@article{oai:nifs-repository.repo.nii.ac.jp:00011132,
 author = {OGAWA,  Kunihiro and ISOBE,  Mitsutaka and TOI,  Kazuo and SHIMIZU,  Akihiro and SPONG,  Donald A. and OSAKABE,  Masaki and YAMAMOTO,  S. and The LHD Experiment Group,},
 issue = {5},
 journal = {Nuclear Fusion},
 month = {Apr},
 note = {Characteristics of fast-ion losses induced by toroidal-Alfv en eigenmodes (TAEs) are investigated over wide parameter ranges of Large Helical Device (LHD) plasmas to reveal the fast-ion loss process. To study fast-ion losses, a scintillator-based lost-fast ion probe is used, and an increment of fast-ion loss flux due to TAEs from the neoclassical orbit loss level (ΔΓfast ion) is measured. The dependence of ΔΓfast ion on the TAE magnetic fluctuation amplitude
(bθTAE) changes from a linear to a quadratic and finally a third power with an increase in the magnetic axis shift. It is found that the dependence of fast-ion loss flux on TAE magnetic fluctuation amplitudes changes at a certain
fluctuation level in a fixed configuration. Experimental results show that in the small bθTAE regime, ΔΓfast ion is proportional to bθTAE, whereas ΔΓfast ion increases with the square of bθTAE in the larger bθTAE regime. A simulation
by orbit-following codes that incorporate magnetic fluctuations with frequency chirping-down due to TAEs suggests the change in the fast-ion loss process from a convective ( ΔΓ ion ∝ bθTAE) to a diffusive (ΔΓfast ion ∝ b2 θTAE) character as bθTAE increases.},
 title = {A study on the TAE-induced fast-ion loss process in LHD},
 volume = {53},
 year = {2013}
}