Damage in graphite tiles irradiated with helium plasmas

Abstract

Plasma-facing materials in fusion devices are irradiated by a high particle flux from a dense plasma. Graphite tiles, widely used as plasma-facing materials, were irradiated with a helium plasma of a high flux and low energy; the damage in the graphite-tile target was investigated. Changes in the surface morphology were observed from scanning electron microscopy; the electrical conductivity was decreased from four-probe measurement; the intensity of the graphite disorder peak was increased from Raman spectroscopy.