Production of high density plasma and study on the influence of a nonuniform magnetic field on the particle transport in the SOL region

Abstract

For the study of plasma-material interaction, a compact linear plasma device was built at JAERI, Naka. Hydrogen plasmas were produced in steady state by gaseous discharges between a hot tungsten filament and an anode. Up to now, the highest plasma density measured at about 20 cm downstream of the anode was 7×10 18 m −3 . In this device, an experimental study on the influence of a nonuniform magnetic field on the particle transport in the SOL region was conducted. The nonuniform magnetic field was produced by attaching ferromagnetic amorphous shells on the semiperiphery of the outer surface of the discharge chamber. Comparing the measured plasma parameters with and without the ferromagnetic amorphous shells, and using a 2-D plasma code, it was concluded that the density in the SOL plasma decreases where the axial magnetic field increases with the azimuth angle, and increases where it decreases with the angle.