Speaker
Prof.
Kazunobu Nagasaki
(Institute of Advanced Energy, Kyoto University)
Description
Experiments of suppressing Alfvén Eigenmodes (AE) have been made by using a second harmonic X-mode electron cyclotron current drive (ECCD) in the helical-axis heliotron device, Heliotron J. The weak magnetic shear under vacuum condition is modified into a positive magnetic shear when counter-ECCD is applied. The experiments show that global Alfvén eigenmodes (GAE) of around 130 kHz and 350 kHz are fully stabilized, and energetic particle modes (EPM) of around 100 kHz are weakened when the EC current of 0.7 kA is driven on axis. The mode amplitude is more reduced as the EC current is larger. These results indicate that the magnetic shear has an effective role in controlling GAEs as well as EPMs. This study extends the possibility of ECH/ECCD as a control knob for EP-driven MHD modes and give understanding of the excitation and damping mechanisms.
| Country or International Organization | Japan |
|---|---|
| Paper Number | EX/P8-19 |
Primary author
Prof.
Kazunobu Nagasaki
(Institute of Advanced Energy, Kyoto University)
Co-authors
Dr
Gavin Weir
(Max-Planck Institute)
Mr
Hideki Kishikawa
(Graduate School of Energy Science, Kyoto University)
Mr
Hirotsugu Matsuda
(Graduate School of Energy Science)
Dr
Hiroyuki Okada
(Institute of Advanced Energy, Kyoto University)
Mr
Kinzo Sakamoto
(Institute of Advanced Energy, Kyoto University)
Mr
Naoki Kenmochi
(Graduate School of Energy Science, Kyoto University)
Dr
Nikolai Marushchenko
(Max-Planck Institute)
Mr
Nutchaphol Inklin
(Graduate School of Energy Science, Kyoto University)
Dr
Satoshi Yamamoto
(Institute of Advanced Energy, Kyoto University)
Dr
Shigeru Konoshima
(Institute of Advanced Energy, Kyoto University)
Dr
Shinichiro Kado
(Institute of Advanced Energy, Kyoto University)
Dr
Shinji Kobayashi
(IAE, Kyoto Univ.)
Dr
Shinsuke OHSHIMA
(Kyoto University)
Dr
Takashi Minami
(Institute of Advanced Energy, Kyoto University)
Dr
Tohru MIZUUCHI
(Institute of Advanced Energy, Kyoto University)
Mr
Xiangxun Lu
(Graduate School of Energy Science, Kyoto University)
Mr
Yoshiaki Otani
(Graduate School of Energy Science, Kyoto University)
Prof.
Yuji Nakamura
(Graduate School of Energy Science)
