Study on energy distribution of reflected particles from plasma facing materials

Reflection of ions at a tungsten target was investigated experimentally in a linear plasma device. The tungsten target plate was set perpendicular to the magnetic field, and irradiated by hydrogen and helium plasma. The experiment measures a current as a function of sheath potential for a fixed angle. The reflected neutral particles from the target plate are measured by neutral-negative charge convertor made of Cu. The experimental results show good agreement with the results calculated with TRIM Monte-Carlo simulation code. A possibility to estimate the ion temperature is shown through the sheath potential dependence of the ion reflection in the low energy range. (C) 1999 Elsevier Science B.V. All rights reserved.