03aE66PGAMMA 10プラグ/バリア部におけるICRF加熱実験
ICRF heating experiments in the plug/barrier cells on GAMMA 10
齋藤裕希、市村真、横山拓郎、隅田脩平、平田真史、池添竜也、飯村拓真、岩本嘉章、渡辺和征、岡田拓也、市村和也、中嶋洋輔
Y.Saito, M.Ichimura, T.Yokoyama, S.Sumida, M.Hirata, R.Ikezoe, T.Iimura, Y.Iwamoto,
K.Watanabe, T.Okada, K.Ichimura, Y.Nakashima
筑波大学プラズマ研究センター
Plasma Research Center, University of Tsukuba
period. Figure 1 shows the temporal evolution ofend loss ion current. The remarkable increase of ion
current is observed during driving DAT antenna.
Figure 2 shows the temporal evolution of Ti//. The
increase of high component of Ti// is observed andrise of effective Ti// is obtained.
From the result of experiment, it is clearlyshown that plug/barrier heating with a frequency of
8.0 MHz affect to increasing of Ti// of end loss ion.
Now, new ICRF antenna has been introduced in theplug/barrier cell. Direct heating experiment in theplug/barrier cell has been performed.

-42[×10 A/cm ]10Ion Current

8642050

100

150
200time [msec]

250

1.00.8
0.63Ti//eff.ch1[eV]T high.ch1[eV]T low.ch1[eV]

20.4

10.2
0140160

180

time[msec]

0200

Ti of high & low components
[keV]

[keV]

Fig.1 The temporal evolution of ion current.

Effective Ti//The GAMMA 10 tandem mirror consists offive mirror cells, which are a central cell, twominimum-B anchor cells located in both sides of
the central cell, and two plug/barrier cells at bothends. Main plasmas are produced in the central celland magneto-hydro-dynamics stability is kept withthe minimum-B configuration in the anchor cells.
Potential for the confinement is created in theplug/barrier cells. Recently, diverter simulation
experiment has been performed in the west end
region of the device. For the diverter simulation
experiment, it is needed to control parameters ofend loss particles.
In GAMMA 10, waves with ion cyclotron
range of frequency (ICRF) have been used forplasma production and heating. Plasma is produced
by use of Type-III antennas in both ends of centralcell. In the anchor cells, Double-Arc Type (DAT)
antenna is installed for direct heating in the anchor
cells. In a typical discharge, waves are excited by
Type-III antennas. DAT antenna is driven with thesame frequency as Type-III antennas. Then,direction of the wave propagation is controlled bychanging phase difference between both antennas.
It becomes possible to heat anchor plasma more
efficiency. [1][2]In this study, heating experiment in west
plug/barrier cell has been performed with west
DAT antenna in order to control ion temperatureand heat flux to the end region. The west DAT
antenna is driven with a frequency of 8.0 MHz thatis the cyclotron frequency near the midplane of theplug/barrier cell. End Loss Ion Energy Analyzer(ELIEA) is used for measurement in the end region.
ELIEA exists in west end of device and detects end
loss ions.[3][4] Energy distribution of end loss ionsis described by combination of high and low
temperature components. Effective Ti// is calculated
from both temperature components.[5]Experimental result is shown in Fig.1 andFig.2. DAT antenna is driven during the hatchedFig.2 The temporal evolution of effective Ti//, and Ti//high and Ti// low components.

[1]Y.Saito et al., Fusion Sci. Technol., 63, No.1T,277-279 (2013).
[2]Y.Ugajin et al., Fusion Sci. Technol., 63, No.1T,268-271(2013).
[3]T.Kuwahara et al., Rev. Sci. Instrum., 65,936-942(1994).
[4]A.W.Molvik, Rev. Sci. Instrum., 52, 704(1981).
[5]K. Ichimura et al., Plasma Fusion Res., vol.7,2405147, 1-4 (2012)