7P45

ヘリオトロン J におけるレーザーパルス遅延機構を有するマルチパストムソン散乱計測装置による非等方速度分布現象の研究の初期結果
First Result of Anisotropic Phenomenon Research Measured
by a Thomson Scattering System with Signal Separation Function
on Heliotron J邱德川 1、南貴司 2、門信一郎 2、松谷遼 1、戸羽佑輔 1、釼持尚輝 3,、大島慎介 2、小林進二 2、王晨宇 1、罗茂源 1、张朋飞 1、岡田浩之 2、水内亨 2、木島滋 2、安原亮 3、稲垣滋 2、長崎百伸 2Dechuan Qiu1, Takashi Minami2, Shinichiro Kado2, Shigeru. Inagaki2, Ryo Matsutani1,Yusuke Toba1, Chenyu Wang1, Maoyuan Luo1, Pengfei, Zhang1, Naoki Kenmochi3,Shinsuke Ohshima2, Shinji Kobayashi2, Hiroyuki Okada2, Tohru Mizuuchi2, Shigeru Konoshima2,
Ryo Yasuhara3, Kazunobu Nagasaki2
1

京都大学エネルギー科学研究科、2 エネルギー理工学研究所、
3
核融合科学研究所
1
Graduate School of Energy Science, Kyoto University, 2Institute of Advanced Energy, Kyoto
University,3National Institute for Fusion Scienceqiu.dechuan.78n@st.kyoto-u.ac.jp
Thomson scattering diagnostic is one reliable method
to determine the electron temperature (Te) following themeasurement of the scattered spectrum. The form of thescattered spectrum is dependent on the electron velocity
distribution (EVD) function and EVD plays a key role inkinetic behavior of plasmas. Thus, anisotropic Te
measurement is helpful in achieving a more complete
information of the EVD and further a better understandingon kinetic behavior of plasmas. By constructing apolarization-controlled MPTS system, beam of one laser
shot can be confined in an optical path passing throughplasma so that beam can be guided into plasma over one
time from two opposite directions alternatively. As aresult, the component of EVD parallel and perpendicular
to the local magnetic field at measured position can berevealed by measuring Te deduced from scatteredspectrums corresponding to two incidences (goingincidence and returning incidence) respectively.
An anisotropy Te measurement was done in a plasma
generated by Electron cyclotron heating (ECH) in
Heliotron J. ECH power and the stored energy Wp in theECH plasma. The plasma is initiated by ECH (𝑁∥ = 0.38)
from 170 ms and maintained only by electron cyclotron
heating until 330 ms. The power of ECH is about 247 kW.
Measured position is at core plasma (r/a~0.26). The angle))))))))))))⃗between local magnetic field and ∆𝑘"#$%" (defined as thedifference between vector of going incident light wave
number and scattering light wave number) and))))))))))))))))))))⃗∆𝑘&'(&)%$%" (defined as the difference between vector ofreturning incident light wave number and scattering lightwave number) are equal to 83.9º and 111.7º respectively.
Measured scattered light signals corresponding togoing and returning incidence are shown in Fig. 1. Basedon the waveform from 0 ns to the yellow vertical line,
which is defined as the timing of appearance of returning
incident signal, overlapping waveform of going incidence

are fitted by exponential function as shown in dashed lines.
As a result, Te measured by going incidence can be
deduced by fitted waveform of going incidence.
Conversely, Te measured by returning incidence can be
deduced by using overlapping waveform minus the fittedwaveform.

Figure 1. Raw and fitted scattered light signal measured by adouble-pass mode of Thomson scattering system on Heliotron J.

Te corresponding to going incidence (160º scattering)and returning incidence (20º scattering) measured at threetimings are shown in Fig. 2: t = 280 ms, t = 300 ms, and t= 320 ms. The values of < (𝑇' +,-º − 𝑇' /-º )/𝑇' +,-º > at
300 ms and 320 ms are 6% ± 26% and 14% ± 17%
respectively, which does not show obvious isotropic
breaking in this experiment. No anisotropy was observed
within the error bars in this initial experiment.

Figure 2. Te anisotropy measurement at 280, 300, and 320 ms.