TY - JOUR
T1 - First demonstration of rotational transform control by electron cyclotron current drive in large helical device
AU - LHD Experimental Group
AU - Notake, Takashi
AU - Shimozuma, Takashi
AU - Kubo, Shin
AU - Idei, Hiroshi
AU - Ida, Katsumi
AU - Watanabe, Kiyomasa
AU - Sakakibara, Satoru
AU - Yamaguchi, Taiki
AU - Yoshinuma, Mikirou
AU - Kobuchi, Takashi
AU - Inagaki, Shigeru
AU - Tokuzawa, Tokihiko
AU - Yoshimura, Yasuo
AU - Igami, Hiroe
AU - Seki, Tetsuo
AU - Tanaka, Hitoshi
AU - Nagasaki, Kazunobu
N1 - Publisher Copyright:
© 2008 The Japan Society of Plasma Science and Nuclear Fusion Research.
PY - 2008
Y1 - 2008
N2 - An active current drive is a promising technique for improving plasma performances by controlling rotational transform and/or magnetic shear profiles in helical devices. A current drive based on electron cyclotron resonance heating is the most appropriate scheme for this purpose in terms of locality of driven current. Optimum conditions for an efficient electron cyclotron current drive (ECCD) in Large Helical Device (LHD) are being investigated using three-dimensional ray-tracing code, which can simulate propagation and power dissipation of electron cyclotron waves with large parallel refractive index. In the present experiment, inversion of directions of driven plasma current corresponding to injected ECCD modes was demonstrated successfully, and the results could be elucidated by the Fisch-Boozer theory. In addition, clear shifts of rotational transform were observed by motional Stark effect polarimetry. Our findings verified that the ECCD can be used as an effective actuator for controlling the rotational transform and magnetic shear profile in LHD.
AB - An active current drive is a promising technique for improving plasma performances by controlling rotational transform and/or magnetic shear profiles in helical devices. A current drive based on electron cyclotron resonance heating is the most appropriate scheme for this purpose in terms of locality of driven current. Optimum conditions for an efficient electron cyclotron current drive (ECCD) in Large Helical Device (LHD) are being investigated using three-dimensional ray-tracing code, which can simulate propagation and power dissipation of electron cyclotron waves with large parallel refractive index. In the present experiment, inversion of directions of driven plasma current corresponding to injected ECCD modes was demonstrated successfully, and the results could be elucidated by the Fisch-Boozer theory. In addition, clear shifts of rotational transform were observed by motional Stark effect polarimetry. Our findings verified that the ECCD can be used as an effective actuator for controlling the rotational transform and magnetic shear profile in LHD.
KW - Electron cyclotron current drive
KW - Large helical device
KW - Magnetic shear control
KW - Motional stark effect
KW - Rotational transform control
UR - https://www.scopus.com/pages/publications/55349108835
UR - https://www.scopus.com/pages/publications/55349108835#tab=citedBy
U2 - 10.1585/pfr.3.S1077
DO - 10.1585/pfr.3.S1077
M3 - Article
AN - SCOPUS:55349108835
SN - 1880-6821
VL - 3
JO - Plasma and Fusion Research
JF - Plasma and Fusion Research
M1 - S1077
ER -