30D15P
ビーム放射分光のヘリオトロンJ密度変調実験への適用
Application of beam emission spectroscopy
to density modulation experiments in Heliotron J
小林進二1, 永榮蓉子2, 門信一郎3, 大石鉄太郎4, 山本聡1, 長崎百伸1,大島慎介1, 田中謙治4,水内亨1, 岡田浩之1, 南貴司1, Lee Hyunyong1, 永岡賢一4, 鈴木康浩4, 渡邊清政4, 村上定義5,中嶋洋輔6, 中村祐司2, 木島滋1, 向井清史4, 東使潔1, 佐野史道1
KOBAYASHI Shinji1, NAGAE Yoko2, KADO Shinichiro3, OISHI Tetsutarou4, et al.
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4

56

IAE, Kyoto Univ., GSES, Kyoto Univ., Sch. Eng., Univ. Tokyo, NIFS, Grad. Sch. Eng, Kyoto Univ., PRC
Tsukuba Univ.

Beam emission spectroscopy (BES) provides theexperimental information of the density fluctuation
at a local region where the sightline intersects thepath of the neutral beam (NB). When we apply theBES diagnostic to the density modulation
experiments, the beam integration effect due to thebeam absorption should be taken into account in thecase of the analysis on the modulation amplitude
and its phase.
Recently, we have installed the BES diagnosticto the Heliotron J device, having a helical-axis
magnetic configuration [1]. The radial profiles ofthe density fluctuation due to the fast-ion driven
MHD activities have been measured. In this study,
we investigate the response of the BES intensity tothe density modulation to discuss the applicabilityof the BES diagnostics to the transport analysis.
Figure 1 shows the temporal evolutions ofplasma parameters obtained in the density
modulation experiments. The plasma was heated by
ECH+NBI. The gas puffing was changed with the#48291, std config.
NBIGaspufW

DIA

DIA

19

r/a=0.07 0.28

0.50
0.70

0.02 I /<I>

225BEBE(A.U.)

0.7

f=50Hze0#48291-#48298 270

0.03nI /<I>

-3n (x10 m )eW (kJ)

ECH
2modulation frequency of_ 50 Hz. The line-averaged
electron density was n e = _ 8.71018m-3 and themodulation
amplitude was ne = 5.41017m-3 (i.e.
__ne/ne  0.06) A modulation of the BES intensity
was observed.
We applied the fast Fourier transform analysis toevaluate the modulation amplitude and its phase.
Figure 2 shows the radial profile of the modulation
amplitude normalized by the mean value of theBES intensity and the phase difference to the gas
puffing signal. The BES modulation amplitude atthe core region (IBE/IBE  0.025) was about thehalf of the modulation amplitude for the line
averaged density. To know the absolute value of themodulation amplitude, the radial profile of thedensity is required. As compared with the phaseobtained by the microwave reflectometer in theprevious density modulation experiments, thechange in the phase difference at r/a>0.5 was muchlarger than that by the reflectometer [2], which may
be due to the beam integration effect. We will
investigate the sensitivity of the density modulation
to the BES intensity using a numerical calculation
including the beam absorption calculation.
[1] S. Kobayashi, et al., RSI 83 10D535 (2012).
[2] 向井, 他 第 27 回年会 02P50 (2010).

0.01

phase
difference

180IBE0.87

0200

220

240 260
time (ms)280300Fig. 1. Time evolution of the heating, gas fueling,
density, stored energy and BES intensity
obtained in the density modulation experiments.

000.20.4 0.6
r/a0.8phase difference (deg.)

1

京大エネ理工研, 2京大エネ科, 3東大院工, 4核融合研, 5京大院工, 6筑波大プラセ

135
1Fig. 2. Radial profile of the normalized modulation
amplitude and phase difference to gas fueling.