@techreport{oai:nifs-repository.repo.nii.ac.jp:00009681,
 author = {Ida,  K. and Osakabe,  M. and Tanaka,  K. and Minami,  T. and Nishimura,  S. and Okamura,  S. and Fujisawa,  A. and Yoshimura,  Y. and Kubo,  S. and Akiyama,  R. and Darrow,  D.S. and Idei,  H. and Iguchi,  H. and Isobe,  M. and Kado,  S. and Kondo,  T. and Lee,  S. and Matsuoka,  K. and Morita,  S. and Nomura,  I. and Ohdachi,  S. and Sasao,  M. and Shimizu,  A. and Tumori,  K. and Takayama,  S. and Takechi,  M. and Takagi,  S. and Takahashi,  C. and Toi,  K. and Watari,  T.},
 month = {Aug},
 note = {A high ion temperature mode (high T_i mode) is observed for neutral beam heated plasmas in the Compact Helical System (CHS) Heliotron/torsatron. The high T_i mode plasma is characterized by a high central ion temperature, T_i(0), and is associated with a peaked electron density profile produced by neutral beam fueling with low wall recycling. Transition from L mode to high T_i mode has been studied in CHS. The central ion temperature in the high T_i mode discharges reaches to 1 keV which is 2.5 times higher than that in the L mode discharges. The ion thermal diffusivity is significantly reduced by a factor of more than 2 - 3 in the high T_i mode plasma. The ion loss cone is observed in neutral particle flux in the energy range of 1 - 6 keV with a narrow range of pitch angle (90 pm 10 degree) in the high T_i mode. However, the degradation of ion energy confinement due to thls loss cone is negligible.},
 title = {Transition from L Mode to High Ion Temperature Mode in CHS Heliotron/Torsatron Plasmas},
 year = {1998}
}