Recent progress of fast-ion loss detector project in magnetic confinement
fusion devices in Japan, Korea and China
M. Isobea,b, Junghee Kimc,d, Yipo Zhange, Jiafeng Changf, K. Ogawaa, Jun-Young Kimd,
Y. Suzukia,b, T. Rheec, Yi Liue, Liqun Huf, Yeong-Kook Ohc, and S. Moritaa,bab

National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, JapanThe Graduate University for Advanced Studies, 322-6 Oroshi-cho, Toki 509-5292, JapancNational Fusion Research Institute, Daejeon 305-806, Korea
dKorea University of Science and Technology, Daejeon 305-350, Korea
eSouthwestern Institute of Physics, P.O. Box 432, Chengdu 610041, ChinafInstitute of Plasma Physics, Chinese Academy of Science, Hefei 230031, China
isobe@nifs.ac.jp

Good confinement of fast ions in fusion plasmas is crucial to the success of the fusion
reactor since fusion-born α particles play an essential role in steady state sustainment offuture burning plasma as a primary heating source. Although unfavorable effect on fast-ion
orbit caused by axisymmetry breaking of the system is one of the oldest issues in fusion,
attention is now being focused on it again because the non-axisymmetric three-dimensional(3D) perturbed field produced by resonant magnetic perturbation (RMP) is often superposed
to mitigate ELMs in recent experiments. Fast-ion-driven MHD instabilities such as toroidal
Alfvén eigenmodes (TAE) and energetic-particle modes (EPM) are also of great concern
since those can potentially lead to fast-ion loss. For reasons above mentioned, tightcollaborative activities on fast-ion physics in fusion were initiated in 2012 in Asian threecountries in the support of the A3 foresight program on critical physics issues specific tosteady state sustainment of high-performance plasmas. Primary purpose of our activity is toobtain comprehensive understanding of fast-ion transport and/or loss caused by 3D field andfast-ion-driven MHD instabilities in toroidal fusion plasmas. Our immediate goal in the earlystage of this program is to set up scintillator-based fast-ion loss detectors (FILDs) onto four
major fusion devices in East Asia, i.e., LHD heliotron [1], KSTAR [2], HL-2A [3], and EAST
tokamaks. In LHD, TAE/EPM-induced fast-ion losses have been intensively studied by using
the FILD [4]. The KSTAR FILD is also successfully working. A study on behavior of fastions due to RMP field is in the center of attention in KSTAR [5]. A recent big step in ourwork is that the operation of the FILD on HL-2A has begun lately. The localized bright spot
appears on the screen while neutral beam (NB) is injected and disappears after NB is turned
off as expected. Also, the measured energy of escaping beam ions matches the beam injectionenergy. Because EAST will be equipped with an NB injector soon, the design of FILD on
EAST is steadily ongoing. The FILD will be installed onto EAST in 2014. In the latter stageof the A3 program, joint experiments will be conducted to reveal common physics issues
related to fast ions in tokamak and heliotron/stellarator. In this paper, current status on
fast-ion loss detector projects in Japan, Korea and China, and representative results fromongoing activities will be presented.
[1] K. Ogawa et al., J. Plasma Fusion Res. SERIES 8 (2009) 655.
[2] Junghee Kim et al., Rev. Sci. Instrum. 83 (2012) 10D305.
[3] Yipo Zhang et al., Rev. Sci. Instrum. 85 (2014) 053502.
[4] M. Isobe et al., Contrib. Plasma Phys. 50 (2010) 540. ; K. Ogawa et al., Nucl. Fusion 53(2013) 053012.
[5] Jun-Young Kim et al., 41st EPS Conference on Plasma Physics. Berlin, 23-27 June 2014.
P4.067.