Simulation Study of ECCD in Helical Plasmas

Abstract

The electron cyclotron current drive (ECCD) is studied in Heliotron J and LHD plasmas using GNET code in order to study the ECCD physics in helical configurations. The magnetic configuration dependence of ECCD is investigated in the Heliotron J plasma. It is found that the current direction is reversed in high bumpiness configuration compared with the other configurations. The ECCD in LHD is also investigated by changing electron cyclotron heating points fixing the configuration. It is found that the direction of the current reverses when we change the heating point from the ripple top to the ripple bottom.