Resistive interchange modes destabilized by helically trapped energetic ions in a helical plasma.
A new bursting m=1/n=1 instability (m,n: poloidal and toroidal mode numbers) with rapid frequency chirping down has been observed for the first time in a helical plasma with intense perpendicular neutral beam injection. This is destabilized in the plasma peripheral region by resonant interaction between helically trapped energetic ions and the resistive interchange mode. A large radial electric field is induced near the edge due to enhanced radial transport of the trapped energetic ions by the mode, and leads to clear change in toroidal plasma flow, suppression of microturbulence, and triggering an improvement of bulk plasma confinement.
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.
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Du
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Toi
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Osakabe
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Ohdachi
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Ido
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Tanaka
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Yokoyama
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Yoshinuma
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Ogawa
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Watanabe
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Isobe
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Nagaoka
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Ozaki
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Sakakibara
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Seki
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Shimizu
Department of Fusion Science, The Graduate University for Advanced Study, 509-5292 Toki, Japan.|National Institute for Fusion Science, 509-5292 Toki, Japan.
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Suzuki
National Institute for Fusion Science, 509-5292 Toki, Japan.
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Tsuchiya