The results of the first experimental series to produce a plasma using the radio frequency discharge (RF) above the ion cyclotron frequency at relatively low magnetic fields (0.5–0.6 T) in the Large Helical Device (LHD) are presented 1.43 MW of RF power produced target plasma with density up to 6 × 1018 m−3 to deuterium. Tangential NBI application into such a plasma increases plasma parameters. Electron temperatures up to ≈0.9 keV and densities up to ≈2.4 × 1019 m−3 had been achieved, and the maximum value of <βdia> was 2.6%. These experiments open possibilities for new regimes of LHD operation which are also interested to W7-X.
This paper presents the results of the first experiments to produce a plasma using radio frequency (RF) discharge at relatively low magnetic fields (0.5-0.6 T) in the Large Helical Device (LHD). The experiments were able to achieve high plasma densities (up to 2.4 × 10^19 m^-3) and electron temperatures (up to 0.9 keV), with a maximum value of <βdia> (average plasma beta) of 2.6%. These results open up new possibilities for LHD operation, which are also of interest to the W7-X fusion experiment.