S. Ide , O. Naito , T. Oikawa , T. Fujita ,
T. Kondoh , M. Seki , K. Ushigusa and the JT-60 Team
Naka Fusion Research Establishment Japan Atomic Energy Research
Institute Naka-machi, Naka-gun, Ibaraki, 311-0193 Japan
Abstract
In JT-60U lower hybrid current drive (LHCD) experiments, a
reversed magnetic shear configuration that was accompanied by the
internal transport barriers was successfully maintained by means of
LHCD almost in the
full current drive quasi-steady state for 4.7 s. The normalized beta was kept
near 1 and the neutron emission rate was almost steady as well indicating no
accumulation of impurities into the plasma. Diagnostics data showed that all
the profiles of the electron and ion temperatures, the electron density and
the current profile were almost unchanged during the LHCD phase. Moreover,
capability of LHCD in H-mode plasmas has been also investigated. It was found
that the lower hybrid waves can be coupled to an H-mode edge plasma even with
the plasma wall distance of about 14 cm. The maximum coupling distance was
found to depend on the edge recycling.
IAEA 1999