FULL TEXT (PDF, 3316KB)
M. Isobe, K. Ogawa, K. Toi, M. Osakabe, K. Nagaoka, T. Tokuzawa, S. Kobayashi, D.A. Spong, D.S. Darrow and LHD experiment group Characteristics of Anomalous Transport and Losses of Energetic Ions Caused by Alfvenic Modes in LHD Plasmas
22 IAEA Fusion Energy Conference, EXW/P7-09
Date of publication:
22 IAEA Fusion Energy Conference, EXW/4-3Rb
Anomalous transport and losses of energetic ions caused by Alfvenic modes in neutral beam-heated Large Helical Device (LHD) plasmas are studied with a scintillator-based lost fast-ion probe (SLIP) and a charge-exchanged neutral particle analyzer. Correlated with recurrent bursting toroidicity-induced Alfven eigenmodes (TAEs), significant increases of energetic-ion losses are observed. Co-going transit energetic ions are responsible for destabilization of TAEs in LHD and are anomalously expelled through a diffusive-type loss mechanism. A particle simulation with a modeled perturbed magnetic field suggests that energetic-ion losses increase as the amplitude of the perturbed field increases. Experimentally measured pitch-angle distributions of escaping beam ions are reproduced by particle simulation.
List of NIFS Report (2010)Return toContents Page Return toNIFS Homepage