaki, Hiroyuki*; Yamaguchi, Yusuke*; Nemoto, Tatsuki*; Katano, Makoto*; Motegi, Yukimi*; Kozawa, Isao*; Muro, Taishi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
no journal, ,
The wave excitation in the ion cyclotron range of frequency (ICRF) is strongly affected by the boundary conditions. The formation of eigenmodes depends on the plasma parameters, their spatial profiles, the magnetic field profile and so on. The main subject of this presentation is the establishment of plasma diagnostics with ICRF waves. In GAMMA 10, the injection of low power ICRF waves into the plasma as active diagnostics has been tested. The preliminary results are reported. In JT-60U, the ion cyclotron emissions (ICEs) due to high energy ions from the neutral beam injections and the fusion reactions have been clearly observed. The frequency spectra of ICEs also depend on the plasma parameters. ICEs for passive diagnostic tools are discussed.
Katano, Makoto*; Ichimura, Makoto*; Yamaguchi, Yusuke*; Motegi, Yukimi*; Muro, Taishi*; Ouchi, Toshiaki*; Oishi, Junya*; Sato, Shoichi*; Ishikawa, Masao; Moriyama, Shinichi; et al.
no journal, ,
The understanding of spontaneously excited waves in plasmas with anisotropic velocity distributions is the main purpose of this presentation. In JT-60U, the ion cyclotron emissions (ICEs) due to fusion product ions have been experimentally observed. By using the local dispersion relation in hot plasmas, the excitation of slow and fast Alfv
n waves are evaluated. The excitation mechanism for ICEs due to fusion product ions are discussed.
Ichimura, Makoto*; Yamaguchi, Yusuke*; Sato, Shoichi*; Katano, Makoto*; Ouchi, Toshiaki*; Muro, Taishi*; Sekihara, Yusuke*; Murakami, Tatsuya*; Moriyama, Shinichi; Kobayashi, Takayuki; et al.
no journal, ,
Fluctuations in the ion cyclotron range of frequency are investigated both on GAMMA 10 and JT-60U. Ion cyclotron emissions (ICEs) due to deuterium-deuterium fusion-product (FP) ions on JT-60U are described. ICE due to H-ions is newly identified. ICE(T) with lower frequency has larger wave numbers than ICE (
He) in the same discharge. The excitation of slow Alfvn waves is elucidated for the first time as the mechanism for ICE due to T-ions. The anisotropy of T-ions at the outer plasma edge is evaluated by using Escape Particle Orbit analysis Code (EPOC).
