Plasma boundary of 3D MHD equilibrium inferred from flow patterns

Ida, Katsumi; Kamiya, Kensaku; Suzuki, Yasuhiro*

This paper provides and proposes a new technique to determine the location of the LCFS that is based on a characterization of the Er structure derived from CXS measurements in the LHD. We found that the spatial derivative in the Er structure had the local maximum value at the region very near, or possibly outside the vacuum LCFS location of vacuum magnetic field at the outer midplane in the low beta plasma.