(EX/P2-18) Study on Ion Temperature Behaviors in Electron and Ion Heating Regimes of ECH, ICRF and NBI Discharges in LHD
S. Morita1),
M. Goto1),
Y. Takeiri1),
J. Miyazawa1),
S. Murakami1),
K. Narihara1),
M. Osakabe1),
T. Akiyama2),
N. Ashikawa1),
M. Emoto1),
M. Fujiwara1),
H. Funaba1),
P. Goncharov3),
Y. Hamada1),
K. Ida1),
H. Idei1),
T. Ido1),
K. Ikeda1),
S. Inagaki1),
M. Isobe1),
K. Itoh1),
O. Kaneko1),
K. Kawahata1),
H. Kawazome4),
K. Khlopenkov1),
T. Kobuchi1),
A. Komori1),
A. Kostrioukov1),
S. Kubo1),
R. Kumazawa1),
Y. Liang1),
S. Masuzaki1),
K. Matsuoka1),
T. Minami1),
T. Morisaki1),
O. Motojima1),
S. Muto1),
T. Mutoh1),
Y. Nagayama1),
Y. Nakamura1),
H. Nakanishi1),
Y. Narushima1),
K. Nishimura1),
A. Nishizawa1),
N. Noda1),
T. Notake5),
H. Nozato6),
S. Ohdachi1),
K. Ohkubo1),
N. Ohyabu1),
Y. Oka1),
T. Ozaki1),
B.J. Peterson1),
A. Sagara1),
T. Saida3),
K. Saito1),
S. Sakakibara1),
R. Sakamoto1),
M. Sasao1),
K. Sato1),
M. Sato1),
T. Satow1),
T. Seki1),
T. Shimozuma1),
M. Shoji1),
S. Sudo1),
H. Suzuki1),
N. Takeuchi5),
N. Tamura1),
K. Tanaka1),
K. Toi1),
T. Tokuzawa1),
Y. Torii5),
K. Tsumori1),
T. Uda1),
K.Y. Watanabe1),
T. Watari1),
Y. Xu1),
H. Yamada1),
I. Yamada1),
S. Yamamoto5),
T. Yamamoto5),
K. Yamazaki1),
M. Yokoyama1),
Y. Yoshimura1),
M. Yoshinuma1)
1) National Institute for Fusion Science, Toki, Japan
2) Research Laboratory for Nuclear Reactors, Tokyo, Institute of Technology, Tokyo, Japan
3) Department of Fusion Science, School of Mathematical and Physical Science, Graduate University for Advanced Studies, Hayama, Japan
4) Graduate School of Energy Science, Kyoto University, Uji, Japan
5) Department of Energy Engineering and Science, Nagoya University, Japan
6) Graduate School of Frontier Sciences, The University of Tokyo, Japan
Abstract. Experiments in helical devices have been limited so far only in
electron heating regime (
Pi Pe). The heating experiments have been
extensively done in LHD in order to realize ion heating regime (
Pi > Pe) and obtain higher Ti in addition to understanding of the
heating mechanism. In off-axis ECH heating Ti is much lower than Te
at low-density and becomes equal at
ne = 1013cm- 3. The ion
heating in NBI H2 discharges is entirely inefficient, since the input power
greater than 70% is absorbed by electrons (
Pi Pe,
Pi/ni Pe/ne) because of the high beam energy of 160 keV. In ICRF heating a new operational range of
Ti > Te was established with
successfully performed ion heating regime (
Pi > Pe,
Pi/ni > Pe/ne) and a comparison with ISS-95 scaling suggested an
improvement of heating efficiency of 60%. Neon discharges were tried using
NBI. Pure neon discharges were successfully obtained with the highest Ti of 5 keV and achievement of
Ti > Te. Reasons are discussed. All
Ti data were analyzed as a function of
Pi/ni. Results
indicated a smooth rise with increasing
Pi/ni and suggested an
importance of the direct power input to bulk ions with
revealing the good heating efficiency of the ICRF discharges.
IAEA 2003