Author/Authors :
Kobayashi، نويسنده , , M. and Feng، نويسنده , , Y. and Morita، نويسنده , , S. and Chowdhuri، نويسنده , , M.B. and Goto، نويسنده , , M. and Masuzaki، نويسنده , , S. and Ohyabu، نويسنده , , N. and Morisaki، نويسنده , , T. and Yamada، نويسنده , , H. and Yamada، نويسنده , , I. and Narihara، نويسنده , , K. and Sato، نويسنده , , K. and Funaba، نويسنده , , H. and Tamura، نويسنده , , N. and Nakamura، نويسنده , , Y. and Komori، نويسنده , , A. and Motojima، نويسنده , , O.، نويسنده ,
Abstract :
Impurity retention (screening) potential in the edge region with stochastic magnetic field in LHD (large helical device) is studied numerically using the three-dimensional edge transport code, EMC3-EIRENE, and experimentally applying VUV and EUV spectrometers. The code predicts an impurity retention regime at high densities, where the friction force dominates over the thermal force. The carbon radiation intensities from each charge state are measured in experiments, and compared with the modelling results. The density dependencies of the calculated and measured radiation intensities agree well with each other, confirming the impurity retention in the edge region of LHD. Geometrical advantages of the stochastic field line structure in this concern are also discussed.
