Measurement of Radial Electric Field Using Doppler Reflectometer in High-Density Plasma of Heliotron J

Abstract

In this study, the radial electric field, E_r, has been measured using a two-channel Doppler microwave reflectometer at high-density plasmas of the Heliotron J helical device. The experimental results show that E_r grows negatively as the energy confinement is improved and the stored energy, W_p, is increased in a high-density plasma produced by neutral beam injection heating and high-intensity gas-puffing (HIGP). In a high-density plasma without HIGP, the E_r radial structure in which the direction of the E_r changes is measured.