29D46P
GAMMA 10における極小磁場部高周波加熱に関する研究
Study of ICRF heating in the minimum-B anchor configuration on GAMMA 10
横山拓郎1, 市村真1, 宇賀神ゆめと1, 齋藤裕希1, 福山淳2, 山口裕資3, 平田真史1
池添竜也1, 佐藤達典1 ,飯村拓真1 ,安中裕大1, 白谷飛鳥1, 今井剛1Takuro YOKOYAMA1, Makoto ICHIMURA1, Yumeto UGAJIN1, Yu-ki SAITO1,Atsushi FUKUYAMA2, Yuusuke YAMAGUCHI3, Mafumi HIRATA1, Ryuya IKEZOE1 etal.
プラズマ研究センター1 京都大学 工学研究科原子力工学専攻 2
福井大学 遠赤外領域研究開発センター3
Plasma Research Center, University of Tsukuba1
Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University2
Research Center for Development of Far-Infrared Region, University of Fukui3
筑波大学

Ion Cyclotron Range of Frequency (ICRF)
heating is the main method for ion-heating,producing plasmas, and keeping Magneto
Hydrodynamic (MHD) stability on the GAMMA 10
tamdem mirror device. Two minimum-B anchor
cells connected to both sides of the central cell
supply the MHD stability [1]. In the standard
discharge, the power of radio-frequency waves
excited from the Type-Ⅲ antennas at the both endsof the central cell heat plasmas at the resonancelayer in the minimum-B anchor cells. High pressureplasmas in the central cell are sustained with thehelp of MHD stability. In order to enhance theion-heating, the direct anchor heating has been
introduced experimentally and theoretically with athree-dimensional full wave code, which isdeveloped by one of authors (A. Fukuyama) [2].
In the previous experiment, it has been
confirmed that the antenna loading of the double
arc type (DAT) antenna increases significantly thanthat of the straight bar-type antenna [3]. Figure 1
shows the dependence of the antenna loadingresistance on applied frequency. In the simulation,
the bar-type antenna is drawn as a straight line, thesingle arc type (SAT) antenna is an elliptical arc,and the DAT antenna is an elliptical arc with twofragments. The current through the antenna is set
5.0 A/m in each antenna, so current of 2.5 A/m is
set in each fragments on the case of DAT antenna.
And these antennas are set as current strap withsame width. Results are shown with followingmarkers. Circles are in the case of the bar-typeantenna, triangles are those of the SAT antenna, andsquares are those of DAT antenna. Open points
indicate the results in the case of 1.0×1018 m-3 andthe solid points in the case of 2.0×1018 m-3 at thecore. Then, it is confirmed that density dependenceis small. And it is confirmed that the antennaloading resistance increase twice or more bychanging shape from the straight bar-type antenna
to the elliptical DAT antenna. By using the DAT

Fig. 1. The dependence of the antenna loading
resistance on density and applied frequencies arecalculated with the three-dimensional numeral
simulation. The open and solid symbols correspond tothe case where background core density is 1.0×1018 m-3
and 2.0×1018 m-3, respectively. The circle, triangle andsquare symbols correspond to the bar-type, SAT, andDAT antennas respectively.

antenna, more effective ion-heating in the east (9.9MHz) and west (10.3 MHz) anchor cells have been
observed in the experiment. We evaluate the wave
excitation in the complex magnetic field
configuration with three-dimensional numeral
simulation code.
Reference1.
2.

3.

M. Ichimura et al., Nucl. Fusion 28, 799 (1988).
Y. Yamaguchi, M. Ichimura, T. Yokoyama et al.,Fusion Science and Technology, 59, No.1T,250-252 (2011).
T. Yokoyama et al., Plasma Fusion Res. 7, 2402136(2012).