Speaker
Mr
Kazuo Toi
(Japan)
Description
The Large Helical Device (LHD) produces H-mode plasmas with large amplitude edge-localized-modes (ELMs). The ELMs are induced by interchange modes destabilized at the iota=1 rational surface in the stochastic field region just outside the last closed flux surface. These large amplitude ELMs expel large amount of plasma stored energy from the edge transport barrier (ETB) region, that is, up to 20% of the stored energy (W_p). Resonant magnetic perturbations (RMPs) with dominant m=1/n=1 component have clearly reduced the ELM amplitude and increased the ELM frequency. In this mitigated case, the energy loss by an ELM pulse is reduced less than 5% of W_p. The RMPs have reduced edge electron density preferentially, without modifying electron and ion temperature profiles noticeably. The RMPs slightly reduced the confinement improvement factor H averaged over ELMing phase for the ISS04 stellarator scaling having gyro-Bohm character.
Country or International Organization of Primary Author
Japan
Primary author
Mr
Kazuo Toi
(Japan)
Co-authors
Dr
Fumitake Watanabe
(Kyoto University)
Prof.
Hiroshi Yamada
(National Institute for Fusion Science)
Dr
Ichihiro Yamada
(National Institute for Fusion Science)
Prof.
Katsumi Ida
(National Institute for Fusion Science)
Prof.
Kazumichi Narihara
(National Institute for Fusion Science)
Prof.
Kazuo Kawahata
(National Institute for Fusion Science)
Dr
Kenji Tanaka
(National Institute for Fusion Science)
Dr
Kunihiro Ogawa
(Nagoya University)
Dr
Mikiro Yoshinuma
(National Institute for Fusion Science)
Dr
Mitsutaka Isobe
(National Institute for Fusion Science)
Dr
Motoshi Goto
(National Institute for Fusion Science)
Dr
Ryo Yasuhara
(National Institute for Fusion Science)
Dr
Satoru Sakakibara
(National Institute for Fusion Science)
Dr
Satoshi Ohdachi
(National Institute for Fusion Science)
Prof.
Shigeru Morita
(National Institute for Fusion Science)
Dr
Suguru Masuzaki
(National Institute for Fusion Science)
Dr
Tokihiko Tokuzawa
(National Institute for Fusion Science)
Dr
Tomohiro Morisaki
(National Institute for Fusion Science)
Dr
Tsuyoshi Akiyama
(National Institute for Fusion Science)
Mr
Xiaodi Du
(The Graduate University for Advanced Study)
Dr
Yasuhiro Suzuki
(National Institute for Fusion Science)
Dr
Yoshiro Narushima
(National Institute for Fusion Science)
