Particle transport measurements in the LHD stochastic magnetic boundary plasma using Mach probes and ion sensitive probe

Spatial profiles of the plasma flow, electron temperature (Te) and ion temperature (Ti) in the stochastic magnetic boundary layer of Large Helical Device (LHD) has been studied by simultaneous measurements using a movable multiple functions probe, which consists of Mach probes and an ion sensitive probe. The tendency of the measured spatial profiles of Te and Ti is similar to the three-dimensional simulation. The results of ion saturation current (Isat) measurement of the upstream and downstream probes indicate that the plasma flow direction is reversed in the stochastic magnetic boundary layer. Isat observations obtained deep inside of the boundary layer contradict the simulation result, even though the existence of flow reversal in the LHD stochastic magnetic boundary layer was qualitatively confirmed.