X-ray diffraction study of a tungsten-based material for the first wall of ITER

Abstract

Abstract Methods of X-ray diffraction (XRD), Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy were applied to POLEMA W sample after He plasma irradiation. The W reflections of the plasma treated sample exhibit an evident asymmetry characterized by a negative asymmetry parameter. Using the Williamson-Hall Plot technique the XRD reflection asymmetry has been successfully quantitatively described in frame of a model with two W phases with slightly different unit cell parameters and essentially different crystallite size and microstrain values.