Measurements of particle transport coefficients using supersonic molecular beam injection modulation on EAST

Abstract

A supersonic molecular beam injection modulation experiment with a developed 11-channel polarimeter-interferometer has been performed on EAST. The particle deposition was determined by the edge density profile measured by microwave reflectometry. The particle transport coefficient profiles in low- and high-density discharges including low confinement and the high confinement mode (L mode and H mode) have been obtained by fitting the line-integrated modulation amplitude and phase profiles. The results show that in ohmic discharge, the difference between the edge and center diffusion coefficients is small compared to that in L and H modes. For convection velocity, the edge coefficients are several times larger than the center coefficients. However, this discrepancy is small in ohmic discharge. The H mode is characterized by a large inward convective velocity at the plasma edge which coincides with the steep pedestal.