Research of edge plasma structure on the HL-1M tokamak

Abstract

In this paper, experimental results of plasma characteristics in several discharges have been measured in the plasma boundary region of the HL-1M tokamak using a multiarray of Mach/Langmuir 6 probes, electrostatic 4 probes and 20 group of 3 probes. In the experiments of Ohmic discharge, lower hybrid current drive, supersonic molecular beam injection, multi-shot pellet injection and neutral beam injection, etc., the correlation between the Reynolds stress and poloidal flow in the edge plasma is obtaimed. The experimental results suggest that the confinement improvement is related to the increasing rotation velocity and to the decreasing edge fluctuation. The results indicate that the sheared poloidal flow can be generated in tokamak plasma due to the radially varying Reynolds stress. The particle confinement with low-density discharge can increase 1—2 times in LHCD. The particle confinement time and poloidal rotation velocity can at least be doubled after MPI, and that the particle confinement time can increase one order of magnitude and can obtain high performance plasma during the experiment of SMBI.