Review of recent experiments on W and high Z materials as plasma-facing components in magnetic fusion devices

Since the 10th PSI conference in 1992, high Z refractory metals have been attracting growing interest as candidates for plasma facing materials, because of their resistance against erosion. In tokamaks such as TEXTOR, ASDEX Upgrade, FTU, Alcator C-Mod, D III-D, considerable effort has been made to study the behavior of high Z impurity in the core and edge plasmas, erosion/re-deposition processes at the limiter/divertor surfaces, hydrogen isotope retention, material development and tests, etc. An interim review of these studies is given. Tentative conclusions are drawn in order to get a view and direction in the future studies.