Author/Authors :
Komori، نويسنده , , A. and Morisaki، نويسنده , , T. and Masuzaki، نويسنده , , S. and Kobayashi، نويسنده , , M. K. Suzuki، نويسنده , , Y. and Sakamoto، نويسنده , , R. and Morita، نويسنده , , S. and Chowdhuri، نويسنده , , M.B. and Goto، نويسنده , , M. and Miyazawa، نويسنده , , J. and Yamada، نويسنده , , I. and Narihara، نويسنده , , K. and Ohyabu، نويسنده , , N. and Sagara، نويسنده , , A. and Yamada، نويسنده , , H. and Motojima، نويسنده , , O.، نويسنده ,
Abstract :
Superdense plasma with a highly peaked electron density profile was obtained in the reduced recycling discharge in the Large Helical Device (LHD). During the discharge, a core region with a density as high as ∼5 × 1020 m−3 and a temperature of ∼0.8 keV is maintained by an Internal Diffusion Barrier (IDB) with a steep density gradient. In spite of such a high density at the core region, no serious impurity accumulation has been observed. According to the numerical calculation with the EMC3–EIRENE code, downstream parallel flow in the ergodic region plays an important role to screen the influx of impurities with its strong friction force. The divertor flux distribution and global recycling properties do not change so much as against the change in the dense core plasma.