@article{oai:nifs-repository.repo.nii.ac.jp:00010884,
 author = {Fujiwara, Yutaka and KAMIO,  Shuji and YAMAGUCHI, Hiroyuki and GARCIA, A.V. and STAGNER, Luke and NUGA, Hideo and SEKI,  Ryosuke and OGAWA,  Kunihiro and ISOBE,  Mitsutaka and YOKOYAMA,  Masayuki and HEIDBRINK, W.W. and OSAKABE,  Masaki and LHD, Experiment Group},
 issue = {11},
 journal = {Nuclear Fusion},
 month = {Sep},
 note = {0000-0003-2985-060X, For understanding the physics of energetic particles, the deuterium experimental campaigns
started in Large Helical Device (LHD) from March 2017. To investigate the behavior of
energetic particles, a Fast-ion D Alpha (FIDA) diagnostic was installed on the LHD. In the
FIDA diagnostic, the Doppler-shifted D alpha light from fast-neutrals are utilized as signals of
energetic particles, where these fast-neutrals are produced by the charge exchange process
between fast-ions in the plasma and actively injected neutrals by neutral beam (NB). The
advantages of the FIDA diagnostic are the velocity and the spatially resolved measurement of
fast-ions at the crossing point between its line of sight (LOS) and the incident line of NB. The
most recent FIDASIM is enhanced to simulate signals produced in three-dimensional magnetic
configurations. The new version of FIDASIM uses the fast-ion distribution function produced
by GNET as input to simulate FIDA signals at LHD. In order to validate the new version of the
code, measurements of radial profiles of fast-ions using the FIDA diagnostic are performed in
magnetohydrodynamic (MHD)-quiescent plasmas. The measured spectra are in good agreement
with the theoretical prediction by 3D-supporting FIDASIM at the center of the plasma
(R = 3.5 m~3.7 m, reff/a99 = −0.28~0.05) on the LHD when the line averaged electron density
is ne_avg < 1.23 × 1019 m−3. On the other hand, the measured spectra are in disagreement with
the theoretical prediction by 3D-supporting FIDASIM at even the center of the plasma when the
line averaged electron density is ne_avg ≥ 1.23 × 1019 m−3.},
 title = {Fast-ion D alpha diagnostic with 3D-supporting FIDASIM in the Large Helical Device},
 volume = {60},
 year = {2020}
}